Tag Archives: Permission sets

How to automate AWS account creation with SSO user assignment

2022-01-25 Rafael Koike

Post Syndicated from Rafael Koike original https://aws.amazon.com/blogs/security/how-to-automate-aws-account-creation-with-sso-user-assignment/

Background

AWS Control Tower offers a straightforward way to set up and govern an Amazon Web Services (AWS) multi-account environment, following prescriptive best practices. AWS Control Tower orchestrates the capabilities of several other AWS services, including AWS Organizations, AWS Service Catalog, and AWS Single Sign-On (AWS SSO), to build a landing zone very quickly. AWS SSO is a cloud-based service that simplifies how you manage SSO access to AWS accounts and business applications using Security Assertion Markup Language (SAML) 2.0. You can use AWS Control Tower to create and provision new AWS accounts and use AWS SSO to assign user access to those newly-created accounts.

Some customers need to provision tens, if not hundreds, of new AWS accounts at one time and assign access to many users. If you are using AWS Control Tower, doing this requires that you provision an AWS account in AWS Control Tower, and then assign the user access to the AWS account in AWS SSO before moving to the next AWS account. This process adds complexity and time for administrators who manage the AWS environment while delaying users’ access to their AWS accounts.

In this blog post, we’ll show you how to automate creating multiple AWS accounts in AWS Control Tower, and how to automate assigning user access to the AWS accounts in AWS SSO, with the ability to repeat the process easily for subsequent batches of accounts. This solution simplifies the provisioning and assignment processes, while enabling automation for your AWS environment, and allows your builders to start using and experimenting on AWS more quickly.

Services used

This solution uses the following AWS services:

High level solution overview

Figure 1 shows the architecture and workflow of the batch AWS account creation and SSO assignment processes.

Figure 1: Batch AWS account creation and SSO assignment automation architecture and workflow

Before starting

This solution is configured to be deployed in the North Virginia Region (us-east-1). But you can change the CloudFormation template to run in any Region that supports all the services required in the solution.

AWS Control Tower Account Factory can take up to 25 minutes to create and provision a new account. During this time, you will be unable to use AWS Control Tower to perform actions such as creating an organizational unit (OU) or enabling a guardrail on an OU. As a recommendation, running this solution during a time period when you do not anticipate using AWS Control Tower’s features is best practice.

Collect needed information

Note: You must have already configured AWS Control Tower, AWS Organizations, and AWS SSO to use this solution.

Before deploying the solution, you need to first collect some information for AWS CloudFormation.

The required information you’ll need to gather in these steps is:

AWS SSO instance ARN
AWS SSO Identity Store ID
Admin email address
Amazon S3 bucket
AWS SSO user group ARN

Prerequisite information: AWS SSO instance ARN

From the web console

You can find this information under Settings in the AWS SSO web console as shown in Figure 2.

Figure 2: AWS SSO instance ARN

From the CLI

You can also get this information by running the following CLI command using AWS Command Line Interface (AWS CLI):

aws sso-admin list-instances

The output is similar to the following:

{
    "Instances": [
        {
        "InstanceArn": "arn:aws:sso:::instance/ssoins-abc1234567",
        "IdentityStoreId": "d-123456abcd"
        }
    ]
}

Make a note of the InstanceArn value from the output, as this will be used in the AWS SSO instance ARN.

Prerequisite information: AWS SSO Identity Store ID

This is available from either the web console or the CLI.

From the web console

You can find this information in the same screen as the AWS SSO Instance ARN, as shown in Figure 3.

Figure 3: AWS SSO identity store ID

From the CLI

To find this from the AWS CLI command aws sso-admin list-instances, use the IdentityStoreId from the second key-value pair returned.

Prerequisite information: Admin email address

The admin email address notified when a new AWS account is created.

This email address is used to receive notifications when a new AWS account is created.

Prerequisite information: S3 bucket

The name of the Amazon S3 bucket where the AWS account list CSV files will be uploaded to automate AWS account creation.

This globally unique bucket name will be used to create a new Amazon S3 Bucket, and the automation script will receive events from new objects uploaded to this bucket.

Prerequisite information: AWS SSO user group ARN

Go to AWS SSO > Groups and select the user group whose permission set you would like to assign to the new AWS account. Copy the Group ID from the selected user group. This can be a local AWS SSO user group, or a third-party identity provider-synced user group.

Note: For the AWS SSO user group, there is no AWS CLI equivalent; you need to use the AWS web console to collect this information.

Figure 4: AWS SSO user group ARN

Prerequisite information: AWS SSO permission set

The ARN of the AWS SSO permission set to be assigned to the user group.

From the web console

To view existing permission sets using the AWS SSO web console, go to AWS accounts > Permission sets. From there, you can see a list of permission sets and their respective ARNs.

Figure 5: AWS SSO permission sets list

You can also select the permission set name and from the detailed permission set window, copy the ARN of the chosen permission set. Alternatively, create your own unique permission set to be assigned to the intended user group.

Figure 6: AWS SSO permission set ARN

From the CLI

To get permission set information from the CLI, run the following AWS CLI command:

aws sso-admin list-permission-sets --instance-arn <SSO Instance ARN>

This command will return an output similar to this:

{
    "PermissionSets": [
    "arn:aws:sso:::permissionSet/ssoins-abc1234567/ps-1234567890abcdef",
    "arn:aws:sso:::permissionSet/ssoins-abc1234567/ps-abcdef1234567890"
    ]
}

If you can’t determine the details for your permission set from the output of the CLI shown above, you can get the details of each permission set by running the following AWS CLI command:

aws sso-admin describe-permission-set --instance-arn <SSO Instance ARN> --permission-set-arn <PermissionSet ARN>

The output will be similar to this:

{
    "PermissionSet": {
    "Name": "AWSPowerUserAccess",
    "PermissionSetArn": "arn:aws:sso:::permissionSet/ssoins-abc1234567/ps-abc123def4567890",
    "Description": "Provides full access to AWS services and resources, but does not allow management of Users and groups",
    "CreatedDate": "2020-08-28T11:20:34.242000-04:00",
    "SessionDuration": "PT1H"
    }
}

The output above lists the name and description of each permission set, which can help you identify which permission set ARN you will use.

Solution initiation

The solution steps are in two parts: the initiation, and the batch account creation and SSO assignment processes.

To initiate the solution

Log in to the management account as the AWS Control Tower administrator, and deploy the provided AWS CloudFormation stack with the required parameters filled out.

Note: To fill out the required parameters of the solution, refer to steps 1 to 6 of the To launch the AWS CloudFormation stack procedure below.
When the stack is successfully deployed, it performs the following actions to set up the batch process. It creates:
- The S3 bucket where you will upload the AWS account list CSV file.
- A DynamoDB table. This table tracks the AWS account creation status.
- A Lambda function, NewAccountHandler.
- A Lambda function, CreateManagedAccount. This function is triggered by the entries in the Amazon DynamoDB table and initiates the batch account creation process.
- An Amazon CloudWatch Events rule to detect the AWS Control Tower CreateManagedAccount lifecycle event.
- Another Lambda function, CreateAccountAssignment. This function is triggered by AWS Control Tower Lifecycle Events via Amazon CloudWatch Events to assign the AWS SSO Permission Set to the specified User Group and AWS account

To create the AWS Account list CSV file

After you deploy the solution stack, you need to create a CSV file based on this sample.csv and upload it to the Amazon S3 bucket created in this solution. This CSV file will be used to automate the new account creation process.

CSV file format

The CSV file must follow the following format:

AccountName,SSOUserEmail,AccountEmail,SSOUserFirstName,SSOUserLastName,OrgUnit,Status,AccountId,ErrorMsg
Test-account-1,[email protected],[email protected],Fname-1,Lname-1,Test-OU-1,,,
Test-account-2,[email protected],[email protected],Fname-2,Lname-2,Test-OU-2,,,
Test-account-3,[email protected],[email protected],Fname-3,Lname-3,Test-OU-1,,,

Where the first line is the column names, and each subsequent line contains the new AWS accounts that you want to create and automatically assign that SSO user group to the permission set.

CSV fields

AccountName:	String between 1 and 50 characters [a-zA-Z0-9_-]
SSOUserEmail:	String with more than seven characters and be a valid email address for the primary AWS Administrator of the new AWS account
AccountEmail:	String with more than seven characters and be a valid email address not used by other AWS accounts
SSOUserFirstName:	String with the first name of the primary AWS Administrator of the new AWS account
SSOUserLastName:	String with the last name of the primary AWS Administrator of the new AWS account
OrgUnit:	String and must be an existing AWS Organizations OrgUnit
Status:	String, for future use
AccountId:	String, for future use
ErrorMsg:	String, for future use

Figure 7 shows the details that are included in our example for the two new AWS accounts that will be created.

Figure 7: Sample AWS account list CSV

The NewAccountHandler function is triggered from an object upload into the Amazon S3 bucket, validates the input file entries, and uploads the validated input file entries to the Amazon DynamoDB table.
The CreateManagedAccount function queries the DynamoDB table to get the details of the next account to be created. If there is another account to be created, then the batch account creation process moves on to Step 4, otherwise it completes.
The CreateManagedAccount function launches the AWS Control Tower Account Factory product in AWS Service Catalog to create and provision a new account.
After Account Factory has completed the account creation workflow, it generates the CreateManagedAccount lifecycle event, and the event log states if the workflow SUCCEEDED or FAILED.
The CloudWatch Events rule detects the CreateManagedAccount AWS Control Tower Lifecycle Event, and triggers the CreateManagedAccount and CreateAccountAssignment functions, and sends email notification to the administrator via AWS SNS.
The CreateManagedAccount function updates the Amazon DynamoDB table with the results of the AWS account creation workflow. If the account was successfully created, it updates the input file entry in the Amazon DynamoDB table with the account ID; otherwise, it updates the entry in the table with the appropriate failure or error reason.
The CreateAccountAssignment function assigns the AWS SSO Permission Set with the appropriate AWS IAM policies to the User Group specified in the Parameters when launching the AWS CloudFormation stack.
When the Amazon DynamoDB table is updated, the Amazon DynamoDB stream triggers the CreateManagedAccount function for subsequent AWS accounts or when new AWS account list CSV files are updated, then steps 1-9 are repeated.

Upload the CSV file

Once the AWS account list CSV file has been created, upload it into the Amazon S3 bucket created by the stack.

Deploying the solution

To launch the AWS CloudFormation stack

Now that all the requirements and the specifications to run the solution are ready, you can launch the AWS CloudFormation stack:

Open the AWS CloudFormation launch wizard in the console.
In the Create stack page, choose Next.

Figure 8: Create stack in CloudFormation
On the Specify stack details page, update the default parameters to use the information you captured in the prerequisites as shown in Figure 9, and choose Next.

Figure 9: Input parameters into AWS CloudFormation
On the Configure stack option page, choose Next.
On the Review page, check the box “I acknowledge that AWS CloudFormation might create IAM resources.” and choose Create Stack.
Once the AWS CloudFormation stack has completed, go to the Amazon S3 web console and select the Amazon S3 bucket that you defined in the AWS CloudFormation stack.
Upload the AWS account list CSV file with the information to create new AWS accounts. See To create the AWS Account list CSV file above for details on creating the CSV file.

Workflow and solution details

When a new file is uploaded to the Amazon S3 bucket, the following actions occur:

When you upload the AWS account list CSV file to the Amazon S3 bucket, the Amazon S3 service triggers an event for newly uploaded objects that invokes the Lambda function NewAccountHandler.
This Lambda function executes the following steps:
- Checks whether the Lambda function was invoked by an Amazon S3 event, or the CloudFormation CREATE event.
- If the event is a new object uploaded from Amazon S3, read the object.
- Validate the content of the CSV file for the required columns and values.
- If the data has a valid format, insert a new item with the data into the Amazon DynamoDB table, as shown in Figure 10 below.
  
  Figure 10: DynamoDB table items with AWS accounts details
- Amazon DynamoDB is configured to initiate the Lambda function CreateManagedAccount when insert, update, or delete items are initiated.
- The Lambda function CreateManagedAccount checks for update event type. When an item is updated in the table, this item is checked by the Lambda function, and if the AWS account is not created, the Lambda function invokes the AWS Control Tower Account Factory from the AWS Service Catalog to create a new AWS account with the details stored in the Amazon DynamoDB item.
- AWS Control Tower Account Factory starts the AWS account creation process. When the account creation process completes, the status of Account Factory will show as Available in Provisioned products, as shown in Figure 11.
  
  Figure 11: AWS Service Catalog provisioned products for AWS account creation
- Based on the Control Tower lifecycle events, the CreateAccountAssignment Lambda function will be invoked when the CreateManagedAccount event is sent to CloudWatch Events. An AWS SNS topic is also triggered to send an email notification to the administrator email address as shown in Figure 12 below.
  
  Figure 12: AWS email notification when account creation completes
- When invoked, the Lambda function CreateAccountAssignment assigns the AWS SSO user group to the new AWS account with the permission set defined in the AWS CloudFormation stack.
  
  Figure 13: New AWS account showing user groups with permission sets assigned

Figure 13 above shows the new AWS account with the user groups and the assigned permission sets. This completes the automation process. The AWS SSO users that are part of the user group will automatically be allowed to access the new AWS account with the defined permission set.

Handling common sources of error

This solution connects multiple components to facilitate the new AWS account creation and AWS SSO permission set assignment. The correctness of the parameters in the AWS CloudFormation stack is important to make sure that when AWS Control Tower creates a new AWS account, it is accessible.

To verify that this solution works, make sure that the email address is a valid email address, you have access to that email, and it is not being used for any existing AWS account. After a new account is created, it is not possible to change its root account email address, so if you input an invalid or inaccessible email, you will need to create a new AWS account and remove the invalid account.

You can view common errors by going to AWS Service Catalog web console. Under Provisioned products, you can see all of your AWS Control Tower Account Factory-launched AWS accounts.

Figure 14: AWS Service Catalog provisioned product with error

Selecting Error under the Status column shows you the source of the error. Figure 15 below is an example of the source of the error:

Figure 15: AWS account creation error explanation

Conclusion

In this post, we’ve shown you how to automate batch creation of AWS accounts in AWS Control Tower and batch assignment of user access to AWS accounts in AWS SSO. When the batch AWS accounts creation and AWS SSO user access assignment processes are complete, the administrator will be notified by emails from AWS SNS. We’ve also explained how to handle some common sources of errors and how to avoid them.

As you automate the batch AWS account creation and user access assignment, you can reduce the time you spend on the undifferentiated heavy lifting work, and onboard your users in your organization much more quickly, so they can start using and experimenting on AWS right away.

To learn more about the best practices of setting up an AWS multi-account environment, check out this documentation for more information.

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

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Use new account assignment APIs for AWS SSO to automate multi-account access

2021-02-08 Akhil Aendapally

Post Syndicated from Akhil Aendapally original https://aws.amazon.com/blogs/security/use-new-account-assignment-apis-for-aws-sso-to-automate-multi-account-access/

In this blog post, we’ll show how you can programmatically assign and audit access to multiple AWS accounts for your AWS Single Sign-On (SSO) users and groups, using the AWS Command Line Interface (AWS CLI) and AWS CloudFormation.

With AWS SSO, you can centrally manage access and user permissions to all of your accounts in AWS Organizations. You can assign user permissions based on common job functions, customize them to meet your specific security requirements, and assign the permissions to users or groups in the specific accounts where they need access. You can create, read, update, and delete permission sets in one place to have consistent role policies across your entire organization. You can then provide access by assigning permission sets to multiple users and groups in multiple accounts all in a single operation.

AWS SSO recently added new account assignment APIs and AWS CloudFormation support to automate access assignment across AWS Organizations accounts. This release addressed feedback from our customers with multi-account environments who wanted to adopt AWS SSO, but faced challenges related to managing AWS account permissions. To automate the previously manual process and save your administration time, you can now use the new AWS SSO account assignment APIs, or AWS CloudFormation templates, to programmatically manage AWS account permission sets in multi-account environments.

With AWS SSO account assignment APIs, you can now build your automation that will assign access for your users and groups to AWS accounts. You can also gain insights into who has access to which permission sets in which accounts across your entire AWS Organizations structure. With the account assignment APIs, your automation system can programmatically retrieve permission sets for audit and governance purposes, as shown in Figure 1.

Figure 1: Automating multi-account access with the AWS SSO API and AWS CloudFormation

Overview

In this walkthrough, we’ll illustrate how to create permission sets, assign permission sets to users and groups in AWS SSO, and grant access for users and groups to multiple AWS accounts by using the AWS Command Line Interface (AWS CLI) and AWS CloudFormation.

To grant user permissions to AWS resources with AWS SSO, you use permission sets. A permission set is a collection of AWS Identity and Access Management (IAM) policies. Permission sets can contain up to 10 AWS managed policies and a single custom policy stored in AWS SSO.

A policy is an object that defines a user’s permissions. Policies contain statements that represent individual access controls (allow or deny) for various tasks. This determines what tasks users can or cannot perform within the AWS account. AWS evaluates these policies when an IAM principal (a user or role) makes a request.

When you provision a permission set in the AWS account, AWS SSO creates a corresponding IAM role on that account, with a trust policy that allows users to assume the role through AWS SSO. With AWS SSO, you can assign more than one permission set to a user in the specific AWS account. Users who have multiple permission sets must choose one when they sign in through the user portal or the AWS CLI. Users will see these as IAM roles.

To learn more about IAM policies, see Policies and permissions in IAM. To learn more about permission sets, see Permission Sets.

Assume you have a company, Example.com, which has three AWS accounts: an organization management account (ExampleOrgMaster), a development account (ExampleOrgDev), and a test account (ExampleOrgTest). Example.com uses AWS Organizations to manage these accounts and has already enabled AWS SSO.

Example.com has the IT security lead, Frank Infosec, who needs PowerUserAccess to the test account (ExampleOrgTest) and SecurityAudit access to the development account (ExampleOrgDev). Alice Developer, the developer, needs full access to Amazon Elastic Compute Cloud (Amazon EC2) and Amazon Simple Storage Service (Amazon S3) through the development account (ExampleOrgDev). We’ll show you how to assign and audit the access for Alice and Frank centrally with AWS SSO, using the AWS CLI.

The flow includes the following steps:

Create three permission sets:
- PowerUserAccess, with the PowerUserAccess policy attached.
- AuditAccess, with the SecurityAudit policy attached.
- EC2-S3-FullAccess, with the AmazonEC2FullAccess and AmazonS3FullAccess policies attached.
Assign permission sets to the AWS account and AWS SSO users:
- Assign the PowerUserAccess and AuditAccess permission sets to Frank Infosec, to provide the required access to the ExampleOrgDev and ExampleOrgTest accounts.
- Assign the EC2-S3-FullAccess permission set to Alice Developer, to provide the required permissions to the ExampleOrgDev account.
Retrieve the assigned permissions by using Account Entitlement APIs for audit and governance purposes.

Note: AWS SSO Permission sets can contain either AWS managed policies or custom policies that are stored in AWS SSO. In this blog we attach AWS managed polices to the AWS SSO Permission sets for simplicity. To help secure your AWS resources, follow the standard security advice of granting least privilege access using AWS SSO custom policy while creating AWS SSO Permission set.

Figure 2: AWS Organizations accounts access for Alice and Frank

To help simplify administration of access permissions, we recommend that you assign access directly to groups rather than to individual users. With groups, you can grant or deny permissions to groups of users, rather than having to apply those permissions to each individual. For simplicity, in this blog you’ll assign permissions directly to the users.

Prerequisites

Before you start this walkthrough, complete these steps:

Identify the AWS accounts to which you want to grant AWS SSO access, and add them to your organization. To learn more, see Managing the AWS accounts in your organization.
Get the permissions that are required to use the AWS SSO console. To learn more, see Permissions Required to Use the AWS SSO Console.
Sign in to the AWS Organizations management account AWS Management Console with AWS SSO administrator credentials. To learn more about AWS Organizations and the management account, see AWS Organizations FAQs.
Enable AWS SSO for your AWS Organizations structure. To learn more, see Enable AWS SSO.
Have your users and groups provisioned in AWS SSO. You can manage your users and groups in AWS SSO internal identity store, connect AWS SSO to your Microsoft Active Directory or integrate with an external identity provider using SAML 2.0 and SCIM 2.0. To learn more about AWS SSO identity store options, see Manage Your Identity Source.

Use the AWS SSO API from the AWS CLI

In order to call the AWS SSO account assignment API by using the AWS CLI, you need to install and configure AWS CLI v2. For more information about AWS CLI installation and configuration, see Installing the AWS CLI and Configuring the AWS CLI.

Step 1: Create permission sets

In this step, you learn how to create EC2-S3FullAccess, AuditAccess, and PowerUserAccess permission sets in AWS SSO from the AWS CLI.

Before you create the permission sets, run the following command to get the Amazon Resource Name (ARN) of the AWS SSO instance and the Identity Store ID, which you will need later in the process when you create and assign permission sets to AWS accounts and users or groups.

aws sso-admin list-instances

Figure 3 shows the results of running the command.

Figure 3: AWS SSO list instances

Next, create the permission set for the security team (Frank) and dev team (Alice), as follows.

Permission set for Alice Developer (EC2-S3-FullAccess)

Run the following command to create the EC2-S3-FullAccess permission set for Alice, as shown in Figure 4.

aws sso-admin create-permission-set --instance-arn '<Instance ARN>' --name 'EC2-S3-FullAccess' --description 'EC2 and S3 access for developers'

Figure 4: Creating the permission set EC2-S3-FullAccess

Permission set for Frank Infosec (AuditAccess)

Run the following command to create the AuditAccess permission set for Frank, as shown in Figure 5.

aws sso-admin create-permission-set --instance-arn '<Instance ARN>' --name 'AuditAccess' --description 'Audit Access for security team on ExampleOrgDev account'

Figure 5: Creating the permission set AuditAccess

Permission set for Frank Infosec (PowerUserAccess)

Run the following command to create the PowerUserAccess permission set for Frank, as shown in Figure 6.

aws sso-admin create-permission-set --instance-arn '<Instance ARN>' --name 'PowerUserAccess' --description 'Power User Access for security team on ExampleOrgDev account'

Figure 6: Creating the permission set PowerUserAccess

Copy the permission set ARN from these responses, which you will need when you attach the managed policies.

Step 2: Assign policies to permission sets

In this step, you learn how to assign managed policies to the permission sets that you created in step 1.

Attach policies to the EC2-S3-FullAccess permission set

Run the following command to attach the amazonec2fullacess AWS managed policy to the EC2-S3-FullAccess permission set, as shown in Figure 7.

aws sso-admin attach-managed-policy-to-permission-set --instance-arn '<Instance ARN>' --permission-set-arn '<Permission Set ARN>' --managed-policy-arn 'arn:aws:iam::aws:policy/amazonec2fullaccess'

Figure 7: Attaching the AWS managed policy amazonec2fullaccess to the EC2-S3-FullAccess permission set

Run the following command to attach the amazons3fullaccess AWS managed policy to the EC2-S3-FullAccess permission set, as shown in Figure 8.

aws sso-admin attach-managed-policy-to-permission-set --instance-arn '<Instance ARN>' --permission-set-arn '<Permission Set ARN>' --managed-policy-arn 'arn:aws:iam::aws:policy/amazons3fullaccess'

Figure 8: Attaching the AWS managed policy amazons3fullaccess to the EC2-S3-FullAccess permission set

Attach a policy to the AuditAccess permission set

Run the following command to attach the SecurityAudit managed policy to the AuditAccess permission set that you created earlier, as shown in Figure 9.

aws sso-admin attach-managed-policy-to-permission-set --instance-arn '<Instance ARN>' --permission-set-arn '<Permission Set ARN>' --managed-policy-arn 'arn:aws:iam::aws:policy/SecurityAudit'

Figure 9: Attaching the AWS managed policy SecurityAudit to the AuditAccess permission set

Attach a policy to the PowerUserAccess permission set

The following command is similar to the previous command; it attaches the PowerUserAccess managed policy to the PowerUserAccess permission set, as shown in Figure 10.

aws sso-admin attach-managed-policy-to-permission-set --instance-arn '<Instance ARN>' --permission-set-arn '<Permission Set ARN>' --managed-policy-arn 'arn:aws:iam::aws:policy/PowerUserAccess'

Figure 10: Attaching AWS managed policy PowerUserAccess to the PowerUserAccess permission set

In the next step, you assign users (Frank Infosec and Alice Developer) to their respective permission sets and assign permission sets to accounts.

Step 3: Assign permission sets to users and groups and grant access to AWS accounts

In this step, you assign the AWS SSO permission sets you created to users and groups and AWS accounts, to grant the required access for these users and groups on respective AWS accounts.

To assign access to an AWS account for a user or group, using a permission set you already created, you need the following:

The principal ID (the ID for the user or group)
The AWS account ID to which you need to assign this permission set

To obtain a user’s or group’s principal ID (UserID or GroupID), you need to use the AWS SSO Identity Store API. The AWS SSO Identity Store service enables you to retrieve all of your identities (users and groups) from AWS SSO. See AWS SSO Identity Store API for more details.

Use the first two commands shown here to get the principal ID for the two users, Alice (Alice’s user name is [email protected]) and Frank (Frank’s user name is [email protected]).

Alice’s user ID

Run the following command to get Alice’s user ID, as shown in Figure 11.

aws identitystore list-users --identity-store-id '<Identity Store ID>' --filter AttributePath='UserName',AttributeValue='[email protected]'

Figure 11: Retrieving Alice’s user ID

Frank’s user ID

Run the following command to get Frank’s user ID, as shown in Figure 12.

aws identitystore list-users --identity-store-id '<Identity Store ID>'--filter AttributePath='UserName',AttributeValue='[email protected]'

Figure 12: Retrieving Frank’s user ID

Note: To get the principal ID for a group, use the following command.
aws identitystore list-groups --identity-store-id '<Identity Store ID>' --filter AttributePath='DisplayName',AttributeValue='<Group Name>'

Assign the EC2-S3-FullAccess permission set to Alice in the ExampleOrgDev account

Run the following command to assign Alice access to the ExampleOrgDev account using the EC2-S3-FullAccess permission set. This will give Alice full access to Amazon EC2 and S3 services in the ExampleOrgDev account.

Note: When you call the CreateAccountAssignment API, AWS SSO automatically provisions the specified permission set on the account in the form of an IAM policy attached to the AWS SSO–created IAM role. This role is immutable: it’s fully managed by the AWS SSO, and it cannot be deleted or changed by the user even if the user has full administrative rights on the account. If the permission set is subsequently updated, the corresponding IAM policies attached to roles in your accounts won’t be updated automatically. In this case, you will need to call ProvisionPermissionSet to propagate these updates.

aws sso-admin create-account-assignment --instance-arn '<Instance ARN>' --permission-set-arn '<Permission Set ARN>' --principal-id '<user/group ID>' --principal-type '<USER/GROUP>' --target-id '<AWS Account ID>' --target-type AWS_ACCOUNT

Figure 13: Assigning the EC2-S3-FullAccess permission set to Alice on the ExampleOrgDev account

Assign the AuditAccess permission set to Frank Infosec in the ExampleOrgDev account

Run the following command to assign Frank access to the ExampleOrgDev account using the EC2-S3- AuditAccess permission set.

aws sso-admin create-account-assignment --instance-arn '<Instance ARN>' --permission-set-arn '<Permission Set ARN>' --principal-id '<user/group ID>' --principal-type '<USER/GROUP>' --target-id '<AWS Account ID>' --target-type AWS_ACCOUNT

Figure 14: Assigning the AuditAccess permission set to Frank on the ExampleOrgDev account

Assign the PowerUserAccess permission set to Frank Infosec in the ExampleOrgTest account

Run the following command to assign Frank access to the ExampleOrgTest account using the PowerUserAccess permission set.

aws sso-admin create-account-assignment --instance-arn '<Instance ARN>' --permission-set-arn '<Permission Set ARN>' --principal-id '<user/group ID>' --principal-type '<USER/GROUP>' --target-id '<AWS Account ID>' --target-type AWS_ACCOUNT

Figure 15: Assigning the PowerUserAccess permission set to Frank on the ExampleOrgTest account

To view the permission sets provisioned on the AWS account, run the following command, as shown in Figure 16.

aws sso-admin list-permission-sets-provisioned-to-account --instance-arn '<Instance ARN>' --account-id '<AWS Account ID>'

Figure 16: View the permission sets (AuditAccess and EC2-S3-FullAccess) assigned to the ExampleOrgDev account

To review the created resources in the AWS Management Console, navigate to the AWS SSO console. In the list of permission sets on the AWS accounts tab, choose the EC2-S3-FullAccess permission set. Under AWS managed policies, the policies attached to the permission set are listed, as shown in Figure 17.

Figure 17: Review the permission set in the AWS SSO console

To see the AWS accounts, where the EC2-S3-FullAccess permission set is currently provisioned, navigate to the AWS accounts tab, as shown in Figure 18.

Figure 18: Review permission set account assignment in the AWS SSO console

Step 4: Audit access

In this step, you learn how to audit access assigned to your users and group by using the AWS SSO account assignment API. In this example, you’ll start from a permission set, review the permissions (AWS-managed policies or a custom policy) attached to the permission set, get the users and groups associated with the permission set, and see which AWS accounts the permission set is provisioned to.

List the IAM managed policies for the permission set

Run the following command to list the IAM managed policies that are attached to a specified permission set, as shown in Figure 19.

aws sso-admin list-managed-policies-in-permission-set --instance-arn '<Instance ARN>' --permission-set-arn '<Permission Set ARN>'

Figure 19: View the managed policies attached to the permission set

List the assignee of the AWS account with the permission set

Run the following command to list the assignee (the user or group with the respective principal ID) of the specified AWS account with the specified permission set, as shown in Figure 20.

aws sso-admin list-account-assignments --instance-arn '<Instance ARN>' --account-id '<Account ID>' --permission-set-arn '<Permission Set ARN>'

Figure 20: View the permission set and the user or group attached to the AWS account

List the accounts to which the permission set is provisioned

Run the following command to list the accounts that are associated with a specific permission set, as shown in Figure 21.

aws sso-admin list-accounts-for-provisioned-permission-set --instance-arn '<Instance ARN>' --permission-set-arn '<Permission Set ARN>'

Figure 21: View AWS accounts to which the permission set is provisioned

In this section of the post, we’ve illustrated how to create a permission set, assign a managed policy to the permission set, and grant access for AWS SSO users or groups to AWS accounts by using this permission set. In the next section, we’ll show you how to do the same using AWS CloudFormation.

Use the AWS SSO API through AWS CloudFormation

In this section, you learn how to use CloudFormation templates to automate the creation of permission sets, attach managed policies, and use permission sets to assign access for a particular user or group to AWS accounts.

Sign in to your AWS Management Console and create a CloudFormation stack by using the following CloudFormation template. For more information on how to create a CloudFormation stack, see Creating a stack on the AWS CloudFormation console.

//start of Template//
{
    "AWSTemplateFormatVersion": "2010-09-09",
  
    "Description": "AWS CloudFormation template to automate multi-account access with AWS Single Sign-On (Entitlement APIs): Create permission sets, assign access for AWS SSO users and groups to AWS accounts using permission sets. Before you use this template, we assume you have enabled AWS SSO for your AWS Organization, added the AWS accounts to which you want to grant AWS SSO access to your organization, signed in to the AWS Management Console with your AWS Organizations management account credentials, and have the required permissions to use the AWS SSO console.",
  
    "Parameters": {
      "InstanceARN" : {
        "Type" : "String",
        "AllowedPattern": "arn:aws:sso:::instance/(sso)?ins-[a-zA-Z0-9-.]{16}",
        "Description" : "Enter AWS SSO InstanceARN. Ex: arn:aws:sso:::instance/ssoins-xxxxxxxxxxxxxxxx",
        "ConstraintDescription": "must be the name of an existing AWS SSO InstanceARN associated with the management account."
      },
      "ExampleOrgDevAccountId" : {
        "Type" : "String",
        "AllowedPattern": "\\d{12}",
        "Description" : "Enter 12-digit Developer AWS Account ID. Ex: 123456789012"
        },
      "ExampleOrgTestAccountId" : {
        "Type" : "String",
        "AllowedPattern": "\\d{12}",
        "Description" : "Enter 12-digit AWS Account ID. Ex: 123456789012"
        },
      "AliceDeveloperUserId" : {
        "Type" : "String",
        "AllowedPattern": "^([0-9a-f]{10}-|)[A-Fa-f0-9]{8}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{12}$",
        "Description" : "Enter Developer UserId. Ex: 926703446b-f10fac16-ab5b-45c3-86c1-xxxxxxxxxxxx"
        },
        "FrankInfosecUserId" : {
            "Type" : "String",
            "AllowedPattern": "^([0-9a-f]{10}-|)[A-Fa-f0-9]{8}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{12}$",
            "Description" : "Enter Test UserId. Ex: 926703446b-f10fac16-ab5b-45c3-86c1-xxxxxxxxxxxx"
            }
    },
    "Resources": {
        "EC2S3Access": {
            "Type" : "AWS::SSO::PermissionSet",
            "Properties" : {
                "Description" : "EC2 and S3 access for developers",
                "InstanceArn" : {
                    "Ref": "InstanceARN"
                },
                "ManagedPolicies" : ["arn:aws:iam::aws:policy/amazonec2fullaccess","arn:aws:iam::aws:policy/amazons3fullaccess"],
                "Name" : "EC2-S3-FullAccess",
                "Tags" : [ {
                    "Key": "Name",
                    "Value": "EC2S3Access"
                 } ]
              }
        },  
        "SecurityAuditAccess": {
            "Type" : "AWS::SSO::PermissionSet",
            "Properties" : {
                "Description" : "Audit Access for Infosec team",
                "InstanceArn" : {
                    "Ref": "InstanceARN"
                },
                "ManagedPolicies" : [ "arn:aws:iam::aws:policy/SecurityAudit" ],
                "Name" : "AuditAccess",
                "Tags" : [ {
                    "Key": "Name",
                    "Value": "SecurityAuditAccess"
                 } ]
              }
        },    
        "PowerUserAccess": {
            "Type" : "AWS::SSO::PermissionSet",
            "Properties" : {
                "Description" : "Power User Access for Infosec team",
                "InstanceArn" : {
                    "Ref": "InstanceARN"
                },
                "ManagedPolicies" : [ "arn:aws:iam::aws:policy/PowerUserAccess"],
                "Name" : "PowerUserAccess",
                "Tags" : [ {
                    "Key": "Name",
                    "Value": "PowerUserAccess"
                 } ]
              }      
        },
        "EC2S3userAssignment": {
            "Type" : "AWS::SSO::Assignment",
            "Properties" : {
                "InstanceArn" : {
                    "Ref": "InstanceARN"
                },
                "PermissionSetArn" : {
                    "Fn::GetAtt": [
                        "EC2S3Access",
                        "PermissionSetArn"
                     ]
                },
                "PrincipalId" : {
                    "Ref": "AliceDeveloperUserId"
                },
                "PrincipalType" : "USER",
                "TargetId" : {
                    "Ref": "ExampleOrgDevAccountId"
                },
                "TargetType" : "AWS_ACCOUNT"
              }
          },
          "SecurityAudituserAssignment": {
            "Type" : "AWS::SSO::Assignment",
            "Properties" : {
                "InstanceArn" : {
                    "Ref": "InstanceARN"
                },
                "PermissionSetArn" : {
                    "Fn::GetAtt": [
                        "SecurityAuditAccess",
                        "PermissionSetArn"
                     ]
                },
                "PrincipalId" : {
                    "Ref": "FrankInfosecUserId"
                },
                "PrincipalType" : "USER",
                "TargetId" : {
                    "Ref": "ExampleOrgDevAccountId"
                },
                "TargetType" : "AWS_ACCOUNT"
              }
          },
          "PowerUserAssignment": {
            "Type" : "AWS::SSO::Assignment",
            "Properties" : {
                "InstanceArn" : {
                    "Ref": "InstanceARN"
                },
                "PermissionSetArn" : {
                    "Fn::GetAtt": [
                        "PowerUserAccess",
                        "PermissionSetArn"
                     ]
                },
                "PrincipalId" : {
                    "Ref": "FrankInfosecUserId"
                },
                "PrincipalType" : "USER",
                "TargetId" : {
                    "Ref": "ExampleOrgTestAccountId"
                },
                "TargetType" : "AWS_ACCOUNT"
              }
          }
    }
}
//End of Template//

When you create the stack, provide the following information for setting the example permission sets for Frank Infosec and Alice Developer, as shown in Figure 22:

The Alice Developer and Frank Infosec user IDs
The ExampleOrgDev and ExampleOrgTest account IDs
The AWS SSO instance ARN

Then launch the CloudFormation stack.

Figure 22: User inputs to launch the CloudFormation template

AWS CloudFormation creates the resources that are shown in Figure 23.

Figure 23: Resources created from the CloudFormation stack

Cleanup

To delete the resources you created by using the AWS CLI, use these commands.

Run the following command to delete the account assignment.

delete-account-assignment --instance-arn '<Instance ARN>' --target-id '<AWS Account ID>' --target-type 'AWS_ACCOUNT' --permission-set-arn '<PermissionSet ARN>' --principal-type '<USER/GROUP>' --principal-id '<user/group ID>'

After the account assignment is deleted, run the following command to delete the permission set.

delete-permission-set --instance-arn '<Instance ARN>' --permission-set-arn '<PermissionSet ARN>'

To delete the resource that you created by using the CloudFormation template, go to the AWS CloudFormation console. Select the appropriate stack you created, and then choose delete. Deleting the CloudFormation stack cleans up the resources that were created.

Summary

In this blog post, we showed how to use the AWS SSO account assignment API to automate the deployment of permission sets, how to add managed policies to permission sets, and how to assign access for AWS users and groups to AWS accounts by using specified permission sets.

To learn more about the AWS SSO APIs available for you, see the AWS Single Sign-On API Reference Guide.

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 SSO forum or contact AWS Support.

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Background

Services used

High level solution overview

Before starting

Collect needed information

Prerequisite information: AWS SSO instance ARN

From the web console

From the CLI

Prerequisite information: AWS SSO Identity Store ID

From the web console

From the CLI

Prerequisite information: Admin email address

Prerequisite information: S3 bucket

Prerequisite information: AWS SSO user group ARN

Prerequisite information: AWS SSO permission set

From the web console

From the CLI

Solution initiation

To initiate the solution

To create the AWS Account list CSV file

CSV file format

CSV fields

Upload the CSV file

Deploying the solution

To launch the AWS CloudFormation stack

Workflow and solution details

Handling common sources of error

Conclusion

Overview

Prerequisites

Use the AWS SSO API from the AWS CLI

Step 1: Create permission sets

Permission set for Alice Developer (EC2-S3-FullAccess)

Permission set for Frank Infosec (AuditAccess)

Permission set for Frank Infosec (PowerUserAccess)

Step 2: Assign policies to permission sets

Attach policies to the EC2-S3-FullAccess permission set

Attach a policy to the AuditAccess permission set

Attach a policy to the PowerUserAccess permission set

Step 3: Assign permission sets to users and groups and grant access to AWS accounts

Alice’s user ID

Frank’s user ID

Assign the EC2-S3-FullAccess permission set to Alice in the ExampleOrgDev account

Assign the AuditAccess permission set to Frank Infosec in the ExampleOrgDev account

Assign the PowerUserAccess permission set to Frank Infosec in the ExampleOrgTest account

Step 4: Audit access

List the IAM managed policies for the permission set

List the assignee of the AWS account with the permission set

List the accounts to which the permission set is provisioned

Use the AWS SSO API through AWS CloudFormation

Cleanup

Summary

The collective thoughts of the interwebz