Tag Archives: AWS Identity and Access Management (IAM)

AWS adds passkey multi-factor authentication (MFA) for root and IAM users

Post Syndicated from Sébastien Stormacq original https://aws.amazon.com/blogs/aws/aws-adds-passkey-multi-factor-authentication-mfa-for-root-and-iam-users/

Security is our top priority at Amazon Web Services (AWS), and today, we’re launching two capabilities to help you strengthen the security posture of your AWS accounts:

MFA is one of the simplest and most effective ways to enhance account security, offering an additional layer of protection to help prevent unauthorized individuals from gaining access to systems or data.

MFA with passkey for your root and IAM users
Passkey is a general term used for the credentials created for FIDO2 authentication.

A passkey is a pair of cryptographic keys generated on your client device when you register for a service or a website. The key pair is bound to the web service domain and unique for each one.

The public part of the key is sent to the service and stored on their end. The private part of the key is either stored in a secured device, such as a security key, or securely shared across your devices connected to your user account when you use cloud services, such as iCloud Keychain, Google accounts, or a password manager such as 1Password.

Typically, the access to the private part of the key is protected by a PIN code or a biometric authentication, such as Apple Face ID or Touch ID or Microsoft Hello, depending on your devices.

When I try to authenticate on a service protected with passkeys, the service sends a challenge to my browser. The browser then requests my device sign the challenge with my private key. This triggers a PIN or biometric authentication to access the secured storage where the private key is stored. The browser returns the signature to the service. When the signature is valid, it confirms I own the private key that matches the public key stored on the service, and the authentication succeeds.

You can read more about this process and the various standards at work (FIDO2, CTAP, WebAuthn) in the post I wrote when AWS launched support for passkeys in AWS IAM Identity Center back in November 2020.

Passkeys can be used to replace passwords. However, for this initial release, we choose to use passkeys as a second factor authentication, in addition to your password. The password is something you know, and the passkey is something you have.

Passkeys are more resistant to phishing attacks than passwords. First, it’s much harder to gain access to a private key protected by your fingerprint, face, or a PIN code. Second, passkeys are bound to a specific web domain, reducing the scope in case of unintentional disclosure.

As an end user, you will benefit from the convenience of use and easy recoverability. You can use the built-in authenticators in your phones and laptops to unlock a cryptographically secured credential to your AWS sign-in experience. And when using a cloud service to store the passkey (such as iCloud keychain, Google accounts, or 1Password), the passkey can be accessed from any of your devices connected to your passkey provider account. This helps you to recover your passkey in the unfortunate case of losing a device.

How to enable passkey MFA for an IAM user
To enable passkey MFA, I navigate to the AWS Identity and Access Management (IAM) section of the console. I select a user, and I scroll down the page to the Multi-factor authentication (MFA) section. Then, I select Assign MFA device.

Note that to help you increase resilience and account recovery, you can have multiple MFA devices enabled for a user.

Enable MFA in AM console

On the next page, I enter an MFA device name, and I select Passkey or security key. Then, I select next.

enable MFA : select passkey

When using a password manager application that supports passkeys, it will pop up and ask if you want to generate and store a passkey using that application. Otherwise, your browser will present you with a couple of options. The exact layout of the screen depends on the operating system (macOS or Windows) and the browser you use. Here is the screen I see on macOS with a Chromium-based browser.

Enable passkey : choose method

The rest of the experience depends on your selection. iCloud Keychain will prompt you for a Touch ID to generate and store the passkey.

In the context of this demo, I want to show you how to bootstrap the passkey on another device, such as a phone. I therefore select Use a phone, tablet, or security key instead. The browser presents me with a QR code. Then, I use my phone to scan the QR code. The phone authenticates me with Face ID and generates and stores the passkey.

Passkey : scan a QR code

This QR code-based flow allows a passkey from one device to be used to sign in on another device (a phone and my laptop in my demo). It is defined by the FIDO specification and known as cross device authentication (CDA).

When everything goes well, the passkey is now registered with the IAM user.

Enable passkey : success

Note that we don’t recommend using IAM users to authenticate human beings to the AWS console. We recommend configuring single sign-on (SSO) with AWS IAM Identity Center instead.

What’s the sign-in experience?
Once MFA is enabled and configured with a passkey, I try to sign in to my account.

The user experience differs based on the operating system, browser, and device you use.

For example, on macOS with iCloud Keychain enabled, the system prompts me for a touch on the Touch ID key. For this demo, I registered the passkey on my phone using CDA. Therefore, the system asks me to scan a QR code with my phone. Once scanned, the phone authenticates me with Face ID to unlock the passkey, and the AWS console terminates the sign-in procedure.

Authenticate with MFA and passkey

Enforcing MFA for root users
The second announcement today is that we have started to enforce the use of MFA for the root user on some AWS accounts. This change was announced last year in a blog post from Stephen Schmidt, Chief Security Officer at Amazon.

To quote Stephen:

Verifying that the most privileged users in AWS are protected with MFA is just the latest step in our commitment to continuously enhance the security posture of AWS customers.

We started with your most sensitive account: your management account for AWS Organizations. The deployment of the policy is progressive, with just a few thousand accounts at a time. Over the coming months, we will progressively deploy the MFA enforcement policy on root users for the majority of the AWS accounts.

When you don’t have MFA enabled on your root user account, and your account is updated, a new message will pop up when you sign in, asking you to enable MFA. You will have a grace period, after which the MFA becomes mandatory.

Enable MFA on root account

You can start to use passkeys for multi-factor authentication today in all AWS Regions, except in China.

We’re enforcing the use of multi-factor authentication in all AWS Regions, except for the two regions in China (Beijing, Ningxia) and for AWS GovCloud (US), because the AWS accounts in these Regions have no root user.

Now go activate passkey MFA for your root user in your accounts.

— seb

Integrate Tableau and Okta with Amazon Redshift using AWS IAM Identity Center

Post Syndicated from Debu Panda original https://aws.amazon.com/blogs/big-data/integrate-tableau-and-okta-with-amazon-redshift-using-aws-iam-identity-center/

This blog post is co-written with Sid Wray and Jake Koskela from Salesforce, and Adiascar Cisneros from Tableau. 

Amazon Redshift is a fast, scalable cloud data warehouse built to serve workloads at any scale. With Amazon Redshift as your data warehouse, you can run complex queries using sophisticated query optimization to quickly deliver results to Tableau, which offers a comprehensive set of capabilities and connectivity options for analysts to efficiently prepare, discover, and share insights across the enterprise. For customers who want to integrate Amazon Redshift with Tableau using single sign-on capabilities, we introduced AWS IAM Identity Center integration to seamlessly implement authentication and authorization.

IAM Identity Center provides capabilities to manage single sign-on access to AWS accounts and applications from a single location. Redshift now integrates with IAM Identity Center, and supports trusted identity propagation, making it possible to integrate with third-party identity providers (IdP) such as Microsoft Entra ID (Azure AD), Okta, Ping, and OneLogin. This integration positions Amazon Redshift as an IAM Identity Center-managed application, enabling you to use database role-based access control on your data warehouse for enhanced security. Role-based access control allows you to apply fine grained access control using row level, column level, and dynamic data masking in your data warehouse.

AWS and Tableau have collaborated to enable single sign-on support for accessing Amazon Redshift from Tableau. Tableau now supports single sign-on capabilities with Amazon Redshift connector to simplify the authentication and authorization. The Tableau Desktop 2024.1 and Tableau Server 2023.3.4 releases support trusted identity propagation with IAM Identity Center. This allows users to seamlessly access Amazon Redshift data within Tableau using their external IdP credentials without needing to specify AWS Identity and Access Management (IAM) roles in Tableau. This single sign-on integration is available for Tableau Desktop, Tableau Server, and Tableau Prep.

In this post, we outline a comprehensive guide for setting up single sign-on to Amazon Redshift using integration with IAM Identity Center and Okta as the IdP. By following this guide, you’ll learn how to enable seamless single sign-on authentication to Amazon Redshift data sources directly from within Tableau Desktop, streamlining your analytics workflows and enhancing security.

Solution overview

The following diagram illustrates the architecture of the Tableau SSO integration with Amazon RedShift, IAM Identity Center, and Okta.

Figure 1: Solution overview for Tableau integration with Amazon Redshift using IAM Identity Center and Okta

The solution depicted in Figure 1 includes the following steps:

  1. The user configures Tableau to access Redshift using IAM Identity Center authentication
  2. On a user sign-in attempt, Tableau initiates a browser-based OAuth flow and redirects the user to the Okta login page to enter the login credentials.
  3. On successful authentication, Okta issues an authentication token (id and access token) to Tableau
  4. Redshift driver then makes a call to Redshift-enabled IAM Identity Center application and forwards the access token.
  5. Redshift passes the token to Identity Center and requests an access token.
  6. Identity Center verifies/validates the token using the OIDC discovery connection to the trusted token issuer and returns an Identity Center generated access token for the same user. In Figure 1, Trusted Token Issuer (TTI) is the Okta server that Identity Center trusts to provide tokens that third-party applications like Tableau uses to call AWS services.
  7. Redshift then uses the token to obtain the user and group membership information from IAM Identity Center.
  8. Tableau user will be able to connect with Amazon Redshift and access data based on the user and group membership returned from IAM Identity Center.

Prerequisites

Before you begin implementing the solution, make sure that you have the following in place:

Walkthrough

In this walkthrough, you build the solution with following steps:

  • Set up the Okta OIDC application
  • Set up the Okta authorization server
  • Set up the Okta claims
  • Setup the Okta access policies and rules
  • Setup trusted token issuer in AWS IAM Identity Center
  • Setup client connections and trusted token issuers
  • Setup the Tableau OAuth config files for Okta
  • Install the Tableau OAuth config file for Tableau Desktop
  • Setup the Tableau OAuth config file for Tableau Server or Tableau Cloud
  • Federate to Amazon Redshift from Tableau Desktop
  • Federate to Amazon Redshift from Tableau Server

Set up the Okta OIDC application

To create an OIDC web app in Okta, you can follow the instructions in this video, or use the following steps to create the wep app in Okta admin console:

Note: The Tableau Desktop redirect URLs should always use localhost. The examples below also use localhost for the Tableau Server hostname for ease of testing in a test environment. For this setup, you should also access the server at localhost in the browser. If you decide to use localhost for early testing, you will also need to configure the gateway to accept localhost using this tsm command:

 tsm configuration set -k gateway.public.host -v localhost

In a production environment, or Tableau Cloud, you should use the full hostname that your users will access Tableau on the web, along with https. If you already have an environment with https configured, you may skip the localhost configuration and use the full hostname from the start.

  1. Sign in to your Okta organization as a user with administrative privileges.
  2. On the admin console, under Applications in the navigation pane, choose Applications.
  3. Choose Create App Integration.
  4. Select OIDC – OpenID Connect as the Sign-in method and Web Application as the Application type.
  5. Choose Next.
  6. In General Settings:
    1. App integration name: Enter a name for your app integration. For example, Tableau_Redshift_App.
    2. Grant type: Select Authorization Code and Refresh Token.
    3. Sign-in redirect URIs: The sign-in redirect URI is where Okta sends the authentication response and ID token for the sign-in request. The URIs must be absolute URIs. Choose Add URl and along with the default URl, add the following URIs.
      • http://localhost:55556/Callback
      • http://localhost:55557/Callback
      • http://localhost:55558/Callback
      • http://localhost/auth/add_oauth_token
    4. Sign-out redirect URIs: keep the default value as http://localhost:8080.
    5. Skip the Trusted Origins section and for Assignments, select Skip group assignment for now.
    6. Choose Save.
Figure 2: OIDC application

Figure 2: OIDC application

  1. In the General Settings section, choose Edit and select Require PKCE as additional verification under Proof Key for Code Exchange (PKCE). This option indicates if a PKCE code challenge is required to verify client requests.
  2. Choose Save.
Figure 3: OIDC App Overview

Figure 3: OIDC App Overview

  1. Select the Assignments tab and then choose Assign to Groups. In this example, we’re assigning awssso-finance and awssso-sales.
  2. Choose Done.

Figure 4: OIDC application group assignments

For more information on creating an OIDC app, see Create OIDC app integrations.

Set up the Okta authorization server

Okta allows you to create multiple custom authorization servers that you can use to protect your own resource servers. Within each authorization server you can define your own OAuth 2.0 scopes, claims, and access policies. If you have an Okta Developer Edition account, you already have a custom authorization server created for you called default.

For this blog post, we use the default custom authorization server. If your application has requirements such as requiring more scopes, customizing rules for when to grant scopes, or you need more authorization servers with different scopes and claims, then you can follow this guide.

Figure 5: Authorization server

Set up the Okta claims

Tokens contain claims that are statements about the subject (for example: name, role, or email address). For this example, we use the default custom claim sub. Follow this guide to create claims.

Figure 6: Create claims

Setup the Okta access policies and rules

Access policies are containers for rules. Each access policy applies to a particular OpenID Connect application. The rules that the policy contains define different access and refresh token lifetimes depending on the nature of the token request. In this example, you create a simple policy for all clients as shown in Figure 7 that follows. Follow this guide to create access policies and rules.

Figure 7: Create access policies

Rules for access policies define token lifetimes for a given combination of grant type, user, and scope. They’re evaluated in priority order and after a matching rule is found, no other rules are evaluated. If no matching rule is found, then the authorization request fails. This example uses the role depicted in Figure 8 that follows. Follow this guide to create rules for your use case.

Figure 8: Access policy rules

Setup trusted token issuer in AWS IAM Identity Center

At this point, you switch to setting up the AWS configuration, starting by adding a trusted token issuer (TTI), which makes it possible to exchange tokens. This involves connecting IAM Identity Center to the Open ID Connect (OIDC) discovery URL of the external OAuth authorization server and defining an attribute-based mapping between the user from the external OAuth authorization server and a corresponding user in Identity Center. In this step, you create a TTI in the centralized management account. To create a TTI:

  1. Open the AWS Management Console and navigate to IAM Identity Center, and then to the Settings page.
  2. Select the Authentication tab and under Trusted token issuers, choose Create trusted token issuer.
  3. On the Set up an external IdP to issue trusted tokens page, under Trusted token issuer details, do the following:
    • For Issuer URL, enter the OIDC discovery URL of the external IdP that will issue tokens for trusted identity propagation. The administrator of the external IdP can provide this URL (for example, https://prod-1234567.okta.com/oauth2/default).

To get the issuer URL from Okta, sign in as an admin to Okta and navigate to Security and then to API and choose default under the Authorization Servers tab and copy the Issuer URL

Figure 9: Authorization server issuer

  1. For Trusted token issuer name, enter a name to identify this trusted token issuer in IAM Identity Center and in the application console.
  2. Under Map attributes, do the following:
    • For Identity provider attribute, select an attribute from the list to map to an attribute in the IAM Identity Center identity store.
    • For IAM Identity Center attribute, select the corresponding attribute for the attribute mapping.
  3. Under Tags (optional), choose Add new tag, enter a value for Key and optionally for Value. Choose Create trusted token issuer. For information about tags, see Tagging AWS IAM Identity Center resources.

This example uses Subject (sub) as the Identity provider attribute to map with Email from the IAM identity Center attribute. Figure 10 that follows shows the set up for TTI.

Figure 10: Create Trusted Token Issuer

Setup client connections and trusted token issuers

In this step, the Amazon Redshift applications that exchange externally generated tokens must be configured to use the TTI you created in the previous step. Also, the audience claim (or aud claim) from Okta must be specified. In this example, you are configuring the Amazon Redshift application in the member account where the Amazon Redshift cluster or serverless instance exists.

  1. Select IAM Identity Center connection from Amazon Redshift console menu.

Figure 11: Amazon Redshift IAM Identity Center connection

  1. Select the Amazon Redshift application that you created as part of the prerequisites.
  2. Select the Client connections tab and choose Edit.
  3. Choose Yes under Configure client connections that use third-party IdPs.
  4. Select the checkbox for Trusted token issuer which you have created in the previous section.
  5. Enter the aud claim value under section Configure selected trusted token issuers. For example, okta_tableau_audience.

To get the audience value from Okta, sign in as an admin to Okta and navigate to Security and then to API and choose default under the Authorization Servers tab and copy the Audience value.

Figure 12: Authorization server audience

Note: The audience claim value must exactly match with IdP audience value otherwise your OIDC connection with third part application like Tableau will fail.

  1. Choose Save.

Figure 13: Adding Audience Claim for Trusted Token Issuer

Setup the Tableau OAuth config files for Okta

At this point, your IAM Identity Center, Amazon Redshift, and Okta configuration are complete. Next, you need to configure Tableau.

To integrate Tableau with Amazon Redshift using IAM Identity Center, you need to use a custom XML. In this step, you use the following XML and replace the values starting with the $ sign and highlighted in bold. The rest of the values can be kept as they are, or you can modify them based on your use case. For detailed information on each of the elements in the XML file, see the Tableau documentation on GitHub.

Note: The XML file will be used for all the Tableau products including Tableau Desktop, Server, and Cloud.

<?xml version="1.0" encoding="utf-8"?>
<pluginOAuthConfig>
<dbclass>redshift</dbclass>
<oauthConfigId>custom_redshift_okta</oauthConfigId>
<clientIdDesktop>$copy_client_id_from_okta_oidc_app</clientIdDesktop>
<clientSecretDesktop>$copy_client_secret_from_okta_oidc_app</clientSecretDesktop>
<redirectUrisDesktop>http://localhost:55556/Callback</redirectUrisDesktop>
<redirectUrisDesktop>http://localhost:55557/Callback</redirectUrisDesktop>
<redirectUrisDesktop>http://localhost:55558/Callback</redirectUrisDesktop>
<authUri>https://$copy_okta_host_value.okta.com/oauth2/default/v1/authorize</authUri>
<tokenUri>https://$copy_okta_host_value.okta.com/oauth2/default/v1/token</tokenUri>
<scopes>openid</scopes>
<scopes>email</scopes>
<scopes>profile</scopes>
<scopes>offline_access</scopes>
<capabilities>
<entry>
<key>OAUTH_CAP_FIXED_PORT_IN_CALLBACK_URL</key>
<value>true</value>
</entry>
<entry>
<key>OAUTH_CAP_PKCE_REQUIRES_CODE_CHALLENGE_METHOD</key>
<value>true</value>
</entry>
<entry>
<key>OAUTH_CAP_REQUIRE_PKCE</key>
<value>true</value>
</entry>
<entry>
<key>OAUTH_CAP_SUPPORTS_STATE</key>
<value>true</value>
</entry>
<entry>
<key>OAUTH_CAP_CLIENT_SECRET_IN_URL_QUERY_PARAM</key>
<value>true</value>
</entry>
<entry>
<key>OAUTH_CAP_SUPPORTS_GET_USERINFO_FROM_ID_TOKEN</key>
<value>true</value>
</entry>
</capabilities>
<accessTokenResponseMaps>
<entry>
<key>ACCESSTOKEN</key>
<value>access_token</value>
</entry>
<entry>
<key>REFRESHTOKEN</key>
<value>refresh_token</value>
</entry>
<entry>
<key>id-token</key>
<value>id_token</value>
</entry>
<entry>
<key>access-token-issue-time</key>
<value>issued_at</value>
</entry>
<entry>
<key>access-token-expires-in</key>
<value>expires_in</value>
</entry>
<entry>
<key>username</key>
<value>preferred_username</value>
</entry>
</accessTokenResponseMaps>
</pluginOAuthConfig>

The following is an example XML file:

<?xml version="1.0" encoding="utf-8"?>
<pluginOAuthConfig>
<dbclass>redshift</dbclass>
<oauthConfigId>custom_redshift_okta</oauthConfigId>
<clientIdDesktop>ab12345z-a5nvb-123b-123b-1c434ghi1234</clientIdDesktop>
<clientSecretDesktop>3243jkbkjb~~ewf.112121.3432423432.asd834k</clientSecretDesktop>
<redirectUrisDesktop>http://localhost:55556/Callback</redirectUrisDesktop>
<redirectUrisDesktop>http://localhost:55557/Callback</redirectUrisDesktop>
<redirectUrisDesktop>http://localhost:55558/Callback</redirectUrisDesktop>
<authUri>https://prod-1234567.okta.com/oauth2/default/v1/authorize</authUri>
<tokenUri>https://prod-1234567.okta.com/oauth2/default/v1/token</tokenUri>
<scopes>openid</scopes>
<scopes>email</scopes>
<scopes>profile</scopes>
<scopes>offline_access</scopes>
<capabilities>
<entry>
<key>OAUTH_CAP_FIXED_PORT_IN_CALLBACK_URL</key>
<value>true</value>
</entry>
<entry>
<key>OAUTH_CAP_PKCE_REQUIRES_CODE_CHALLENGE_METHOD</key>
<value>true</value>
</entry>
<entry>
<key>OAUTH_CAP_REQUIRE_PKCE</key>
<value>true</value>
</entry>
<entry>
<key>OAUTH_CAP_SUPPORTS_STATE</key>
<value>true</value>
</entry>
<entry>
<key>OAUTH_CAP_CLIENT_SECRET_IN_URL_QUERY_PARAM</key>
<value>true</value>
</entry>
<entry>
<key>OAUTH_CAP_SUPPORTS_GET_USERINFO_FROM_ID_TOKEN</key>
<value>true</value>
</entry>
</capabilities>
<accessTokenResponseMaps>
<entry>
<key>ACCESSTOKEN</key>
<value>access_token</value>
</entry>
<entry>
<key>REFRESHTOKEN</key>
<value>refresh_token</value>
</entry>
<entry>
<key>id-token</key>
<value>id_token</value>
</entry>
<entry>
<key>access-token-issue-time</key>
<value>issued_at</value>
</entry>
<entry>
<key>access-token-expires-in</key>
<value>expires_in</value>
</entry>
<entry>
<key>username</key>
<value>preferred_username</value>
</entry>
</accessTokenResponseMaps>
</pluginOAuthConfig>

Install the Tableau OAuth config file for Tableau Desktop

After the configuration XML file is created, it must be copied to a location to be used by Amazon Redshift Connector from Tableau Desktop. Save the file from the previous step as .xml and save it under Documents\My Tableau Repository\OAuthConfigs.

Note: Currently this integration isn’t supported in macOS because the Redshift ODBC 2.X driver isn’t supported yet for MAC. It will be supported soon.

Setup the Tableau OAuth config file for Tableau Server or Tableau Cloud

To integrate with Amazon Redshift using IAM Identity Center authentication, you must install the Tableau OAuth config file in Tableau Server or Tableau Cloud

  1. Sign in to the Tableau Server or Tableau Cloud using admin credentials.
  2. Navigate to Settings.
  3. Go to OAuth Clients Registry and select Add OAuth Client
  4. Choose following settings:
    • Connection Type: Amazon Redshift
    • OAuth Provider: Custom_IdP
    • Client ID: Enter your IdP client ID value
    • Client Secret: Enter your client secret value
    • Redirect URL: Enter http://localhost/auth/add_oauth_token. This example uses localhost for testing in a local environment. You should use the full hostname with https.
    • Choose OAuth Config File. Select the XML file that you configured in the previous section.
    • Select Add OAuth Client and choose Save.

Figure 14: Create an OAuth connection in Tableau Server or Tableau Cloud

Federate to Amazon Redshift from Tableau Desktop

Now you’re ready to connect to Amazon Redshift from Tableau through federated sign-in using IAM Identity Center authentication. In this step, you create a Tableau Desktop report and publish it to Tableau Server.

  1. Open Tableau Desktop.
  2. Select Amazon Redshift Connector and enter the following values:
    1. Server: Enter the name of the server that hosts the database and the name of the database you want to connect to.
    2. Port: Enter 5439.
    3. Database: Enter your database name. This example uses dev.
    4. Authentication: Select OAuth.
    5. Federation Type: Select Identity Center.
    6. Identity Center Namespace: You can leave this value blank.
    7. OAuth Provider: This value should automatically be pulled from your configured XML. It will be the value from the element oauthConfigId.
    8. Select Require SSL.
    9. Choose Sign in.

Figure 15: Tableau Desktop OAuth connection

  1. Enter your IdP credentials in the browser pop-up window.

Figure 16: Okta Login Page

  1. When authentication is successful, you will see the message shown in Figure 17 that follows.

Figure 17: Successful authentication using Tableau

Congratulations! You’re signed in using IAM Identity Center integration with Amazon Redshift and are ready to explore and analyze your data using Tableau Desktop.

Figure 18: Successfully connected using Tableau Desktop

Figure 19 is a screenshot from the Amazon Redshift system table (sys_query_history) showing that user Ethan from Okta is accessing the sales report.

Figure 19: User audit in sys_query_history

After signing in, you can create your own Tableau Report on the desktop version and publish it to your Tableau Server. For this example, we created and published a report named SalesReport.

Federate to Amazon Redshift from Tableau Server

After you have published the report from Tableau Desktop to Tableau Server, sign in as a non-admin user and view the published report (SalesReport in this example) using IAM Identity Center authentication.

  1. Sign in to the Tableau Server site as a non-admin user.
  2. Navigate to Explore and go to the folder where your published report is stored.
  3. Select the report and choose Sign In.

Figure 20: Tableau Server Sign In

  1. To authenticate, enter your non-admin Okta credentials in the browser pop-up.

Figure 21: Okta Login Page

  1. After your authentication is successful, you can access the report.

Figure 22: Tableau report

Clean up

Complete the following steps to clean up your resources:

  1. Delete the IdP applications that you have created to integrate with IAM Identity Center.
  2. Delete the IAM Identity Center configuration.
  3. Delete the Amazon Redshift application and the Amazon Redshift provisioned cluster or serverless instance that you created for testing.
  4. Delete the IAM role and IAM policy that you created for IAM Identity Center and Amazon Redshift integration.
  5. Delete the permission set from IAM Identity Center that you created for Amazon Redshift Query Editor V2 in the management account.

Conclusion

This post covered streamlining access management for data analytics by using Tableau’s capability to support single sign-on based on the OAuth 2.0 OpenID Connect (OIDC) protocol. The solution enables federated user authentication, where user identities from an external IdP are trusted and propagated to Amazon Redshift. You walked through the steps to configure Tableau Desktop and Tableau Server to integrate seamlessly with Amazon Redshift using IAM Identity Center for single sign-on. By harnessing this integration of a third party IdP with IAM Identity Center, users can securely access Amazon Redshift data sources within Tableau without managing separate database credentials.

Listed below are key resources to learn more about Amazon Redshift integration with IAM Identity Center


About the Authors

Debu-PandaDebu Panda is a Senior Manager, Product Management at AWS. He is an industry leader in analytics, application platform, and database technologies, and has more than 25 years of experience in the IT world.

Sid Wray is a Senior Product Manager at Salesforce based in the Pacific Northwest with nearly 20 years of experience in Digital Advertising, Data Analytics, Connectivity Integration and Identity and Access Management. He currently focuses on supporting ISV partners for Salesforce Data Cloud.

Adiascar Cisneros is a Tableau Senior Product Manager based in Atlanta, GA. He focuses on the integration of the Tableau Platform with AWS services to amplify the value users get from our products and accelerate their journey to valuable, actionable insights. His background includes analytics, infrastructure, network security, and migrations.

Jade Koskela is a Principal Software Engineer at Salesforce. He has over a decade of experience building Tableau with a focus on areas including data connectivity, authentication, and identity federation.

Harshida Patel is a Principal Solutions Architect, Analytics with AWS.

Maneesh Sharma is a Senior Database Engineer at AWS with more than a decade of experience designing and implementing large-scale data warehouse and analytics solutions. He collaborates with various Amazon Redshift Partners and customers to drive better integration.

Ravi Bhattiprolu is a Senior Partner Solutions Architect at Amazon Web Services (AWS). He collaborates with strategic independent software vendor (ISV) partners like Salesforce and Tableau to design and deliver innovative, well-architected cloud products, integrations, and solutions to help joint AWS customers achieve their business goals.

Investigating lateral movements with Amazon Detective investigation and Security Lake integration

Post Syndicated from Yue Zhu original https://aws.amazon.com/blogs/security/investigating-lateral-movements-with-amazon-detective-investigation-and-security-lake-integration/

According to the MITRE ATT&CK framework, lateral movement consists of techniques that threat actors use to enter and control remote systems on a network. In Amazon Web Services (AWS) environments, threat actors equipped with illegitimately obtained credentials could potentially use APIs to interact with infrastructures and services directly, and they might even be able to use APIs to evade defenses and gain direct access to Amazon Elastic Compute Cloud (Amazon EC2) instances. To help customers secure their AWS environments, AWS offers several security services, such as Amazon GuardDuty, a threat detection service that monitors for malicious activity and anomalous behavior, and Amazon Detective, an investigation service that helps you investigate, and respond to, security events in your AWS environment.

After the service is turned on, Amazon Detective automatically collects logs from your AWS environment to help you analyze and investigate security events in-depth. At re:Invent 2023, Detective released Detective Investigations, a one-click investigation feature that automatically investigates AWS Identity and Access Management (IAM) users and roles for indicators of compromise (IoC), and Security Lake integration, which enables customers to retrieve log data from Amazon Security Lake to use as original evidence for deeper analysis with access to more detailed parameters.

In this post, you will learn about the use cases behind these features, how to run an investigation using the Detective Investigation feature, and how to interpret the contents of investigation reports. In addition, you will also learn how to use the Security Lake integration to retrieve raw logs to get more details of the impacted resources.

Triage a suspicious activity

As a security analyst, one of the common workflows in your daily job is to respond to suspicious activities raised by security event detection systems. The process might start when you get a ticket about a GuardDuty finding in your daily operations queue, alerting you that suspicious or malicious activity has been detected in your environment. To view more details of the finding, one of the options is to use the GuardDuty console.

In the GuardDuty console, you will find more details about the finding, such as the account and AWS resources that are in scope, the activity that caused the finding, the IP address that caused the finding and information about its possible geographic location, and times of the first and last occurrences of the event. To triage the finding, you might need more information to help you determine if it is a false positive.

Every GuardDuty finding has a link labeled Investigate with Detective in the details pane. This link allows you to pivot to the Detective console based on aspects of the finding you are investigating to their respective entity profiles. The finding Recon:IAMUser/MaliciousIPCaller.Custom that’s shown in Figure 1 results from an API call made by an IP address that’s on the custom threat list, and GuardDuty observed it made API calls that were commonly used in reconnaissance activity, which commonly occurs prior to attempts at compromise. To investigate this finding, because it involves an IAM role, you can select the Role session link and it will take you to the role session’s profile in the Detective console.

Figure 1: Example finding in the GuardDuty console, with Investigate with Detective pop-up window

Figure 1: Example finding in the GuardDuty console, with Investigate with Detective pop-up window

Within the AWS Role session profile page, you will find security findings from GuardDuty and AWS Security Hub that are associated with the AWS role session, API calls the AWS role session made, and most importantly, new behaviors. Behaviors that deviate from expectations can be used as indicators of compromises to give you more information to determine if the AWS resource might be compromised. Detective highlights new behaviors first observed during the scope time of the events related to the finding that weren’t observed during the Detective baseline time window of 45 days.

If you switch to the New behavior tab within the AWS role session profile, you will find the Newly observed geolocations panel (Figure 2). This panel highlights geolocations of IP addresses where API calls were made from that weren’t observed in the baseline profile. Detective determines the location of requests using MaxMind GeoIP databases based on the IP address that was used to issue requests.

Figure 2: Detective’s Newly observed geolocations panel

Figure 2: Detective’s Newly observed geolocations panel

If you choose Details on the right side of each row, the row will expand and provide details of the API calls made from the same locations from different AWS resources, and you can drill down and get to the API calls made by the AWS resource from a specific geolocation (Figure 3). When analyzing these newly observed geolocations, a question you might consider is why this specific AWS role session made API calls from Bellevue, US. You’re pretty sure that your company doesn’t have a satellite office there, nor do your coworkers who have access to this role work from there. You also reviewed the AWS CloudTrail management events of this AWS role session, and you found some unusual API calls for services such as IAM.

Figure 3: Detective’s Newly observed geolocations panel expanded on details

Figure 3: Detective’s Newly observed geolocations panel expanded on details

You decide that you need to investigate further, because this role session’s anomalous behavior from a new geolocation is sufficiently unexpected, and it made unusual API calls that you would like to know the purpose of. You want to gather anomalous behaviors and high-risk API methods that can be used by threat actors to make impacts. Because you’re investigating an AWS role session rather than investigating a single role session, you decide you want to know what happened in other role sessions associated with the AWS role in case threat actors spread their activities across multiple sessions. To help you examine multiple role sessions automatically with additional analytics and threat intelligence, Detective introduced the Detective Investigation feature at re:Invent 2023.

Run an IAM investigation

Amazon Detective Investigation uses machine learning (ML) models and AWS threat intelligence to automatically analyze resources in your AWS environment to identify potential security events. It identifies tactics, techniques, and procedures (TTPs) used in a potential security event. The MITRE ATT&CK framework is used to classify the TTPs. You can use this feature to help you speed up the investigation and identify indicators of compromise and other TTPs quickly.

To continue with your investigation, you should investigate the role and its usage history as a whole to cover all involved role sessions at once. This addresses the potential case where threat actors assumed the same role under different session names. In the AWS role session profile page that’s shown in Figure 4, you can quickly identify and pivot to the corresponding AWS role profile page under the Assumed role field.

Figure 4: Detective’s AWS role session profile page

Figure 4: Detective’s AWS role session profile page

After you pivot to the AWS role profile page (Figure 5), you can run the automated investigations by choosing Run investigation.

Figure 5: Role profile page, from which an investigation can be run

Figure 5: Role profile page, from which an investigation can be run

The first thing to do in a new investigation is to choose the time scope you want to run the investigation for. Then, choose Confirm (Figure 6).

Figure 6: Setting investigation scope time

Figure 6: Setting investigation scope time

Next, you will be directed to the Investigations page (Figure 7), where you will be able to see the status of your investigation. Once the investigation is done, you can choose the hyperlinked investigation ID to access the investigation report.

Figure 7: Investigations page, with new report

Figure 7: Investigations page, with new report

Another way to run an investigation is to choose Investigations on the left menu panel in the Detective console, and then choose Run investigation. You will then be taken to the page where you will specify the AWS role Amazon Resource Number (ARN) you’re investigating, and the scope time (Figure 8). Then you can choose Run investigation to commence an investigation.

Figure 8: Configuring a new investigation from scratch rather than from an existing finding

Figure 8: Configuring a new investigation from scratch rather than from an existing finding

Detective also offers StartInvestigation and GetInvestigation APIs for running Detective Investigations and retrieving investigation reports programmatically.

Interpret the investigation report

The investigation report (Figure 9) includes information on anomalous behaviors, potential TTP mappings of observed CloudTrail events, and indicators of compromises of the resource (in this example, an IAM principal) that was investigated.

At the top of the report, you will find a severity level computed based on the observed behaviors during the scope window, as well as a summary statement to give you a quick understanding of what was found. In Figure 9, the AWS role that was investigated engaged in the following unusual behaviors:

  • Seven tactics showing that the API calls made by this AWS role were mapped to seven tactics of the MITRE ATT&CK framework.
  • Eleven cases of impossible travel representing API calls made from two geolocations that are too far apart for the same user to have physically travelled between them to make the calls from both, within the time span involved.
  • Zero flagged IP addresses. Detective would flag IP addresses that are considered suspicious according to its threat intelligence sources.
  • Two new Autonomous System Organizations (ASOs) which are entities with assigned Autonomous System Numbers (ASNs) as used in Border Gateway Protocol (BGP) routing.
  • Nine new user agents were used to make API calls that weren’t observed in the 45 days prior to the events being investigated.

These indicators of compromise represent unusual behaviors that have either not been observed before in the AWS account involved or that are intrinsically considered high risk. The following summary panel includes the report that shows a detailed breakdown of the investigation results.

Unusual activities are important factors that you should look for during investigations, and sudden behavior change can be a sign of compromise. When you’re investigating an AWS role that can be assumed by different users from different AWS Regions, you are likely to need to examine activity at the granularity of the specific AWS role session that made the APIs calls. Within the report, you can do this by choosing the hyperlinked role name in the summary panel, and it will take you to the AWS role profile page.

Figure 9: Investigation report summary page

Figure 9: Investigation report summary page

Further down on the investigation report is the TTP Mapping from CloudTrail Management Events panel. Detective Investigations maps CloudTrail events to the MITRE ATT&CK framework to help you understand how an API can be used by threat actors. For each mapped API, you can see the tactics, techniques, and procedures it can be used for. In Figure 10, at the top there is a summary of TTPs with different severity levels. At the bottom is a breakdown of potential TTP mappings of observed CloudTrail management events during the investigation scope time.

When you select one of the cards, a side panel appears on the right to give you more details about the APIs. It includes information such as the IP address that made the API call, the details of the TTP the API call was mapped to, and if the API call succeeded or failed. This information can help you understand how these APIs can potentially be used by threat actors to modify your environment, and whether or not the API call succeeded tells you if it might have affected the security of your AWS resources. In the example that’s shown in Figure 10, the IAM role successfully made API calls that are mapped to Lateral Movement in the ATT&CK framework.

Figure 10: Investigation report page with event ATT CK mapping

Figure 10: Investigation report page with event ATT CK mapping

The report also includes additional indicators of compromise (Figure 11). You can find these if you select the Indicators tab next to Overview. Within this tab, you can find the indicators identified during the scope time, and if you select one indicator, details for that indicator will appear on the right. In the example in Figure 11, the IAM role made API calls with a user agent that wasn’t used by this IAM role or other IAM principals in this account, and indicators like this one show sudden behavior change of your IAM principal. You should review them and identify the ones that aren’t expected. To learn more about indicators of compromise in Detective Investigation, see the Amazon Detective User Guide.

Figure 11: Indicators of compromise identified during scope time

Figure 11: Indicators of compromise identified during scope time

At this point, you’ve analyzed the new and unusual behaviors the IAM role made and learned that the IAM role made API calls using new user agents and from new ASOs. In addition, you went through the API calls that were mapped to the MITRE ATT&CK framework. Among the TTPs, there were three API calls that are classified as lateral movements. These should attract attention for the following reasons: first, the purpose of these API calls is to gain access to the EC2 instance involved; and second, ec2-instance-connect:SendSSHPublicKey was run successfully.

Based on the procedure description in the report, this API would grant threat actors temporary SSH access to the target EC2 instance. To gather original evidence, examine the raw logs stored in Security Lake. Security Lake is a fully managed security data lake service that automatically centralizes security data from AWS environments, SaaS providers, on-premises sources, and other sources into a purpose-built data lake stored in your account.

Retrieve raw logs

You can use Security Lake integration to retrieve raw logs from your Security Lake tables within the Detective console as original evidence. If you haven’t enabled the integration yet, you can follow the Integration with Amazon Security Lake guide to enable it. In the context of the example investigation earlier, these logs include details of which EC2 instance was associated with the ec2-instance-connect:SendSSHPublicKey API call. Within the AWS role profile page investigated earlier, if you scroll down to the bottom of the page, you will find the Overall API call volume panel (Figure 12). You can search for the specific API call using the Service and API method filters. Next, choose the magnifier icon, which will initiate a Security Lake query to retrieve the raw logs of the specific CloudTrail event.

Figure 12: Finding the CloudTrail record for a specific API call held in Security Lake

Figure 12: Finding the CloudTrail record for a specific API call held in Security Lake

You can identify the target EC2 instance the API was issued against from the query results (Figure 13). To determine whether threat actors actually made an SSH connection to the target EC2 instance as a result of the API call, you should examine the EC2 instance’s profile page:

Figure 13: Reviewing a CloudTrail log record from Security Lake

Figure 13: Reviewing a CloudTrail log record from Security Lake

From the profile page of the EC2 instance in the Detective console, you can go to the Overall VPC flow volume panel and filter the Amazon Virtual Private Cloud (Amazon VPC) flow logs using the attributes related to the threat actor identified as having made the SSH API call. In Figure 14, you can see the IP address that tried to connect to 22/tcp, which is the SSH port of the target instance. It’s common for threat actors to change their IP address in an attempt to evade detection, and you can remove the IP address filter to see inbound connections to port 22/tcp of your EC2 instance.

Figure 14: Examining SSH connections to the target instance in the Detective profile page

Figure 14: Examining SSH connections to the target instance in the Detective profile page

Iterate the investigation

At this point, you’ve made progress with the help of Detective Investigations and Security Lake integration. You started with a GuardDuty finding, and you got to the point where you were able to identify some of the intent of the threat actors and uncover the specific EC2 instance they were targeting. Your investigation shouldn’t stop here because you’ve successfully identified the EC2 instance, which is the next target to investigate.

You can reuse this whole workflow by starting with the EC2 instance’s New behavior panel, run Detective Investigations on the IAM role attached to the EC2 instance and other IAM principals you think are worth taking a closer look at, then use the Security Lake integration to gather raw logs of the APIs made by the EC2 instance to identify the specific actions taken and their potential consequences.

Conclusion

In this post, you’ve seen how you can use the Amazon Detective Investigation feature to investigate IAM user and role activity and use the Security Lake integration to determine the specific EC2 instances a threat actor appeared to be targeting.

The Detective Investigation feature is automatically enabled for both existing and new customers in AWS Regions that support Detective where Detective has been activated. The Security Lake integration feature can be enabled in your Detective console. If you don’t currently use Detective, you can start a free 30-day trial. For more information on Detective Investigation and Security Lake integration, see Investigating IAM resources using Detective investigations and Security Lake integration.

 
If you have feedback about this post, submit comments in the Comments section below. If you have questions about this post, contact AWS Support.

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Yue Zhu

Yue Zhu

Yue is a security engineer at AWS. Before AWS, he worked as a security engineer focused on threat detection, incident response, vulnerability management, and security tooling development. Outside of work, Yue enjoys reading, cooking, and cycling.

Detecting and remediating inactive user accounts with Amazon Cognito

Post Syndicated from Harun Abdi original https://aws.amazon.com/blogs/security/detecting-and-remediating-inactive-user-accounts-with-amazon-cognito/

For businesses, particularly those in highly regulated industries, managing user accounts isn’t just a matter of security but also a compliance necessity. In sectors such as finance, healthcare, and government, where regulations often mandate strict control over user access, disabling stale user accounts is a key compliance activity. In this post, we show you a solution that uses serverless technologies to track and disable inactive user accounts. While this process is particularly relevant for those in regulated industries, it can also be beneficial for other organizations looking to maintain a clean and secure user base.

The solution focuses on identifying inactive user accounts in Amazon Cognito and automatically disabling them. Disabling a user account in Cognito effectively restricts the user’s access to applications and services linked with the Amazon Cognito user pool. After their account is disabled, the user cannot sign in, access tokens are revoked for their account and they are unable to perform API operations that require user authentication. However, the user’s data and profile within the Cognito user pool remain intact. If necessary, the account can be re-enabled, allowing the user to regain access and functionality.

While the solution focuses on the example of a single Amazon Cognito user pool in a single account, you also learn considerations for multi-user pool and multi-account strategies.

Solution overview

In this section, you learn how to configure an AWS Lambda function that captures the latest sign-in records of users authenticated by Amazon Cognito and write this data to an Amazon DynamoDB table. A time-to-live (TTL) indicator is set on each of these records based on the user inactivity threshold parameter defined when deploying the solution. This TTL represents the maximum period a user can go without signing in before their account is disabled. As these items reach their TTL expiry in DynamoDB, a second Lambda function is invoked to process the expired items and disable the corresponding user accounts in Cognito. For example, if the user inactivity threshold is configured to be 7 days, the accounts of users who don’t sign in within 7 days of their last sign-in will be disabled. Figure 1 shows an overview of the process.

Note: This solution functions as a background process and doesn’t disable user accounts in real time. This is because DynamoDB Time to Live (TTL) is designed for efficiency and to remain within the constraints of the Amazon Cognito quotas. Set your users’ and administrators’ expectations accordingly, acknowledging that there might be a delay in the reflection of changes and updates.

Figure 1: Architecture diagram for tracking user activity and disabling inactive Amazon Cognito users

Figure 1: Architecture diagram for tracking user activity and disabling inactive Amazon Cognito users

As shown in Figure 1, this process involves the following steps:

  1. An application user signs in by authenticating to Amazon Cognito.
  2. Upon successful user authentication, Cognito initiates a post authentication Lambda trigger invoking the PostAuthProcessorLambda function.
  3. The PostAuthProcessorLambda function puts an item in the LatestPostAuthRecordsDDB DynamoDB table with the following attributes:
    1. sub: A unique identifier for the authenticated user within the Amazon Cognito user pool.
    2. timestamp: The time of the user’s latest sign-in, formatted in UTC ISO standard.
    3. username: The authenticated user’s Cognito username.
    4. userpool_id: The identifier of the user pool to which the user authenticated.
    5. ttl: The TTL value, in seconds, after which a user’s inactivity will initiate account deactivation.
  4. Items in the LatestPostAuthRecordsDDB DynamoDB table are automatically purged upon reaching their TTL expiry, launching events in DynamoDB Streams.
  5. DynamoDB Streams events are filtered to allow invocation of the DDBStreamProcessorLambda function only for TTL deleted items.
  6. The DDBStreamProcessorLambda function runs to disable the corresponding user accounts in Cognito.

Implementation details

In this section, you’re guided through deploying the solution, demonstrating how to integrate it with your existing Amazon Cognito user pool and exploring the solution in more detail.

Note: This solution begins tracking user activity from the moment of its deployment. It can’t retroactively track or manage user activities that occurred prior to its implementation. To make sure the solution disables currently inactive users in the first TTL period after deploying the solution, you should do a one-time preload of those users into the DynamoDB table. If this isn’t done, the currently inactive users won’t be detected because users are detected as they sign in. For the same reason, users who create accounts but never sign in won’t be detected either. To detect user accounts that sign up but never sign in, implement a post confirmation Lambda trigger to invoke a Lambda function that processes user sign-up records and writes them to the DynamoDB table.

Prerequisites

Before deploying this solution, you must have the following prerequisites in place:

  • An existing Amazon Cognito user pool. This user pool is the foundation upon which the solution operates. If you don’t have a Cognito user pool set up, you must create one before proceeding. See Creating a user pool.
  • The ability to launch a CloudFormation template. The second prerequisite is the capability to launch an AWS CloudFormation template in your AWS environment. The template provisions the necessary AWS services, including Lambda functions, a DynamoDB table, and AWS Identity and Access Management (IAM) roles that are integral to the solution. The template simplifies the deployment process, allowing you to set up the entire solution with minimal manual configuration. You must have the necessary permissions in your AWS account to launch CloudFormation stacks and provision these services.

To deploy the solution

  1. Choose the following Launch Stack button to deploy the solution’s CloudFormation template:

    Launch Stack

    The solution deploys in the AWS US East (N. Virginia) Region (us-east-1) by default. To deploy the solution in a different Region, use the Region selector in the console navigation bar and make sure that the services required for this walkthrough are supported in your newly selected Region. For service availability by Region, see AWS Services by Region.

  2. On the Quick Create Stack screen, do the following:
    1. Specify the stack details.
      1. Stack name: The stack name is an identifier that helps you find a particular stack from a list of stacks. A stack name can contain only alphanumeric characters (case sensitive) and hyphens. It must start with an alphabetic character and can’t be longer than 128 characters.
      2. CognitoUserPoolARNs: A comma-separated list of Amazon Cognito user pool Amazon Resource Names (ARNs) to monitor for inactive users.
      3. UserInactiveThresholdDays: Time (in days) that the user account is allowed to be inactive before it’s disabled.
    2. Scroll to the bottom, and in the Capabilities section, select I acknowledge that AWS CloudFormation might create IAM resources with custom names.
    3. Choose Create Stack.

Integrate with your existing user pool

With the CloudFormation template deployed, you can set up Lambda triggers in your existing user pool. This is a key step for tracking user activity.

Note: This walkthrough is using the new AWS Management Console experience. Alternatively, These steps could also be done using CloudFormation.

To integrate with your existing user pool

  1. Navigate to the Amazon Cognito console and select your user pool.
  2. Navigate to User pool properties.
  3. Under Lambda triggers, choose Add Lambda trigger. Select the Authentication radio button, then add a Post authentication trigger and assign the PostAuthProcessorLambda function.

Note: Amazon Cognito allows you to set up one Lambda trigger per event. If you already have a configured post authentication Lambda trigger, you can refactor the existing Lambda function, adding new features directly to minimize the cold starts associated with invoking additional functions (for more information, see Anti-patterns in Lambda-based applications). Keep in mind that when Cognito calls your Lambda function, the function must respond within 5 seconds. If it doesn’t and if the call can be retried, Cognito retries the call. After three unsuccessful attempts, the function times out. You can’t change this 5-second timeout value.

Figure 2: Add a post-authentication Lambda trigger and assign a Lambda function

Figure 2: Add a post-authentication Lambda trigger and assign a Lambda function

When you add a Lambda trigger in the Amazon Cognito console, Cognito adds a resource-based policy to your function that permits your user pool to invoke the function. When you create a Lambda trigger outside of the Cognito console, including a cross-account function, you must add permissions to the resource-based policy of the Lambda function. Your added permissions must allow Cognito to invoke the function on behalf of your user pool. You can add permissions from the Lambda console or use the Lambda AddPermission API operation. To configure this in CloudFormation, you can use the AWS::Lambda::Permission resource.

Explore the solution

The solution should now be operational. It’s configured to begin monitoring user sign-in activities and automatically disable inactive user accounts according to the user inactivity threshold. Use the following procedures to test the solution:

Note: When testing the solution, you can set the UserInactiveThresholdDays CloudFormation parameter to 0. This minimizes the time it takes for user accounts to be disabled.

Step 1: User authentication

  1. Create a user account (if one doesn’t exist) in the Amazon Cognito user pool integrated with the solution.
  2. Authenticate to the Cognito user pool integrated with the solution.
     
    Figure 3: Example user signing in to the Amazon Cognito hosted UI

    Figure 3: Example user signing in to the Amazon Cognito hosted UI

Step 2: Verify the sign-in record in DynamoDB

Confirm the sign-in record was successfully put in the LatestPostAuthRecordsDDB DynamoDB table.

  1. Navigate to the DynamoDB console.
  2. Select the LatestPostAuthRecordsDDB table.
  3. Select Explore Table Items.
  4. Locate the sign-in record associated with your user.
     
Figure 4: Locating the sign-in record associated with the signed-in user

Figure 4: Locating the sign-in record associated with the signed-in user

Step 3: Confirm user deactivation in Amazon Cognito

After the TTL expires, validate that the user account is disabled in Amazon Cognito.

  1. Navigate to the Amazon Cognito console.
  2. Select the relevant Cognito user pool.
  3. Under Users, select the specific user.
  4. Verify the Account status in the User information section.
     
Figure 5: Screenshot of the user that signed in with their account status set to disabled

Figure 5: Screenshot of the user that signed in with their account status set to disabled

Note: TTL typically deletes expired items within a few days. Depending on the size and activity level of a table, the actual delete operation of an expired item can vary. TTL deletes items on a best effort basis, and deletion might take longer in some cases.

The user’s account is now disabled. A disabled user account can’t be used to sign in, but still appears in the responses to GetUser and ListUsers API requests.

Design considerations

In this section, you dive deeper into the key components of this solution.

DynamoDB schema configuration:

The DynamoDB schema has the Amazon Cognito sub attribute as the partition key. The Cognito sub is a globally unique user identifier within Cognito user pools that cannot be changed. This configuration ensures each user has a single entry in the table, even if the solution is configured to track multiple user pools. See Other considerations for more about tracking multiple user pools.

Using DynamoDB Streams and Lambda to disable TTL deleted users

This solution uses DynamoDB TTL and DynamoDB Streams alongside Lambda to process user sign-in records. The TTL feature automatically deletes items past their expiration time without write throughput consumption. The deleted items are captured by DynamoDB Streams and processed using Lambda. You also apply event filtering within the Lambda event source mapping, ensuring that the DDBStreamProcessorLambda function is invoked exclusively for TTL-deleted items (see the following code example for the JSON filter pattern). This approach reduces invocations of the Lambda functions, simplifies code, and reduces overall cost.

{
    "Filters": [
        {
            "Pattern": { "userIdentity": { "type": ["Service"], "principalId": ["dynamodb.amazonaws.com"] } }
        }
    ]
}

Handling API quotas:

The DDBStreamProcessorLambda function is configured to comply with the AdminDisableUser API’s quota limits. It processes messages in batches of 25, with a parallelization factor of 1. This makes sure that the solution remains within the nonadjustable 25 requests per second (RPS) limit for AdminDisableUser, avoiding potential API throttling. For more details on these limits, see Quotas in Amazon Cognito.

Dead-letter queues:

Throughout the architecture, dead-letter queues (DLQs) are used to handle message processing failures gracefully. They make sure that unprocessed records aren’t lost but instead are queued for further inspection and retry.

Other considerations

The following considerations are important for scaling the solution in complex environments and maintaining its integrity. The ability to scale and manage the increased complexity is crucial for successful adoption of the solution.

Multi-user pool and multi-account deployment

While this solution discussed a single Amazon Cognito user pool in a single AWS account, this solution can also function in environments with multiple user pools. This involves deploying the solution and integrating with each user pool as described in Integrating with your existing user pool. Because of the AdminDisableUser API’s quota limit for the maximum volume of requests in one AWS Region in one AWS account, consider deploying the solution separately in each Region in each AWS account to stay within the API limits.

Efficient processing with Amazon SQS:

Consider using Amazon Simple Queue Service (Amazon SQS) to add a queue between the PostAuthProcessorLambda function and the LatestPostAuthRecordsDDB DynamoDB table to optimize processing. This approach decouples user sign-in actions from DynamoDB writes, and allows for batching writes to DynamoDB, reducing the number of write requests.

Clean up

Avoid unwanted charges by cleaning up the resources you’ve created. To decommission the solution, follow these steps:

  1. Remove the Lambda trigger from the Amazon Cognito user pool:
    1. Navigate to the Amazon Cognito console.
    2. Select the user pool you have been working with.
    3. Go to the Triggers section within the user pool settings.
    4. Manually remove the association of the Lambda function with the user pool events.
  2. Remove the CloudFormation stack:
    1. Open the CloudFormation console.
    2. Locate and select the CloudFormation stack that was used to deploy the solution.
    3. Delete the stack.
    4. CloudFormation will automatically remove the resources created by this stack, including Lambda functions, Amazon SQS queues, and DynamoDB tables.

Conclusion

In this post, we walked you through a solution to identify and disable stale user accounts based on periods of inactivity. While the example focuses on a single Amazon Cognito user pool, the approach can be adapted for more complex environments with multiple user pools across multiple accounts. For examples of Amazon Cognito architectures, see the AWS Architecture Blog.

Proper planning is essential for seamless integration with your existing infrastructure. Carefully consider factors such as your security environment, compliance needs, and user pool configurations. You can modify this solution to suit your specific use case.

Maintaining clean and active user pools is an ongoing journey. Continue monitoring your systems, optimizing configurations, and keeping up-to-date on new features. Combined with well-architected preventive measures, automated user management systems provide strong defenses for your applications and data.

For further reading, see the AWS Well-Architected Security Pillar and more posts like this one on the AWS Security Blog.

If you have feedback about this post, submit comments in the Comments section. If you have questions about this post, start a new thread on the Amazon Cognito re:Post forum or contact AWS Support.

Harun Abdi

Harun Abdi

Harun is a Startup Solutions Architect based in Toronto, Canada. Harun loves working with customers across different sectors, supporting them to architect reliable and scalable solutions. In his spare time, he enjoys playing soccer and spending time with friends and family.

Dylan Souvage

Dylan Souvage

Dylan is a Partner Solutions Architect based in Austin, Texas. Dylan loves working with customers to understand their business needs and enable them in their cloud journey. In his spare time, he enjoys going out in nature and going on long road trips.

How to use Regional AWS STS endpoints

Post Syndicated from Darius Januskis original https://aws.amazon.com/blogs/security/how-to-use-regional-aws-sts-endpoints/

This blog post provides recommendations that you can use to help improve resiliency in the unlikely event of disrupted availability of the global (now legacy) AWS Security Token Service (AWS STS) endpoint. Although the global (legacy) AWS STS endpoint https://sts.amazonaws.com is highly available, it’s hosted in a single AWS Region—US East (N. Virginia)—and like other endpoints, it doesn’t provide automatic failover to endpoints in other Regions. In this post I will show you how to use Regional AWS STS endpoints in your configurations to improve the performance and resiliency of your workloads.

For authentication, it’s best to use temporary credentials instead of long-term credentials to help reduce risks, such as inadvertent disclosure, sharing, or theft of credentials. With AWS STS, trusted users can request temporary, limited-privilege credentials to access AWS resources.

Temporary credentials include an access key pair and a session token. The access key pair consists of an access key ID and a secret key. AWS STS generates temporary security credentials dynamically and provides them to the user when requested, which eliminates the need for long-term storage. Temporary security credentials have a limited lifetime so you don’t have to manage or rotate them.

To get these credentials, you can use several different methods:

Figure 1: Methods to request credentials from AWS STS

Figure 1: Methods to request credentials from AWS STS

Global (legacy) and Regional AWS STS endpoints

To connect programmatically to an AWS service, you use an endpoint. An endpoint is the URL of the entry point for AWS STS.

AWS STS provides Regional endpoints in every Region. AWS initially built AWS STS with a global endpoint (now legacy) https://sts.amazonaws.com, which is hosted in the US East (N. Virginia) Region (us-east-1). Regional AWS STS endpoints are activated by default for Regions that are enabled by default in your AWS account. For example, https://sts.us-east-2.amazonaws.com is the US East (Ohio) Regional endpoint. By default, AWS services use Regional AWS STS endpoints. For example, IAM Roles Anywhere uses the Regional STS endpoint that corresponds to the trust anchor. For a complete list of AWS STS endpoints for each Region, see AWS Security Token Service endpoints and quotas. You can’t activate an AWS STS endpoint in a Region that is disabled. For more information on which AWS STS endpoints are activated by default and which endpoints you can activate or deactivate, see Regions and endpoints.

As noted previously, the global (legacy) AWS STS endpoint https://sts.amazonaws.com is hosted in a single Region — US East (N. Virginia) — and like other endpoints, it doesn’t provide automatic failover to endpoints in other Regions. If your workloads on AWS or outside of AWS are configured to use the global (legacy) AWS STS endpoint https://sts.amazonaws.com, you introduce a dependency on a single Region: US East (N. Virginia). In the unlikely event that the endpoint becomes unavailable in that Region or connectivity between your resources and that Region is lost, your workloads won’t be able to use AWS STS to retrieve temporary credentials, which poses an availability risk to your workloads.

AWS recommends that you use Regional AWS STS endpoints (https://sts.<region-name>.amazonaws.com) instead of the global (legacy) AWS STS endpoint.

In addition to improved resiliency, Regional endpoints have other benefits:

  • Isolation and containment — By making requests to an AWS STS endpoint in the same Region as your workloads, you can minimize cross-Region dependencies and align the scope of your resources with the scope of your temporary security credentials to help address availability and security concerns. For example, if your workloads are running in the US East (Ohio) Region, you can target the Regional AWS STS endpoint in the US East (Ohio) Region (us-east-2) to remove dependencies on other Regions.
  • Performance — By making your AWS STS requests to an endpoint that is closer to your services and applications, you can access AWS STS with lower latency and shorter response times.

Figure 2 illustrates the process for using an AWS principal to assume an AWS Identity and Access Management (IAM) role through the AWS STS AssumeRole API, which returns a set of temporary security credentials:

Figure 2: Assume an IAM role by using an API call to a Regional AWS STS endpoint

Figure 2: Assume an IAM role by using an API call to a Regional AWS STS endpoint

Calls to AWS STS within the same Region

You should configure your workloads within a specific Region to use only the Regional AWS STS endpoint for that Region. By using a Regional endpoint, you can use AWS STS in the same Region as your workloads, removing cross-Region dependency. For example, workloads in the US East (Ohio) Region should use only the Regional endpoint https://sts.us-east-2.amazonaws.com to call AWS STS. If a Regional AWS STS endpoint becomes unreachable, your workloads shouldn’t call AWS STS endpoints outside of the operating Region. If your workload has a multi-Region resiliency requirement, your other active or standby Region should use a Regional AWS STS endpoint for that Region and should be deployed such that the application can function despite a Regional failure. You should direct STS traffic to the STS endpoint within the same Region, isolated and independent from other Regions, and remove dependencies on the global (legacy) endpoint.

Calls to AWS STS from outside AWS

You should configure your workloads outside of AWS to call the appropriate Regional AWS STS endpoints that offer the lowest latency to your workload located outside of AWS. If your workload has a multi-Region resiliency requirement, build failover logic for AWS STS calls to other Regions in the event that Regional AWS STS endpoints become unreachable. Temporary security credentials obtained from Regional AWS STS endpoints are valid globally for the default session duration or duration that you specify.

How to configure Regional AWS STS endpoints for your tools and SDKs

I recommend that you use the latest major versions of the AWS Command Line Interface (CLI) or AWS SDK to call AWS STS APIs.

AWS CLI

By default, the AWS CLI version 2 sends AWS STS API requests to the Regional AWS STS endpoint for the currently configured Region. If you are using AWS CLI v2, you don’t need to make additional changes.

By default, the AWS CLI v1 sends AWS STS requests to the global (legacy) AWS STS endpoint. To check the version of the AWS CLI that you are using, run the following command: $ aws –version.

When you run AWS CLI commands, the AWS CLI looks for credential configuration in a specific order—first in shell environment variables and then in the local AWS configuration file (~/.aws/config).

AWS SDK

AWS SDKs are available for a variety of programming languages and environments. Since July 2022, major new versions of the AWS SDK default to Regional AWS STS endpoints and use the endpoint corresponding to the currently configured Region. If you use a major version of the AWS SDK that was released after July 2022, you don’t need to make additional changes.

An AWS SDK looks at various configuration locations until it finds credential configuration values. For example, the AWS SDK for Python (Boto3) adheres to the following lookup order when it searches through sources for configuration values:

  1. A configuration object created and passed as the AWS configuration parameter when creating a client
  2. Environment variables
  3. The AWS configuration file ~/.aws/config

If you still use AWS CLI v1, or your AWS SDK version doesn’t default to a Regional AWS STS endpoint, you have the following options to set the Regional AWS STS endpoint:

Option 1 — Use a shared AWS configuration file setting

The configuration file is located at ~/.aws/config on Linux or macOS, and at C:\Users\USERNAME\.aws\config on Windows. To use the Regional endpoint, add the sts_regional_endpoints parameter.

The following example shows how you can set the value for the Regional AWS STS endpoint in the US East (Ohio) Region (us-east-2), by using the default profile in the AWS configuration file:

[default]
region = us-east-2
sts_regional_endpoints = regional

The valid values for the AWS STS endpoint parameter (sts_regional_endpoints) are:

  • legacy (default) — Uses the global (legacy) AWS STS endpoint, sts.amazonaws.com.
  • regional — Uses the AWS STS endpoint for the currently configured Region.

Note: Since July 2022, major new versions of the AWS SDK default to Regional AWS STS endpoints and use the endpoint corresponding to the currently configured Region. If you are using AWS CLI v1, you must use version 1.16.266 or later to use the AWS STS endpoint parameter.

You can use the --debug option with the AWS CLI command to receive the debug log and validate which AWS STS endpoint was used.

$ aws sts get-caller-identity \
$ --region us-east-2 \
$ --debug

If you search for UseGlobalEndpoint in your debug log, you’ll find that the UseGlobalEndpoint parameter is set to False, and you’ll see the Regional endpoint provider fully qualified domain name (FQDN) when the Regional AWS STS endpoint is configured in a shared AWS configuration file or environment variables:

2023-09-11 18:51:11,300 – MainThread – botocore.regions – DEBUG – Calling endpoint provider with parameters: {'Region': 'us-east-2', 'UseDualStack': False, 'UseFIPS': False, 'UseGlobalEndpoint': False}
2023-09-11 18:51:11,300 – MainThread – botocore.regions – DEBUG – Endpoint provider result: https://sts.us-east-2.amazonaws.com

For a list of AWS SDKs that support shared AWS configuration file settings for Regional AWS STS endpoints, see Compatibility with AWS SDKS.

Option 2 — Use environment variables

Environment variables provide another way to specify configuration options. They are global and affect calls to AWS services. Most SDKs support environment variables. When you set the environment variable, the SDK uses that value until the end of your shell session or until you set the variable to a different value. To make the variables persist across future sessions, set them in your shell’s startup script.

The following example shows how you can set the value for the Regional AWS STS endpoint in the US East (Ohio) Region (us-east-2) by using environment variables:

Linux or macOS

$ export AWS_DEFAULT_REGION=us-east-2
$ export AWS_STS_REGIONAL_ENDPOINTS=regional

You can run the command $ (echo $AWS_DEFAULT_REGION; echo $AWS_STS_REGIONAL_ENDPOINTS) to validate the variables. The output should look similar to the following:

us-east-2
regional

Windows

C:\> set AWS_DEFAULT_REGION=us-east-2
C:\> set AWS_STS_REGIONAL_ENDPOINTS=regional

The following example shows how you can configure an STS client with the AWS SDK for Python (Boto3) to use a Regional AWS STS endpoint by setting the environment variable:

import boto3
import os
os.environ["AWS_DEFAULT_REGION"] = "us-east-2"
os.environ["AWS_STS_REGIONAL_ENDPOINTS"] = "regional"

You can use the metadata attribute sts_client.meta.endpoint_url to inspect and validate how an STS client is configured. The output should look similar to the following:

>>> sts_client = boto3.client("sts")
>>> sts_client.meta.endpoint_url
'https://sts.us-east-2.amazonaws.com'

For a list of AWS SDKs that support environment variable settings for Regional AWS STS endpoints, see Compatibility with AWS SDKs.

Option 3 — Construct an endpoint URL

You can also manually construct an endpoint URL for a specific Regional AWS STS endpoint.

The following example shows how you can configure the STS client with AWS SDK for Python (Boto3) to use a Regional AWS STS endpoint by setting a specific endpoint URL:

import boto3
sts_client = boto3.client('sts', region_name='us-east-2', endpoint_url='https://sts.us-east-2.amazonaws.com')

Use a VPC endpoint with AWS STS

You can create a private connection to AWS STS from the resources that you deployed in your Amazon VPCs. AWS STS integrates with AWS PrivateLink by using interface VPC endpoints. The network traffic on AWS PrivateLink stays on the global AWS network backbone and doesn’t traverse the public internet. When you configure a VPC endpoint for AWS STS, the traffic for the Regional AWS STS endpoint traverses to that endpoint.

By default, the DNS in your VPC will update the entry for the Regional AWS STS endpoint to resolve to the private IP address of the VPC endpoint for AWS STS in your VPC. The following output from an Amazon Elastic Compute Cloud (Amazon EC2) instance shows the DNS name for the AWS STS endpoint resolving to the private IP address of the VPC endpoint for AWS STS:

[ec2-user@ip-10-120-136-166 ~]$ nslookup sts.us-east-2.amazonaws.com
Server:         10.120.0.2
Address:        10.120.0.2#53

Non-authoritative answer:
Name:   sts.us-east-2.amazonaws.com
Address: 10.120.138.148

After you create an interface VPC endpoint for AWS STS in your Region, set the value for the respective Regional AWS STS endpoint by using environment variables to access AWS STS in the same Region.

The output of the following log shows that an AWS STS call was made to the Regional AWS STS endpoint:

POST
/

content-type:application/x-www-form-urlencoded; charset=utf-8
host:sts.us-east-2.amazonaws.com

Log AWS STS requests

You can use AWS CloudTrail events to get information about the request and endpoint that was used for AWS STS. This information can help you identify AWS STS request patterns and validate if you are still using the global (legacy) STS endpoint.

An event in CloudTrail is the record of an activity in an AWS account. CloudTrail events provide a history of both API and non-API account activity made through the AWS Management Console, AWS SDKs, command line tools, and other AWS services.

Log locations

  • Requests to Regional AWS STS endpoints sts.<region-name>.amazonaws.com are logged in CloudTrail within their respective Region.
  • Requests to the global (legacy) STS endpoint sts.amazonaws.com are logged within the US East (N. Virginia) Region (us-east-1).

Log fields

  • Requests to Regional AWS STS endpoints and global endpoint are logged in the tlsDetails field in CloudTrail. You can use this field to determine if the request was made to a Regional or global (legacy) endpoint.
  • Requests made from a VPC endpoint are logged in the vpcEndpointId field in CloudTrail.

The following example shows a CloudTrail event for an STS request to a Regional AWS STS endpoint with a VPC endpoint.

"eventType": "AwsApiCall",
"managementEvent": true,
"recipientAccountId": "123456789012",
"vpcEndpointId": "vpce-021345abcdef6789",
"eventCategory": "Management",
"tlsDetails": {
    "tlsVersion": "TLSv1.2",
    "cipherSuite": "ECDHE-RSA-AES128-GCM-SHA256",
    "clientProvidedHostHeader": "sts.us-east-2.amazonaws.com"
}

The following example shows a CloudTrail event for an STS request to the global (legacy) AWS STS endpoint.

"eventType": "AwsApiCall",
"managementEvent": true,
"recipientAccountId": "123456789012",
"eventCategory": "Management",
"tlsDetails": {
    "tlsVersion": "TLSv1.2",
    "cipherSuite": "ECDHE-RSA-AES128-GCM-SHA256",
    "clientProvidedHostHeader": "sts.amazonaws.com"
}

To interactively search and analyze your AWS STS log data, use AWS CloudWatch Logs Insights or Amazon Athena.

CloudWatch Logs Insights

The following example shows how to run a CloudWatch Logs Insights query to look for API calls made to the global (legacy) AWS STS endpoint. Before you can query CloudTrail events, you must configure a CloudTrail trail to send events to CloudWatch Logs.

filter eventSource="sts.amazonaws.com" and tlsDetails.clientProvidedHostHeader="sts.amazonaws.com"
| fields eventTime, recipientAccountId, eventName, tlsDetails.clientProvidedHostHeader, sourceIPAddress, userIdentity.arn, @message
| sort eventTime desc

The query output shows event details for an AWS STS call made to the global (legacy) AWS STS endpoint https://sts.amazonaws.com.

Figure 3: Use a CloudWatch Log Insights query to look for STS API calls

Figure 3: Use a CloudWatch Log Insights query to look for STS API calls

Amazon Athena

The following example shows how to query CloudTrail events with Amazon Athena and search for API calls made to the global (legacy) AWS STS endpoint.

SELECT
    eventtime,
    recipientaccountid,
    eventname,
    tlsdetails.clientProvidedHostHeader,
    sourceipaddress,
    eventid,
    useridentity.arn
FROM "cloudtrail_logs"
WHERE
    eventsource = 'sts.amazonaws.com' AND
    tlsdetails.clientProvidedHostHeader = 'sts.amazonaws.com'
ORDER BY eventtime DESC

The query output shows STS calls made to the global (legacy) AWS STS endpoint https://sts.amazonaws.com.

Figure 4: Use Athena to search for STS API calls and identify STS endpoints

Figure 4: Use Athena to search for STS API calls and identify STS endpoints

Conclusion

In this post, you learned how to use Regional AWS STS endpoints to help improve resiliency, reduce latency, and increase session token usage for the operating Regions in your AWS environment.

AWS recommends that you check the configuration and usage of AWS STS endpoints in your environment, validate AWS STS activity in your CloudTrail logs, and confirm that Regional AWS STS endpoints are used.

If you have questions, post them in the Security Identity and Compliance re:Post topic or reach out to AWS Support.

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Darius Januskis

Darius is a Senior Solutions Architect at AWS helping global financial services customers in their journey to the cloud. He is a passionate technology enthusiast who enjoys working with customers and helping them build well-architected solutions. His core interests include security, DevOps, automation, and serverless technologies.

Best practices for managing Terraform State files in AWS CI/CD Pipeline

Post Syndicated from Arun Kumar Selvaraj original https://aws.amazon.com/blogs/devops/best-practices-for-managing-terraform-state-files-in-aws-ci-cd-pipeline/

Introduction

Today customers want to reduce manual operations for deploying and maintaining their infrastructure. The recommended method to deploy and manage infrastructure on AWS is to follow Infrastructure-As-Code (IaC) model using tools like AWS CloudFormation, AWS Cloud Development Kit (AWS CDK) or Terraform.

One of the critical components in terraform is managing the state file which keeps track of your configuration and resources. When you run terraform in an AWS CI/CD pipeline the state file has to be stored in a secured, common path to which the pipeline has access to. You need a mechanism to lock it when multiple developers in the team want to access it at the same time.

In this blog post, we will explain how to manage terraform state files in AWS, best practices on configuring them in AWS and an example of how you can manage it efficiently in your Continuous Integration pipeline in AWS when used with AWS Developer Tools such as AWS CodeCommit and AWS CodeBuild. This blog post assumes you have a basic knowledge of terraform, AWS Developer Tools and AWS CI/CD pipeline. Let’s dive in!

Challenges with handling state files

By default, the state file is stored locally where terraform runs, which is not a problem if you are a single developer working on the deployment. However if not, it is not ideal to store state files locally as you may run into following problems:

  • When working in teams or collaborative environments, multiple people need access to the state file
  • Data in the state file is stored in plain text which may contain secrets or sensitive information
  • Local files can get lost, corrupted, or deleted

Best practices for handling state files

The recommended practice for managing state files is to use terraform’s built-in support for remote backends. These are:

Remote backend on Amazon Simple Storage Service (Amazon S3): You can configure terraform to store state files in an Amazon S3 bucket which provides a durable and scalable storage solution. Storing on Amazon S3 also enables collaboration that allows you to share state file with others.

Remote backend on Amazon S3 with Amazon DynamoDB: In addition to using an Amazon S3 bucket for managing the files, you can use an Amazon DynamoDB table to lock the state file. This will allow only one person to modify a particular state file at any given time. It will help to avoid conflicts and enable safe concurrent access to the state file.

There are other options available as well such as remote backend on terraform cloud and third party backends. Ultimately, the best method for managing terraform state files on AWS will depend on your specific requirements.

When deploying terraform on AWS, the preferred choice of managing state is using Amazon S3 with Amazon DynamoDB.

AWS configurations for managing state files

  1. Create an Amazon S3 bucket using terraform. Implement security measures for Amazon S3 bucket by creating an AWS Identity and Access Management (AWS IAM) policy or Amazon S3 Bucket Policy. Thus you can restrict access, configure object versioning for data protection and recovery, and enable AES256 encryption with SSE-KMS for encryption control.
  1. Next create an Amazon DynamoDB table using terraform with Primary key set to LockID. You can also set any additional configuration options such as read/write capacity units. Once the table is created, you will configure the terraform backend to use it for state locking by specifying the table name in the terraform block of your configuration.
  1. For a single AWS account with multiple environments and projects, you can use a single Amazon S3 bucket. If you have multiple applications in multiple environments across multiple AWS accounts, you can create one Amazon S3 bucket for each account. In that Amazon S3 bucket, you can create appropriate folders for each environment, storing project state files with specific prefixes.

Now that you know how to handle terraform state files on AWS, let’s look at an example of how you can configure them in a Continuous Integration pipeline in AWS.

Architecture

Architecture on how to use terraform in an AWS CI pipeline

Figure 1: Example architecture on how to use terraform in an AWS CI pipeline

This diagram outlines the workflow implemented in this blog:

  1. The AWS CodeCommit repository contains the application code
  2. The AWS CodeBuild job contains the buildspec files and references the source code in AWS CodeCommit
  3. The AWS Lambda function contains the application code created after running terraform apply
  4. Amazon S3 contains the state file created after running terraform apply. Amazon DynamoDB locks the state file present in Amazon S3

Implementation

Pre-requisites

Before you begin, you must complete the following prerequisites:

Setting up the environment

  1. You need an AWS access key ID and secret access key to configure AWS CLI. To learn more about configuring the AWS CLI, follow these instructions.
  2. Clone the repo for complete example: git clone https://github.com/aws-samples/manage-terraform-statefiles-in-aws-pipeline
  3. After cloning, you could see the following folder structure:
AWS CodeCommit repository structure

Figure 2: AWS CodeCommit repository structure

Let’s break down the terraform code into 2 parts – one for preparing the infrastructure and another for preparing the application.

Preparing the Infrastructure

  1. The main.tf file is the core component that does below:
      • It creates an Amazon S3 bucket to store the state file. We configure bucket ACL, bucket versioning and encryption so that the state file is secure.
      • It creates an Amazon DynamoDB table which will be used to lock the state file.
      • It creates two AWS CodeBuild projects, one for ‘terraform plan’ and another for ‘terraform apply’.

    Note – It also has the code block (commented out by default) to create AWS Lambda which you will use at a later stage.

  1. AWS CodeBuild projects should be able to access Amazon S3, Amazon DynamoDB, AWS CodeCommit and AWS Lambda. So, the AWS IAM role with appropriate permissions required to access these resources are created via iam.tf file.
  1. Next you will find two buildspec files named buildspec-plan.yaml and buildspec-apply.yaml that will execute terraform commands – terraform plan and terraform apply respectively.
  1. Modify AWS region in the provider.tf file.
  1. Update Amazon S3 bucket name, Amazon DynamoDB table name, AWS CodeBuild compute types, AWS Lambda role and policy names to required values using variable.tf file. You can also use this file to easily customize parameters for different environments.

With this, the infrastructure setup is complete.

You can use your local terminal and execute below commands in the same order to deploy the above-mentioned resources in your AWS account.

terraform init
terraform validate
terraform plan
terraform apply

Once the apply is successful and all the above resources have been successfully deployed in your AWS account, proceed with deploying your application. 

Preparing the Application

  1. In the cloned repository, use the backend.tf file to create your own Amazon S3 backend to store the state file. By default, it will have below values. You can override them with your required values.
bucket = "tfbackend-bucket" 
key    = "terraform.tfstate" 
region = "eu-central-1"
  1. The repository has sample python code stored in main.py that returns a simple message when invoked.
  1. In the main.tf file, you can find the below block of code to create and deploy the Lambda function that uses the main.py code (uncomment these code blocks).
data "archive_file" "lambda_archive_file" {
    ……
}

resource "aws_lambda_function" "lambda" {
    ……
}
  1. Now you can deploy the application using AWS CodeBuild instead of running terraform commands locally which is the whole point and advantage of using AWS CodeBuild.
  1. Run the two AWS CodeBuild projects to execute terraform plan and terraform apply again.
  1. Once successful, you can verify your deployment by testing the code in AWS Lambda. To test a lambda function (console):
    • Open AWS Lambda console and select your function “tf-codebuild”
    • In the navigation pane, in Code section, click Test to create a test event
    • Provide your required name, for example “test-lambda”
    • Accept default values and click Save
    • Click Test again to trigger your test event “test-lambda”

It should return the sample message you provided in your main.py file. In the default case, it will display “Hello from AWS Lambda !” message as shown below.

Sample Amazon Lambda function response

Figure 3: Sample Amazon Lambda function response

  1. To verify your state file, go to Amazon S3 console and select the backend bucket created (tfbackend-bucket). It will contain your state file.
Amazon S3 bucket with terraform state file

Figure 4: Amazon S3 bucket with terraform state file

  1. Open Amazon DynamoDB console and check your table tfstate-lock and it will have an entry with LockID.
Amazon DynamoDB table with LockID

Figure 5: Amazon DynamoDB table with LockID

Thus, you have securely stored and locked your terraform state file using terraform backend in a Continuous Integration pipeline.

Cleanup

To delete all the resources created as part of the repository, run the below command from your terminal.

terraform destroy

Conclusion

In this blog post, we explored the fundamentals of terraform state files, discussed best practices for their secure storage within AWS environments and also mechanisms for locking these files to prevent unauthorized team access. And finally, we showed you an example of how efficiently you can manage them in a Continuous Integration pipeline in AWS.

You can apply the same methodology to manage state files in a Continuous Delivery pipeline in AWS. For more information, see CI/CD pipeline on AWS, Terraform backends types, Purpose of terraform state.

Arun Kumar Selvaraj

Arun Kumar Selvaraj is a Cloud Infrastructure Architect with AWS Professional Services. He loves building world class capability that provides thought leadership, operating standards and platform to deliver accelerated migration and development paths for his customers. His interests include Migration, CCoE, IaC, Python, DevOps, Containers and Networking.

Manasi Bhutada

Manasi Bhutada is an ISV Solutions Architect based in the Netherlands. She helps customers design and implement well architected solutions in AWS that address their business problems. She is passionate about data analytics and networking. Beyond work she enjoys experimenting with food, playing pickleball, and diving into fun board games.

How to enforce creation of roles in a specific path: Use IAM role naming in hierarchy models

Post Syndicated from Varun Sharma original https://aws.amazon.com/blogs/security/how-to-enforce-creation-of-roles-in-a-specific-path-use-iam-role-naming-in-hierarchy-models/

An AWS Identity and Access Management (IAM) role is an IAM identity that you create in your AWS account that has specific permissions. An IAM role is similar to an IAM user because it’s an AWS identity with permission policies that determine what the identity can and cannot do on AWS. However, as outlined in security best practices in IAM, AWS recommends that you use IAM roles instead of IAM users. An IAM user is uniquely associated with one person, while a role is intended to be assumable by anyone who needs it. An IAM role doesn’t have standard long-term credentials such as a password or access keys associated with it. Instead, when you assume a role, it provides you with temporary security credentials for your role session that are only valid for certain period of time.

This blog post explores the effective implementation of security controls within IAM roles, placing a specific focus on the IAM role’s path feature. By organizing IAM roles hierarchically using paths, you can address key challenges and achieve practical solutions to enhance IAM role management.

Benefits of using IAM paths

A fundamental benefit of using paths is the establishment of a clear and organized organizational structure. By using paths, you can handle diverse use cases while creating a well-defined framework for organizing roles on AWS. This organizational clarity can help you navigate complex IAM setups and establish a cohesive structure that’s aligned with your organizational needs.

Furthermore, by enforcing a specific structure, you can gain precise control over the scope of permissions assigned to roles, helping to reduce the risk of accidental assignment of overly permissive policies. By assisting in preventing inadvertent policy misconfigurations and assisting in coordinating permissions with the planned organizational structure, this proactive solution improves security. This approach is highly effective when you consistently apply established naming conventions to paths, role names, and policies. Enforcing a uniform approach to role naming enhances the standardization and efficiency of IAM role management. This practice fosters smooth collaboration and reduces the risk of naming conflicts.

Path example

In IAM, a role path is a way to organize and group IAM roles within your AWS account. You specify the role path as part of the role’s Amazon Resource Name (ARN).

As an example, imagine that you have a group of IAM roles related to development teams, and you want to organize them under a path. You might structure it like this:

Role name: Dev App1 admin
Role path: /D1/app1/admin/
Full ARN: arn:aws:iam::123456789012:role/D1/app1/admin/DevApp1admin

Role name: Dev App2 admin
Role path: /D2/app2/admin/
Full ARN: arn:aws:iam::123456789012:role/D2/app2/admin/DevApp2admin

In this example, the IAM roles DevApp1admin and DevApp2admin are organized under two different development team paths: D1/app1/admin and D2/app2/admin, respectively. The role path provides a way to group roles logically, making it simpler to manage and understand their purpose within the context of your organization.

Solution overview

Figure 1: Sample architecture

Figure 1: Sample architecture

The sample architecture in Figure 1 shows how you can separate and categorize the enterprise roles and development team roles into a hierarchy model by using a path in an IAM role. Using this hierarchy model, you can enable several security controls at the level of the service control policy (SCP), IAM policy, permissions boundary, or the pipeline. I recommend that you avoid incorporating business unit names in paths because they could change over time.

Here is what the IAM role path looks like as an ARN:

arn:aws:iam::123456789012:role/EnT/iam/adm/IAMAdmin

In this example, in the resource name, /EnT/iam/adm/ is the role path, and IAMAdmin is the role name.

You can now use the role path as part of a policy, such as the following:

arn:aws:iam::123456789012:role/EnT/iam/adm/*

In this example, in the resource name, /EnT/iam/adm/ is the role path, and * indicates any IAM role inside this path.

Walkthrough of examples for preventative controls

Now let’s walk through some example use cases and SCPs for a preventative control that you can use based on the path of an IAM role.

PassRole preventative control example

The following SCP denies passing a role for enterprise roles, except for roles that are part of the IAM admin hierarchy within the overall enterprise hierarchy.

		{
	"Version": "2012-10-17",
	"Statement": [
		{
			"Sid": "DenyEnTPassRole",
			"Effect": "Deny",
			"Action": "iam:PassRole",
			"Resource": "arn:aws:iam::*:role/EnT/*",
			"Condition": {
				"ArnNotLike": {
					"aws:PrincipalArn": "arn:aws:iam::*:role/EnT/fed/iam/*"
				}
			}
		}
	]
}

With just a couple of statements in the SCP, this preventative control helps provide protection to your high-privilege roles for enterprise roles, regardless of the role’s name or current status.

This example uses the following paths:

  • /EnT/ — enterprise roles (roles owned by the central teams, such as cloud center of excellence, central security, and networking teams)
  • /fed/ — federated roles, which have interactive access
  • /iam/ — roles that are allowed to perform IAM actions, such as CreateRole, AttachPolicy, or DeleteRole

IAM actions preventative control example

The following SCP restricts IAM actions, including CreateRole, DeleteRole, AttachRolePolicy, and DetachRolePolicy, on the enterprise path.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "DenyIAMActionsonEnTRoles",
            "Effect": "Deny",
            "Action": [
                "iam:CreateRole",
                "iam:DeleteRole",
                "iam:DetachRolePolicy",
                "iam:AttachRolePolicy"
            ],
            "Resource": "arn:aws:iam::*:role/EnT/*",
            "Condition": {
                "ArnNotLike": {
                    "aws:PrincipalArn": "arn:aws:iam::*:role/EnT/fed/iam/*"
                }
            }
        }
    ]
}

This preventative control denies an IAM role that is outside of the enterprise hierarchy from performing the actions CreateRole, DeleteRole, DetachRolePolicy, and AttachRolePolicy in this hierarchy. Every IAM role will be denied those API actions except the one with the path as arn:aws:iam::*:role/EnT/fed/iam/*

The example uses the following paths:

  • /EnT/ — enterprise roles (roles owned by the central teams, such as cloud center of excellence, central security, or network automation teams)
  • /fed/ — federated roles, which have interactive access
  • /iam/ — roles that are allowed to perform IAM actions (in this case, CreateRole, DeteleRole, DetachRolePolicy, and AttachRolePolicy)

IAM policies preventative control example

The following SCP policy denies attaching certain high-privilege AWS managed policies such as AdministratorAccess outside of certain IAM admin roles. This is especially important in an environment where business units have self-service capabilities.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "RolePolicyAttachment",
            "Effect": "Deny",
            "Action": "iam:AttachRolePolicy",
            "Resource": "arn:aws:iam::*:role/EnT/fed/iam/*",
            "Condition": {
                "ArnNotLike": {
                    "iam:PolicyARN": "arn:aws:iam::aws:policy/AdministratorAccess"
                }
            }
        }
    ]
}

AssumeRole preventative control example

The following SCP doesn’t allow non-production roles to assume a role in production accounts. Make sure to replace <Your production OU ID> and <your org ID> with your own information.

{
	"Version": "2012-10-17",
	"Statement": [
		{
			"Sid": "DenyAssumeRole",
			"Effect": "Deny",
			"Action": "sts:AssumeRole",
			"Resource": "*",
			"Condition": {
				"StringLike": {
					"aws:PrincipalArn": "arn:aws:iam::*:role/np/*"
				},
				"ForAnyValue:StringLike": {
					"aws:ResourceOrgPaths": "<your org ID>/r-xxxx/<Your production OU ID>/*"
				}
			}
		}
	]
}

This example uses the /np/ path, which specifies non-production roles. The SCP denies non-production IAM roles from assuming a role in the production organizational unit (OU) (in our example, this is represented by <your org ID>/r-xxxx/<Your production OU ID>/*”). Depending on the structure of your organization, the ResourceOrgPaths will have one of the following formats:

  • “o-a1b2c3d4e5/*”
  • “o-a1b2c3d4e5/r-ab12/ou-ab12-11111111/*”
  • “o-a1b2c3d4e5/r-ab12/ou-ab12-11111111/ou-ab12-22222222/”

Walkthrough of examples for monitoring IAM roles (detective control)

Now let’s walk through two examples of detective controls.

AssumeRole in CloudTrail Lake

The following is an example of a detective control to monitor IAM roles in AWS CloudTrail Lake.

SELECT
    userIdentity.arn as "Username", eventTime, eventSource, eventName, sourceIPAddress, errorCode, errorMessage
FROM
    <Event data store ID>
WHERE
    userIdentity.arn IS NOT NULL
    AND eventName = 'AssumeRole'
    AND userIdentity.arn LIKE '%/np/%'
    AND errorCode = 'AccessDenied'
    AND eventTime > '2023-07-01 14:00:00'
    AND eventTime < '2023-11-08 18:00:00';

This query lists out AssumeRole events for non-production roles in the organization for AccessDenied errors. The output is stored in an Amazon Simple Storage Service (Amazon S3) bucket from CloudTrail Lake, from which the csv file can be downloaded. The following shows some example output:

Username,eventTime,eventSource,eventName,sourceIPAddress,errorCode,errorMessage
arn:aws:sts::123456789012:assumed-role/np/test,2023-12-09 10:35:45.000,iam.amazonaws.com,AssumeRole,11.11.113.113,AccessDenied,User: arn:aws:sts::123456789012:assumed-role/np/test is not authorized to perform: sts:AssumeRole on resource: arn:aws:iam::123456789012:role/hello because no identity-based policy allows the sts:AssumeRole action

You can modify the query to audit production roles as well.

CreateRole in CloudTrail Lake

Another example of a CloudTrail Lake query for a detective control is as follows:

SELECT
    userIdentity.arn as "Username", eventTime, eventSource, eventName, sourceIPAddress, errorCode, errorMessage
FROM
    <Event data store ID>
WHERE
    userIdentity.arn IS NOT NULL
    AND eventName = 'CreateRole'
    AND userIdentity.arn LIKE '%/EnT/fed/iam/%'
    AND eventTime > '2023-07-01 14:00:00'
    AND eventTime < '2023-11-08 18:00:00';

This query lists out CreateRole events for roles in the /EnT/fed/iam/ hierarchy. The following are some example outputs:

Username,eventTime,eventSource,eventName,sourceIPAddress,errorCode,errorMessage

arn:aws:sts::123456789012:assumed-role/EnT/fed/iam/security/test,2023-12-09 16:31:11.000,iam.amazonaws.com,CreateRole,10.10.10.10,AccessDenied,User: arn:aws:sts::123456789012:assumed-role/EnT/fed/iam/security/test is not authorized to perform: iam:CreateRole on resource: arn:aws:iam::123456789012:role/EnT/fed/iam/security because no identity-based policy allows the iam:CreateRole action

arn:aws:sts::123456789012:assumed-role/EnT/fed/iam/security/test,2023-12-09 16:33:10.000,iam.amazonaws.com,CreateRole,10.10.10.10,AccessDenied,User: arn:aws:sts::123456789012:assumed-role/EnT/fed/iam/security/test is not authorized to perform: iam:CreateRole on resource: arn:aws:iam::123456789012:role/EnT/fed/iam/security because no identity-based policy allows the iam:CreateRole action

Because these roles can create additional enterprise roles, you should audit roles created in this hierarchy.

Important considerations

When you implement specific paths for IAM roles, make sure to consider the following:

  • The path of an IAM role is part of the ARN. After you define the ARN, you can’t change it later. Therefore, just like the name of the role, consider what the path should be during the early discussions of design.
  • IAM roles can’t have the same name, even on different paths.
  • When you switch roles through the console, you need to include the path because it’s part of the role’s ARN.
  • The path of an IAM role can’t exceed 512 characters. For more information, see IAM and AWS STS quotas.
  • The role name can’t exceed 64 characters. If you intend to use a role with the Switch Role feature in the AWS Management Console, then the combined path and role name can’t exceed 64 characters.
  • When you create a role through the console, you can’t set an IAM role path. To set a path for the role, you need to use automation, such as AWS Command Line Interface (AWS CLI) commands or SDKs. For example, you might use an AWS CloudFormation template or a script that interacts with AWS APIs to create the role with the desired path.

Conclusion

By adopting the path strategy, you can structure IAM roles within a hierarchical model, facilitating the implementation of security controls on a scalable level. You can make these controls effective for IAM roles by applying them to a path rather than specific roles, which sets this approach apart.

This strategy can help you elevate your overall security posture within IAM, offering a forward-looking solution for enterprises. By establishing a scalable IAM hierarchy, you can help your organization navigate dynamic changes through a robust identity management structure. A well-crafted hierarchy reduces operational overhead by providing a versatile framework that makes it simpler to add or modify roles and policies. This scalability can help streamline the administration of IAM and help your organization manage access control in evolving environments.

If you have feedback about this post, submit comments in the Comments section below. If you have questions about this post, start a new thread on the AWS Security, Identity, & Compliance re:Post or contact AWS Support.

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Varun Sharma

Varun Sharma

Varun is an AWS Cloud Security Engineer who wears his security cape proudly. With a knack for unravelling the mysteries of Amazon Cognito and IAM, Varun is a go-to subject matter expert for these services. When he’s not busy securing the cloud, you’ll find him in the world of security penetration testing. And when the pixels are at rest, Varun switches gears to capture the beauty of nature through the lens of his camera.

IAM Access Analyzer simplifies inspection of unused access in your organization

Post Syndicated from Achraf Moussadek-Kabdani original https://aws.amazon.com/blogs/security/iam-access-analyzer-simplifies-inspection-of-unused-access-in-your-organization/

AWS Identity and Access Management (IAM) Access Analyzer offers tools that help you set, verify, and refine permissions. You can use IAM Access Analyzer external access findings to continuously monitor your AWS Organizations organization and Amazon Web Services (AWS) accounts for public and cross-account access to your resources, and verify that only intended external access is granted. Now, you can use IAM Access Analyzer unused access findings to identify unused access granted to IAM roles and users in your organization.

If you lead a security team, your goal is to manage security for your organization at scale and make sure that your team follows best practices, such as the principle of least privilege. When your developers build on AWS, they create IAM roles for applications and team members to interact with AWS services and resources. They might start with broad permissions while they explore AWS services for their use cases. To identify unused access, you can review the IAM last accessed information for a given IAM role or user and refine permissions gradually. If your company has a multi-account strategy, your roles and policies are created in multiple accounts. You then need visibility across your organization to make sure that teams are working with just the required access.

Now, IAM Access Analyzer simplifies inspection of unused access by reporting unused access findings across your IAM roles and users. IAM Access Analyzer continuously analyzes the accounts in your organization to identify unused access and creates a centralized dashboard with findings. From a delegated administrator account for IAM Access Analyzer, you can use the dashboard to review unused access findings across your organization and prioritize the accounts to inspect based on the volume and type of findings. The findings highlight unused roles, unused access keys for IAM users, and unused passwords for IAM users. For active IAM users and roles, the findings provide visibility into unused services and actions. With the IAM Access Analyzer integration with Amazon EventBridge and AWS Security Hub, you can automate and scale rightsizing of permissions by using event-driven workflows.

In this post, we’ll show you how to set up and use IAM Access Analyzer to identify and review unused access in your organization.

Generate unused access findings

To generate unused access findings, you need to create an analyzer. An analyzer is an IAM Access Analyzer resource that continuously monitors your accounts or organization for a given finding type. You can create an analyzer for the following findings:

An analyzer for unused access findings is a new analyzer that continuously monitors roles and users, looking for permissions that are granted but not actually used. This analyzer is different from an analyzer for external access findings; you need to create a new analyzer for unused access findings even if you already have an analyzer for external access findings.

You can centrally view unused access findings across your accounts by creating an analyzer at the organization level. If you operate a standalone account, you can get unused access findings by creating an analyzer at the account level. This post focuses on the organization-level analyzer setup and management by a central team.

Pricing

IAM Access Analyzer charges for unused access findings based on the number of IAM roles and users analyzed per analyzer per month. You can still use IAM Access Analyzer external access findings at no additional cost. For more details on pricing, see IAM Access Analyzer pricing.

Create an analyzer for unused access findings

To enable unused access findings for your organization, you need to create your analyzer by using the IAM Access Analyzer console or APIs in your management account or a delegated administrator account. A delegated administrator is a member account of the organization that you can delegate with administrator access for IAM Access Analyzer. A best practice is to use your management account only for tasks that require the management account and use a delegated administrator for other tasks. For steps on how to add a delegated administrator for IAM Access Analyzer, see Delegated administrator for IAM Access Analyzer.

To create an analyzer for unused access findings (console)

  1. From the delegated administrator account, open the IAM Access Analyzer console, and in the left navigation pane, select Analyzer settings.
  2. Choose Create analyzer.
  3. On the Create analyzer page, do the following, as shown in Figure 1:
    1. For Findings type, select Unused access analysis.
    2. Provide a Name for the analyzer.
    3. Select a Tracking period. The tracking period is the threshold beyond which IAM Access Analyzer considers access to be unused. For example, if you select a tracking period of 90 days, IAM Access Analyzer highlights the roles that haven’t been used in the last 90 days.
    4. Set your Selected accounts. For this example, we select Current organization to review unused access across the organization.
    5. Select Create.
       
    Figure 1: Create analyzer page

    Figure 1: Create analyzer page

Now that you’ve created the analyzer, IAM Access Analyzer starts reporting findings for unused access across the IAM users and roles in your organization. IAM Access Analyzer will periodically scan your IAM roles and users to update unused access findings. Additionally, if one of your roles, users or policies is updated or deleted, IAM Access Analyzer automatically updates existing findings or creates new ones. IAM Access Analyzer uses a service-linked role to review last accessed information for all roles, user access keys, and user passwords in your organization. For active IAM roles and users, IAM Access Analyzer uses IAM service and action last accessed information to identify unused permissions.

Note: Although IAM Access Analyzer is a regional service (that is, you enable it for a specific AWS Region), unused access findings are linked to IAM resources that are global (that is, not tied to a Region). To avoid duplicate findings and costs, enable your analyzer for unused access in the single Region where you want to review and operate findings.

IAM Access Analyzer findings dashboard

Your analyzer aggregates findings from across your organization and presents them on a dashboard. The dashboard aggregates, in the selected Region, findings for both external access and unused access—although this post focuses on unused access findings only. You can use the dashboard for unused access findings to centrally review the breakdown of findings by account or finding types to identify areas to prioritize for your inspection (for example, sensitive accounts, type of findings, type of environment, or confidence in refinement).

Unused access findings dashboard – Findings overview

Review the findings overview to identify the total findings for your organization and the breakdown by finding type. Figure 2 shows an example of an organization with 100 active findings. The finding type Unused access keys is present in each of the accounts, with the most findings for unused access. To move toward least privilege and to avoid long-term credentials, the security team should clean up the unused access keys.

Figure 2: Unused access finding dashboard

Figure 2: Unused access finding dashboard

Unused access findings dashboard – Accounts with most findings

Review the dashboard to identify the accounts with the highest number of findings and the distribution per finding type. In Figure 2, the Audit account has the highest number of findings and might need attention. The account has five unused access keys and six roles with unused permissions. The security team should prioritize this account based on volume of findings and review the findings associated with the account.

Review unused access findings

In this section, we’ll show you how to review findings. We’ll share two examples of unused access findings, including unused access key findings and unused permissions findings.

Finding example: unused access keys

As shown previously in Figure 2, the IAM Access Analyzer dashboard showed that accounts with the most findings were primarily associated with unused access keys. Let’s review a finding linked to unused access keys.

To review the finding for unused access keys

  1. Open the IAM Access Analyzer console, and in the left navigation pane, select Unused access.
  2. Select your analyzer to view the unused access findings.
  3. In the search dropdown list, select the property Findings type, the Equals operator, and the value Unused access key to get only Findings type = Unused access key, as shown in Figure 3.
     
    Figure 3: List of unused access findings

    Figure 3: List of unused access findings

  4. Select one of the findings to get a view of the available access keys for an IAM user, their status, creation date, and last used date. Figure 4 shows an example in which one of the access keys has never been used, and the other was used 137 days ago.
     
    Figure 4: Finding example - Unused IAM user access keys

    Figure 4: Finding example – Unused IAM user access keys

From here, you can investigate further with the development teams to identify whether the access keys are still needed. If they aren’t needed, you should delete the access keys.

Finding example: unused permissions

Another goal that your security team might have is to make sure that the IAM roles and users across your organization are following the principle of least privilege. Let’s walk through an example with findings associated with unused permissions.

To review findings for unused permissions

  1. On the list of unused access findings, apply the filter on Findings type = Unused permissions.
  2. Select a finding, as shown in Figure 5. In this example, the IAM role has 148 unused actions on Amazon Relational Database Service (Amazon RDS) and has not used a service action for 200 days. Similarly, the role has unused actions for other services, including Amazon Elastic Compute Cloud (Amazon EC2), Amazon Simple Storage Service (Amazon S3), and Amazon DynamoDB.
     
    Figure 5: Finding example - Unused permissions

    Figure 5: Finding example – Unused permissions

The security team now has a view of the unused actions for this role and can investigate with the development teams to check if those permissions are still required.

The development team can then refine the permissions granted to the role to remove the unused permissions.

Unused access findings notify you about unused permissions for all service-level permissions and for 200 services at the action-level. For the list of supported actions, see IAM action last accessed information services and actions.

Take actions on findings

IAM Access Analyzer categorizes findings as active, resolved, and archived. In this section, we’ll show you how you can act on your findings.

Resolve findings

You can resolve unused access findings by deleting unused IAM roles, IAM users, IAM user credentials, or permissions. After you’ve completed this, IAM Access Analyzer automatically resolves the findings on your behalf.

To speed up the process of removing unused permissions, you can use IAM Access Analyzer policy generation to generate a fine-grained IAM policy based on your access analysis. For more information, see the blog post Use IAM Access Analyzer to generate IAM policies based on access activity found in your organization trail.

Archive findings

You can suppress a finding by archiving it, which moves the finding from the Active tab to the Archived tab in the IAM Access Analyzer console. To archive a finding, open the IAM Access Analyzer console, select a Finding ID, and in the Next steps section, select Archive, as shown in Figure 6.

Figure 6: Archive finding in the AWS management console

Figure 6: Archive finding in the AWS management console

You can automate this process by creating archive rules that archive findings based on their attributes. An archive rule is linked to an analyzer, which means that you can have archive rules exclusively for unused access findings.

To illustrate this point, imagine that you have a subset of IAM roles that you don’t expect to use in your tracking period. For example, you might have an IAM role that is used exclusively for break glass access during your disaster recovery processes—you shouldn’t need to use this role frequently, so you can expect some unused access findings. For this example, let’s call the role DisasterRecoveryRole. You can create an archive rule to automatically archive unused access findings associated with roles named DisasterRecoveryRole, as shown in Figure 7.

Figure 7: Example of an archive rule

Figure 7: Example of an archive rule

Automation

IAM Access Analyzer exports findings to both Amazon EventBridge and AWS Security Hub. Security Hub also forwards events to EventBridge.

Using an EventBridge rule, you can match the incoming events associated with IAM Access Analyzer unused access findings and send them to targets for processing. For example, you can notify the account owners so that they can investigate and remediate unused IAM roles, user credentials, or permissions.

For more information, see Monitoring AWS Identity and Access Management Access Analyzer with Amazon EventBridge.

Conclusion

With IAM Access Analyzer, you can centrally identify, review, and refine unused access across your organization. As summarized in Figure 8, you can use the dashboard to review findings and prioritize which accounts to review based on the volume of findings. The findings highlight unused roles, unused access keys for IAM users, and unused passwords for IAM users. For active IAM roles and users, the findings provide visibility into unused services and actions. By reviewing and refining unused access, you can improve your security posture and get closer to the principle of least privilege at scale.

Figure 8: Process to address unused access findings

Figure 8: Process to address unused access findings

The new IAM Access Analyzer unused access findings and dashboard are available in AWS Regions, excluding the AWS GovCloud (US) Regions and AWS China Regions. To learn more about how to use IAM Access Analyzer to detect unused accesses, see the IAM Access Analyzer documentation.

If you have feedback about this post, submit comments in the Comments section below. If you have questions about this post, contact AWS Support.

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Achraf Moussadek-Kabdani

Achraf Moussadek-Kabdani

Achraf is a Senior Security Specialist at AWS. He works with global financial services customers to assess and improve their security posture. He is both a builder and advisor, supporting his customers to meet their security objectives while making security a business enabler.

Author

Yevgeniy Ilyin

Yevgeniy is a Solutions Architect at AWS. He has over 20 years of experience working at all levels of software development and solutions architecture and has used programming languages from COBOL and Assembler to .NET, Java, and Python. He develops and code clouds native solutions with a focus on big data, analytics, and data engineering.

Mathangi Ramesh

Mathangi Ramesh

Mathangi is the product manager for IAM. She enjoys talking to customers and working with data to solve problems. Outside of work, Mathangi is a fitness enthusiast and a Bharatanatyam dancer. She holds an MBA degree from Carnegie Mellon University.

How to improve cross-account access for SaaS applications accessing customer accounts

Post Syndicated from Ashwin Phadke original https://aws.amazon.com/blogs/security/how-to-improve-cross-account-access-for-saas-applications-accessing-customer-accounts/

Several independent software vendors (ISVs) and software as a service (SaaS) providers need to access their customers’ Amazon Web Services (AWS) accounts, especially if the SaaS product accesses data from customer environments. SaaS providers have adopted multiple variations of this third-party access scenario. In some cases, the providers ask the customer for an access key and a secret key, which is not recommended because these are long-term user credentials and require processes to be built for periodic rotation. However, in most cases, the provider has an integration guide with specific details on creating a cross-account AWS Identity and Access Management (IAM) role.

In all these scenarios, as a SaaS vendor, you should add the necessary protections to your SaaS implementation. At AWS, security is the top priority and we recommend that customers follow best practices and incorporate security in their product design. In this blog post intended for SaaS providers, I describe three ways to improve your cross-account access implementation for your products.

Why is this important?

As a security specialist, I’ve worked with multiple ISV customers on improving the security of their products, specifically on this third-party cross-account access scenario. Consumers of your SaaS products don’t want to give more access permissions than are necessary for the product’s proper functioning. At the same time, you should maintain and provide a secure SaaS product to protect your customers’ and your own AWS accounts from unauthorized access or privilege escalations.

Let’s consider a hypothetical scenario with a simple SaaS implementation where a customer is planning to use a SaaS product. In Figure 1, you can see that the SaaS product has multiple different components performing separate functions, for example, a SaaS product with separate components performing compute analysis, storage analysis, and log analysis. The SaaS provider asks the customer to provide IAM user credentials and uses those in their product to access customer resources. Let’s look at three techniques for improving the cross-account access for this scenario. Each technique builds on the previous one, so you could adopt an incremental approach to implement these techniques.

Figure 1: SaaS architecture using customer IAM user credentials

Figure 1: SaaS architecture using customer IAM user credentials

Technique 1 – Using IAM roles and an external ID

As stated previously, IAM user credentials are long-term, so customers would need to implement processes to rotate these periodically and share them with the ISV.

As a better option, SaaS product components can use IAM roles, which provide short-term credentials to the component assuming the role. These credentials need to be refreshed depending on the role’s session duration setting (the default is 1 hour) to continue accessing the resources. IAM roles also provide an advantage for auditing purposes because each time an IAM principal assumes a role, a new session is created, and this can be used to identify and audit activity for separate sessions.

When using IAM roles for third-party access, an important consideration is the confused deputy problem, where an unauthorized entity could coerce the product components into performing an action against another customers’ resources. To mitigate this problem, a highly recommended approach is to use the external ID parameter when assuming roles in customers’ accounts. It’s important and recommended that you generate these external ID parameters to make sure they’re unique for each of your customers, for example, using a customer ID or similar attribute. For external ID character restrictions, see the IAM quotas page. Your customers will use this external ID in their IAM role’s trust policy, and your product components will pass this as a parameter in all AssumeRole API calls to customer environments. An example of the trust policy principal and condition blocks for the role to be assumed in the customer’s account follows:

    "Principal": {"AWS": "<SaaS Provider’s AWS account ID>"},
    "Condition": {"StringEquals": {"sts:ExternalId": "<Unique ID Assigned by SaaS Provider>"}}
Figure 2: SaaS architecture using an IAM role and external ID

Figure 2: SaaS architecture using an IAM role and external ID

Technique 2 – Using least-privilege IAM policies and role chaining

As an IAM best practice, we recommend that an IAM role should only have the minimum set of permissions as required to perform its functions. When your customers create an IAM role in Technique 1, they might inadvertently provide more permissions than necessary to use your product. The role could have permissions associated with multiple AWS services and might become overly permissive. If you provide granular permissions for separate AWS services, you might reach the policy size quota or policies per role quota. See IAM quotas for more information. That’s why, in addition to Technique 1, we recommend that each component have a separate IAM role in the customer’s account with only the minimum permissions required for its functions.

As a part of your integration guide to the customer, you should ask them to create appropriate IAM policies for these IAM roles. There needs to be a clear separation of duties and least privilege access for the product components. For example, an account-monitoring SaaS provider might use a separate IAM role for Amazon Elastic Compute Cloud (Amazon EC2) monitoring and another one for AWS CloudTrail monitoring. Your components will also use separate IAM roles in your own AWS account. However, you might want to provide a single integration IAM role to customers to establish the trust relationship with each component role in their account. In effect, you will be using the concept of role chaining to access your customer’s accounts. The auditing mechanisms on the customer’s end will only display the integration IAM role sessions.

When using role chaining, you must be aware of certain caveats and limitations. Your components will each have separate roles: Role A, which will assume the integration role (Role B), and then use the Role B credentials to assume the customer role (Role C) in customer’s accounts. You need to properly define the correct permissions for each of these roles, because the permissions of the previous role aren’t passed while assuming the role. Optionally, you can pass an IAM policy document known as a session policy as a parameter while assuming the role, and the effective permissions will be a logical intersection of the passed policy and the attached permissions for the role. To learn more about these session policies, see session policies.

Another consideration of using role chaining is that it limits your AWS Command Line Interface (AWS CLI) or AWS API role session duration to a maximum of one hour. This means that you must track the sessions and perform credential refresh actions every hour to continue accessing the resources.

Figure 3: SaaS architecture with role chaining

Figure 3: SaaS architecture with role chaining

Technique 3 – Using role tags and session tags for attribute-based access control

When you create your IAM roles for role chaining, you define which entity can assume the role. You will need to add each component-specific IAM role to the integration role’s trust relationship. As the number of components within your product increases, you might reach the maximum length of the role trust policy. See IAM quotas for more information.

That’s why, in addition to the above two techniques, we recommend using attribute-based access control (ABAC), which is an authorization strategy that defines permissions based on tag attributes. You should tag all the component IAM roles with role tags and use these role tags as conditions in the trust policy for the integration role as shown in the following example. Optionally, you could also include instructions in the product integration guide for tagging customers’ IAM roles with certain role tags and modify the IAM policy of the integration role to allow it to assume only roles with those role tags. This helps in reducing IAM policy length and minimizing the risk of reaching the IAM quota.

"Condition": {
     "StringEquals": {"iam:ResourceTag/<Product>": "<ExampleSaaSProduct>"}

Another consideration for improving the auditing and traceability for your product is IAM role session tags. These could be helpful if you use CloudTrail log events for alerting on specific role sessions. If your SaaS product also operates on CloudTrail logs, you could use these session tags to identify the different sessions from your product. As opposed to role tags, which are tags attached to an IAM role, session tags are key-value pair attributes that you pass when you assume an IAM role. These can be used to identify a session and further control or restrict access to resources based on the tags. Session tags can also be used along with role chaining. When you use session tags with role chaining, you can set the keys as transitive to make sure that you pass them to subsequent sessions. CloudTrail log events for these role sessions will contain the session tags, transitive tags, and role (also called principal) tags.

Conclusion

In this post, we discussed three incremental techniques that build on each other and are important for SaaS providers to improve security and access control while implementing cross-account access to their customers. As a SaaS provider, it’s important to verify that your product adheres to security best practices. When you improve security for your product, you’re also improving security for your customers.

To see more tutorials about cross-account access concepts, visit the AWS documentation on IAM Roles, ABAC, and session tags.

If you have feedback about this post, submit comments in the Comments section below. If you have questions about this post, start a new thread on the AWS Identity and Access Management re:Post or contact AWS Support.

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Ashwin Phadke

Ashwin Phadke

Ashwin is a Sr. Solutions Architect, working with large enterprises and ISV customers to build highly available, scalable, and secure applications, and to help them successfully navigate through their cloud journey. He is passionate about information security and enjoys working on creative solutions for customers’ security challenges.

Optimize AWS administration with IAM paths

Post Syndicated from David Rowe original https://aws.amazon.com/blogs/security/optimize-aws-administration-with-iam-paths/

As organizations expand their Amazon Web Services (AWS) environment and migrate workloads to the cloud, they find themselves dealing with many AWS Identity and Access Management (IAM) roles and policies. These roles and policies multiply because IAM fills a crucial role in securing and controlling access to AWS resources. Imagine you have a team creating an application. You create an IAM role to grant them access to the necessary AWS resources, such as Amazon Simple Storage Service (Amazon S3) buckets, Amazon Key Management Service (Amazon KMS) keys, and Amazon Elastic File Service (Amazon EFS) shares. With additional workloads and new data access patterns, the number of IAM roles and policies naturally increases. With the growing complexity of resources and data access patterns, it becomes crucial to streamline access and simplify the management of IAM policies and roles

In this blog post, we illustrate how you can use IAM paths to organize IAM policies and roles and provide examples you can use as a foundation for your own use cases.

How to use paths with your IAM roles and policies

When you create a role or policy, you create it with a default path. In IAM, the default path for resources is “/”. Instead of using a default path, you can create and use paths and nested paths as a structure to manage IAM resources. The following example shows an IAM role named S3Access in the path developer:

arn:aws:iam::111122223333:role/developer/S3Access

Service-linked roles are created in a reserved path /aws-service-role/. The following is an example of a service-linked role path.

arn:aws:iam::*:role/aws-service-role/SERVICE-NAME.amazonaws.com/SERVICE-LINKED-ROLE-NAME

The following example is of an IAM policy named S3ReadOnlyAccess in the path security:

arn:aws:iam::111122223333:policy/security/S3ReadOnlyAccess

Why use IAM paths with roles and policies?

By using IAM paths with roles and policies, you can create groupings and design a logical separation to simplify management. You can use these groupings to grant access to teams, delegate permissions, and control what roles can be passed to AWS services. In the following sections, we illustrate how to use IAM paths to create groupings of roles and policies by referencing a fictional company and its expansion of AWS resources.

First, to create roles and policies with a path, you use the IAM API or AWS Command Line Interface (AWS CLI) to run aws cli create-role.

The following is an example of an AWS CLI command that creates a role in an IAM path.

aws iam create-role --role-name <ROLE-NAME> --assume-role-policy-document file://assume-role-doc.json --path <PATH>

Replace <ROLE-NAME> and <PATH> in the command with your role name and role path respectively. Use a trust policy for the trust document that matches your use case. An example trust policy that allows Amazon Elastic Compute Cloud (Amazon EC2) instances to assume this role on your behalf is below:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "sts:AssumeRole"
            ],
            "Principal": {
                "Service": [
                    "ec2.amazonaws.com"
                ]
            }
        }
    ]
}

The following is an example of an AWS CLI command that creates a policy in an IAM path.

aws iam create-policy --policy-name <POLICY-NAME> --path <PATH> --policy-document file://policy.json

IAM paths sample implementation

Let’s assume you’re a cloud platform architect at AnyCompany, a startup that’s planning to expand its AWS environment. By the end of the year, AnyCompany is going to expand from one team of developers to multiple teams, all of which require access to AWS. You want to design a scalable way to manage IAM roles and policies to simplify the administrative process to give permissions to each team’s roles. To do that, you create groupings of roles and policies based on teams.

Organize IAM roles with paths

AnyCompany decided to create the following roles based on teams.

Team name Role name IAM path Has access to
Security universal-security-readonly /security/ All resources
Team A database administrators DBA-role-A /teamA/ TeamA’s databases
Team B database administrators DBA-role-B /teamB/ TeamB’s databases

The following are example Amazon Resource Names (ARNs) for the roles listed above. In this example, you define IAM paths to create a grouping based on team names.

  1. arn:aws:iam::444455556666:role/security/universal-security-readonly-role
  2. arn:aws:iam::444455556666:role/teamA/DBA-role-A
  3. arn:aws:iam::444455556666:role/teamB/DBA-role-B

Note: Role names must be unique within your AWS account regardless of their IAM paths. You cannot have two roles named DBA-role, even if they’re in separate paths.

Organize IAM policies with paths

After you’ve created roles in IAM paths, you will create policies to provide permissions to these roles. The same path structure that was defined in the IAM roles is used for the IAM policies. The following is an example of how to create a policy with an IAM path. After you create the policy, you can attach the policy to a role using the attach-role-policy command.

aws iam create-policy --policy-name <POLICY-NAME> --policy-document file://policy-doc.json --path <PATH>
  1. arn:aws:iam::444455556666:policy/security/universal-security-readonly-policy
  2. arn:aws:iam::444455556666:policy/teamA/DBA-policy-A
  3. arn:aws:iam::444455556666:policy/teamB/DBA-policy-B

Grant access to groupings of IAM roles with resource-based policies

Now that you’ve created roles and policies in paths, you can more readily define which groups of principals can access a resource. In this deny statement example, you allow only the roles in the IAM path /teamA/ to act on your bucket, and you deny access to all other IAM principals. Rather than use individual roles to deny access to the bucket, which would require you to list every role, you can deny access to an entire group of principals by path. If you create a new role in your AWS account in the specified path, you don’t need to modify the policy to include them. The path-based deny statement will apply automatically.

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Action": "s3:*",
      "Effect": "Deny",
      "Resource": [
		"arn:aws:s3:::EXAMPLE-BUCKET",
		"arn:aws:s3:::EXAMPLE-BUCKET/*"
		],
      "Principal": "*",
"Condition": {
        "ArnNotLike": {
          "aws:PrincipalArn": "arn:aws:iam::*:role/teamA/*"
        }
      }
}
  ]
}

Delegate access with IAM paths

IAM paths can also enable teams to more safely create IAM roles and policies and allow teams to only use the roles and policies contained by the paths. Paths can help prevent teams from privilege escalation by denying the use of roles that don’t belong to their team.

Continuing the example above, AnyCompany established a process that allows each team to create their own IAM roles and policies, providing they’re in a specified IAM path. For example, AnyCompany allows team A to create IAM roles and policies for team A in the path /teamA/:

  1. arn:aws:iam::444455556666:role/teamA/<role-name>
  2. arn:aws:iam::444455556666:policy/teamA/<policy-name>

Using IAM paths, AnyCompany can allow team A to more safely create and manage their own IAM roles and policies and safely pass those roles to AWS services using the iam:PassRole permission.

At AnyCompany, four IAM policies using IAM paths allow teams to more safely create and manage their own IAM roles and policies. Following recommended best practices, AnyCompany uses infrastructure as code (IaC) for all IAM role and policy creation. The four path-based policies that follow will be attached to each team’s CI/CD pipeline role, which has permissions to create roles. The following example focuses on team A, and how these policies enable them to self-manage their IAM credentials.

  1. Create a role in the path and modify inline policies on the role: This policy allows three actions: iam:CreateRole, iam:PutRolePolicy, and iam:DeleteRolePolicy. When this policy is attached to a principal, that principal is allowed to create roles in the IAM path /teamA/ and add and delete inline policies on roles in that IAM path.
    {
      "Version": "2012-10-17",
      "Statement": [
    {
            "Effect": "Allow",
            "Action": [
                "iam:CreateRole",
                "iam:PutRolePolicy",
                "iam:DeleteRolePolicy"
            ],
            "Resource": "arn:aws:iam::444455556666:role/teamA/*"
        }
    ]
    }

  2. Add and remove managed policies: The second policy example allows two actions: iam:AttachRolePolicy and iam:DetachRolePolicy. This policy allows a principal to attach and detach managed policies in the /teamA/ path to roles that are created in the /teamA/ path.
    {
      "Version": "2012-10-17",
      "Statement": [
    
    {
            "Effect": "Allow",
            "Action": [
                "iam:AttachRolePolicy",
                "iam:DetachRolePolicy"
            ],
            "Resource": "arn:aws:iam::444455556666:role/teamA/*",
            "Condition": {
                "ArnLike": {
                    "iam:PolicyARN": "arn:aws:iam::444455556666:policy/teamA/*"
                }          
            }
        }
    ]}

  3. Delete roles, tag and untag roles, read roles: The third policy allows a principal to delete roles, tag and untag roles, and retrieve information about roles that are created in the /teamA/ path.
    {
      "Version": "2012-10-17",
      "Statement": [
    
    
    {
            "Effect": "Allow",
            "Action": [
                "iam:DeleteRole",
                "iam:TagRole",
                "iam:UntagRole",
                "iam:GetRole",
                "iam:GetRolePolicy"
            ],
            "Resource": "arn:aws:iam::444455556666:role/teamA/*"
        }]}

  4. Policy management in IAM path: The final policy example allows access to create, modify, get, and delete policies that are created in the /teamA/ path. This includes creating, deleting, and tagging policies.
    {
      "Version": "2012-10-17",
      "Statement": [
    
    {
            "Effect": "Allow",
            "Action": [
                "iam:CreatePolicy",
                "iam:DeletePolicy",
                "iam:CreatePolicyVersion",            
                "iam:DeletePolicyVersion",
                "iam:GetPolicy",
                "iam:TagPolicy",
                "iam:UntagPolicy",
                "iam:SetDefaultPolicyVersion",
                "iam:ListPolicyVersions"
             ],
            "Resource": "arn:aws:iam::444455556666:policy/teamA/*"
        }]}

Safely pass roles with IAM paths and iam:PassRole

To pass a role to an AWS service, a principal must have the iam:PassRole permission. IAM paths are the recommended option to restrict which roles a principal can pass when granted the iam:PassRole permission. IAM paths help verify principals can only pass specific roles or groupings of roles to an AWS service.

At AnyCompany, the security team wants to allow team A to add IAM roles to an instance profile and attach it to Amazon EC2 instances, but only if the roles are in the /teamA/ path. The IAM action that allows team A to provide the role to the instance is iam:PassRole. The security team doesn’t want team A to be able to pass other roles in the account, such as an administrator role.

The policy that follows allows passing of a role that was created in the /teamA/ path and does not allow the passing of other roles such as an administrator role.

{
    "Version": "2012-10-17",
    "Statement": [{
        "Effect": "Allow",
        "Action": "iam:PassRole",
        "Resource": "arn:aws:iam::444455556666:role/teamA/*"
    }]
}

How to create preventative guardrails for sensitive IAM paths

You can use service control policies (SCP) to restrict access to sensitive roles and policies within specific IAM paths. You can use an SCP to prevent the modification of sensitive roles and policies that are created in a defined path.

You will see the IAM path under the resource and condition portion of the statement. Only the role named IAMAdministrator created in the /security/ path can create or modify roles in the security path. This SCP allows you to delegate IAM role and policy management to developers with confidence that they won’t be able to create, modify, or delete any roles or policies in the security path.

{
    "Version": "2012-10-17",
    "Statement": [
        {
	    "Sid": "RestrictIAMWithPathManagement",
            "Effect": "Deny",
            "Action": [
                "iam:AttachRolePolicy",
                "iam:CreateRole",
                "iam:DeleteRole",
                "iam:DeleteRolePermissionsBoundary",
                "iam:DeleteRolePolicy",
                "iam:DetachRolePolicy",
                "iam:PutRolePermissionsBoundary",
                "iam:PutRolePolicy",
                "iam:UpdateRole",
                "iam:UpdateAssumeRolePolicy",
                "iam:UpdateRoleDescription",
                "sts:AssumeRole",
                "iam:TagRole",
                "iam:UntagRole"
            ],
            "Resource": [
                "arn:aws:iam::*:role/security/* "
            ],
            "Condition": {
                "ArnNotLike": {
                    "aws:PrincipalARN": "arn:aws:iam::444455556666:role/security/IAMAdministrator"
                }
            }
        }
    ]
}

This next example shows you how you can safely exempt IAM roles created in the security path from specific controls in your organization. The policy denies all roles except the roles created in the /security/ IAM path to close member accounts.

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "PreventCloseAccount",
      "Effect": "Deny",
      "Action": "organizations:CloseAccount",
      "Resource": "*",
      "Condition": {
        "ArnNotLikeIfExists": {
          "aws:PrincipalArn": [
            "arn:aws:iam::*:role/security/*"
          ]
        }
      }
    }
  ]
}

Additional considerations when using IAM paths

You should be aware of some additional considerations when you start using IAM paths.

  1. Paths are immutable for IAM roles and policies. To change a path, you must delete the IAM resource and recreate the IAM resource in the alternative path. Deleting roles or instance profiles has step-by-step instructions to delete an IAM resource.
  2. You can only create IAM paths using AWS API or command line tools. You cannot create IAM paths with the AWS console.
  3. IAM paths aren’t added to the uniqueness of the role name. Role names must be unique within your account without the path taken into consideration.
  4. AWS reserves several paths including /aws-service-role/ and you cannot create roles in this path.

Conclusion

IAM paths provide a powerful mechanism for effectively grouping IAM resources. Path-based groupings can streamline access management across AWS services. In this post, you learned how to use paths with IAM principals to create structured access with IAM roles, how to delegate and segregate access within an account, and safely pass roles using iam:PassRole. These techniques can empower you to fine-tune your AWS access management and help improve security while streamlining operational workflows.

You can use the following references to help extend your knowledge of IAM paths. This post references the processes outlined in the user guides and blog post, and sources the IAM policies from the GitHub repositories.

  1. AWS Organizations User Guide, SCP General Examples
  2. AWS-Samples Service-control-policy-examples GitHub Repository
  3. AWS Security Blog: IAM Policy types: How and when to use them
  4. AWS-Samples how-and-when-to-use-aws-iam-policy-blog-samples GitHub Repository

 
If you have feedback about this post, submit comments in the Comments section below. If you have questions about this post, contact AWS Support.

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David Rowe

David Rowe

As a Senior Solutions Architect, David unites diverse global teams to drive cloud transformation through strategies and intuitive identity solutions. He creates consensus, guiding teams to adopt emerging technologies. He thrives on bringing together cross-functional perspectives to transform vision into reality in dynamic industries.

Use IAM Roles Anywhere to help you improve security in on-premises container workloads

Post Syndicated from Ulrich Hinze original https://aws.amazon.com/blogs/security/use-iam-roles-anywhere-to-help-you-improve-security-in-on-premises-container-workloads/

This blog post demonstrates how to help meet your security goals for a containerized process running outside of Amazon Web Services (AWS) as part of a hybrid cloud architecture. Managing credentials for such systems can be challenging, including when a workload needs to access cloud resources. IAM Roles Anywhere lets you exchange static AWS Identity and Access Management (IAM) user credentials with temporary security credentials in this scenario, reducing security risks while improving developer convenience.

In this blog post, we focus on these key areas to help you set up IAM Roles Anywhere in your own environment: determining whether an existing on-premises public key infrastructure (PKI) can be used with IAM Roles Anywhere, creating the necessary AWS resources, creating an IAM Roles Anywhere enabled Docker image, and using this image to issue AWS Command Line Interface (AWS CLI) commands. In the end, you will be able to issue AWS CLI commands through a Docker container, using credentials from your own PKI.

The AWS Well-Architected Framework and AWS IAM best practices documentation recommend that you use temporary security credentials over static credentials wherever possible. For workloads running on AWS—such as Amazon Elastic Compute Cloud (Amazon EC2) instances, AWS Lambda functions, or Amazon Elastic Kubernetes Service (Amazon EKS) pods—assigning and assuming IAM roles is a secure mechanism for distributing temporary credentials that can be used to authenticate against the AWS API. Before the release of IAM Roles Anywhere, developers had to use IAM users with long-lived, static credentials (access key IDs and secret access keys) to call the AWS API from outside of AWS. Now, by establishing trust between your on-premises PKI or AWS Private Certificate Authority (AWS Private CA) with IAM Roles Anywhere, you can also use IAM roles for workloads running outside of AWS.

This post provides a walkthrough for containerized environments. Containers make the setup for different environments and operating systems more uniform, making it simpler for you to follow the solution in this post and directly apply the learnings to your existing containerized setup. However, you can apply the same pattern to non-container environments.

At the end of this walkthrough, you will issue an AWS CLI command to list Amazon S3 buckets in an AWS account (aws s3 ls). This is a simplified mechanism to show that you have successfully authenticated to AWS using IAM Roles Anywhere. Typically, in applications that consume AWS functionality, you instead would use an AWS Software Development Kit (SDK) for the programming language of your application. You can apply the same concepts from this blog post to enable the AWS SDK to use IAM Roles Anywhere.

Prerequisites

To follow along with this post, you must have these tools installed:

  • The latest version of the AWS CLI, to create IAM Roles Anywhere resources
  • jq, to extract specific information from AWS API responses
  • Docker, to create and run the container image
  • OpenSSL, to create cryptographic keys and certificates

Make sure that the principal used by the AWS CLI has enough permissions to perform the commands described in this blog post. For simplicity, you can apply the following least-privilege IAM policy:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "IAMRolesAnywhereBlog",
            "Effect": "Allow",
            "Action": [
                "iam:CreateRole",
                "iam:DeleteRole",
                "iam:PutRolePolicy",
                "iam:DeleteRolePolicy",
                "iam:PassRole",
                "rolesanywhere:CreateTrustAnchor",
                "rolesanywhere:ListTrustAnchors",
                "rolesanywhere:DeleteTrustAnchor",
                "rolesanywhere:CreateProfile",
                "rolesanywhere:ListProfiles",
                "rolesanywhere:DeleteProfile"
            ],
            "Resource": [
                "arn:aws:iam::*:role/bucket-lister",
                "arn:aws:rolesanywhere:*:*:trust-anchor/*",
                "arn:aws:rolesanywhere:*:*:profile/*"
            ]
        }
    ]
}

This blog post assumes that you have configured a default AWS Region for the AWS CLI. If you have not, refer to the AWS CLI configuration documentation for different ways to configure the AWS Region.

Considerations for production use cases

To use IAM Roles Anywhere, you must establish trust with a private PKI. Certificates that are issued by this certificate authority (CA) are then used to sign CreateSession API requests. The API returns temporary AWS credentials: the access key ID, secret access key, and session key. For strong security, you should specify that the certificates are short-lived and the CA automatically rotates expiring certificates.

To simplify the setup for demonstration purposes, this post explains how to manually create a CA and certificate by using OpenSSL. For a production environment, this is not a suitable approach, because it ignores security concerns around the CA itself and excludes automatic certificate rotation or revocation capabilities. You need to use your existing PKI to provide short-lived and automatically rotated certificates in your production environment. This post shows how to validate whether your private CA and certificates meet IAM Roles Anywhere requirements.

If you don’t have an existing PKI that fulfils these requirements, you can consider using AWS Private Certificate Authority (Private CA) for a convenient way to help you with this process.

In order to use IAM Roles Anywhere in your container workload, it must have access to certificates that are issued by your private CA.

Solution overview

Figure 1 describes the relationship between the different resources created in this blog post.

Figure 1: IAM Roles Anywhere relationship between different components and resources

Figure 1: IAM Roles Anywhere relationship between different components and resources

To establish a trust relationship with the existing PKI, you will use its CA certificate to create an IAM Roles Anywhere trust anchor. You will create an IAM role with permissions to list all buckets in the account. The IAM role’s trust policy states that it can be assumed only from IAM Roles Anywhere, narrowing down which exact end-entity certificate can be used to assume it. The IAM Roles Anywhere profile defines which IAM role can be assumed in a session.

The container that is authenticating with IAM Roles Anywhere needs to present a valid certificate issued by the PKI, as well as Amazon Resource Names (ARNs) for the trust anchor, profile, and role. The container finally uses the certificate’s private key to sign a CreateSession API call, returning temporary AWS credentials. These temporary credentials are then used to issue the aws s3 ls command, which lists all buckets in the account.

Create and verify the CA and certificate

To start, you can either use your own CA and certificate or, to follow along without your own CA, manually create a CA and certificate by using OpenSSL. Afterwards, you can verify that the CA and certificate comply with IAM Roles Anywhere requirements.

To create the CA and certificate

Note: Manually creating and signing RSA keys into X.509 certificates is not a suitable approach for production environments. This section is intended only for demonstration purposes.

  1. Create an OpenSSL config file called v3.ext, with the following content.
    [ req ]
    default_bits                    = 2048
    distinguished_name              = req_distinguished_name
    x509_extensions                 = v3_ca
    
    [ v3_cert ]
    basicConstraints                = critical, CA:FALSE
    keyUsage                        = critical, digitalSignature
    
    [ v3_ca ]
    subjectKeyIdentifier            = hash
    authorityKeyIdentifier          = keyid:always,issuer:always
    basicConstraints                = CA: true
    keyUsage                        = Certificate Sign
    
    [ req_distinguished_name ]
    countryName                     = Country Name (2 letter code)
    countryName_default             = US
    countryName_min                 = 2
    countryName_max                 = 2
    
    stateOrProvinceName             = State or Province Name (full name)
    stateOrProvinceName_default     = Washington
    
    localityName                    = Locality Name (eg, city)
    localityName_default            = Seattle

  2. Create the CA RSA private key ca-key.pem and choose a passphrase.
    openssl genrsa -aes256 -out ca-key.pem 2048

  3. Create the CA X.509 certificate ca-cert.pem, keeping the default settings for all options.
    openssl req -new -x509 -nodes -days 1095 -config v3.ext -key ca-key.pem -out ca-cert.pem

    The CA certificate is valid for three years. For recommendations on certificate validity, refer to the AWS Private CA documentation.

  4. Create an RSA private key key.pem, choose a new passphrase, and create a certificate signing request (CSR) csr.pem for the container. For Common Name (eg, fully qualified host name), enter myContainer. Leave the rest of the options blank.
    openssl req -newkey rsa:2048 -days 1 -keyout key.pem -out csr.pem

  5. Use the CA private key, CA certificate, and CSR to issue an X.509 certificate cert.pem for the container.
    openssl x509 -req -days 1 -sha256 -set_serial 01 -in csr.pem -out cert.pem -CA ca-cert.pem -CAkey ca-key.pem -extfile v3.ext -extensions v3_cert

To verify the CA and certificate

  1. Check whether your CA certificate satisfies IAM Roles Anywhere constraints.
    openssl x509 -text -noout -in ca-cert.pem

    The output should contain the following.

    Certificate:
        Data:
            Version: 3 (0x2)
        ...
        Signature Algorithm: sha256WithRSAEncryption
        ...
            X509v3 extensions:
        ...
                X509v3 Basic Constraints:
                    CA:TRUE
                X509v3 Key Usage:
                    Certificate Sign
        ...

  2. Check whether your certificate satisfies IAM Roles Anywhere constraints.
    openssl x509 -text -noout -in cert.pem

    The output should contain the following.

    Certificate:
        Data:
            Version: 3 (0x2)
        ...
        Signature Algorithm: sha256WithRSAEncryption
        ...
            X509v3 extensions:
        ...
                X509v3 Basic Constraints:
                    CA:FALSE
                X509v3 Key Usage:
                    Digital Signature
        ...

    Note that IAM Roles Anywhere also supports stronger encryption algorithms than SHA256.

Create IAM resources

After you verify that your PKI complies with IAM Roles Anywhere requirements, you’re ready to create IAM resources. Before you start, make sure you have configured the AWS CLI, including setting a default AWS Region.

To create the IAM role

  1. Create a file named policy.json that specifies a set of permissions that your container process needs. For this walkthrough, you will issue the simple AWS CLI command aws s3 ls, which needs the following permissions:
    {
      "Version": "2012-10-17",
      "Statement": [
        {
          "Effect": "Allow",
          "Action": [
             "s3:ListAllMyBuckets"
          ],
          "Resource": "*"
        }
      ]
    }

  2. Create a file named trust-policy.json that contains the assume role policy for an IAM role by the service IAM Roles Anywhere. Note that this policy defines which certificate can assume the role. We define this based on the common name (CN) of the certificate, but you can explore other possibilities in the IAM Roles Anywhere documentation.
    {
      "Version": "2012-10-17",
      "Statement": [
        {
          "Effect": "Allow",
          "Principal": {
              "Service": "rolesanywhere.amazonaws.com"
          },
          "Action": [
            "sts:AssumeRole",
            "sts:TagSession",
            "sts:SetSourceIdentity"
          ],
          "Condition": {
            "StringEquals": {
              "aws:PrincipalTag/x509Subject/CN": "myContainer"
            }
          }
        }
      ]
    }

  3. Create the IAM role named bucket-lister.
    aws iam create-role --role-name bucket-lister --assume-role-policy-document file://trust-policy.json

    The response should be a JSON document that describes the role.

  4. Attach the IAM policy document that you created earlier.
    aws iam put-role-policy --role-name bucket-lister --policy-name list-buckets --policy-document file://policy.json

    This command returns without a response.

To enable authentication with IAM Roles Anywhere

  1. Establish trust between IAM Roles Anywhere and an on-premises PKI by making the CA certificate known to IAM Roles Anywhere using a trust anchor. Create an IAM Roles Anywhere trust anchor from the CA certificate by using the following command:
    aws rolesanywhere create-trust-anchor --enabled --name myPrivateCA --source sourceData={x509CertificateData="$(cat ca-cert.pem)"},sourceType=CERTIFICATE_BUNDLE

    The response should be a JSON document that describes the trust anchor.

  2. Create an IAM Roles Anywhere profile. Make sure to replace <AWS_ACCOUNT ID> with your own information.
    aws rolesanywhere create-profile --enabled --name bucket-lister --role-arns "arn:aws:iam::<AWS_ACCOUNT_ID>:role/bucket-lister"

    The response should be a JSON document that describes the profile.

Create the Docker image

The Docker image that you will create in this step enables you to issue commands with the AWS CLI that are authenticated by using IAM Roles Anywhere.

To create the Docker image

  1. Create a file named docker-entrypoint.sh that configures the AWS CLI to use the IAM Roles Anywhere signing helper.
    #!/bin/sh
    set -e
    
    openssl rsa -in $ROLESANYWHERE_KEY_LOCATION -passin env:ROLESANYWHERE_KEY_PASSPHRASE -out /tmp/key.pem > /dev/null 2>&1
    
    echo "[default]" > ~/.aws/config
    echo "  credential_process = aws_signing_helper credential-process \
        --certificate $ROLESANYWHERE_CERT_LOCATION \
        --private-key /tmp/key.pem \
        --trust-anchor-arn $ROLESANYWHERE_TRUST_ANCHOR_ARN \
        --profile-arn $ROLESANYWHERE_PROFILE_ARN \
        --role-arn $ROLESANYWHERE_ROLE_ARN" >> ~/.aws/config
    
    exec "$@"

  2. Create a file named Dockerfile. This contains a multi-stage build. The first stage builds the IAM Roles Anywhere signing helper. The second stage copies the compiled signing helper binary into the official AWS CLI Docker image and changes the container entry point to the script you created earlier.
    FROM ubuntu:22.04 AS signing-helper-builder
    WORKDIR /build
    
    RUN apt update && apt install -y git build-essential golang-go
    
    RUN git clone --branch v1.1.1 https://github.com/aws/rolesanywhere-credential-helper.git
    RUN go env -w GOPRIVATE=*
    RUN go version
    
    RUN cd rolesanywhere-credential-helper && go build -buildmode=pie -ldflags "-X main.Version=1.0.2 -linkmode=external -extldflags=-static -w -s" -trimpath -o build/bin/aws_signing_helper main.go
    
    
    FROM amazon/aws-cli:2.11.27
    COPY --from=signing-helper-builder /build/rolesanywhere-credential-helper/build/bin/aws_signing_helper /usr/bin/aws_signing_helper
    
    RUN yum install -y openssl shadow-utils
    
    COPY ./docker-entrypoint.sh /docker-entrypoint.sh
    RUN chmod +x /docker-entrypoint.sh
    
    RUN useradd user
    USER user
    
    RUN mkdir ~/.aws
    
    ENTRYPOINT ["/bin/bash", "/docker-entrypoint.sh", "aws"]

    Note that the first build stage can remain the same for other use cases, such as for applications using an AWS SDK. Only the second stage would need to be adapted. Diving deeper into the technical details of the first build stage, note that building the credential helper from its source keeps the build independent of the processor architecture. The build process also statically packages dependencies that are not present in the official aws-cli Docker image. Depending on your use case, you may opt to download pre-built artifacts from the credential helper download page instead.

  3. Create the image as follows.
    docker build -t rolesanywhere .

Use the Docker image

To use the Docker image, use the following commands to run the created image manually. Make sure to replace <PRIVATE_KEY_PASSSPHRASE> with your own data.

profile_arn=$(aws rolesanywhere list-profiles  | jq -r '.profiles[] | select(.name=="bucket-lister") | .profileArn')
trust_anchor_arn=$(aws rolesanywhere list-trust-anchors | jq -r '.trustAnchors[] | select(.name=="myPrivateCA") | .trustAnchorArn')
role_arn=$(aws iam list-roles | jq -r '.Roles[] | select(.RoleName=="bucket-lister") | .Arn')

docker run -it -v $(pwd):/rolesanywhere -e ROLESANYWHERE_CERT_LOCATION=/rolesanywhere/cert.pem -e ROLESANYWHERE_KEY_LOCATION=/rolesanywhere/key.pem -e ROLESANYWHERE_KEY_PASSPHRASE=<PRIVATE_KEY_PASSSPHRASE> -e ROLESANYWHERE_TRUST_ANCHOR_ARN=$trust_anchor_arn -e ROLESANYWHERE_PROFILE_ARN=$profile_arn -e ROLESANYWHERE_ROLE_ARN=$role_arn rolesanywhere s3 ls

This command should return a list of buckets in your account.

Because we only granted permissions to list buckets, other commands that use this certificate, like the following, will fail with an UnauthorizedOperation error.

docker run -it -v $(pwd):/rolesanywhere -e ROLESANYWHERE_CERT_LOCATION=/rolesanywhere/cert.pem -e ROLESANYWHERE_KEY_LOCATION=/rolesanywhere/key.pem -e ROLESANYWHERE_KEY_PASSPHRASE=<PRIVATE_KEY_PASSSPHRASE> -e ROLESANYWHERE_TRUST_ANCHOR_ARN=$trust_anchor_arn -e ROLESANYWHERE_PROFILE_ARN=$profile_arn -e ROLESANYWHERE_ROLE_ARN=$role_arn rolesanywhere ec2 describe-instances --region us-east-1

Note that if you use a certificate that uses a different common name than myContainer, this command will instead return an AccessDeniedException error as it fails to assume the role bucket-lister.

To use the image in your own environment, consider the following:

  • How to provide the private key and certificate to your container. This depends on how and where your PKI provides certificates. As an example, consider a PKI that rotates certificate files in a host directory, which you can then mount as a directory to your container.
  • How to configure the environment variables. Some variables mentioned earlier, like ROLESANYWHERE_TRUST_ANCHOR_ARN, can be shared across containers, while ROLESANYWHERE_PROFILE_ARN and ROLESANYWHERE_ROLE_ARN should be scoped to a particular container.

Clean up

None of the resources created in this walkthrough incur additional AWS costs. But if you want to clean up AWS resources you created earlier, issue the following commands.

  • Delete the IAM policy from the IAM role.
    aws iam delete-role-policy --role-name bucket-lister --policy-name list-buckets

  • Delete the IAM role.
    aws iam delete-role --role-name bucket-lister

  • Delete the IAM Roles Anywhere profile.
    profile_id=$(aws rolesanywhere list-profiles | jq -r '.profiles[] | select(.name=="bucket-lister") | .profileId')
    aws rolesanywhere delete-profile --profile-id $profile_id

  • Delete the IAM Roles Anywhere trust anchor.
    trust_anchor_id=$(aws rolesanywhere list-trust-anchors | jq -r '.trustAnchors[] | select(.name=="myPrivateCA") | .trustAnchorId')
    aws rolesanywhere delete-trust-anchor --trust-anchor-id $trust_anchor_id

  • Delete the key material you created earlier to avoid accidentally reusing it or storing it in version control.
    rm ca-key.pem ca-cert.pem key.pem csr.pem cert.pem

What’s next

After you reconfigure your on-premises containerized application to access AWS resources by using IAM Roles Anywhere, assess your other hybrid workloads running on-premises that have access to AWS resources. The technique we described in this post isn’t limited to containerized workloads. We encourage you to identify other places in your on-premises infrastructure that rely on static IAM credentials and gradually switch them to use IAM Roles Anywhere.

Conclusion

In this blog post, you learned how to use IAM Roles Anywhere to help you meet security goals in your on-premises containerized system. Improve your security posture by using temporary credentials instead of static credentials to authenticate against the AWS API. Use your existing private CA to make credentials short-lived and automatically rotate them.

For more information, check out the IAM Roles Anywhere documentation. The workshop Deep Dive on AWS IAM Roles Anywhere provides another walkthrough that isn’t specific to Docker containers. If you have any questions, you can start a new thread on AWS re:Post or reach out to AWS Support.

Want more AWS Security news? Follow us on Twitter.

Ulrich Hinze

Ulrich Hinze

Ulrich is a Solutions Architect at AWS. He partners with software companies to architect and implement cloud-based solutions on AWS. Before joining AWS, he worked for AWS customers and partners in software engineering, consulting, and architecture roles for over 8 years.

Alex Paramonov

Alex Paramonov

Alex is an AWS Solutions Architect for Independent Software Vendors in Germany, passionate about Serverless and how it can solve real world problems. Before joining AWS, he worked with large and medium software development companies as a Full-stack Software Engineer and consultant.

Introducing IAM Access Analyzer custom policy checks

Post Syndicated from Mitch Beaumont original https://aws.amazon.com/blogs/security/introducing-iam-access-analyzer-custom-policy-checks/

AWS Identity and Access Management (IAM) Access Analyzer was launched in late 2019. Access Analyzer guides customers toward least-privilege permissions across Amazon Web Services (AWS) by using analysis techniques, such as automated reasoning, to make it simpler for customers to set, verify, and refine IAM permissions. Today, we are excited to announce the general availability of IAM Access Analyzer custom policy checks, a new IAM Access Analyzer feature that helps customers accurately and proactively check IAM policies for critical permissions and increases in policy permissiveness.

In this post, we’ll show how you can integrate custom policy checks into builder workflows to automate the identification of overly permissive IAM policies and IAM policies that contain permissions that you decide are sensitive or critical.

What is the problem?

Although security teams are responsible for the overall security posture of the organization, developers are the ones creating the applications that require permissions. To enable developers to move fast while maintaining high levels of security, organizations look for ways to safely delegate the ability of developers to author IAM policies. Many AWS customers implement manual IAM policy reviews before deploying developer-authored policies to production environments. Customers follow this practice to try to prevent excessive or unwanted permissions finding their way into production. Depending on the volume and complexity of the policies that need to be reviewed; these reviews can be intensive and take time. The result is a slowdown in development and potential delay in deployment of applications and services. Some customers write custom tooling to remove the manual burden of policy reviews, but this can be costly to build and maintain.

How do custom policy checks solve that problem?

Custom policy checks are a new IAM Access Analyzer capability that helps security teams accurately and proactively identify critical permissions in their policies. Custom policy checks can also tell you if a new version of a policy is more permissive than the previous version. Custom policy checks use automated reasoning, a form of static analysis, to provide a higher level of security assurance in the cloud. For more information, see Formal Reasoning About the Security of Amazon Web Services.

Custom policy checks can be embedded in a continuous integration and continuous delivery (CI/CD) pipeline so that checks can be run against policies without having to deploy the policies. In addition, developers can run custom policy checks from their local development environments and get fast feedback about whether or not the policies they are authoring are in line with your organization’s security standards.

How to analyze IAM policies with custom policy checks

In this section, we provide step-by-step instructions for using custom policy checks to analyze IAM policies.

Prerequisites

To complete the examples in our walkthrough, you will need the following:

  1. An AWS account, and an identity that has permissions to use the AWS services, and create the resources, used in the following examples. For more information, see the full sample code used in this blog post on GitHub.
  2. An installed and configured AWS CLI. For more information, see Configure the AWS CLI.
  3. The AWS Cloud Development Kit (AWS CDK). For installation instructions, refer to Install the AWS CDK.

Example 1: Use custom policy checks to compare two IAM policies and check that one does not grant more access than the other

In this example, you will create two IAM identity policy documents, NewPolicyDocument and ExistingPolicyDocument. You will use the new CheckNoNewAccess API to compare these two policies and check that NewPolicyDocument does not grant more access than ExistingPolicyDocument.

Step 1: Create two IAM identity policy documents

  1. Use the following command to create ExistingPolicyDocument.
    cat << EOF > existing-policy-document.json
    {
        "Version": "2012-10-17",
        "Statement": [
            {
                "Effect": "Allow",
                "Action": [
                    "ec2:StartInstances",
                    "ec2:StopInstances"
                ],
                "Resource": "arn:aws:ec2:*:*:instance/*",
                "Condition": {
                    "StringEquals": {
                        "aws:ResourceTag/Owner": "\${aws:username}"
                    }
                }
            }
        ]
    }
    EOF

  2. Use the following command to create NewPolicyDocument.
    cat << EOF > new-policy-document.json
    {
        "Version": "2012-10-17",
        "Statement": [
            {
                "Effect": "Allow",
                "Action": [
                    "ec2:StartInstances",
                    "ec2:StopInstances"
                ],
                "Resource": "arn:aws:ec2:*:*:instance/*"
            }
        ]
    }
    EOF

Notice that ExistingPolicyDocument grants access to the ec2:StartInstances and ec2:StopInstances actions if the condition key aws:ResourceTag/Owner resolves to true. In other words, the value of the tag matches the policy variable aws:username. NewPolicyDocument grants access to the same actions, but does not include a condition key.

Step 2: Check the policies by using the AWS CLI

  1. Use the following command to call the CheckNoNewAccess API to check whether NewPolicyDocument grants more access than ExistingPolicyDocument.
    aws accessanalyzer check-no-new-access \
    --new-policy-document file://new-policy-document.json \
    --existing-policy-document file://existing-policy-document.json \
    --policy-type IDENTITY_POLICY

After a moment, you will see a response from Access Analyzer. The response will look similar to the following.

{
    "result": "FAIL",
    "message": "The modified permissions grant new access compared to your existing policy.",
    "reasons": [
        {
            "description": "New access in the statement with index: 1.",
            "statementIndex": 1
        }
    ]
}

In this example, the validation returned a result of FAIL. This is because NewPolicyDocument is missing the condition key, potentially granting any principal with this identity policy attached more access than intended or needed.

Example 2: Use custom policy checks to check that an IAM policy does not contain sensitive permissions

In this example, you will create an IAM identity-based policy that contains a set of permissions. You will use the CheckAccessNotGranted API to check that the new policy does not give permissions to disable AWS CloudTrail or delete any associated trails.

Step 1: Create a new IAM identity policy document

  • Use the following command to create IamPolicyDocument.
    cat << EOF > iam-policy-document.json
    {
        "Version": "2012-10-17",
        "Statement": [
            {
                "Effect": "Allow",
                "Action": [
                    "cloudtrail:StopLogging",
                    "cloudtrail:Delete*"
                ],
                "Resource": ["*"] 
            }
        ]
    }
    EOF

Step 2: Check the policy by using the AWS CLI

  • Use the following command to call the CheckAccessNotGranted API to check if the new policy grants permission to the set of sensitive actions. In this example, you are asking Access Analyzer to check that IamPolicyDocument does not contain the actions cloudtrail:StopLogging or cloudtrail:DeleteTrail (passed as a list to the access parameter).
    aws accessanalyzer check-access-not-granted \
    --policy-document file://iam-policy-document.json \
    --access actions=cloudtrail:StopLogging,cloudtrail:DeleteTrail \
    --policy-type IDENTITY_POLICY

Because the policy that you created contains both cloudtrail:StopLogging and cloudtrail:DeleteTrail actions, Access Analyzer returns a FAIL.

{
    "result": "FAIL",
    "message": "The policy document grants access to perform one or more of the listed actions.",
    "reasons": [
        {
            "description": "One or more of the listed actions in the statement with index: 0.",
            "statementIndex": 0
        }
    ]
}

Example 3: Integrate custom policy checks into the developer workflow

Building on the previous two examples, in this example, you will automate the analysis of the IAM policies defined in an AWS CloudFormation template. Figure 1 shows the workflow that will be used. The workflow will initiate each time a pull request is created against the main branch of an AWS CodeCommit repository called my-iam-policy (the commit stage in Figure 1). The first check uses the CheckNoNewAccess API to determine if the updated policy is more permissive than a reference IAM policy. The second check uses the CheckAccessNotGranted API to automatically check for critical permissions within the policy (the validation stage in Figure 1). In both cases, if the updated policy is more permissive, or contains critical permissions, a comment with the results of the validation is posted to the pull request. This information can then be used to decide whether the pull request is merged into the main branch for deployment (the deploy stage is shown in Figure 1).

Figure 1: Diagram of the pipeline that will check policies

Figure 1: Diagram of the pipeline that will check policies

Step 1: Deploy the infrastructure and set up the pipeline

  1. Use the following command to download and unzip the Cloud Development Kit (CDK) project associated with this blog post.
    git clone https://github.com/aws-samples/access-analyzer-automated-policy-analysis-blog.git
    cd ./access-analyzer-automated-policy-analysis-blog

  2. Create a virtual Python environment to contain the project dependencies by using the following command.
    python3 -m venv .venv

  3. Activate the virtual environment with the following command.
    source .venv/bin/activate

  4. Install the project requirements by using the following command.
    pip install -r requirements.txt

  5. Use the following command to update the CDK CLI to the latest major version.
    npm install -g aws-cdk@2 --force

  6. Before you can deploy the CDK project, use the following command to bootstrap your AWS environment. Bootstrapping is the process of creating resources needed for deploying CDK projects. These resources include an Amazon Simple Storage Service (Amazon S3) bucket for storing files and IAM roles that grant permissions needed to perform deployments.
    cdk bootstrap

  7. Finally, use the following command to deploy the pipeline infrastructure.
    cdk deploy --require-approval never

    The deployment will take a few minutes to complete. Feel free to grab a coffee and check back shortly.

    When the deployment completes, there will be two stack outputs listed: one with a name that contains CodeCommitRepo and another with a name that contains ConfigBucket. Make a note of the values of these outputs, because you will need them later.

    The deployed pipeline is displayed in the AWS CodePipeline console and should look similar to the pipeline shown in Figure 2.

    Figure 2: AWS CodePipeline and CodeBuild Management Console view

    Figure 2: AWS CodePipeline and CodeBuild Management Console view

    In addition to initiating when a pull request is created, the newly deployed pipeline can also be initiated when changes to the main branch of the AWS CodeCommit repository are detected. The pipeline has three stages, CheckoutSources, IAMPolicyAnalysis, and deploy. The CheckoutSource stage checks out the contents of the my-iam-policy repository when the pipeline is triggered due to a change in the main branch.

    The IAMPolicyAnalysis stage, which runs after the CheckoutSource stage or when a pull request has been created against the main branch, has two actions. The first action, Check no new access, verifies that changes to the IAM policies in the CloudFormation template do not grant more access than a pre-defined reference policy. The second action, Check access not granted, verifies that those same updates do not grant access to API actions that are deemed sensitive or critical. Finally, the Deploy stage will deploy the resources defined in the CloudFormation template, if the actions in the IAMPolicyAnalysis stage are successful.

    To analyze the IAM policies, the Check no new access and Check access not granted actions depend on a reference policy and a predefined list of API actions, respectively.

  8. Use the following command to create the reference policy.
    cd ../ 
    cat << EOF > cnna-reference-policy.json
    {
        "Version": "2012-10-17",
        "Statement": [
            {
                "Effect": "Allow",
                "Action": "*",
                "Resource": "*"
            },
            {
                "Effect": "Deny",
                "Action": "iam:PassRole",
                "Resource": "arn:aws:iam::*:role/my-sensitive-roles/*"
            }
        ]
    }	
    EOF

    This reference policy sets out the maximum permissions for policies that you plan to validate with custom policy checks. The iam:PassRole permission is a permission that allows an IAM principal to pass an IAM role to an AWS service, like Amazon Elastic Compute Cloud (Amazon EC2) or AWS Lambda. The reference policy says that the only way that a policy is more permissive is if it allows iam:PassRole on this group of sensitive resources: arn:aws:iam::*:role/my-sensitive-roles/*”.

    Why might a reference policy be useful? A reference policy helps ensure that a particular combination of actions, resources, and conditions is not allowed in your environment. Reference policies typically allow actions and resources in one statement, then deny the problematic permissions in a second statement. This means that a policy that is more permissive than the reference policy allows access to a permission that the reference policy has denied.

    In this example, a developer who is authorized to create IAM roles could, intentionally or unintentionally, create an IAM role for an AWS service (like EC2 for AWS Lambda) that has permission to pass a privileged role to another service or principal, leading to an escalation of privilege.

  9. Use the following command to create a list of sensitive actions. This list will be parsed during the build pipeline and passed to the CheckAccessNotGranted API. If the policy grants access to one or more of the sensitive actions in this list, a result of FAIL will be returned. To keep this example simple, add a single API action, as follows.
    cat << EOF > sensitive-actions.file
    dynamodb:DeleteTable
    EOF

  10. So that the CodeBuild projects can access the dependencies, use the following command to copy the cnna-reference-policy.file and sensitive-actions.file to an S3 bucket. Refer to the stack outputs you noted earlier and replace <ConfigBucket> with the name of the S3 bucket created in your environment.
    aws s3 cp ./cnna-reference-policy.json s3://<ConfgBucket>/cnna-reference-policy.json
    aws s3 cp ./sensitive-actions.file s3://<ConfigBucket>/sensitive-actions.file

Step 2: Create a new CloudFormation template that defines an IAM policy

With the pipeline deployed, the next step is to clone the repository that was created and populate it with a CloudFormation template that defines an IAM policy.

  1. Install git-remote-codecommit by using the following command.
    pip install git-remote-codecommit

    For more information on installing and configuring git-remote-codecommit, see the AWS CodeCommit User Guide.

  2. With git-remote-codecommit installed, use the following command to clone the my-iam-policy repository from AWS CodeCommit.
    git clone codecommit://my-iam-policy && cd ./my-iam-policy

    If you’ve configured a named profile for use with the AWS CLI, use the following command, replacing <profile> with the name of your named profile.

    git clone codecommit://<profile>@my-iam-policy && cd ./my-iam-policy

  3. Use the following command to create the CloudFormation template in the local clone of the repository.
    cat << EOF > ec2-instance-role.yaml
    ---
    AWSTemplateFormatVersion: 2010-09-09
    Description: CloudFormation Template to deploy base resources for access_analyzer_blog
    Resources:
      EC2Role:
        Type: AWS::IAM::Role
        Properties:
          AssumeRolePolicyDocument:
            Version: 2012-10-17
            Statement:
            - Effect: Allow
              Principal:
                Service: ec2.amazonaws.com
              Action: sts:AssumeRole
          Path: /
          Policies:
          - PolicyName: my-application-permissions
            PolicyDocument:
              Version: 2012-10-17
              Statement:
              - Effect: Allow
                Action:
                  - 'ec2:RunInstances'
                  - 'lambda:CreateFunction'
                  - 'lambda:InvokeFunction'
                  - 'dynamodb:Scan'
                  - 'dynamodb:Query'
                  - 'dynamodb:UpdateItem'
                  - 'dynamodb:GetItem'
                Resource: '*'
              - Effect: Allow
                Action:
                  - iam:PassRole 
                Resource: "arn:aws:iam::*:role/my-custom-role"
            
      EC2InstanceProfile:
        Type: AWS::IAM::InstanceProfile
        Properties:
          Path: /
          Roles:
            - !Ref EC2Role
    EOF

The actions in the IAMPolicyValidation stage are run by a CodeBuild project. CodeBuild environments run arbitrary commands that are passed to the project using a buildspec file. Each project has already been configured to use an inline buildspec file.

You can inspect the buildspec file for each project by opening the project’s Build details page as shown in Figure 3.

Figure 3: AWS CodeBuild console and build details

Figure 3: AWS CodeBuild console and build details

Step 3: Run analysis on the IAM policy

The next step involves checking in the first version of the CloudFormation template to the repository and checking two things. First, that the policy does not grant more access than the reference policy. Second, that the policy does not contain any of the sensitive actions defined in the sensitive-actions.file.

  1. To begin tracking the CloudFormation template created earlier, use the following command.
    git add ec2-instance-role.yaml 

  2. Commit the changes you have made to the repository.
    git commit -m 'committing a new CFN template with IAM policy'

  3. Finally, push these changes to the remote repository.
    git push

  4. Pushing these changes will initiate the pipeline. After a few minutes the pipeline should complete successfully. To view the status of the pipeline, do the following:
    1. Navigate to https://<region>.console.aws.amazon.com/codesuite/codepipeline/pipelines (replacing <region> with your AWS Region).
    2. Choose the pipeline called accessanalyzer-pipeline.
    3. Scroll down to the IAMPolicyValidation stage of the pipeline.
    4. For both the check no new access and check access not granted actions, choose View Logs to inspect the log output.
  5. If you inspect the build logs for both the check no new access and check access not granted actions within the pipeline, you should see that there were no blocking or non-blocking findings, similar to what is shown in Figure 4. This indicates that the policy was validated successfully. In other words, the policy was not more permissive than the reference policy, and it did not include any of the critical permissions.
    Figure 4: CodeBuild log entry confirming that the IAM policy was successfully validated

    Figure 4: CodeBuild log entry confirming that the IAM policy was successfully validated

Step 4: Create a pull request to merge a new update to the CloudFormation template

In this step, you will make a change to the IAM policy in the CloudFormation template. The change deliberately makes the policy grant more access than the reference policy. The change also includes a critical permission.

  1. Use the following command to create a new branch called add-new-permissions in the local clone of the repository.
    git checkout -b add-new-permissions

  2. Next, edit the IAM policy in ec2-instance-role.yaml to include an additional API action, dynamodb:Delete* and update the resource property of the inline policy to use an IAM role in the /my-sensitive-roles/*” path. You can copy the following example, if you’re unsure of how to do this.
    ---
    AWSTemplateFormatVersion: 2010-09-09
    Description: CloudFormation Template to deploy base resources for access_analyzer_blog
    Resources:
      EC2Role:
        Type: AWS::IAM::Role
        Properties:
          AssumeRolePolicyDocument:
            Version: 2012-10-17
            Statement:
            - Effect: Allow
              Principal:
                Service: ec2.amazonaws.com
              Action: sts:AssumeRole
          Path: /
          Policies:
          - PolicyName: my-application-permissions
            PolicyDocument:
              Version: 2012-10-17
              Statement:
              - Effect: Allow
                Action:
                  - 'ec2:RunInstances'
                  - 'lambda:CreateFunction'
                  - 'lambda:InvokeFunction'
                  - 'dynamodb:Scan'
                  - 'dynamodb:Query'
                  - 'dynamodb:UpdateItem'
                  - 'dynamodb:GetItem'
                  - 'dynamodb:Delete*'
                Resource: '*'
              - Effect: Allow
                Action:
                  - iam:PassRole 
                Resource: "arn:aws:iam::*:role/my-sensitive-roles/my-custom-admin-role"
            
      EC2InstanceProfile:
        Type: AWS::IAM::InstanceProfile
        Properties:
          Path: /
          Roles:
            - !Ref EC2Role

  3. Commit the policy change and push the updated policy document to the repo by using the following commands.
    git add ec2-instance-role.yaml 
    git commit -m "adding new permission and allowing my ec2 instance to assume a pass sensitive IAM role"

  4. The add-new-permissions branch is currently a local branch. Use the following command to push the branch to the remote repository. This action will not initiate the pipeline, because the pipeline only runs when changes are made to the repository’s main branch.
    git push -u origin add-new-permissions

  5. With the new branch and changes pushed to the repository, follow these steps to create a pull request:
    1. Navigate to https://console.aws.amazon.com/codesuite/codecommit/repositories (don’t forget to the switch to the correct Region).
    2. Choose the repository called my-iam-policy.
    3. Choose the branch add-new-permissions from the drop-down list at the top of the repository screen.
      Figure 5: my-iam-policy repository with new branch available

      Figure 5: my-iam-policy repository with new branch available

    4. Choose Create pull request.
    5. Enter a title and description for the pull request.
    6. (Optional) Scroll down to see the differences between the current version and new version of the CloudFormation template highlighted.
    7. Choose Create pull request.
  6. The creation of the pull request will Initiate the pipeline to fetch the CloudFormation template from the repository and run the check no new access and check access not granted analysis actions.
  7. After a few minutes, choose the Activity tab for the pull request. You should see a comment from the pipeline that contains the results of the failed validation.
    Figure 6: Results from the failed validation posted as a comment to the pull request

    Figure 6: Results from the failed validation posted as a comment to the pull request

Why did the validations fail?

The updated IAM role and inline policy failed validation for two reasons. First, the reference policy said that no one should have more permissions than the reference policy does. The reference policy in this example included a deny statement for the iam:PassRole permission with a resource of /my-sensitive-role/*. The new created inline policy included an allow statement for the iam:PassRole permission with a resource of arn:aws:iam::*:role/my-sensitive-roles/my-custom-admin-role. In other words, the new policy had more permissions than the reference policy.

Second, the list of critical permissions included the dynamodb:DeleteTable permission. The inline policy included a statement that would allow the EC2 instance to perform the dynamodb:DeleteTable action.

Cleanup

Use the following command to delete the infrastructure that was provisioned as part of the examples in this blog post.

cdk destroy 

Conclusion

In this post, I introduced you to two new IAM Access Analyzer APIs: CheckNoNewAccess and CheckAccessNotGranted. The main example in the post demonstrated one way in which you can use these APIs to automate security testing throughout the development lifecycle. The example did this by integrating both APIs into the developer workflow and validating the developer-authored IAM policy when the developer created a pull request to merge changes into the repository’s main branch. The automation helped the developer to get feedback about the problems with the IAM policy quickly, allowing the developer to take action in a timely way. This is often referred to as shifting security left — identifying misconfigurations early and automatically supporting an iterative, fail-fast model of continuous development and testing. Ultimately, this enables teams to make security an inherent part of a system’s design and architecture and can speed up product development workflow.

You can find the full sample code used in this blog post on GitHub.

To learn more about IAM Access Analyzer and the new custom policy checks feature, see the IAM Access Analyzer documentation.

If you have feedback about this post, submit comments in the Comments section below. If you have questions about this post, contact AWS Support.

Want more AWS Security news? Follow us on Twitter.

Mitch Beaumont

Mitch Beaumont

Mitch is a Principal Solutions Architect for AWS, based in Sydney, Australia. Mitch works with some of Australia’s largest financial services customers, helping them to continually raise the security bar for the products and features that they build and ship. Outside of work, Mitch enjoys spending time with his family, photography, and surfing.

Author

Matt Luttrell

Matt is a Principal Solutions Architect on the AWS Identity Solutions team. When he’s not spending time chasing his kids around, he enjoys skiing, cycling, and the occasional video game.

Amazon EKS Pod Identity simplifies IAM permissions for applications on Amazon EKS clusters

Post Syndicated from Donnie Prakoso original https://aws.amazon.com/blogs/aws/amazon-eks-pod-identity-simplifies-iam-permissions-for-applications-on-amazon-eks-clusters/

Starting today, you can use Amazon EKS Pod Identity to simplify your applications that access AWS services. This enhancement provides you with a seamless and easy to configure experience that lets you define required IAM permissions for your applications in Amazon Elastic Kubernetes Service (Amazon EKS) clusters so you can connect with AWS services outside the cluster.

Amazon EKS Pod Identity helps you solve growing challenges for managing permissions across many of your EKS clusters.

Simplifying experience with Amazon EKS Pod Identity
In 2019, we introduced IAM roles for service accounts (IRSA). IRSA lets you associate an IAM role with a Kubernetes service account. This helps you to implement the principle of least privilege by giving pods only the permissions they need. This approach prioritizes pods in IAM and helps developers configure applications with fine-grained permissions that enable the least privileged access to AWS services.

Now, with Amazon EKS Pod Identity, it’s even easier to configure and automate granting AWS permissions to Kubernetes identities. As the cluster administrator, you no longer need to switch between Amazon EKS and IAM services to authenticate your applications to all AWS resources.

The overall workflow to start using Amazon EKS Pod Identity can be summarized in a few simple steps:

  • Step 1: Create an IAM role with required permissions for your application and specify pods.eks.amazonaws.com as the service principal in its trust policy.
  • Step 2: Install Amazon EKS Pod Identity Agent add-on using the Amazon EKS console or AWS Command Line Interface (AWS CLI).
  • Step 3: Map the role to a service account directly in the Amazon EKS console, APIs, or AWS CLI.

Once it’s done, any new pods that use that service account will automatically be configured to receive IAM credentials.

Let’s get started
Let me show you how you can get started with EKS Pod Identity. For the demo in this post, I need to configure permission for a simple API running in my Amazon EKS cluster, which will return the list of files in my Amazon Simple Storage Service (Amazon S3) bucket.

First, I need to create an IAM role to provide the required permissions so my applications can run properly. In my case, I need to configure permissions to access my S3 bucket.

Next, on the same IAM role, I need to configure its trust policy and configure the principal to pods.eks.amazonaws.com. The following is the IAM template that I use:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Principal": {
                "Service": "pods.eks.amazonaws.com"
            },
            "Action": [
                "sts:AssumeRole",
                "sts:TagSession"
            ]
        }
    ]
}

At this stage, my IAM role is ready, and now we need to configure the Amazon EKS Pod Identity Agent in my cluster. For this article, I’m using my existing EKS cluster. If you want to learn how to do that, visit Getting started with Amazon EKS.

Moving on, I navigate to the Amazon EKS dashboard and then select my EKS cluster.

In my EKS cluster page, I need to select the Add-ons tab and then choose Get more add-ons.

Then, I need to add the Amazon EKS Pod Identity Agent add-on.

On the next page, I can add additional configuration if needed. In this case, I leave the default configuration and choose Next.

Then, I just need to review my add-on configuration and choose Create.

After a few minutes, the Amazon EKS Pod Identity Agent add-on is active for my cluster.

Once I have Amazon EKS Pod Identity in my cluster, I need to associate the IAM role to my Kubernetes pods.

I need to navigate to the Access tab in my EKS cluster. On the Pod Identity associations section, I select Create Pod Identity association to map my IAM role to Kubernetes pods.

Here, I use the IAM role that I created in the beginning. I also need to define my Kubernetes namespace and service account. If they don’t exist yet, I can type in the name of the namespace and service account. If they already exist, I can select them from the dropdown. Then, I choose Create.

Those are all the steps I need to do to configure IAM permissions for my applications running on Amazon EKS with EKS Pod Identity. Now, I can see my IAM role is listed in Pod Identity associations.

When I test my API running on Amazon EKS, it runs as expected and returns the list of files in my S3 bucket.

curl -X https://<API-URL> -H "Accept: application/json" 

{
   "files": [
         "test-file-1.md",
         "test-file-2.md"
    ]        
}

I found that Amazon EKS Pod Identity simplifies the experience of managing IAM roles for my applications running on Amazon EKS. I can easily reuse IAM roles across multiple EKS clusters without needing to update the role trust policy each time a new cluster is created.

New AWS APIs to configure EKS Pod Identity
You also have the flexibility to configure Amazon EKS Pod Identity for your cluster using AWS CLI. Amazon EKS Pod Identity provides a new set of APIs that you can use.

For example, I can use aws eks create-addon to install the Amazon EKS Pod Identity Agent add-on into my cluster. Here’s the AWS CLI command:

$ aws eks create-addon \
--cluster-name <CLUSTER_NAME> \
--addon-name eks-pod-identity-agent \
--addon-version v1.0.0-eksbuild.1

{
    "addon": {
    "addonName": "eks-pod-identity-agent",
    "clusterName": "<CLUSTER_NAME>",
    "status": "CREATING",
    "addonVersion": "v1.0.0-eksbuild.1",
    "health": {
        "issues": []
        },
    "addonArn": "<ARN>",
    "createdAt": 1697734297.597,
    "modifiedAt": 1697734297.612,
    "tags": {}
    }
}

Another example of what you can do with AWS APIs is to map the IAM role into your Kubernetes pods.

$ aws eks create-pod-identity-association \
  --cluster-name <CLUSTER_NAME> \
  --namespace <NAMESPACE> \
  --service-account <SERVICE_ACCOUNT_NAME> \
  --role-arn <IAM_ROLE_ARN>

Things to know

Availability – Amazon EKS Pod Identity is available in all AWS Regions supported by Amazon EKS, except the AWS GovCloud (US-East), AWS GovCloud (US-West), China (Beijing, operated by Sinnet), and China (Ningxia, operated by NWCD).

Pricing – Amazon EKS Pod Identity is available at no charge.

Supported Amazon EKS cluster  – Amazon EKS Pod Identity supports Kubernetes running version 1.24 and above in Amazon EKS. You can see EKS Pod Identity cluster versions for more information.

Supported AWS SDK versions – You need to update your application to use the latest AWS SDK versions. Check out AWS developer tools to find out how to install and update your AWS SDK.

Get started today and visit EKS Pod Identities documentation page to learn more about how to simplify IAM management for your applications.

Happy building!
Donnie

How to use the PassRole permission with IAM roles

Post Syndicated from Liam Wadman original https://aws.amazon.com/blogs/security/how-to-use-the-passrole-permission-with-iam-roles/

iam:PassRole is an AWS Identity and Access Management (IAM) permission that allows an IAM principal to delegate or pass permissions to an AWS service by configuring a resource such as an Amazon Elastic Compute Cloud (Amazon EC2) instance or AWS Lambda function with an IAM role. The service then uses that role to interact with other AWS resources in your accounts. Typically, workloads, applications, or services run with different permissions than the developer who creates them, and iam:PassRole is the mechanism in AWS to specify which IAM roles can be passed to AWS services, and by whom.

In this blog post, we’ll dive deep into iam:PassRole, explain how it works and what’s required to use it, and cover some best practices for how to use it effectively.

A typical example of using iam:PassRole is a developer passing a role’s Amazon Resource Name (ARN) as a parameter in the Lambda CreateFunction API call. After the developer makes the call, the service verifies whether the developer is authorized to do so, as seen in Figure 1.

Figure 1: Developer passing a role to a Lambda function during creation

Figure 1: Developer passing a role to a Lambda function during creation

The following command shows the parameters the developer needs to pass during the CreateFunction API call. Notice that the role ARN is a parameter, but there is no passrole parameter.

aws lambda create-function 
    --function-name my-function 
    --runtime nodejs14.x 
    --zip-file fileb://my-function.zip 
    --handler my-function.handler 
    --role arn:aws:iam::123456789012:role/service-role/MyTestFunction-role-tges6bf4

The API call will create the Lambda function only if the developer has the iam:PassRole permission as well as the CreateFunction API permissions. If the developer is lacking either of these, the request will be denied.

Now that the permissions have been checked and the Function resource has been created, the Lambda service principal will assume the role you passed whenever your function is invoked and use the role to make requests to other AWS services in your account.

Understanding IAM PassRole

When we say that iam:PassRole is a permission, we mean specifically that it is not an API call; it is an IAM action that can be specified within an IAM policy. The iam:PassRole permission is checked whenever a resource is created with an IAM service role or is updated with a new IAM service role.

Here is an example IAM policy that allows a principal to pass a role named lambda_role.

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": "iam:PassRole",
      "Resource": [
        "arn:aws:iam::111122223333:role/lambda_role"
      ]
    }
  ]
}

The roles that can be passed are specified in the Resource element of the IAM policy. It is possible to list multiple IAM roles, and it is possible to use a wildcard (*) to match roles that begins with the pattern you specify. Use a wildcard as the last characters only when you’re matching a role pattern, to help prevent over-entitlement.

Note: We recommend that you avoid using resource ”*” with the iam:PassRole action in most cases, because this could grant someone the permission to pass any role, opening the possibility of unintended privilege escalation.

The iam:PassRole action can only grant permissions when used in an identity-based policy attached to an IAM role or user, and it is governed by all relevant AWS policy types, such as service control policies (SCPs) and VPC endpoint policies.

When a principal attempts to pass a role to an AWS service, there are three prerequisites that must be met to allow the service to use that role:

  1. The principal that attempts to pass the role must have the iam:PassRole permission in an identity-based policy with the role desired to be passed in the Resource field, all IAM conditions met, and no implicit or explicit denies in other policies such as SCPs, VPC endpoint policies, session policies, or permissions boundaries.
  2. The role that is being passed is configured via the trust policy to trust the service principal of the service you’re trying to pass it to. For example, the role that you pass to Amazon EC2 has to trust the Amazon EC2 service principal, ec2.amazonaws.com.

    To learn more about role trust policies, see this blog post. In certain scenarios, the resource may end up being created or modified even if a passed IAM role doesn’t trust the required service principal, but the AWS service won’t be able to use the role to perform actions.

  3. The role being passed and the principal passing the role must both be in the same AWS account.

Best practices for using iam:PassRole

In this section, you will learn strategies to use when working with iam:PassRole within your AWS account.

Place iam:PassRole in its own policy statements

As we demonstrated earlier, the iam:PassRole policy action takes an IAM role for a resource. If you specify a wildcard as a resource in a policy granting iam:PassRole permission, it means that the principals to whom this policy applies will be able to pass any role in that account, allowing them to potentially escalate their privilege beyond what you intended.

To be able to specify the Resource value and be more granular in comparison to other permissions you might be granting in the same policy, we recommend that you keep the iam:PassRole action in its own policy statement, as indicated by the following example.

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": "iam:PassRole",
      "Resource": [
        "arn:aws:iam::111122223333:role/lambda_role"
      ]
    },
    {
      "Effect": "Allow",
      "Action": "cloudwatch:GetMetricData",
      "Resource": [
        "*"
      ]
    }
  ]
}

Use IAM paths or naming conventions to organize IAM roles within your AWS accounts

You can use IAM paths or a naming convention to grant a principal access to pass IAM roles using wildcards (*) in a portion of the role ARN. This reduces the need to update IAM policies whenever new roles are created.

In your AWS account, you might have IAM roles that are used for different reasons, for example roles that are used for your applications, and roles that are used by your security team. In most circumstances, you would not want your developers to associate a security team’s role to the resources they are creating, but you still want to allow them to create and pass business application roles.

You may want to give developers the ability to create roles for their applications, as long as they are safely governed. You can do this by verifying that those roles have permissions boundaries attached to them, and that they are created in a specific IAM role path. You can then allow developers to pass only the roles in that path. To learn more about using permissions boundaries, see our Example Permissions Boundaries GitHub repo.

In the following example policy, access is granted to pass only the roles that are in the /application_role/ path.

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": "iam:PassRole",
      "Resource": [
        "arn:aws:iam::111122223333:role/application_role/*"
      ]
    }
  ]
}

Protect specific IAM paths with an SCP

You can also protect specific IAM paths by using an SCP.

In the following example, the SCP prevents your principals from passing a role unless they have a tag of “team” with a value of “security” when the role they are trying to pass is in the IAM path /security_app_roles/.

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Deny",
      "Action": "iam:PassRole",
      "Resource": "arn:aws:iam::*:role/security_app_roles/*",
      "Condition": {
        "StringNotEquals": {
          "aws:PrincipalTag/team": "security"
        }
      }
    }
  ]
}

Similarly, you can craft a policy to only allow a specific naming convention or IAM path to pass a role in a specific path. For example, the following SCP shows how to prevent a role outside of the IAM path security_response_team from passing a role in the IAM path security_app_roles.

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Deny",
      "Action": "iam:PassRole",
      "Resource": "arn:aws:iam::*:role/security_app_roles/*",
      "Condition": {
        "ArnNotLike": {
          "aws:PrincipalARN": "arn:aws:iam::*:role/security_response_team/*"
        }
      }
    }
  ]
}

Using variables and tags with iam:PassRole

iam:PassRole does not support using the iam:ResourceTag or aws:ResourceTag condition keys to specify which roles can be passed. However, the IAM policy language supports using variables as part of the Resource element in an IAM policy.

The following IAM policy example uses the aws:PrincipalTag condition key as a variable in the Resource element. That allows this policy to construct the IAM path based on the values of the caller’s IAM tags or Session tags.

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": "iam:PassRole",
      "Resource": [
"arn:aws:iam::111122223333:role/${aws:PrincipalTag/AllowedRolePath}/*"
      ]
    }
  ]
}

If there was no value set for the AllowedRolePath tag, the resource would not match any role ARN, and no iam:PassRole permissions would be granted.

Pass different IAM roles for different use cases, and for each AWS service

As a best practice, use a single IAM role for each use case, and avoid situations where the same role is used by multiple AWS services.

We recommend that you also use different IAM roles for different workloads in your AWS accounts, even if those workloads are built on the same AWS service. This will allow you to grant only the permissions necessary to your workloads and make it possible to adhere to the principle of least privilege.

Using iam:PassRole condition keys

The iam:PassRole action has two available condition keys, iam:PassedToService and iam:AssociatedResourceArn.

iam:PassedToService allows you to specify what service a role may be passed to. iam:AssociatedResourceArn allows you to specify what resource ARNs a role may be associated with.

As mentioned previously, we typically recommend that customers use an IAM role with only one AWS service wherever possible. This is best accomplished by listing a single AWS service in a role’s trust policy, reducing the need to use the iam:PassedToService condition key in the calling principal’s identity-based policy. In circumstances where you have an IAM role that can be assumed by more than one AWS service, you can use iam:PassedToService to specify which service the role can be passed to. For example, the following policy allows ExampleRole to be passed only to the Amazon EC2 service.

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": "iam:PassRole",
      "Resource": "arn:aws:iam::*:role/ExampleRole",
      "Condition": {
        "StringEquals": {
          "iam:PassedToService": "ec2.amazonaws.com"
        }
      }
    }
  ]
}

When you use iam:AssociatedResourceArn, it’s important to understand that ARN formats typically do not change, but each AWS resource will have a unique ARN. Some AWS resources have non-predictable components, such as EC2 instance IDs in their ARN. This means that when you’re using iam:AssociatedResourceArn, if an AWS resource is ever deleted and a new resource created, you might need to modify the IAM policy with a new resource ARN to allow a role to be associated with it.

Most organizations prefer to limit who can delete and modify resources in their AWS accounts, rather than limit what resource a role can be associated with. An example of this would be limiting which principals can modify a Lambda function, rather than limiting which function a role can be associated with, because in order to pass a role to Lambda, the principals would need permissions to update the function itself.

Using iam:PassRole with service-linked roles

If you’re dealing with a service that uses service-linked roles (SLRs), most of the time you don’t need the iam:PassRole permission. This is because in most cases such services will create and manage the SLR on your behalf, so that you don’t pass a role as part of a service configuration, and therefore, the iam:PassRole permission check is not performed.

Some AWS services allow you to create multiple SLRs and pass them when you create or modify resources by using those services. In this case, you need the iam:PassRole permission on service-linked roles, just the same as you do with a service role.

For example, Amazon EC2 Auto Scaling allows you to create multiple SLRs with specific suffixes and then pass a role ARN in the request as part of the ec2:CreateAutoScalingGroup API action. For the Auto Scaling group to be successfully created, you need permissions to perform both the ec2:CreateAutoScalingGroup and iam:PassRole actions.

SLRs are created in the /aws-service-role/ path. To help confirm that principals in your AWS account are only passing service-linked roles that they are allowed to pass, we recommend using suffixes and IAM policies to separate SLRs owned by different teams.

For example, the following policy allows only SLRs with the _BlueTeamSuffix to be passed.

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": "iam:PassRole",
      "Resource": [
        "arn:aws:iam::*:role/aws-service-role/*_BlueTeamSuffix"
      ]
    }
  ]
}

You could attach this policy to the role used by the blue team to allow them to pass SLRs they’ve created for their use case and that have their specific suffix.

AWS CloudTrail logging

Because iam:PassRole is not an API call, there is no entry in AWS CloudTrail for it. To identify what role was passed to an AWS service, you must check the CloudTrail trail for events that created or modified the relevant AWS service’s resource.

In Figure 2, you can see the CloudTrail log created after a developer used the Lambda CreateFunction API call with the role ARN noted in the role field.

Figure 2: CloudTrail log of a CreateFunction API call

Figure 2: CloudTrail log of a CreateFunction API call

PassRole and VPC endpoints

Earlier, we mentioned that iam:PassRole is subject to VPC endpoint policies. If a request that requires the iam:PassRole permission is made over a VPC endpoint with a custom VPC endpoint policy configured, iam:PassRole should be allowed through the Action element of that VPC endpoint policy, or the request will be denied.

Conclusion

In this post, you learned about iam:PassRole, how you use it to interact with AWS services and resources, and the three prerequisites to successfully pass a role to a service. You now also know best practices for using iam:PassRole in your AWS accounts. To learn more, see the documentation on granting a user permissions to pass a role to an AWS service.

If you have feedback about this post, submit comments in the Comments section below. If you have questions about this post, start a new thread on the AWS Security, Identity, & Compliance re:Post or contact AWS Support.

Want more AWS Security news? Follow us on Twitter.

Author

Laura Reith

Laura is an Identity Solutions Architect at AWS, where she thrives on helping customers overcome security and identity challenges.

Liam Wadman

Liam Wadman

Liam is a Solutions Architect with the Identity Solutions team. When he’s not building exciting solutions on AWS or helping customers, he’s often found in the hills of British Columbia on his mountain bike. Liam points out that you cannot spell LIAM without IAM.

Writing IAM Policies: Grant Access to User-Specific Folders in an Amazon S3 Bucket

Post Syndicated from Dylan Souvage original https://aws.amazon.com/blogs/security/writing-iam-policies-grant-access-to-user-specific-folders-in-an-amazon-s3-bucket/

November 14, 2023: We’ve updated this post to use IAM Identity Center and follow updated IAM best practices.

In this post, we discuss the concept of folders in Amazon Simple Storage Service (Amazon S3) and how to use policies to restrict access to these folders. The idea is that by properly managing permissions, you can allow federated users to have full access to their respective folders and no access to the rest of the folders.

Overview

Imagine you have a team of developers named Adele, Bob, and David. Each of them has a dedicated folder in a shared S3 bucket, and they should only have access to their respective folders. These users are authenticated through AWS IAM Identity Center (successor to AWS Single Sign-On).

In this post, you’ll focus on David. You’ll walk through the process of setting up these permissions for David using IAM Identity Center and Amazon S3. Before you get started, let’s first discuss what is meant by folders in Amazon S3, because it’s not as straightforward as it might seem. To learn how to create a policy with folder-level permissions, you’ll walk through a scenario similar to what many people have done on existing files shares, where every IAM Identity Center user has access to only their own home folder. With folder-level permissions, you can granularly control who has access to which objects in a specific bucket.

You’ll be shown a policy that grants IAM Identity Center users access to the same Amazon S3 bucket so that they can use the AWS Management Console to store their information. The policy allows users in the company to upload or download files from their department’s folder, but not to access any other department’s folder in the bucket.

After the policy is explained, you’ll see how to create an individual policy for each IAM Identity Center user.

Throughout the rest of this post, you will use a policy, which will be associated with an IAM Identity Center user named David. Also, you must have already created an S3 bucket.

Note: S3 buckets have a global namespace and you must change the bucket name to a unique name.

For this blog post, you will need an S3 bucket with the following structure (the example bucket name for the rest of the blog is “my-new-company-123456789”):

/home/Adele/
/home/Bob/
/home/David/
/confidential/
/root-file.txt

Figure 1: Screenshot of the root of the my-new-company-123456789 bucket

Figure 1: Screenshot of the root of the my-new-company-123456789 bucket

Your S3 bucket structure should have two folders, home and confidential, with a file root-file.txt in the main bucket directory. Inside confidential you will have no items or folders. Inside home there should be three sub-folders: Adele, Bob, and David.

Figure 2: Screenshot of the home/ directory of the my-new-company-123456789 bucket

Figure 2: Screenshot of the home/ directory of the my-new-company-123456789 bucket

A brief lesson about Amazon S3 objects

Before explaining the policy, it’s important to review how Amazon S3 objects are named. This brief description isn’t comprehensive, but will help you understand how the policy works. If you already know about Amazon S3 objects and prefixes, skip ahead to Creating David in Identity Center.

Amazon S3 stores data in a flat structure; you create a bucket, and the bucket stores objects. S3 doesn’t have a hierarchy of sub-buckets or folders; however, tools like the console can emulate a folder hierarchy to present folders in a bucket by using the names of objects (also known as keys). When you create a folder in S3, S3 creates a 0-byte object with a key that references the folder name that you provided. For example, if you create a folder named photos in your bucket, the S3 console creates a 0-byte object with the key photos/. The console creates this object to support the idea of folders. The S3 console treats all objects that have a forward slash (/) character as the last (trailing) character in the key name as a folder (for example, examplekeyname/)

To give you an example, for an object that’s named home/common/shared.txt, the console will show the shared.txt file in the common folder in the home folder. The names of these folders (such as home/ or home/common/) are called prefixes, and prefixes like these are what you use to specify David’s department folder in his policy. By the way, the slash (/) in a prefix like home/ isn’t a reserved character — you could name an object (using the Amazon S3 API) with prefixes such as home:common:shared.txt or home-common-shared.txt. However, the convention is to use a slash as the delimiter, and the Amazon S3 console (but not S3 itself) treats the slash as a special character for showing objects in folders. For more information on organizing objects in the S3 console using folders, see Organizing objects in the Amazon S3 console by using folders.

Creating David in Identity Center

IAM Identity Center helps you securely create or connect your workforce identities and manage their access centrally across AWS accounts and applications. Identity Center is the recommended approach for workforce authentication and authorization on AWS for organizations of any size and type. Using Identity Center, you can create and manage user identities in AWS, or connect your existing identity source, including Microsoft Active Directory, Okta, Ping Identity, JumpCloud, Google Workspace, and Azure Active Directory (Azure AD). For further reading on IAM Identity Center, see the Identity Center getting started page.

Begin by setting up David as an IAM Identity Center user. To start, open the AWS Management Console and go to IAM Identity Center and create a user.

Note: The following steps are for Identity Center without System for Cross-domain Identity Management (SCIM) turned on, the add user option won’t be available if SCIM is turned on.

  1. From the left pane of the Identity Center console, select Users, and then choose Add user.
    Figure 3: Screenshot of IAM Identity Center Users page.

    Figure 3: Screenshot of IAM Identity Center Users page.

  2. Enter David as the Username, enter an email address that you have access to as you will need this later to confirm your user, and then enter a First name, Last name, and Display name.
  3. Leave the rest as default and choose Add user.
  4. Select Users from the left navigation pane and verify you’ve created the user David.
    Figure 4: Screenshot of adding users to group in Identity Center.

    Figure 4: Screenshot of adding users to group in Identity Center.

  5. Now that you’re verified the user David has been created, use the left pane to navigate to Permission sets, then choose Create permission set.
    Figure 5: Screenshot of permission sets in Identity Center.

    Figure 5: Screenshot of permission sets in Identity Center.

  6. Select Custom permission set as your Permission set type, then choose Next.
    Figure 6: Screenshot of permission set types in Identity Center.

    Figure 6: Screenshot of permission set types in Identity Center.

David’s policy

This is David’s complete policy, which will be associated with an IAM Identity Center federated user named David by using the console. This policy grants David full console access to only his folder (/home/David) and no one else’s. While you could grant each user access to their own bucket, keep in mind that an AWS account can have up to 100 buckets by default. By creating home folders and granting the appropriate permissions, you can instead allow thousands of users to share a single bucket.

{
 “Version”:”2012-10-17”,
 “Statement”: [
   {
     “Sid”: “AllowUserToSeeBucketListInTheConsole”,
     “Action”: [“s3:ListAllMyBuckets”, “s3:GetBucketLocation”],
     “Effect”: “Allow”,
     “Resource”: [“arn:aws:s3:::*”]
   },
  {
     “Sid”: “AllowRootAndHomeListingOfCompanyBucket”,
     “Action”: [“s3:ListBucket”],
     “Effect”: “Allow”,
     “Resource”: [“arn:aws:s3::: my-new-company-123456789”],
     “Condition”:{“StringEquals”:{“s3:prefix”:[“”,”home/”, “home/David”],”s3:delimiter”:[“/”]}}
    },
   {
     “Sid”: “AllowListingOfUserFolder”,
     “Action”: [“s3:ListBucket”],
     “Effect”: “Allow”,
     “Resource”: [“arn:aws:s3:::my-new-company-123456789”],
     “Condition”:{“StringLike”:{“s3:prefix”:[“home/David/*”]}}
   },
   {
     “Sid”: “AllowAllS3ActionsInUserFolder”,
     “Effect”: “Allow”,
     “Action”: [“s3:*”],
     “Resource”: [“arn:aws:s3:::my-new-company-123456789/home/David/*”]
   }
 ]
}
  1. Now, copy and paste the preceding IAM Policy into the inline policy editor. In this case, you use the JSON editor. For information on creating policies, see Creating IAM policies.
    Figure 7: Screenshot of the inline policy inside the permissions set in Identity Center.

    Figure 7: Screenshot of the inline policy inside the permissions set in Identity Center.

  2. Give your permission set a name and a description, then leave the rest at the default settings and choose Next.
  3. Verify that you modify the policies to have the bucket name you created earlier.
  4. After your permission set has been created, navigate to AWS accounts on the left navigation pane, then select Assign users or groups.
    Figure 8: Screenshot of the AWS accounts in Identity Center.

    Figure 8: Screenshot of the AWS accounts in Identity Center.

  5. Select the user David and choose Next.
    Figure 9: Screenshot of the AWS accounts in Identity Center.

    Figure 9: Screenshot of the AWS accounts in Identity Center.

  6. Select the permission set you created earlier, choose Next, leave the rest at the default settings and choose Submit.
    Figure 10: Screenshot of the permission sets in Identity Center.

    Figure 10: Screenshot of the permission sets in Identity Center.

    You’ve now created and attached the permissions required for David to view his S3 bucket folder, but not to view the objects in other users’ folders. You can verify this by signing in as David through the AWS access portal.

    Figure 11: Screenshot of the settings summary in Identity Center.

    Figure 11: Screenshot of the settings summary in Identity Center.

  7. Navigate to the dashboard in IAM Identity Center and go to the Settings summary, then choose the AWS access portal URL.
    Figure 12: Screenshot of David signing into the console via the Identity Center dashboard URL.

    Figure 12: Screenshot of David signing into the console via the Identity Center dashboard URL.

  8. Sign in as the user David with the one-time password you received earlier when creating David.
    Figure 13: Second screenshot of David signing into the console through the Identity Center dashboard URL.

    Figure 13: Second screenshot of David signing into the console through the Identity Center dashboard URL.

  9. Open the Amazon S3 console.
  10. Search for the bucket you created earlier.
    Figure 14: Screenshot of my-new-company-123456789 bucket in the AWS console.

    Figure 14: Screenshot of my-new-company-123456789 bucket in the AWS console.

  11. Navigate to David’s folder and verify that you have read and write access to the folder. If you navigate to other users’ folders, you’ll find that you don’t have access to the objects inside their folders.

David’s policy consists of four blocks; let’s look at each individually.

Block 1: Allow required Amazon S3 console permissions

Before you begin identifying the specific folders David can have access to, you must give him two permissions that are required for Amazon S3 console access: ListAllMyBuckets and GetBucketLocation.

   {
      "Sid": "AllowUserToSeeBucketListInTheConsole",
      "Action": ["s3:GetBucketLocation", "s3:ListAllMyBuckets"],
      "Effect": "Allow",
      "Resource": ["arn:aws:s3:::*"]
   }

The ListAllMyBuckets action grants David permission to list all the buckets in the AWS account, which is required for navigating to buckets in the Amazon S3 console (and as an aside, you currently can’t selectively filter out certain buckets, so users must have permission to list all buckets for console access). The console also does a GetBucketLocation call when users initially navigate to the Amazon S3 console, which is why David also requires permission for that action. Without these two actions, David will get an access denied error in the console.

Block 2: Allow listing objects in root and home folders

Although David should have access to only his home folder, he requires additional permissions so that he can navigate to his folder in the Amazon S3 console. David needs permission to list objects at the root level of the my-new-company-123456789 bucket and to the home/ folder. The following policy grants these permissions to David:

   {
      "Sid": "AllowRootAndHomeListingOfCompanyBucket",
      "Action": ["s3:ListBucket"],
      "Effect": "Allow",
      "Resource": ["arn:aws:s3:::my-new-company-123456789"],
      "Condition":{"StringEquals":{"s3:prefix":["","home/", "home/David"],"s3:delimiter":["/"]}}
   }

Without the ListBucket permission, David can’t navigate to his folder because he won’t have permissions to view the contents of the root and home folders. When David tries to use the console to view the contents of the my-new-company-123456789 bucket, the console will return an access denied error. Although this policy grants David permission to list all objects in the root and home folders, he won’t be able to view the contents of any files or folders except his own (you specify these permissions in the next block).

This block includes conditions, which let you limit under what conditions a request to AWS is valid. In this case, David can list objects in the my-new-company-123456789 bucket only when he requests objects without a prefix (objects at the root level) and objects with the home/ prefix (objects in the home folder). If David tries to navigate to other folders, such as confidential/, David is denied access. Additionally, David needs permissions to list prefix home/David to be able to use the search functionality of the console instead of scrolling down the list of users’ folders.

To set these root and home folder permissions, I used two conditions: s3:prefix and s3:delimiter. The s3:prefix condition specifies the folders that David has ListBucket permissions for. For example, David can list the following files and folders in the my-new-company-123456789 bucket:

/root-file.txt
/confidential/
/home/Adele/
/home/Bob/
/home/David/

But David cannot list files or subfolders in the confidential/home/Adele, or home/Bob folders.

Although the s3:delimiter condition isn’t required for console access, it’s still a good practice to include it in case David makes requests by using the API. As previously noted, the delimiter is a character—such as a slash (/)—that identifies the folder that an object is in. The delimiter is useful when you want to list objects as if they were in a file system. For example, let’s assume the my-new-company-123456789 bucket stored thousands of objects. If David includes the delimiter in his requests, he can limit the number of returned objects to just the names of files and subfolders in the folder he specified. Without the delimiter, in addition to every file in the folder he specified, David would get a list of all files in any subfolders.

Block 3: Allow listing objects in David’s folder

In addition to the root and home folders, David requires access to all objects in the home/David/ folder and any subfolders that he might create. Here’s a policy that allows this:

{
      “Sid”: “AllowListingOfUserFolder”,
      “Action”: [“s3:ListBucket”],
      “Effect”: “Allow”,
      “Resource”: [“arn:aws:s3:::my-new-company-123456789”],
      "Condition":{"StringLike":{"s3:prefix":["home/David/*"]}}
    }

In the condition above, you use a StringLike expression in combination with the asterisk (*) to represent an object in David’s folder, where the asterisk acts as a wildcard. That way, David can list files and folders in his folder (home/David/). You couldn’t include this condition in the previous block (AllowRootAndHomeListingOfCompanyBucket) because it used the StringEquals expression, which would interpret the asterisk (*) as an asterisk, not as a wildcard.

In the next section, the AllowAllS3ActionsInUserFolder block, you’ll see that the Resource element specifies my-new-company/home/David/*, which looks like the condition that I specified in this section. You might think that you can similarly use the Resource element to specify David’s folder in this block. However, the ListBucket action is a bucket-level operation, meaning the Resource element for the ListBucket action applies only to bucket names and doesn’t take folder names into account. So, to limit actions at the object level (files and folders), you must use conditions.

Block 4: Allow all Amazon S3 actions in David’s folder

Finally, you specify David’s actions (such as read, write, and delete permissions) and limit them to just his home folder, as shown in the following policy:

    {
      "Sid": "AllowAllS3ActionsInUserFolder",
      "Effect": "Allow",
      "Action": ["s3:*"],
      "Resource": ["arn:aws:s3:::my-new-company-123456789/home/David/*"]
    }

For the Action element, you specified s3:*, which means David has permission to do all Amazon S3 actions. In the Resource element, you specified David’s folder with an asterisk (*) (a wildcard) so that David can perform actions on the folder and inside the folder. For example, David has permission to change his folder’s storage class. David also has permission to upload files, delete files, and create subfolders in his folder (perform actions in the folder).

An easier way to manage policies with policy variables

In David’s folder-level policy you specified David’s home folder. If you wanted a similar policy for users like Bob and Adele, you’d have to create separate policies that specify their home folders. Instead of creating individual policies for each IAM Identity Center user, you can use policy variables and create a single policy that applies to multiple users (a group policy). Policy variables act as placeholders. When you make a request to a service in AWS, the placeholder is replaced by a value from the request when the policy is evaluated.

For example, you can use the previous policy and replace David’s user name with a variable that uses the requester’s user name through attributes and PrincipalTag as shown in the following policy (copy this policy to use in the procedure that follows):

{
	"Version": "2012-10-17",
	"Statement": [
		{
			"Sid": "AllowUserToSeeBucketListInTheConsole",
			"Action": [
				"s3:ListAllMyBuckets",
				"s3:GetBucketLocation"
			],
			"Effect": "Allow",
			"Resource": [
				"arn:aws:s3:::*"
			]
		},
		{
			"Sid": "AllowRootAndHomeListingOfCompanyBucket",
			"Action": [
				"s3:ListBucket"
			],
			"Effect": "Allow",
			"Resource": [
				"arn:aws:s3:::my-new-company-123456789"
			],
			"Condition": {
				"StringEquals": {
					"s3:prefix": [
						"",
						"home/",
						"home/${aws:PrincipalTag/userName}"
					],
					"s3:delimiter": [
						"/"
					]
				}
			}
		},
		{
			"Sid": "AllowListingOfUserFolder",
			"Action": [
				"s3:ListBucket"
			],
			"Effect": "Allow",
			"Resource": [
				"arn:aws:s3:::my-new-company-123456789"
			],
			"Condition": {
				"StringLike": {
					"s3:prefix": [
						"home/${aws:PrincipalTag/userName}/*"
					]
				}
			}
		},
		{
			"Sid": "AllowAllS3ActionsInUserFolder",
			"Effect": "Allow",
			"Action": [
				"s3:*"
			],
			"Resource": [
				"arn:aws:s3:::my-new-company-123456789/home/${aws:PrincipalTag/userName}/*"
			]
		}
	]
}
  1. To implement this policy with variables, begin by opening the IAM Identity Center console using the main AWS admin account (ensuring you’re not signed in as David).
  2. Select Settings on the left-hand side, then select the Attributes for access control tab.
    Figure 15: Screenshot of Settings inside Identity Center.

    Figure 15: Screenshot of Settings inside Identity Center.

  3. Create a new attribute for access control, entering userName as the Key and ${path:userName} as the Value, then choose Save changes. This will add a session tag to your Identity Center user and allow you to use that tag in an IAM policy.
    Figure 16: Screenshot of managing attributes inside Identity Center settings.

    Figure 16: Screenshot of managing attributes inside Identity Center settings.

  4. To edit David’s permissions, go back to the IAM Identity Center console and select Permission sets.
    Figure 17: Screenshot of permission sets inside Identity Center with Davids-Permissions selected.

    Figure 17: Screenshot of permission sets inside Identity Center with Davids-Permissions selected.

  5. Select David’s permission set that you created previously.
  6. Select Inline policy and then choose Edit to update David’s policy by replacing it with the modified policy that you copied at the beginning of this section, which will resolve to David’s username.
    Figure 18: Screenshot of David’s policy inside his permission set inside Identity Center.

    Figure 18: Screenshot of David’s policy inside his permission set inside Identity Center.

You can validate that this is set up correctly by signing in to David’s user through the Identity Center dashboard as you did before and verifying you have access to the David folder and not the Bob or Adele folder.

Figure 19: Screenshot of David’s S3 folder with access to a .jpg file inside.

Figure 19: Screenshot of David’s S3 folder with access to a .jpg file inside.

Whenever a user makes a request to AWS, the variable is replaced by the user name of whoever made the request. For example, when David makes a request, ${aws:PrincipalTag/userName} resolves to David; when Adele makes the request, ${aws:PrincipalTag/userName} resolves to Adele.

It’s important to note that, if this is the route you use to grant access, you must control and limit who can set this username tag on an IAM principal. Anyone who can set this tag can effectively read/write to any of these bucket prefixes. It’s important that you limit access and protect the bucket prefixes and who can set the tags. For more information, see What is ABAC for AWS, and the Attribute-based access control User Guide.

Conclusion

By using Amazon S3 folders, you can follow the principle of least privilege and verify that the right users have access to what they need, and only to what they need.

See the following example policy that only allows API access to the buckets, and only allows for adding, deleting, restoring, and listing objects inside the folders:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "AllowAllS3ActionsInUserFolder",
            "Effect": "Allow",
            "Action": [
                "s3:DeleteObject",
                "s3:DeleteObjectTagging",
                "s3:DeleteObjectVersion",
                "s3:DeleteObjectVersionTagging",
                "s3:GetObject",
                "s3:GetObjectTagging",
                "s3:GetObjectVersion",
                "s3:GetObjectVersionTagging",
                "s3:ListBucket",
                "s3:PutObject",
                "s3:PutObjectTagging",
                "s3:PutObjectVersionTagging",
                "s3:RestoreObject"
            ],
            "Resource": [
		   "arn:aws:s3:::my-new-company-123456789",
                "arn:aws:s3:::my-new-company-123456789/home/${aws:PrincipalTag/userName}/*"
            ],
            "Condition": {
                "StringLike": {
                    "s3:prefix": [
                        "home/${aws:PrincipalTag/userName}/*"
                    ]
                }
            }
        }
    ]
}

We encourage you to think about what policies your users might need and restrict the access by only explicitly allowing what is needed.

Here are some additional resources for learning about Amazon S3 folders and about IAM policies, and be sure to get involved at the community forums:

 
If you have feedback about this post, submit comments in the Comments section below. If you have questions about this post, contact AWS Support.

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Dylan Souvage

Dylan Souvage

Dylan is a Solutions Architect based in Toronto, Canada. Dylan loves working with customers to understand their business needs and enable them in their cloud journey. In his spare time, he enjoys going out in nature, going on long road trips, and traveling to warm, sunny places.

Abhra Sinha

Abhra Sinha

Abhra is a Toronto-based Senior Solutions Architect at AWS. Abhra enjoys being a trusted advisor to customers, working closely with them to solve their technical challenges and help build a secure scalable architecture on AWS. In his spare time, he enjoys Photography and exploring new restaurants.

Divyajeet Singh

Divyajeet Singh

Divyajeet (DJ) is a Sr. Solutions Architect at AWS Canada. He loves working with customers to help them solve their unique business challenges using the cloud. In his free time, he enjoys spending time with family and friends, and exploring new places.

Amazon MSK IAM authentication now supports all programming languages

Post Syndicated from Ali Alemi original https://aws.amazon.com/blogs/big-data/amazon-msk-iam-authentication-now-supports-all-programming-languages/

The AWS Identity and Access Management (IAM) authentication feature in Amazon Managed Streaming for Apache Kafka (Amazon MSK) now supports all programming languages. Administrators can simplify and standardize access control to Kafka resources using IAM. This support is based on SASL/OUATHBEARER, an open standard for authorization and authentication. Both Amazon MSK provisioned and serverless cluster types support the new Amazon MSK IAM expansion to all programming languages.

In this post, we show how you can connect your applications to MSK clusters with minimal code changes using the open-sourced client helper libraries and code samples for popular languages, including JavaPythonGoJavaScript, and .NET. You can also use standard IAM access controls such as temporary role-based credentials and precisely scoped permission policies more broadly with the multiple language support on Amazon MSK.

For clients that need to connect from other VPCs to an MSK cluster, whether in a same or a different AWS account, you can enable multi-VPC private connectivity and cluster policy support. IAM access control via cluster policy helps you manage all access to the cluster and topics in one place. For example, you can control which IAM principals have write access to certain topics, and which principals can only read from them. Users who are using IAM client authentication can also add permissions for required kafka-cluster actions in the cluster resource policy.

Solution overview

You can get started by using IAM principals as identities for your Apache Kafka clients and define identity policies to provide them precisely scoped access permissions. After IAM authentication is enabled for your cluster, you can configure client applications to use the IAM authentication with minimal code changes.

The code changes allow your clients to use SASL/OAUTHBEARER, a Kafka supported token-based access mechanism, to pass the credentials required for IAM authentication. In this post, we show how you can make these code changes by using the provided code libraries and examples.

With this launch, new code libraries for the following programming languages are available in the AWS GitHub repo:

The following diagram shows the conceptual process flow of using SASL/OAUTHBEARER with IAM access control for non-Java clients.

The workflow contains the following steps:

  1. The client generates an OAUTHBEARER token with the help of the provided library. The token contains a signed base64 encoded transformation of your IAM identity credentials.
  2. The client sends this to Amazon MSK using the IAM bootstrap broker addresses along with its request to access Apache Kafka resources.
  3. The MSK broker decodes the OATHBEARER token, validates the credentials, and checks if the client is authorized to perform the requested action according to the policy attached to the IAM identity.
  4. When the token expires, the client Kafka library automatically refreshes the token by making another call to the specified token provider.

Create IAM identities and policies

IAM access control for non-Java clients is supported for MSK clusters with Kafka version 2.7.1 and above. Before you start, you need to configure the IAM identities and policies that define the client’s permissions to access resources on the cluster. The following is an example authorization policy for a cluster named MyTestCluster. To understand the semantics of the action and resource elements, see Semantics of actions and resources.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "kafka-cluster:Connect",
                "kafka-cluster:AlterCluster",
                "kafka-cluster:DescribeCluster"
            ],
            "Resource": [
                "arn:aws:kafka:us-east-1:0123456789012:cluster/MyTestCluster/abcd1234-0123-abcd-5678-1234abcd-1"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "kafka-cluster:*Topic*",
                "kafka-cluster:WriteData",
                "kafka-cluster:ReadData"
            ],
            "Resource": [
                "arn:aws:kafka:us-east-1:0123456789012:topic/MyTestCluster/*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "kafka-cluster:AlterGroup",
                "kafka-cluster:DescribeGroup"
            ],
            "Resource": [
                "arn:aws:kafka:us-east-1:0123456789012:group/MyTestCluster/*"
            ]
        }
    ]
}

Set up the MSK cluster

You need to enable the IAM access control authentication scheme for your MSK provisioned cluster and wait until the cluster finishes updating and turns to the Active state. This is because SASL/OAUTHBEARER uses the same broker addresses for IAM authentication.

Configure the client

You should make code changes to your application that allow the clients to use SASL/OAUTHBEARER to pass the credentials required for IAM authentication. Next, update your application to use the bootstrap server addresses for IAM authentication. You also need to make sure the security group associated with your MSK cluster has an inbound rule allowing the traffic from the client applications in the same VPC as the cluster to the TCP port 9098.

You must use a Kafka client library that provides support for SASL with OAUTHBRARER authentication.

In this post, we use the JavaScript programming language. We also use https://github.com/tulios/kafkajs as our Kafka client library.

Amazon MSK provides you with a new code library per each language that generates the OAUTHBEARER token.

  1. To get started working with the Amazon MSK IAM SASL signer for JavaScript with your Kafka client library, run the following command:
    npm install https://github.com/aws/aws-msk-iam-sasl-signer-js

  2. You need to import the installed Amazon MSK IAM SASL signer library in your code:
    const { Kafka } = require('kafkajs')
    
    const { generateAuthToken } = require('aws-msk-iam-sasl-signer-js')

  3. Next, your application code needs to define a token provider that wraps the function that generates new tokens:
    async function oauthBearerTokenProvider(region) {
        // Uses AWS Default Credentials Provider Chain to fetch credentials
        const authTokenResponse = await generateAuthToken({ region });
        return {
            value: authTokenResponse.token
        }
    }

  4. Specify security_protocol as SASL_SSL and sasl_mechanism as oauthbearer in your JavaScript Kafka client properties, and pass the token provider in the configuration object:
    const run = async () => {
        const kafka = new Kafka({
            clientId: 'my-app',
            brokers: [bootstrap server addresses for IAM],
            ssl: true,
            sasl: {
                mechanism: 'oauthbearer',
                oauthBearerProvider: () => oauthBearerTokenProvider('us-east-1')
            }
        })
    
        const producer = kafka.producer()
        const consumer = kafka.consumer({ groupId: 'test-group' })
    
        // Producing
        await producer.connect()
        await producer.send({
            topic: 'test-topic',
            messages: [
                { value: 'Hello KafkaJS user!' },
            ],
        })
    
        // Consuming
        await consumer.connect()
        await consumer.subscribe({ topic: 'test-topic', fromBeginning: true })
    
        await consumer.run({
            eachMessage: async ({ topic, partition, message }) => {
                console.log({
                    partition,
                    offset: message.offset,
                    value: message.value.toString(),
                })
            },
        })
    }
    
    run().catch(console.error)

You are now finished with all the code changes. For more examples of generating auth tokens or for more troubleshooting tips, refer to the following GitHub repo.

Conclusion

IAM access control for Amazon MSK enables you to handle both authentication and authorization for your MSK cluster. This eliminates the need to use one mechanism for authentication and another for authorization. For example, when a client tries to write to your cluster, Amazon MSK uses IAM to check whether that client is an authenticated identity and also whether it is authorized to produce to your cluster.

With today’s launch, Amazon MSK IAM authentication now supports all programming languages. This means you can connect your applications in all languages without worrying about implementing separate authentication and authorization mechanisms. For workloads that require Amazon MSK multi-VPC private connectivity and cluster policy support, you can now simplify connectivity to your MSK brokers and manage all access to the cluster and topics in one place that is your cluster policy.

For further reading on Amazon MSK, visit the official product page.


About the author

Ali Alemi is a Streaming Specialist Solutions Architect at AWS. Ali advises AWS customers with architectural best practices and helps them design real-time analytics data systems that are reliable, secure, efficient, and cost-effective. He works backward from customer’s use cases and designs data solutions to solve their business problems. Prior to joining AWS, Ali supported several public sector customers and AWS consulting partners in their application modernization journey and migration to the cloud.

Set up AWS Private Certificate Authority to issue certificates for use with IAM Roles Anywhere

Post Syndicated from Chris Sciarrino original https://aws.amazon.com/blogs/security/set-up-aws-private-certificate-authority-to-issue-certificates-for-use-with-iam-roles-anywhere/

Traditionally, applications or systems—defined as pieces of autonomous logic functioning without direct user interaction—have faced challenges associated with long-lived credentials such as access keys. In certain circumstances, long-lived credentials can increase operational overhead and the scope of impact in the event of an inadvertent disclosure.

To help mitigate these risks and follow the best practice of using short-term credentials, Amazon Web Services (AWS) introduced IAM Roles Anywhere, a feature of AWS Identity and Access Management (IAM). With the introduction of IAM Roles Anywhere, systems running outside of AWS can exchange X.509 certificates to assume an IAM role and receive temporary IAM credentials from AWS Security Token Service (AWS STS).

You can use IAM Roles Anywhere to help you implement a secure and manageable authentication method. It uses the same IAM policies and roles as within AWS, simplifying governance and policy management across hybrid cloud environments. Additionally, the certificates used in this process come with a built-in validity period defined when the certificate request is created, enhancing the security by providing a time-limited trust for the identities. Furthermore, customers in high security environments can optionally keep private keys for the certificates stored in PKCS #11-compatible hardware security modules for extra protection.

For organizations that lack an existing public key infrastructure (PKI), AWS Private Certificate Authority allows for the creation of a certificate hierarchy without the complexity of self-hosting a PKI.

With the introduction of IAM Roles Anywhere, there is now an accompanying requirement to manage certificates and their lifecycle. AWS Private CA is an AWS managed service that can issue x509 certificates for hosts. This makes it ideal for use with IAM Roles Anywhere. However, AWS Private CA doesn’t natively deploy certificates to hosts.

Certificate deployment is an essential part of managing the certificate lifecycle for IAM Roles Anywhere, the absence of which can lead to operational inefficiencies. Fortunately, there is a solution. By using AWS Systems Manager with its Run Command capability, you can automate issuing and renewing certificates from AWS Private CA. This simplifies the management process of IAM Roles Anywhere on a large scale.

In this blog post, we walk you through an architectural pattern that uses AWS Private CA and Systems Manager to automate issuing and renewing x509 certificates. This pattern smooths the integration of non-AWS hosts with IAM Roles Anywhere. It can help you replace long-term credentials while reducing operational complexity of IAM Roles Anywhere with certificate vending automation.

While IAM Roles Anywhere supports both Windows and Linux, this solution is designed for a Linux environment. Windows users integrating with Active Directory should check out the AWS Private CA Connector for Active Directory. By implementing this architectural pattern, you can distribute certificates to your non-AWS Linux hosts, thereby enabling them to use IAM Roles Anywhere. This approach can help you simplify certificate management tasks.

Architecture overview

Figure 1: Architecture overview

Figure 1: Architecture overview

The architectural pattern we propose (Figure 1) is composed of multiple stages, involving AWS services including Amazon EventBridge, AWS Lambda, Amazon DynamoDB, and Systems Manager.

  1. Amazon EventBridge Scheduler invokes a Lambda function called CertCheck twice daily.
  2. The Lambda function scans a DynamoDB table to identify instances that require certificate management. It specifically targets instances managed by Systems Manager, which the administrator populates into the table.
  3. The information about the instances with no certificate and instances requiring new certificates due to expiry of existing ones is received by CertCheck.
  4. Depending on the certificate’s expiration date for a particular instance, a second Lambda function called CertIssue is launched.
  5. CertIssue instructs Systems Manager to apply a run command on the instance.
  6. Run Command generates a certificate signing request (CSR) and a private key on the instance.
  7. The CSR is retrieved by Systems Manager, the private key remains securely on the instance.
  8. CertIssue then retrieves the CSR from Systems Manager.
  9. CertIssue uses the CSR to request a signed certificate from AWS Private CA.
  10. On successful certificate issuance, AWS Private CA creates an event through EventBridge that contains the ID of the newly issued certificate.
  11. This event subsequently invokes a third Lambda function called CertDeploy.
  12. CertDeploy retrieves the certificate from AWS Private CA and invokes Systems Manager to launch Run Command with the certificate data and updates the certificate’s expiration date in the DynamoDB table for future reference.
  13. Run Command conducts a brief test to verify the certificate’s functionality, and upon success, stores the signed certificate on the instance.
  14. The instance can then exchange the certificate for AWS credentials through IAM Roles Anywhere.

Additionally, on a certificate rotation failure, an Amazon Simple Notification Service (Amazon SNS) notification is delivered to an email address specified during the AWS CloudFormation deployment.

The solution enables periodic certificate rotation. If a certificate is nearing expiration, the process initiates the generation of a new private key and CSR, thus issuing a new certificate. Newly generated certificates, private keys, and CSRs replace the existing ones.

With certificates in place, they can be used by IAM Roles Anywhere to obtain short-term IAM credentials. For more details on setting up IAM Roles Anywhere, see the IAM Roles Anywhere User Guide.

Costs

Although this solution offers significant benefits, it’s important to consider the associated costs before you deploy. To provide a cost estimate, managing certificates for 100 hosts would cost approximately $85 per month. However, for a larger deployment of 1,100 hosts with the Systems Manager advanced tier, the cost would be around $5937 per month. These pricing estimates include the rotation of certificates six times a month.

AWS Private CA in short-lived mode incurs a monthly charge of $50, and each certificate issuance costs $0.058. Systems Manager Hybrid Activation standard has no additional cost for managing fewer than 1,000 hosts. If you have more than 1,000 hosts, the advanced plan must be used at an approximate cost of $5 per host per month. DynamoDB, Amazon SNS, and Lambda costs should be under $5 per month per service for under 1000 hosts. For environments with over 1,000 hosts, it might be worthwhile to explore other options of machine to machine authentication or another option for distributing certificates.

Please note that the estimated pricing mentioned here is specific to the us-east-1 AWS Region and can be calculated for other regions using the AWS Pricing Calculator.

Prerequisites

You should have several items already set up to make it easier to follow along with the blog.

Enabling Systems manager hybrid activation

To create a hybrid activation, follow these steps:

  1. Open the AWS Management Console for Systems Manager, go to Hybrid activations and choose Create an Activation.
    Figure 2: Hybrid activation page

    Figure 2: Hybrid activation page

  2. Enter a description [optional] for the activation and adjust the Instance limit value to the maximum you need, then choose Create activation.
    Figure 3: Create hybrid activation

    Figure 3: Create hybrid activation

  3. This gives you a green banner with an Activation Code and Activation ID. Make a note of these.
    Figure 4: Successful hybrid activation with activation code and ID

    Figure 4: Successful hybrid activation with activation code and ID

  4. Install the AWS Systems Manager Agent (SSM Agent) on the hosts to be managed. Follow the instructions for the appropriate operating system. In the example commands, replace <activation-code>, <activation-id>, and <region> with the activation code and ID from the previous step and your Region. Here is an example of commands to run for an Ubuntu host:
    mkdir /tmp/ssm
    
    curl https://s3.amazonaws.com/ec2-downloads-windows/SSMAgent/latest/debian_amd64/amazon-ssm-agent.deb -o /tmp/ssm/amazon-ssm-agent.deb
    
    sudo dpkg -i /tmp/ssm/amazon-ssm-agent.deb
    
    sudo service amazon-ssm-agent stop
    
    sudo -E amazon-ssm-agent -register -code "<activation-code>" -id "<activation-id>" -region <region> 
    
    sudo service amazon-ssm-agent start
    

You should see a message confirming the instance was successfully registered with Systems Manager.

Note: If you receive errors during Systems Manager registration about the Region having invalid characters, verify that the Region is not in quotation marks.

Deploy with CloudFormation

We’ve created a Git repository with a CloudFormation template that sets up the aforementioned architecture. An existing S3 bucket is required for CloudFormation to upload the Lambda package.

To launch the CloudFormation stack:

  1. Clone the Git repository that contains the CloudFormation template and the Lambda function code.
    git clone https://github.com/aws-samples/aws-privateca-certificate-deployment-automator.git
    

  2. cd into the directory created by Git.
    cd aws-privateca-certificate-deployment-automator
    

  3. Launch the CloudFormation stack within the cloned Git directory using the cf_template.yaml file, replacing <DOC-EXAMPLE-BUCKET> with the name of your S3 bucket from the prerequisites.
    aws cloudformation package --template-file cf_template.yaml --output-template-file packaged.yaml --s3-bucket <DOC-EXAMPLE-BUCKET>
    

Note: These commands should be run on the system you plan to use to deploy the CloudFormation and have the Git and AWS CLI installed.

After successfully running the CloudFormation package command, run the CloudFormation deploy command. The template supports various parameters to change the path where the certificates and keys will be generated. Adjust the paths as needed with the parameter-overrides flag, but verify that they exist on the hosts. Replace the <email> placeholder with one that you want to receive alerts for failures. The stack name must be in lower case.

aws cloudformation deploy --template packaged.yaml --stack-name ssm-pca-stack --capabilities CAPABILITY_NAMED_IAM --parameter-overrides SNSSubscriberEmail=<email>

The available CloudFormation parameters are listed in the following table:

Parameter Default value Use
AWSSigningHelperPath /root Default path on the host for the AWS Signing Helper binary
CACertPath /tmp Default path on the host the CA certificate will be created in
CACertValidity 10 Default CA certificate length in years
CACommonNam ca.example.com Default CA certificate common name
CACountry US Default CA certificate country code
CertPath /tmp Default path on the host the certificates will be created in
CSRPath /tmp Default path on the host the certificates will be created in
KeyAlgorithm RSA_2048 Default algorithm use to create the CA private key
KeyPath /tmp Default path on the host the private keys will be created in
OrgName Example Corp Default CA certificate organization name
SigningAlgorithm SHA256WITHRSA Default CA signing algorithm for issued certificates

After the CloudFormation stack is ready, manually add the hosts requiring certificate management into the DynamoDB table.

You will also receive an email at the email address specified to accept the SNS topic subscription. Make sure to choose the Confirm Subscription link as shown in Figure 5.

Figure 5: SNS topic subscription confirmation

Figure 5: SNS topic subscription confirmation

Add data to the DynamoDB table

  1. Open the AWS Systems Manager console and select Fleet Manager.
  2. Choose Managed Nodes and copy the Node ID value. The node ID value in the Fleet Manager as shown in Figure 6 will be the host ID to be used in a subsequent step.
    Figure 6: Systems Manager Node ID

    Figure 6: Systems Manager Node ID

  3. Open the DynamoDB console and select Dashboard and then Tables in the left navigation pane.
    Figure 7: DynamoDB menu

    Figure 7: DynamoDB menu

  4. Select the certificates table.
    Figure 8: DynamoDB tables

    Figure 8: DynamoDB tables

  5. Choose Explore table items and then choose Create item.
  6. Enter the node ID as a value for the hostID attribute as copied in step 2.
    Figure 9: DynamoDB table hostID attribute creation

    Figure 9: DynamoDB table hostID attribute creation

Additional string attributes listed in the following table can be added to the item to specify paths for the certificates on a per host basis. If these attributes aren’t created, either the default paths or overrides in the CloudFormation parameters will be used.

Additional supported attributes Use
certPath Path on the host the certificate will be created in
keyPath Path on the host the private key will be created in
signinghelperPath Path on the host for the AWS Signing Helper binary
cacertPath Path on the host the CA certificate will be created in

The CertCheck Lambda function created by the CloudFormation template runs twice daily to verify that the certificates for these hosts are kept up to date. If necessary, you can use the Lambda invoke command to run the Lambda function on-demand.

aws lambda invoke --function-name CertCheck-Trigger --cli-binary-format raw-in-base64-out response.json

The certificate expiration and serial number metadata are stored in the DynamoDB table certificate. Select the certificates table and choose Explore table items to view the data.

Figure 10: DynamoDB table item with certificate expiration and serial for a host

Figure 10: DynamoDB table item with certificate expiration and serial for a host

Validation

To validate successful certificate deployment, you should find four files in the location specified in the CloudFormation parameter or DynamoDB table attribute, as shown in the following table.

File Use Location
{host}.crt The certificate containing the public key, signed by AWS Private CA. certPath attribute in DynamoDB. Otherwise, default specified by the certPath CF parameter.
ca_chain_certificate.crt The certificate chain including intermediates from AWS Private CA. cacertPath attribute in DynamoDB. Otherwise, default specified by the CACertPath CF parameter.
{host}.key The private key for the certificate. keyPath attribute in DynamoDB. Otherwise, default specified by the KeyPath CF parameter.
{host}.csr The CSR used to generate the signed certificate. Default specified by the CSRPath CF parameter.

These certificates can now be used to configure the host for IAM Roles Anywhere. See Obtaining temporary security credentials from AWS Identity and Access Management Roles Anywhere for using the signing helper tool provided by IAM Roles Anywhere. The signing helper must be installed on the instance for the validation to work. You can pass the location of the signing helper as a parameter to the CloudFormation template.

Note: As a security best practice, it’s important to use permissions and ACLs to keep the private key secure and restrict access to it. The automation will create and set the private key with chmod 400 permissions. Chmod command is used to change the permission for a file or directory. Chmod 400 permission will allow owner of the file to read the file while restricting others from reading, writing, or running the file.

Revoke a certificate

AWS Private CA also supports generating a certificate revocation list (CRL), which can be imported to IAM Roles Anywhere. The CloudFormation template automatically sets up the CRL process between AWS Private CA and IAM Roles Anywhere.

Figure 11: Certificate revocation process

Figure 11: Certificate revocation process

Within 30 minutes after revocation, AWS Private CA generates a CRL file and uploads it to the CRL S3 bucket that was created by the CloudFormation template. Then, the CRLProcessor Lambda function receives a notification through EventBridge of the new CRL file and passes it to the IAM Roles Anywhere API.

To revoke a certificate, use the AWS CLI. In the following example, replace <certificate-authority-arn>, <certificate-serial>, and<revocation-reason> with your own information.

aws acm-pca revoke-certificate --certificate-authority-arn <certificate-authority-arn> --certificate-serial <certificate-serial> --revocation-reason <revocation-reason>

The AWS Private CA ARN can be found in the Cloudformation stack outputs under the name PCAARN. The certificate serial number are listed in the DynamoDB table for each host as previously mentioned. The revocation reasons can be one of these possible values:

  • UNSPECIFIED
  • KEY_COMPROMISE
  • CERTIFICATE_AUTHORITY_COMPROMISE
  • AFFILIATION_CHANGED
  • SUPERSEDED
  • CESSATION_OF_OPERATION
  • PRIVILEGE_WITHDRAWN
  • A_A_COMPROMISE

Revoking a certificate won’t automatically generate a new certificate for the host. See Manually rotate certificates.

Manually rotate certificates

The certificates are set to expire weekly and are rotated the day of expiration. If you need to manually replace a certificate sooner, remove the expiration date for the host’s record in the DynamoDB table (see Figure 12). On the next run of the Lambda function, the lack of an expiration date will cause the certificate for that host to be replaced. To immediately renew a certificate or test the rotation function, remove the expiration date from the DynamoDB table and run the following Lambda invoke command. After the certificates have been rotated, the new expiration date will be listed in the table.

aws lambda invoke --function-name CertCheck-Trigger --cli-binary-format raw-in-base64-out response.json

Conclusion

By using AWS IAM Roles Anywhere, systems outside of AWS can use short-term credentials in the form of x509 certificates in exchange for AWS STS credentials. This can help you improve your security in a hybrid environment by reducing the use of long-term access keys as credentials.

For organizations without an existing enterprise PKI, the solution described in this post provides an automated method of generating and rotating certificates using AWS Private CA and AWS Systems Manager. We showed you how you can use Systems Manager to set up a non-AWS host with certificates for use with IAM Roles Anywhere and ensure they’re rotated regularly.

Deploy this solution today and move towards IAM Roles Anywhere to remove long term credentials for programmatic access. For more information, see the IAM Roles Anywhere blog article or post your queries on AWS re:Post.

If you have feedback about this post, submit comments in the Comments section below. If you have questions about this post, start a new thread on IAM re:Post or contact AWS Support.

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Chris Sciarrino

Chris Sciarrino

Chris is a Senior Solutions Architect and a member of the AWS security field community based in Toronto, Canada. He works with enterprise customers helping them design solutions on AWS. Outside of work, Chris enjoys spending his time hiking and skiing with friends and listening to audiobooks.

Ravikant Sharma/>

Ravikant Sharma

Ravikant is a Solutions Architect based in London. He specializes in cloud security and financial services. He helps Fintech and Web3 startups build and scale their business using AWS Cloud. Prior to AWS, he worked at Citi Singapore as Vice President – API management, where he played a pivotal role in implementing Open API security frameworks and Open Banking regulations.

Rahul Gautam

Rahul Gautam

Rahul is a Security and Compliance Specialist Solutions Architect based in London. He helps customers in adopting AWS security services to meet and improve their security posture in the cloud. Before joining the SSA team, Rahul spent 5 years as a Cloud Support Engineer in AWS Premium Support. Outside of work, Rahul enjoys travelling as much as he can.

AWS Weekly Roundup—Reserve GPU capacity for short ML workloads, Finch is GA, and more—November 6, 2023

Post Syndicated from Marcia Villalba original https://aws.amazon.com/blogs/aws/aws-weekly-roundup-reserve-gpu-capacity-for-short-ml-workloads-finch-is-ga-and-more-november-6-2023/

The year is coming to an end, and there are only 50 days until Christmas and 21 days to AWS re:Invent! If you are in Las Vegas, come and say hi to me. I will be around the Serverlesspresso booth most of the time.

Last week’s launches
Here are some launches that got my attention during the previous week.

Amazon EC2 – Amazon EC2 announced Capacity Blocks for ML. This means that you can now reserve GPU compute capacity for your short-duration ML workloads. Learn more about this launch on the feature page and announcement blog post.

Finch – Finch is now generally available. Finch is an open source tool for local container development on macOS (using Intel or Apple Silicon). It provides a command line developer tool for building, running, and publishing Linux containers on macOS. Learn more about Finch in this blog post written by Phil Estes or on the Finch website.

AWS X-Ray – AWS X-Ray now supports W3C format trace IDs for distributed tracing. AWS X-Ray supports trace IDs generated through OpenTelemetry or any other framework that conforms to the W3C Trace Context specification.

Amazon Translate Amazon Translate introduces a brevity customization to reduce translation output length. This is a new feature that you can enable in your real-time translations where you need a shorter translation to meet caption size limits. This translation is not literal, but it will preserve the underlying message.

AWS IAM IAM increased the actions last accessed to 60 more services. This functionality is very useful when fine-tuning the permissions of the roles, identifying unused permissions, and granting the least amount of permissions that your roles need.

AWS IAM Access AnalyzerIAM Access Analyzer policy generator expanded support to identify over 200 AWS services to help you create fine-grained policies based on your AWS CloudTrail access activity.

For a full list of AWS announcements, be sure to keep an eye on the What’s New at AWS page.

Other AWS news
Some other news and blog posts that you may have missed:

AWS Compute BlogDaniel Wirjo and Justin Plock wrote a very interesting article about how you can send and receive webhooks on AWS using different AWS serverless services. This is a good read if you are working with webhooks on your application, as it not only shows you how to build these solutions but also what considerations you should have when building them.

AWS Storage Blog Bimal Gajjar and Andrew Peace wrote a very useful blog post about how to handle event ordering and duplicate events with Amazon S3 Event Notifications. This is a common challenge for many customers.

Amazon Science BlogDavid Fan wrote an article about how to build better foundation models for video representation. This article is based on a paper that Prime Video presented at a conference about this topic.

The Official AWS Podcast – Listen each week for updates on the latest AWS news and deep dives into exciting use cases. There are also official AWS podcasts in several languages. Check out the ones in FrenchGermanItalian, and Spanish.

AWS open-source news and updates – This is a newsletter curated by my colleague Ricardo to bring you the latest open source projects, posts, events, and more.

Upcoming AWS events
Check your calendars and sign up for these AWS events:

AWS Community Days – Join a community-led conference run by AWS user group leaders in your region: Ecuador (November 7), Mexico (November 11), Montevideo (November 14), Central Asia (Kazakhstan, Uzbekistan, Kyrgyzstan, and Mongolia on November 17–18), and Guatemala (November 18).

AWS re:Invent (November 27–December 1) – Join us to hear the latest from AWS, learn from experts, and connect with the global cloud community. Browse the session catalog and attendee guides and check out the highlights for generative artificial intelligence (AI).

That’s all for this week. Check back next Monday for another Weekly Roundup!

— Marcia

This post is part of our Weekly Roundup series. Check back each week for a quick roundup of interesting news and announcements from AWS!

Refine permissions for externally accessible roles using IAM Access Analyzer and IAM action last accessed

Post Syndicated from Nini Ren original https://aws.amazon.com/blogs/security/refine-permissions-for-externally-accessible-roles-using-iam-access-analyzer-and-iam-action-last-accessed/

When you build on Amazon Web Services (AWS) across accounts, you might use an AWS Identity and Access Management (IAM) role to allow an authenticated identity from outside your account—such as an IAM entity or a user from an external identity provider—to access the resources in your account. IAM roles have two types of policies attached to them: a trust policy that allows access to an external entity, and a permissions policy that defines what actions the role can take. This blog post focuses on how to use AWS Identity and Access Management Access Analyzer cross-account access findings and IAM action last accessed information to refine the permissions policies of your IAM roles that have a trust policy.

IAM Access Analyzer helps you set, verify, and refine permissions. To learn more about how IAM Access Analyzer guides you toward least-privilege permissions, visit Using AWS IAM Access Analyzer. Action last accessed information helps you identify unused permissions and refine the access of your IAM roles to only the actions they use. IAM now provides action last accessed information for more than 140 services such as Amazon Kinesis Data Streams and Data Firehose, Amazon DynamoDB, and Amazon Simple Queue Service (Amazon SQS).

This blog post walks you through how to use IAM Access Analyzer and action last accessed to refine the required permissions for your IAM roles that have a trust policy, which allows entities outside of your account to assume a role and access your resources.

Use IAM roles to grant access to an external entity

You can create an IAM role that grants permissions for an entity outside your account to access the resources in your account. For example, if you’re an application developer, you might grant cross-account access to your AWS resources by using a role and attaching a trust policy to the role.

To allow an external entity access to your resources by using a role, you first create a role with a role trust policy to grant access to entities outside your account, and then grant permissions that specify which actions the role can take. The external entities can then assume the role in your account and access your resources based on the permissions you granted to the role. See Cross-account access using roles for more information.

You should restrict the access of roles that grant access outside of your account to just the permissions required to perform a specific task.

Use IAM Access Analyzer cross-account access findings to identify roles that grant access to external entities

When you use role trust policies to grant account access to entities outside your account, those entities can access and take the allowed actions on your resources. IAM Access Analyzer continuously monitors your account to identify the resources in your account that can be accessed from outside your account and helps you verify whether the access permissions meet your intent. For the example in this post, if you were to add a new trust policy to your
ApplicationRole
to grant permissions to an external account to access an application in your account, IAM Access Analyzer would let you know that ApplicationRole is accessible by entities from outside your account.

Use IAM action last accessed information to identify and remove unused permissions

After you’ve identified the IAM roles that grant access to entities outside your account, review what those roles can do and remove unused permissions. You can use action last accessed to show you the latest timestamp when your IAM role used an action, analyze its access permissions, and remove unused permissions.

Refine permissions for externally accessible roles by using IAM Access Analyzer cross-account access findings and action last accessed information

This example demonstrates how you can combine the information from IAM Access Analyzer cross-account access findings and IAM action last accessed information to identify roles that can be assumed from outside your account, review unused and unnecessary actions, and reduce the permissions available to external roles.

To view action last accessed information in the IAM console

  1. Open the AWS Management Console and go to the IAM console, and then select Access analyzer in the navigation pane.
  2. If you’ve already created an analyzer, go to Step 3. Otherwise, follow Identify Unintended Resource Access with IAM Access Analyzer to create an analyzer.
  3. Review your findings on the IAM Access Analyzer tab.
  4. Under Active findings, for Filter active findings, enter AWS::IAM::Role. The list of Active findings shows you the roles that can be accessed by entities outside your account.
  5. Figure 1: Findings filtered by resource types

    Figure 1: Findings filtered by resource types

  6. Under the Finding ID column, select a finding for a role (for example, ApplicationRole) that you want to review.
  7. A new page for the Finding ID will appear. Choose the resource ARN link in the Resource field under the Details section.
  8. Figure 2: Findings page

    Figure 2: Findings page

  9. A new page for the role will appear. Select the Access Advisor tab to review the last accessed information of your services for this role. This tab displays the AWS services to which the role has permissions. Action last accessed reports the actions listed in the IAM action last accessed information services and actions. The tracking period for services is the last 400 days—fewer if your AWS Region began tracking within the last 400 days. Learn more about Where AWS tracks last accessed information.
  10. Figure 3: Last accessed information of allowed services

    Figure 3: Last accessed information of allowed services

  11. In this exercise, we will use DynamoDB as an example. Under Allowed services, for Search, enter Amazon DynamoDB and under the Service column, choose Amazon DynamoDB. This will take you to a new section titled Allowed management actions for Amazon DynamoDB, which displays the action last accessed information of your role for DynamoDB. The Action column displays the action, the Last Accessed column displays the timestamp of when access was last attempted, and the Region accessed column displays in which region access was last attempted.
  12. The Action column on the resulting Allowed management actions for Amazon DynamoDB section includes the actions to which the role has permissions, when the role last accessed each action, and the Region accessed. You can sort the actions by choosing the arrow next to Last accessed.
  13. Figure 4: Action last accessed information for Amazon DynamoDB

    Figure 4: Action last accessed information for Amazon DynamoDB

  14. Because you want to remove unused permissions, filter for all unused actions for the role by selecting Services not accessed from the Last accessed dropdown list. This will show you the actions that haven’t been accessed during the tracking period.
  15. Figure 5: Action last accessed information ordered by not accessed

    Figure 5: Action last accessed information ordered by not accessed

  16. To return to the service view, choose Back to Allowed services and then select the Permissions tab. Select the plus sign to the left of DynamoDBAccess to see the JSON of the customer managed policy.
  17. Figure 6: The JSON code of the customer managed policy

    Figure 6: The JSON code of the customer managed policy

  18. Choose Edit and remove dynamodb:* and replace it with just the actions that have been used recently such as: DescribeTable and DescribeKinesisStreamingDestination. Not all actions are reported by action last accessed. Review the list of actions that action last accessed information reports and when action last accessed started tracking the action for the service in an AWS Region.
  19. Choose Next and then Save changes. Return to the Access Advisor tab to confirm that all the retained permissions have been used recently.

Conclusion

In this post, you learned how to use IAM Access Analyzer and action last accessed information to identify and refine permissions for externally accessible roles in your journey toward least privilege. You first used IAM Access Analyzer cross-account access findings to identify IAM roles that can be accessed from outside your account. You then used IAM action last accessed information to review the permissions those roles are using and to remove unused permissions.

For more information about IAM Access Analyzer cross-account findings, see Findings for public and cross-account access. For more information about action last accessed information, see Things to know about last accessed information and the IAM action last accessed information services and actions.

If you have feedback about this post, submit comments in the Comments section below. If you have questions about this post, start a new thread on the AWS re:Post or contact AWS Support.

Nini Ren

Nini Ren

Nini is a product manager for AWS Identity and Access Management and AWS Resource Access Manager. He enjoys working with customers to develop solutions that create value for their businesses. Nini holds an MBA from The Wharton School, a Master of computer and information technology from the University of Pennsylvania, and an AB in chemistry and physics from Harvard College.

Mathangi Ramesh

Mathangi Ramesh

Mathangi is a product manager for AWS Identity and Access Management. She enjoys talking to customers and working with data to solve problems. Outside of work, Mathangi is a fitness enthusiast and a Bharatanatyam dancer. She holds an MBA degree from Carnegie Mellon University.