AWS Secrets Manager now enables you to create and manage your resource-based policies using the Secrets Manager console. With this launch, we are also improving your security posture by both identifying and preventing creation of resource policies that grant overly broad access to your secrets across your Amazon Web Services (AWS) accounts. To achieve this, we use the Zelkova engine to mathematically analyze access granted by your resource policy and alert you if such permissions are found. The analysis verifies access across all resource-policy statements, actions, and the set of condition keys used in your policies. To be considered non-public, the resource policy must grant access only to fixed values (values that don’t contain a wildcard) of one or more of the following: aws:SourceArn, aws:SourceVpc, aws:SourceVpce, aws:SourceAccount, aws:SourceIP, and ensure the Principal does not include a “*” entry.
If the policy grants Public or overly broad access to your secrets across AWS accounts, Secrets Manager will block you from applying the policy in the console and alert you with a dashboard message. This prevents your policy from accidentally granting broader access to your secrets, instead ensuring you are restricting it to the intended AWS accounts, AWS services, and AWS Identity and Access Management (IAM) entities. Access to AWS Secrets Manager requires AWS credentials. Those credentials must contain permission to access the AWS resources you want to access, such as your Secrets Manager secrets. In this blog post, we use Public or broad access to refer to values (or a combination of values) in the resource policy that result in a wide access across AWS accounts and principals.
With AWS Secrets Manager, you have the option to store, rotate, manage, and retrieve many types of secrets. These can be database usernames and passwords, API keys, string values, and binary data. AWS supports the ability to share these secrets cross-account by applying resource policies via the AWS Command Line Interface (AWS CLI) and now via the Secrets Manager console.
Why would you need to share a secret? There are many reasons. Perhaps you have database credentials managed in a central account that are needed by applications in your production account. Maybe you have the binary stored for an encryption key that other accounts will use to create AWS Key Management Service (AWS KMS) keys in their accounts. To achieve this goal while ensuring a secure transfer of information and least privilege permissions, you will need a resource-based policy on your secret, a resource-based policy on your AWS KMS Customer Managed Key (CMK) used for encrypting the secret, and a user-based policy on your IAM principal.
You can still create a policy using AWS CLI or AWS SDK permitting access to a broader scope of entities if your business needs dictate. If you do permit this type of broader access, AWS Secrets Manager will show a notification in your dashboard, as shown in Figure 2, below.
Figure 1. This shows the warning when you try to create a resource policy that grants broad access to your secrets via the AWS Secrets Manager console.
Figure 2. This alert pops up when you click on a secret that has a resource policy attached via the CLI that grants broad access to the secret.
In the example below, you’ll see how to use the AWS Secrets Manager console to attach a resource-based policy and allow access to your secret from a secondary account. A secret in the CENTRAL_SECURITY_ACCOUNT will be set to allow it to be accessed by an IAM role in the PRODUCTION_ACCOUNT.
In this example:
SECURITY_SECRET = The secret created in the CENTRAL_SECURITY_ACCOUNT.
SECURITY_CMK = The AWS KMS CMK used to encrypt the SECURITY_SECRET.
PRODUCTION_ROLE = The AWS IAM role used to access the SECURITY_SECRET.
PRODUCTION_ACCOUNT = The AWS account that owns the AWS IAM role used for cross-account access.
Overview of solution
The architecture of the solution can be broken down into four steps, which are outlined in Figure 3. The four main steps are:
Create the resource-based policy via the AWS Secrets Manager console on the SECURITY_SECRET in the CENTRAL_SECURITY_ACCOUNT.
Update the SECURITY_CMK policy in the CENTRAL_SECURITY_ACCOUNT to allow the role from the PRODUCTION account access.
Grant the AWS IAM role in the PRODUCTION_ACCOUNT permissions to access the secret.
Test and verify access from the PRODUCTION_ACCOUNT.
Figure 3. A visual overview of the four steps to use the AWS Secrets Manager console to attach a resource-based policy, allow access to your secret from a secondary account, and test and verify the process.
Prerequisites
To use the example in this post, you need:
An AWS account.
An IAM Role with permissions to make modifications in both the CENTRAL_SECURITY_ACCOUNT and the PRODUCTION_ACCOUNT.
An IAM role in the PRODUCTION_ACCOUNT you wish to grant permissions to access the SECURITY_SECRET.
Deploying the solution
Step 1: Create a resource-based policy in your CENTRAL_SECURITY account on the SECURITY_SECRET secret
Choose Edit Permissions next to Resource Permissions (optional).
Figure 4. The dashboard view where you edit permissions.
This will bring you to the page to add the resource policy. It will give you a basic template as shown in Figure 5, below.
Figure 5. The basic template to add the resource policy.
Since the full policy is provided for you in this example, delete the template from the text box.
Copy the policy below and paste it in the text box. Make sure to replace PRODUCTION with your AWS account ID. You can also adjust the permissions you grant if needed. This policy allows a specific role in the PRODUCTION_ACCOUNT account to retrieve the current version of your secret. In the example, my IAM Role is called PRODUCTION_ROLE. Note you do not need to replace AWSCURRENT with any other value.
As shown in Figure 6, below, you’ll see this in the resource policy text area (with your AWS account ID in place of PRODUCTION).
Figure 6. The example resource policy shown in the console.
Choose Save.
Step 2: Update the resource-based policy in your CENTRAL_SECURITY account on the SECURITY_CMK
Note: Secrets in AWS Secrets Manager are encrypted by default. However, it is important for you to provide authorization for IAM Principals that need to access your secrets. Complete authorization requires access to the secret and the KMS CMK used to encrypt it, which prevents accidental public permissions on the secret. It is important to maintain both sets of authorization to provide appropriate access to secrets.
Log in to the AWS KMS console in the CENTRAL_SECURITY_ACCOUNT.
Choose SECURITY_CMK.
Next to Key policy choose the Edit button.
Paste the below code snippet into your key policy to allow the PRODUCTION_ACCOUNT access:
You will need to replace PRODUCTION with your production account ID, PRODUCTION_ROLE with your production Role name, CENTRAL_SECURITY with your security account ID, and SECURITY_CMK with the CMK key ID of your security CMK. If you forget to swap out the account IDs in the policy with your own, you’ll see an error message similar to the one shown in Figure 7, below.
Figure 7. Error message that appears if you don’t swap out your account number correctly.
Choose Save changes.
Step 3: Add permissions to the PRODUCTION_ROLE in the PRODUCTION account
Log in to the AWS IAM console in the PRODUCTION_ACCOUNT account.
In the left navigation pane, choose Roles.
Select PRODUCTION_ROLE.
Under the Permissions tab, choose Add inline policy.
You will need to replace CENTRAL_SECURITY with your security account id, SECURITY_SECRET with the secret id, and SECURITY_CMK with the CMK key id of your security CMK.
Choose Review policy.
Name the policy Central_Security_Account_Security-Secret-Access, and choose Create policy.
Step 4: Test access to the SECURITY_SECRET from the PRODUCTION account
Verification of access via AWS CLI
From the AWS CLI, use the PRODUCTION_ROLE credentials to run the get-secret-value command.
Returned output should look like the example, below, in Figure 8.
Scroll down to where it shows Resource Permissions (optional), and you’ll see your resource policy stored in the console, as shown in Figure 8, below.
Figure 8. What the example resource policy looks like in the console.
Conclusion
In this post, you saw how to add a resource-based policy on a secret in AWS Secrets Manager using the console, and how to update your AWS KMS CMK resource-based policy to enable access. The example showed setting up cross-account access, and allowing a role from the PRODUCTION_ACCOUNT to use the secret in the CENTRAL_SECURITY_ACCOUNT. By using the AWS Secrets Manager console to set up the resource-based policy, you now have a straight-forward, visual way to add and manage resource-based policies for your secrets and receive notifications if that policy is too broad.
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 Secrets Manager forum or contact AWS Support.
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There has been a lot of work in recent years to use BPF to push policy decisions into the kernel. But sometimes, it seems, what is really wanted is a way for a BPF program to punt a decision back to user space. That is the objective behind this patch set giving the secure computing (seccomp) mechanism a way to pass complex decisions to a user-space helper program.
Last year, we released Amazon Connect, a cloud-based contact center service that enables any business to deliver better customer service at low cost. This service is built based on the same technology that empowers Amazon customer service associates. Using this system, associates have millions of conversations with customers when they inquire about their shipping or order information. Because we made it available as an AWS service, you can now enable your contact center agents to make or receive calls in a matter of minutes. You can do this without having to provision any kind of hardware. 2
There are several advantages of building your contact center in the AWS Cloud, as described in our documentation. In addition, customers can extend Amazon Connect capabilities by using AWS products and the breadth of AWS services. In this blog post, we focus on how to get analytics out of the rich set of data published by Amazon Connect. We make use of an Amazon Connect data stream and create an end-to-end workflow to offer an analytical solution that can be customized based on need.
Solution overview
The following diagram illustrates the solution.
In this solution, Amazon Connect exports its contact trace records (CTRs) using Amazon Kinesis. CTRs are data streams in JSON format, and each has information about individual contacts. For example, this information might include the start and end time of a call, which agent handled the call, which queue the user chose, queue wait times, number of holds, and so on. You can enable this feature by reviewing our documentation.
In this architecture, we use Kinesis Firehose to capture Amazon Connect CTRs as raw data in an Amazon S3 bucket. We don’t use the recent feature added by Kinesis Firehose to save the data in S3 as Apache Parquet format. We use AWS Glue functionality to automatically detect the schema on the fly from an Amazon Connect data stream.
The primary reason for this approach is that it allows us to use attributes and enables an Amazon Connect administrator to dynamically add more fields as needed. Also by converting data to parquet in batch (every couple of hours) compression can be higher. However, if your requirement is to ingest the data in Parquet format on realtime, we recoment using Kinesis Firehose recently launched feature. You can review this blog post for further information.
By default, Firehose puts these records in time-series format. To make it easy for AWS Glue crawlers to capture information from new records, we use AWS Lambda to move all new records to a single S3 prefix called flatfiles. Our Lambda function is configured using S3 event notification. To comply with AWS Glue and Athena best practices, the Lambda function also converts all column names to lowercase. Finally, we also use the Lambda function to start AWS Glue crawlers. AWS Glue crawlers identify the data schema and update the AWS Glue Data Catalog, which is used by extract, transform, load (ETL) jobs in AWS Glue in the latter half of the workflow.
You can see our approach in the Lambda code following.
from __future__ import print_function
import json
import urllib
import boto3
import os
import re
s3 = boto3.resource('s3')
client = boto3.client('s3')
def convertColumntoLowwerCaps(obj):
for key in obj.keys():
new_key = re.sub(r'[\W]+', '', key.lower())
v = obj[key]
if isinstance(v, dict):
if len(v) > 0:
convertColumntoLowwerCaps(v)
if new_key != key:
obj[new_key] = obj[key]
del obj[key]
return obj
def lambda_handler(event, context):
bucket = event['Records'][0]['s3']['bucket']['name']
key = urllib.unquote_plus(event['Records'][0]['s3']['object']['key'].encode('utf8'))
try:
client.download_file(bucket, key, '/tmp/file.json')
with open('/tmp/out.json', 'w') as output, open('/tmp/file.json', 'rb') as file:
i = 0
for line in file:
for object in line.replace("}{","}\n{").split("\n"):
record = json.loads(object,object_hook=convertColumntoLowwerCaps)
if i != 0:
output.write("\n")
output.write(json.dumps(record))
i += 1
newkey = 'flatfiles/' + key.replace("/", "")
client.upload_file('/tmp/out.json', bucket,newkey)
s3.Object(bucket,key).delete()
return "success"
except Exception as e:
print(e)
print('Error coping object {} from bucket {}'.format(key, bucket))
raise e
We trigger AWS Glue crawlers based on events because this approach lets us capture any new data frame that we want to be dynamic in nature. CTR attributes are designed to offer multiple custom options based on a particular call flow. Attributes are essentially key-value pairs in nested JSON format. With the help of event-based AWS Glue crawlers, you can easily identify newer attributes automatically.
We recommend setting up an S3 lifecycle policy on the flatfiles folder that keeps records only for 24 hours. Doing this optimizes AWS Glue ETL jobs to process a subset of files rather than the entire set of records.
After we have data in the flatfiles folder, we use AWS Glue to catalog the data and transform it into Parquet format inside a folder called parquet/ctr/. The AWS Glue job performs the ETL that transforms the data from JSON to Parquet format. We use AWS Glue crawlers to capture any new data frame inside the JSON code that we want to be dynamic in nature. What this means is that when you add new attributes to an Amazon Connect instance, the solution automatically recognizes them and incorporates them in the schema of the results.
After AWS Glue stores the results in Parquet format, you can perform analytics using Amazon Redshift Spectrum, Amazon Athena, or any third-party data warehouse platform. To keep this solution simple, we have used Amazon Athena for analytics. Amazon Athena allows us to query data without having to set up and manage any servers or data warehouse platforms. Additionally, we only pay for the queries that are executed.
Try it out!
You can get started with our sample AWS CloudFormation template. This template creates the components starting from the Kinesis stream and finishes up with S3 buckets, the AWS Glue job, and crawlers. To deploy the template, open the AWS Management Console by clicking the following link.
In the console, specify the following parameters:
BucketName: The name for the bucket to store all the solution files. This name must be unique; if it’s not, template creation fails.
etlJobSchedule: The schedule in cron format indicating how often the AWS Glue job runs. The default value is every hour.
KinesisStreamName: The name of the Kinesis stream to receive data from Amazon Connect. This name must be different from any other Kinesis stream created in your AWS account.
s3interval: The interval in seconds for Kinesis Firehose to save data inside the flatfiles folder on S3. The value must between 60 and 900 seconds.
sampledata: When this parameter is set to true, sample CTR records are used. Doing this lets you try this solution without setting up an Amazon Connect instance. All examples in this walkthrough use this sample data.
Select the “I acknowledge that AWS CloudFormation might create IAM resources.” check box, and then choose Create. After the template finishes creating resources, you can see the stream name on the stack Outputs tab.
If you haven’t created your Amazon Connect instance, you can do so by following the Getting Started Guide. When you are done creating, choose your Amazon Connect instance in the console, which takes you to instance settings. Choose Data streaming to enable streaming for CTR records. Here, you can choose the Kinesis stream (defined in the KinesisStreamName parameter) that was created by the CloudFormation template.
Now it’s time to generate the data by making or receiving calls by using Amazon Connect. You can go to Amazon Connect Cloud Control Panel (CCP) to make or receive calls using a software phone or desktop phone. After a few minutes, we should see data inside the flatfiles folder. To make it easier to try this solution, we provide sample data that you can enable by setting the sampledata parameter to true in your CloudFormation template.
You can navigate to the AWS Glue console by choosing Jobs on the left navigation pane of the console. We can select our job here. In my case, the job created by CloudFormation is called glueJob-i3TULzVtP1W0; yours should be similar. You run the job by choosing Run job for Action.
After that, we wait for the AWS Glue job to run and to finish successfully. We can track the status of the job by checking the History tab.
When the job finishes running, we can check the Database section. There should be a new table created called ctr in Parquet format.
To query the data with Athena, we can select the ctr table, and for Action choose View data.
Doing this takes us to the Athena console. If you run a query, Athena shows a preview of the data.
When we can query the data using Athena, we can visualize it using Amazon QuickSight. Before connecting Amazon QuickSight to Athena, we must make sure to grant Amazon QuickSight access to Athena and the associated S3 buckets in the account. For more information on doing this, see Managing Amazon QuickSight Permissions to AWS Resources in the Amazon QuickSight User Guide. We can then create a new data set in Amazon QuickSight based on the Athena table that was created.
After setting up permissions, we can create a new analysis in Amazon QuickSight by choosing New analysis.
Then we add a new data set.
We choose Athena as the source and give the data source a name (in this case, I named it connectctr).
Choose the name of the database and the table referencing the Parquet results.
Then choose Visualize.
After that, we should see the following screen.
Now we can create some visualizations. First, search for the agent.username column, and drag it to the AutoGraph section.
We can see the agents and the number of calls for each, so we can easily see which agents have taken the largest amount of calls. If we want to see from what queues the calls came for each agent, we can add the queue.arn column to the visual.
After following all these steps, you can use Amazon QuickSight to add different columns from the call records and perform different types of visualizations. You can build dashboards that continuously monitor your connect instance. You can share those dashboards with others in your organization who might need to see this data.
Conclusion
In this post, you see how you can use services like AWS Lambda, AWS Glue, and Amazon Athena to process Amazon Connect call records. The post also demonstrates how to use AWS Lambda to preprocess files in Amazon S3 and transform them into a format that recognized by AWS Glue crawlers. Finally, the post shows how to used Amazon QuickSight to perform visualizations.
You can use the provided template to analyze your own contact center instance. Or you can take the CloudFormation template and modify it to process other data streams that can be ingested using Amazon Kinesis or stored on Amazon S3.
Luis Caro is a Big Data Consultant for AWS Professional Services. He works with our customers to provide guidance and technical assistance on big data projects, helping them improving the value of their solutions when using AWS.
Peter Dalbhanjan is a Solutions Architect for AWS based in Herndon, VA. Peter has a keen interest in evangelizing AWS solutions and has written multiple blog posts that focus on simplifying complex use cases. At AWS, Peter helps with designing and architecting variety of customer workloads.
Previously, I showed you how to rotate Amazon RDS database credentials automatically with AWS Secrets Manager. In addition to database credentials, AWS Secrets Manager makes it easier to rotate, manage, and retrieve API keys, OAuth tokens, and other secrets throughout their lifecycle. You can configure Secrets Manager to rotate these secrets automatically, which can help you meet your compliance needs. You can also use Secrets Manager to rotate secrets on demand, which can help you respond quickly to security events. In this post, I show you how to store an API key in Secrets Manager and use a custom Lambda function to rotate the key automatically. I’ll use a Twitter API key and bearer token as an example; you can reference this example to rotate other types of API keys.
The instructions are divided into four main phases:
Store a Twitter API key and bearer token in Secrets Manager.
Create a custom Lambda function to rotate the bearer token.
Configure your application to retrieve the bearer token from Secrets Manager.
Configure Secrets Manager to use the custom Lambda function to rotate the bearer token automatically.
For the purpose of this post, I use the placeholder Demo/Twitter_Api_Key to denote the API key, the placeholder Demo/Twitter_bearer_token to denote the bearer token, and placeholder Lambda_Rotate_Bearer_Token to denote the custom Lambda function. Be sure to replace these placeholders with the resource names from your account.
Phase 1: Store a Twitter API key and bearer token in Secrets Manager
Twitter enables developers to register their applications and retrieve an API key, which includes a consumer_key and consumer_secret. Developers use these to generate a bearer token that applications can then use to authenticate and retrieve information from Twitter. At any given point of time, you can use an API key to create only one valid bearer token.
Start by storing the API key in Secrets Manager. Here’s how:
Figure 1: The “Store a new secret” button in the AWS Secrets Manager console
Select Other type of secrets (because you’re storing an API key).
Input the consumer_key and consumer_secret, and then select Next.
Figure 2: Select the consumer_key and the consumer_secret
Specify values for Secret Name and Description, then select Next. For this example, I use Demo/Twitter_API_Key.
Figure 3: Set values for “Secret Name” and “Description”
On the next screen, keep the default setting, Disable automatic rotation, because you’ll use the same API key to rotate bearer tokens programmatically and automatically. Applications and employees will not retrieve this API key. Select Next.
Figure 4: Keep the default “Disable automatic rotation” setting
Review the information on the next screen and, if everything looks correct, select Store. You’ve now successfully stored a Twitter API key in Secrets Manager.
Next, store the bearer token in Secrets Manager. Here’s how:
From the Secrets Manager console, select Store a new secret, select Other type of secrets, input details (access_token, token_type, and ARN of the API key) about the bearer token, and then select Next.
Figure 5: Add details about the bearer token
Specify values for Secret Name and Description, and then select Next. For this example, I use Demo/Twitter_bearer_token.
Figure 6: Again set values for “Secret Name” and “Description”
Keep the default rotation setting, Disable automatic rotation, and then select Next. You’ll enable rotation after you’ve updated the application to use Secrets Manager APIs to retrieve secrets.
Review the information and select Store. You’ve now completed storing the bearer token in Secrets Manager. I take note of the sample code provided on the review page. I’ll use this code to update my application to retrieve the bearer token using Secrets Manager APIs.
Figure 7: The sample code you can use in your app
Phase 2: Create a custom Lambda function to rotate the bearer token
While Secrets Manager supports rotating credentials for databases hosted on Amazon RDS natively, it also enables you to meet your unique rotation-related use cases by authoring custom Lambda functions. Now that you’ve stored the API key and bearer token, you’ll create a Lambda function to rotate the bearer token. For this example, I’ll create my Lambda function using Python 3.6.
Figure 8: In the Lambda console, select “Create function”
Select Author from scratch. For this example, I use the name Lambda_Rotate_Bearer_Token for my Lambda function. I also set the Runtime environment as Python 3.6.
Figure 9: Create a new function from scratch
This Lambda function requires permissions to call AWS resources on your behalf. To grant these permissions, select Create a custom role. This opens a console tab.
Select Create a new IAM Role and specify the value for Role Name. For this example, I use Role_Lambda_Rotate_Twitter_Bearer_Token.
Figure 10: For “IAM Role,” select “Create a new IAM role”
Next, to define the IAM permissions, copy and paste the following IAM policy in the View Policy Document text-entry field. Be sure to replace the placeholder ARN-OF-Demo/Twitter_API_Key with the ARN of your secret.
Figure 11: The IAM policy pasted in the “View Policy Document” text-entry field
Now, select Allow. This brings me back to the Lambda console with the appropriate Role selected.
Select Create function.
Figure 12: Select the “Create function” button in the lower-right corner
Copy the following Python code and paste it in the Function code section.
import base64
import json
import logging
import os
import boto3
from botocore.vendored import requests
logger = logging.getLogger()
logger.setLevel(logging.INFO)
def lambda_handler(event, context):
"""Secrets Manager Twitter Bearer Token Handler
This handler uses the master-user rotation scheme to rotate a bearer token of a Twitter app.
The Secret PlaintextString is expected to be a JSON string with the following format:
{
'access_token': ,
'token_type': ,
'masterarn':
}
Args:
event (dict): Lambda dictionary of event parameters. These keys must include the following:
- SecretId: The secret ARN or identifier
- ClientRequestToken: The ClientRequestToken of the secret version
- Step: The rotation step (one of createSecret, setSecret, testSecret, or finishSecret)
context (LambdaContext): The Lambda runtime information
Raises:
ResourceNotFoundException: If the secret with the specified arn and stage does not exist
ValueError: If the secret is not properly configured for rotation
KeyError: If the secret json does not contain the expected keys
"""
arn = event['SecretId']
token = event['ClientRequestToken']
step = event['Step']
# Setup the client and environment variables
service_client = boto3.client('secretsmanager', endpoint_url=os.environ['SECRETS_MANAGER_ENDPOINT'])
oauth2_token_url = os.environ['TWITTER_OAUTH2_TOKEN_URL']
oauth2_invalid_token_url = os.environ['TWITTER_OAUTH2_INVALID_TOKEN_URL']
tweet_search_url = os.environ['TWITTER_SEARCH_URL']
# Make sure the version is staged correctly
metadata = service_client.describe_secret(SecretId=arn)
if not metadata['RotationEnabled']:
logger.error("Secret %s is not enabled for rotation" % arn)
raise ValueError("Secret %s is not enabled for rotation" % arn)
versions = metadata['VersionIdsToStages']
if token not in versions:
logger.error("Secret version %s has no stage for rotation of secret %s." % (token, arn))
raise ValueError("Secret version %s has no stage for rotation of secret %s." % (token, arn))
if "AWSCURRENT" in versions[token]:
logger.info("Secret version %s already set as AWSCURRENT for secret %s." % (token, arn))
return
elif "AWSPENDING" not in versions[token]:
logger.error("Secret version %s not set as AWSPENDING for rotation of secret %s." % (token, arn))
raise ValueError("Secret version %s not set as AWSPENDING for rotation of secret %s." % (token, arn))
# Call the appropriate step
if step == "createSecret":
create_secret(service_client, arn, token, oauth2_token_url, oauth2_invalid_token_url)
elif step == "setSecret":
set_secret(service_client, arn, token, oauth2_token_url)
elif step == "testSecret":
test_secret(service_client, arn, token, tweet_search_url)
elif step == "finishSecret":
finish_secret(service_client, arn, token)
else:
logger.error("lambda_handler: Invalid step parameter %s for secret %s" % (step, arn))
raise ValueError("Invalid step parameter %s for secret %s" % (step, arn))
def create_secret(service_client, arn, token, oauth2_token_url, oauth2_invalid_token_url):
"""Get a new bearer token from Twitter
This method invalidates existing bearer token for the Twitter app and retrieves a new one from Twitter.
If a secret version with AWSPENDING stage exists, updates it with the newly retrieved bearer token and if
the AWSPENDING stage does not exist, creates a new version of the secret with that stage label.
Args:
service_client (client): The secrets manager service client
arn (string): The secret ARN or other identifier
token (string): The ClientRequestToken associated with the secret version
oauth2_token_url (string): The Twitter API endpoint to request a bearer token
oauth2_invalid_token_url (string): The Twitter API endpoint to invalidate a bearer token
Raises:
ValueError: If the current secret is not valid JSON
KeyError: If the secret json does not contain the expected keys
ResourceNotFoundException: If the current secret is not found
"""
# Make sure the current secret exists and try to get the master arn from the secret
try:
current_secret_dict = get_secret_dict(service_client, arn, "AWSCURRENT")
master_arn = current_secret_dict['masterarn']
logger.info("createSecret: Successfully retrieved secret for %s." % arn)
except service_client.exceptions.ResourceNotFoundException:
return
# create bearer token credentials to be passed as authorization string to Twitter
bearer_token_credentials = encode_credentials(service_client, master_arn, "AWSCURRENT")
# get the bearer token from Twitter
bearer_token_from_twitter = get_bearer_token(bearer_token_credentials,oauth2_token_url)
# invalidate the current bearer token
invalidate_bearer_token(oauth2_invalid_token_url,bearer_token_credentials,bearer_token_from_twitter)
# get a new bearer token from Twitter
new_bearer_token = get_bearer_token(bearer_token_credentials, oauth2_token_url)
# if a secret version with AWSPENDING stage exists, update it with the lastest bearer token
# if the AWSPENDING stage does not exist, then create the version with AWSPENDING stage
try:
pending_secret_dict = get_secret_dict(service_client, arn, "AWSPENDING", token)
pending_secret_dict['access_token'] = new_bearer_token
service_client.put_secret_value(SecretId=arn, ClientRequestToken=token, SecretString=json.dumps(pending_secret_dict), VersionStages=['AWSPENDING'])
logger.info("createSecret: Successfully invalidated the bearer token of the secret %s and updated the pending version" % arn)
except service_client.exceptions.ResourceNotFoundException:
current_secret_dict['access_token'] = new_bearer_token
service_client.put_secret_value(SecretId=arn, ClientRequestToken=token, SecretString=json.dumps(current_secret_dict), VersionStages=['AWSPENDING'])
logger.info("createSecret: Successfully invalidated the bearer token of the secret %s and and created the pending version." % arn)
def set_secret(service_client, arn, token, oauth2_token_url):
"""Validate the pending secret with that in Twitter
This method checks wether the bearer token in Twitter is the same as the one in the version with AWSPENDING stage.
Args:
service_client (client): The secrets manager service client
arn (string): The secret ARN or other identifier
token (string): The ClientRequestToken associated with the secret version
oauth2_token_url (string): The Twitter API endopoint to get a bearer token
Raises:
ResourceNotFoundException: If the secret with the specified arn and stage does not exist
ValueError: If the secret is not valid JSON or master credentials could not be used to login to DB
KeyError: If the secret json does not contain the expected keys
"""
# First get the pending version of the bearer token and compare it with that in Twitter
pending_secret_dict = get_secret_dict(service_client, arn, "AWSPENDING")
master_arn = pending_secret_dict['masterarn']
# create bearer token credentials to be passed as authorization string to Twitter
bearer_token_credentials = encode_credentials(service_client, master_arn, "AWSCURRENT")
# get the bearer token from Twitter
bearer_token_from_twitter = get_bearer_token(bearer_token_credentials, oauth2_token_url)
# if the bearer tokens are same, invalidate the bearer token in Twitter
# if not, raise an exception that bearer token in Twitter was changed outside Secrets Manager
if pending_secret_dict['access_token'] == bearer_token_from_twitter:
logger.info("createSecret: Successfully verified the bearer token of arn %s" % arn)
else:
raise ValueError("The bearer token of the Twitter app was changed outside Secrets Manager. Please check.")
def test_secret(service_client, arn, token, tweet_search_url):
"""Test the pending secret by calling a Twitter API
This method tries to use the bearer token in the secret version with AWSPENDING stage and search for tweets
with 'aws secrets manager' string.
Args:
service_client (client): The secrets manager service client
arn (string): The secret ARN or other identifier
token (string): The ClientRequestToken associated with the secret version
Raises:
ResourceNotFoundException: If the secret with the specified arn and stage does not exist
ValueError: If the secret is not valid JSON or pending credentials could not be used to login to the database
KeyError: If the secret json does not contain the expected keys
"""
# First get the pending version of the bearer token and compare it with that in Twitter
pending_secret_dict = get_secret_dict(service_client, arn, "AWSPENDING", token)
# Now verify you can search for tweets using the bearer token
if verify_bearer_token(pending_secret_dict['access_token'], tweet_search_url):
logger.info("testSecret: Successfully authorized with the pending secret in %s." % arn)
return
else:
logger.error("testSecret: Unable to authorize with the pending secret of secret ARN %s" % arn)
raise ValueError("Unable to connect to Twitter with pending secret of secret ARN %s" % arn)
def finish_secret(service_client, arn, token):
"""Finish the rotation by marking the pending secret as current
This method moves the secret from the AWSPENDING stage to the AWSCURRENT stage.
Args:
service_client (client): The secrets manager service client
arn (string): The secret ARN or other identifier
token (string): The ClientRequestToken associated with the secret version
Raises:
ResourceNotFoundException: If the secret with the specified arn and stage does not exist
"""
# First describe the secret to get the current version
metadata = service_client.describe_secret(SecretId=arn)
current_version = None
for version in metadata["VersionIdsToStages"]:
if "AWSCURRENT" in metadata["VersionIdsToStages"][version]:
if version == token:
# The correct version is already marked as current, return
logger.info("finishSecret: Version %s already marked as AWSCURRENT for %s" % (version, arn))
return
current_version = version
break
# Finalize by staging the secret version current
service_client.update_secret_version_stage(SecretId=arn, VersionStage="AWSCURRENT", MoveToVersionId=token, RemoveFromVersionId=current_version)
logger.info("finishSecret: Successfully set AWSCURRENT stage to version %s for secret %s." % (version, arn))
def encode_credentials(service_client, arn, stage):
"""Encodes the Twitter credentials
This helper function encodes the Twitter credentials (consumer_key and consumer_secret)
Args:
service_client (client):The secrets manager service client
arn (string): The secret ARN or other identifier
stage (stage): The stage identifying the secret version
Returns:
encoded_credentials (string): base64 encoded authorization string for Twitter
Raises:
KeyError: If the secret json does not contain the expected keys
"""
required_fields = ['consumer_key','consumer_secret']
master_secret_dict = get_secret_dict(service_client, arn, stage)
for field in required_fields:
if field not in master_secret_dict:
raise KeyError("%s key is missing from the secret JSON" % field)
encoded_credentials = base64.urlsafe_b64encode(
'{}:{}'.format(master_secret_dict['consumer_key'], master_secret_dict['consumer_secret']).encode('ascii')).decode('ascii')
return encoded_credentials
def get_bearer_token(encoded_credentials, oauth2_token_url):
"""Gets a bearer token from Twitter
This helper function retrieves the current bearer token from Twitter, given a set of credentials.
Args:
encoded_credentials (string): Twitter credentials for authentication
oauth2_token_url (string): REST API endpoint to request a bearer token from Twitter
Raises:
KeyError: If the secret json does not contain the expected keys
"""
headers = {
'Authorization': 'Basic {}'.format(encoded_credentials),
'Content-Type': 'application/x-www-form-urlencoded;charset=UTF-8',
}
data = 'grant_type=client_credentials'
response = requests.post(oauth2_token_url, headers=headers, data=data)
response_data = response.json()
if response_data['token_type'] == 'bearer':
bearer_token = response_data['access_token']
return bearer_token
else:
raise RuntimeError('unexpected token type: {}'.format(response_data['token_type']))
def invalidate_bearer_token(oauth2_invalid_token_url, bearer_token_credentials, bearer_token):
"""Invalidates a Bearer Token of a Twitter App
This helper function invalidates a bearer token of a Twitter app.
If successful, it returns the invalidated bearer token, else None
Args:
oauth2_invalid_token_url (string): The Twitter API endpoint to invalidate a bearer token
bearer_token_credentials (string): encoded consumer key and consumer secret to authenticate with Twitter
bearer_token (string): The bearer token to be invalidated
Returns:
invalidated_bearer_token: The invalidated bearer token
Raises:
ResourceNotFoundException: If the secret with the specified arn and stage does not exist
ValueError: If the secret is not valid JSON
KeyError: If the secret json does not contain the expected keys
"""
headers = {
'Authorization': 'Basic {}'.format(bearer_token_credentials),
'Content-Type': 'application/x-www-form-urlencoded;charset=UTF-8',
}
data = 'access_token=' + bearer_token
invalidate_response = requests.post(oauth2_invalid_token_url, headers=headers, data=data)
invalidate_response_data = invalidate_response.json()
if invalidate_response_data:
return
else:
raise RuntimeError('Invalidate bearer token request failed')
def verify_bearer_token(bearer_token, tweet_search_url):
"""Verifies access to Twitter APIs using a bearer token
This helper function verifies that the bearer token is valid by calling Twitter's search/tweets API endpoint
Args:
bearer_token (string): The current bearer token for the application
Returns:
True or False
Raises:
KeyError: If the response of search tweets API call fails
"""
headers = {
'Authorization' : 'Bearer {}'.format(bearer_token),
'Content-Type': 'application/x-www-form-urlencoded;charset=UTF-8',
}
search_results = requests.get(tweet_search_url, headers=headers)
try:
search_results.json()['statuses']
return True
except:
return False
def get_secret_dict(service_client, arn, stage, token=None):
"""Gets the secret dictionary corresponding for the secret arn, stage, and token
This helper function gets credentials for the arn and stage passed in and returns the dictionary by parsing the JSON string
Args:
service_client (client): The secrets manager service client
arn (string): The secret ARN or other identifier
token (string): The ClientRequestToken associated with the secret version, or None if no validation is desired
stage (string): The stage identifying the secret version
Returns:
SecretDictionary: Secret dictionary
Raises:
ResourceNotFoundException: If the secret with the specified arn and stage does not exist
ValueError: If the secret is not valid JSON
"""
# Only do VersionId validation against the stage if a token is passed in
if token:
secret = service_client.get_secret_value(SecretId=arn, VersionId=token, VersionStage=stage)
else:
secret = service_client.get_secret_value(SecretId=arn, VersionStage=stage)
plaintext = secret['SecretString']
# Parse and return the secret JSON string
return json.loads(plaintext)
Here’s what it will look like:
Figure 13: The Python code pasted in the “Function code” section
On the same page, provide the following environment variables:
Note: Resources used in this example are in US East (Ohio) region. If you intend to use another AWS Region, change the SECRETS_MANAGER_ENDPOINT set in the Environment variables to the appropriate region.
You’ve now created a Lambda function that can rotate the bearer token:
Figure 15: The new Lambda function
Before you can configure Secrets Manager to use this Lambda function, you need to update the function policy of the Lambda function. A function policy permits AWS services, such as Secrets Manager, to invoke a Lambda function on behalf of your application. You can attach a Lambda function policy from the AWS Command Line Interface (AWS CLI) or SDK. To attach a function policy, call the add-permission Lambda API from the AWS CLI.
Phase 3: Configure your application to retrieve the bearer token from Secrets Manager
Now that you’ve stored the bearer token in Secrets Manager, update the application to retrieve the bearer token from Secrets Manager instead of hard-coding this information in a configuration file or source code. For this example, I show you how to configure a Python application to retrieve this secret from Secrets Manager.
import config
def no_secrets_manager_sample()
# Get the bearer token from a config file.
Bearer_token = config.bearer_token
# Use the bearer token to authenticate requests to Twitter
Use the sample code from section titled Phase 1 and update the application to retrieve the bearer token from Secrets Manager. The following code sets up the client and retrieves and decrypts the secret Demo/Twitter_bearer_token.
# Use this code snippet in your app.
import boto3
from botocore.exceptions import ClientError
def get_secret():
secret_name = "Demo/Twitter_bearer_token"
endpoint_url = "https://secretsmanager.us-east-2.amazonaws.com"
region_name = "us-east-2"
session = boto3.session.Session()
client = session.client(
service_name='secretsmanager',
region_name=region_name,
endpoint_url=endpoint_url
)
try:
get_secret_value_response = client.get_secret_value(
SecretId=secret_name
)
except ClientError as e:
if e.response['Error']['Code'] == 'ResourceNotFoundException':
print("The requested secret " + secret_name + " was not found")
elif e.response['Error']['Code'] == 'InvalidRequestException':
print("The request was invalid due to:", e)
elif e.response['Error']['Code'] == 'InvalidParameterException':
print("The request had invalid params:", e)
else:
# Decrypted secret using the associated KMS CMK
# Depending on whether the secret was a string or binary, one of these fields will be populated
if 'SecretString' in get_secret_value_response:
secret = get_secret_value_response['SecretString']
else:
binary_secret_data = get_secret_value_response['SecretBinary']
# Your code goes here.
Applications require permissions to access Secrets Manager. My application runs on Amazon EC2 and uses an IAM role to get access to AWS services. I’ll attach the following policy to my IAM role, and you should take a similar action with your IAM role. This policy uses the GetSecretValue action to grant my application permissions to read secrets from Secrets Manager. This policy also uses the resource element to limit my application to read only the Demo/Twitter_bearer_token secret from Secrets Manager. Read the AWS Secrets Manager documentation to understand the minimum IAM permissions required to retrieve a secret.
{
"Version": "2012-10-17",
"Statement": {
"Sid": "RetrieveBearerToken",
"Effect": "Allow",
"Action": "secretsmanager:GetSecretValue",
"Resource": Input ARN of the secret Demo/Twitter_bearer_token here
}
}
Note: To improve the resiliency of your applications, associate your application with two API keys/bearer tokens. This is a higher availability option because you can continue to use one bearer token while Secrets Manager rotates the other token. Read the AWS documentation to learn how AWS Secrets Manager rotates your secrets.
Phase 4: Enable and verify rotation
Now that you’ve stored the secret in Secrets Manager and created a Lambda function to rotate this secret, configure Secrets Manager to rotate the secret Demo/Twitter_bearer_token.
From the Secrets Manager console, go to the list of secrets and choose the secret you created in the first step (in my example, this is named Demo/Twitter_bearer_token).
Scroll to Rotation configuration, and then select Edit rotation.
Figure 16: Select the “Edit rotation” button
To enable rotation, select Enable automatic rotation, and then choose how frequently you want Secrets Manager to rotate this secret. For this example, I set the rotation interval to 30 days. I also choose the rotation Lambda function, Lambda_Rotate_Bearer_Token, from the drop-down list.
Figure 17: “Edit rotation configuration” options
The banner on the next screen confirms that I have successfully configured rotation and the first rotation is in progress, which enables you to verify that rotation is functioning as expected. Secrets Manager will rotate this credential automatically every 30 days.
Figure 18: Confirmation notice
Summary
In this post, I showed you how to configure Secrets Manager to manage and rotate an API key and bearer token used by applications to authenticate and retrieve information from Twitter. You can use the steps described in this blog to manage and rotate other API keys, as well.
Secrets Manager helps you protect access to your applications, services, and IT resources without the upfront investment and on-going maintenance costs of operating your own secrets management infrastructure. To get started, open the Secrets Manager console. To learn more, read the Secrets Manager documentation.
If you have comments about this post, submit them in the Comments section below. If you have questions about anything in this post, start a new thread on the Secrets Manager forum or contact AWS Support.
Want more AWS Security news? Follow us on Twitter.
This post is courtesy of Otavio Ferreira, Manager, Amazon SNS, AWS Messaging.
Amazon SNS message filtering provides a set of string and numeric matching operators that allow each subscription to receive only the messages of interest. Hence, SNS message filtering can simplify your pub/sub messaging architecture by offloading the message filtering logic from your subscriber systems, as well as the message routing logic from your publisher systems.
After you set the subscription attribute that defines a filter policy, the subscribing endpoint receives only the messages that carry attributes matching this filter policy. Other messages published to the topic are filtered out for this subscription. In this way, the native integration between SNS and Amazon CloudWatch provides visibility into the number of messages delivered, as well as the number of messages filtered out.
CloudWatch metrics are captured automatically for you. To get started with SNS message filtering, see Filtering Messages with Amazon SNS.
Message Filtering Metrics
The following six CloudWatch metrics are relevant to understanding your SNS message filtering activity:
NumberOfMessagesPublished – Inbound traffic to SNS. This metric tracks all the messages that have been published to the topic.
NumberOfNotificationsDelivered – Outbound traffic from SNS. This metric tracks all the messages that have been successfully delivered to endpoints subscribed to the topic. A delivery takes place either when the incoming message attributes match a subscription filter policy, or when the subscription has no filter policy at all, which results in a catch-all behavior.
NumberOfNotificationsFilteredOut – This metric tracks all the messages that were filtered out because they carried attributes that didn’t match the subscription filter policy.
NumberOfNotificationsFilteredOut-NoMessageAttributes – This metric tracks all the messages that were filtered out because they didn’t carry any attributes at all and, consequently, didn’t match the subscription filter policy.
NumberOfNotificationsFilteredOut-InvalidAttributes – This metric keeps track of messages that were filtered out because they carried invalid or malformed attributes and, thus, didn’t match the subscription filter policy.
NumberOfNotificationsFailed – This last metric tracks all the messages that failed to be delivered to subscribing endpoints, regardless of whether a filter policy had been set for the endpoint. This metric is emitted after the message delivery retry policy is exhausted, and SNS stops attempting to deliver the message. At that moment, the subscribing endpoint is likely no longer reachable. For example, the subscribing SQS queue or Lambda function has been deleted by its owner. You may want to closely monitor this metric to address message delivery issues quickly.
Message filtering graphs
Through the AWS Management Console, you can compose graphs to display your SNS message filtering activity. The graph shows the number of messages published, delivered, and filtered out within the timeframe you specify (1h, 3h, 12h, 1d, 3d, 1w, or custom).
To compose an SNS message filtering graph with CloudWatch:
Open the CloudWatch console.
Choose Metrics, SNS, All Metrics, and Topic Metrics.
Select all metrics to add to the graph, such as:
NumberOfMessagesPublished
NumberOfNotificationsDelivered
NumberOfNotificationsFilteredOut
Choose Graphed metrics.
In the Statistic column, switch from Average to Sum.
Title your graph with a descriptive name, such as “SNS Message Filtering”
After you have your graph set up, you may want to copy the graph link for bookmarking, emailing, or sharing with co-workers. You may also want to add your graph to a CloudWatch dashboard for easy access in the future. Both actions are available to you on the Actions menu, which is found above the graph.
Summary
SNS message filtering defines how SNS topics behave in terms of message delivery. By using CloudWatch metrics, you gain visibility into the number of messages published, delivered, and filtered out. This enables you to validate the operation of filter policies and more easily troubleshoot during development phases.
SNS message filtering can be implemented easily with existing AWS SDKs by applying message and subscription attributes across all SNS supported protocols (Amazon SQS, AWS Lambda, HTTP, SMS, email, and mobile push). CloudWatch metrics for SNS message filtering is available now, in all AWS Regions.
Side projects are the things you do at home, after work, for your own “entertainment”, or to satisfy your desire to learn new stuff, in case your workplace doesn’t give you that opportunity (or at least not enough of it). Side projects are also a way to build stuff that you think is valuable but not necessarily “commercialisable”. Many side projects are open-sourced sooner or later and some of them contribute to the pool of tools at other people’s disposal.
I’ve outlined one recommendation about side projects before – do them with technologies that are new to you, so that you learn important things that will keep you better positioned in the software world.
But there are more benefits than that – serendipitous benefits, for example. And I’d like to tell some personal stories about that. I’ll focus on a few examples from my list of side projects to show how, through a sort-of butterfly effect, they helped shape my career.
The computoser project, no matter how cool algorithmic music composition, didn’t manage to have much of a long term impact. But it did teach me something apart from niche musical theory – how to read a bulk of scientific papers (mostly computer science) and understand them without being formally trained in the particular field. We’ll see how that was useful later.
Then there was the “State alerts” project – a website that scraped content from public institutions in my country (legislation, legislation proposals, decisions by regulators, new tenders, etc.), made them searchable, and “subscribable” – so that you get notified when a keyword of interest is mentioned in newly proposed legislation, for example. (I obviously subscribed for “information technologies” and “electronic”).
And that project turned out to have a significant impact on the following years. First, I chose a new technology to write it with – Scala. Which turned out to be of great use when I started working at TomTom, and on the 3rd day I was transferred to a Scala project, which was way cooler and much more complex than the original one I was hired for. It was a bit ironic, as my colleagues had just read that “I don’t like Scala” a few weeks earlier, but nevertheless, that was one of the most interesting projects I’ve worked on, and it went on for two years. Had I not known Scala, I’d probably be gone from TomTom much earlier (as the other project was restructured a few times), and I would not have learned many of the scalability, architecture and AWS lessons that I did learn there.
But the very same project had an even more important follow-up. Because if its “civic hacking” flavour, I was invited to join an informal group of developers (later officiated as an NGO) who create tools that are useful for society (something like MySociety.org). That group gathered regularly, discussed both tools and policies, and at some point we put up a list of policy priorities that we wanted to lobby policy makers. One of them was open source for the government, the other one was open data. As a result of our interaction with an interim government, we donated the official open data portal of my country, functioning to this day.
As a result of that, a few months later we got a proposal from the deputy prime minister’s office to “elect” one of the group for an advisor to the cabinet. And we decided that could be me. So I went for it and became advisor to the deputy prime minister. The job has nothing to do with anything one could imagine, and it was challenging and fascinating. We managed to pass legislation, including one that requires open source for custom projects, eID and open data. And all of that would not have been possible without my little side project.
As for my latest side project, LogSentinel – it became my current startup company. And not without help from the previous two mentioned above – the computer science paper reading was of great use when I was navigating the crypto papers landscape, and from the government job I not only gained invaluable legal knowledge, but I also “got” a co-founder.
Some other side projects died without much fanfare, and that’s fine. But the ones above shaped my “story” in a way that would not have been possible otherwise.
And I agree that such serendipitous chain of events could have happened without side projects – I could’ve gotten these opportunities by meeting someone at a bar (unlikely, but who knows). But we, as software engineers, are capable of tilting chance towards us by utilizing our skills. Side projects are our “extracurricular activities”, and they often lead to unpredictable, but rather positive chains of events. They would rarely be the only factor, but they are certainly great at unlocking potential.
GDPR day, May 25, 2018, is nearly here. On that day, will your inbox explode with update notices, opt-in agreements, and offers from lawyers searching for GDPR violators? Perhaps all the companies on earth that are not GDPR ready will just dissolve into dust. More likely, there will be some changes, but business as usual will continue and we’ll all be more aware of data privacy. Let’s go with the last one.
What’s Different With GDPR at Backblaze
The biggest difference you’ll notice is a completely updated Privacy Policy. Last week we sent out a service email announcing the new Privacy Policy. Some people asked what was different. Basically everything. About 95% of the agreement was rewritten. In the agreement, we added in the appropriate provisions required by GDPR, and hopefully did a better job specifying the data we collect from you, why we collect it, and what we are going to do with it.
As a reminder, at Backblaze your data falls into two catagories. The first type of data is the data you store with us — stored data. These are the files and objects you upload and store, and as needed, restore. We do not share this data. We do not process this data, except as requested by you to store and restore the data. We do not analyze this data looking for keywords, tags, images, etc. No one outside of Backblaze has access to this data unless you explicitly shared the data by providing that person access to one or more files.
The second type of data is your account data. Some of your account data is considered personal data. This is the information we collect from you to provide our Personal Backup, Business Backup and B2 Cloud Storage services. Examples include your email address to provide access to your account, or the name of your computer so we can organize your files like they are arranged on your computer to make restoration easier. We have written a number of Help Articles covering the different ways this information is collected and processed. In addition, these help articles outline the various “rights” granted via GDPR. We will continue to add help articles over the coming weeks to assist in making it easy to work with us to understand and exercise your rights.
What’s New With GDPR at Backblaze
The most obvious addition is the Data Processing Addendum (DPA). This covers how we protect the data you store with us, i.e. stored data. As noted above, we don’t do anything with your data, except store it and keep it safe until you need it. Now we have a separate document saying that.
It is important to note the new Data Processing Addendum is now incorporated by reference into our Terms of Service, which everyone agrees to when they sign up for any of our services. Now all of our customers have a shiny new Data Processing Agreement to go along with the updated Privacy Policy. We promise they are not long or complicated, and we encourage you to read them. If you have any questions, stop by our GDPR help section on our website.
Patience, Please
Every company we have dealt with over the last few months is working hard to comply with GDPR. It has been a tough road whether you tried to do it yourself or like Backblaze, hired an EU-based law firm for advice. Over the coming weeks and months as you reach out to discover and assert your rights, please have a little patience. We are all going through a steep learning curve as GDPR gets put into practice. Along the way there are certain to be some growing pains — give us a chance, we all want to get it right.
Regardless, at Backblaze we’ve been diligently protecting our customers’ data for over 11 years and nothing that will happen on May 25th will change that.
It is the season for web sites to be updating their privacy policies and obtaining consent from their users for whatever data they collect. LWN, being short of staff with the time or interest to work in this area, is rather late to this game. The first step is an updated privacy policy, which we’re now putting out for review. Little has changed from the current version; we still don’t collect much data, share data with others, or attempt to monetize what we have in any way. We would like to ask interested readers to have a look and let us know about any potential problems they see.
AWS Identity and Access Management (IAM) now makes it easier for you to control access to your AWS resources by using the AWS organization of IAM principals (users and roles). For some services, you grant permissions using resource-based policies to specify the accounts and principals that can access the resource and what actions they can perform on it. Now, you can use a new condition key, aws:PrincipalOrgID, in these policies to require all principals accessing the resource to be from an account in the organization. For example, let’s say you have an Amazon S3 bucket policy and you want to restrict access to only principals from AWS accounts inside of your organization. To accomplish this, you can define the aws:PrincipalOrgID condition and set the value to your organization ID in the bucket policy. Your organization ID is what sets the access control on the S3 bucket. Additionally, when you use this condition, policy permissions apply when you add new accounts to this organization without requiring an update to the policy.
In this post, I walk through the details of the new condition and show you how to restrict access to only principals in your organization using S3.
Condition concepts
Before I introduce the new condition, let’s review the condition element of an IAM policy. A condition is an optional IAM policy element you can use to specify special circumstances under which the policy grants or denies permission. A condition includes a condition key, operator, and value for the condition. There are two types of conditions: service-specific conditions and global conditions. Service-specific conditions are specific to certain actions in an AWS service. For example, the condition key ec2:InstanceType supports specific EC2 actions. Global conditions support all actions across all AWS services.
Now that I’ve reviewed the condition element in an IAM policy, let me introduce the new condition.
AWS:PrincipalOrgID Condition Key
You can use this condition key to apply a filter to the Principal element of a resource-based policy. You can use any string operator, such as StringLike, with this condition and specify the AWS organization ID for as its value.
Condition key
Description
Operator(s)
Value
aws:PrincipalOrgID
Validates if the principal accessing the resource belongs to an account in your organization.
Example: Restrict access to only principals from my organization
Let’s consider an example where I want to give specific IAM principals in my organization direct access to my S3 bucket, 2018-Financial-Data, that contains sensitive financial information. I have two accounts in my AWS organization with multiple account IDs, and only some IAM users from these accounts need access to this financial report.
To grant this access, I author a resource-based policy for my S3 bucket as shown below. In this policy, I list the individuals who I want to grant access. For the sake of this example, let’s say that while doing so, I accidentally specify an incorrect account ID. This means a user named Steve, who is not in an account in my organization, can now access my financial report. To require the principal account to be in my organization, I add a condition to my policy using the global condition key aws:PrincipalOrgID. This condition requires that only principals from accounts in my organization can access the S3 bucket. This means that although Steve is one of the principals in the policy, he can’t access the financial report because the account that he is a member of doesn’t belong to my organization.
In the policy above, I specify the principals that I grant access to using the principal element of the statement. Next, I add s3:GetObject as the action and 2018-Financial-Data/* as the resource to grant read access to my S3 bucket. Finally, I add the new condition key aws:PrincipalOrgID and specify my organization ID in the condition element of the statement to make sure only the principals from the accounts in my organization can access this bucket.
Summary
You can now use the aws:PrincipalOrgID condition key in your resource-based policies to more easily restrict access to IAM principals from accounts in your AWS organization. For more information about this global condition key and policy examples using aws:PrincipalOrgID, read the IAM documentation.
If you have comments about this post, submit them in the Comments section below. If you have questions about or suggestions for this solution, start a new thread on the IAM forum or contact AWS Support.
Want more AWS Security news? Follow us on Twitter.
Thanks to Susan Ferrell, Senior Technical Writer, for a great blog post on how to use CodeCommit branch-level permissions. —-
AWS CodeCommit users have been asking for a way to restrict commits to some repository branches to just a few people. In this blog post, we’re going to show you how to do that by creating and applying a conditional policy, an AWS Identity and Access Management (IAM) policy that contains a context key.
Why would I do this?
When you create a branch in an AWS CodeCommit repository, the branch is available, by default, to all repository users. Here are some scenarios in which refining access might help you:
You maintain a branch in a repository for production-ready code, and you don’t want to allow changes to this branch except from a select group of people.
You want to limit the number of people who can make changes to the default branch in a repository.
You want to ensure that pull requests cannot be merged to a branch except by an approved group of developers.
We’ll show you how to create a policy in IAM that prevents users from pushing commits to and merging pull requests to a branch named master. You’ll attach that policy to one group or role in IAM, and then test how users in that group are affected when that policy is applied. We’ll explain how it works, so you can create custom policies for your repositories.
What you need to get started
You’ll need to sign in to AWS with sufficient permissions to:
Create and apply policies in IAM.
Create groups in IAM.
Add users to those groups.
Apply policies to those groups.
You can use existing IAM groups, but because you’re going to be changing permissions, you might want to first test this out on groups and users you’ve created specifically for this purpose.
You’ll need a repository in AWS CodeCommit with at least two branches: master and test-branch. For information about how to create repositories, see Create a Repository. For information about how to create branches, see Create a Branch. In this blog post, we’ve named the repository MyDemoRepo. You can use an existing repository with branches of another name, if you prefer.
Let’s get started!
Create two groups in IAM
We’re going to set up two groups in IAM: Developers and Senior_Developers. To start, both groups will have the same managed policy, AWSCodeCommitPowerUsers, applied. Users in each group will have exactly the same permissions to perform actions in IAM.
Figure 1: Two example groups in IAM, with distinct users but the same managed policy applied to each group
In the navigation pane, choose Groups, and then choose Create New Group.
In the Group Name box, type Developers, and then choose Next Step.
In the list of policies, select the check box for AWSCodeCommitPowerUsers, then choose Next Step.
Choose Create Group.
Now, follow these steps to create the Senior_Developers group and attach the AWSCodeCommitPowerUsers managed policy. You now have two empty groups with the same policy attached.
Create users in IAM
Next, add at least one unique user to each group. You can use existing IAM users, but because you’ll be affecting their access to AWS CodeCommit, you might want to create two users just for testing purposes. Let’s go ahead and create Arnav and Mary.
In the navigation pane, choose Users, and then choose Add user.
For the new user, type Arnav_Desai.
Choose Add another user, and then type Mary_Major.
Select the type of access (programmatic access, access to the AWS Management Console, or both). In this blog post, we’ll be testing everything from the console, but if you want to test AWS CodeCommit using the AWS CLI, make sure you include programmatic access and console access.
For Console password type, choose Custom password. Each user is assigned the password that you type in the box. Write these down so you don’t forget them. You’ll need to sign in to the console using each of these accounts.
Choose Next: Permissions.
On the Set permissions page, choose Add user to group. Add Arnav to the Developers group. Add Mary to the Senior_Developers group.
Choose Next: Review to see all of the choices you made up to this point. When you are ready to proceed, choose Create user.
Sign in as Arnav, and then follow these steps to go to the master branch and add a file. Then sign in as Mary and follow the same steps.
On the Dashboard page, from the list of repositories, choose MyDemoRepo.
In the Code view, choose the branch named master.
Choose Add file, and then choose Create file. Type some text or code in the editor.
Provide information to other users about who added this file to the repository and why.
In Author name, type the name of the user (Arnav or Mary).
In Email address, type an email address so that other repository users can contact you about this change.
In Commit message, type a brief description to help you remember why you added this file or any other details you might find helpful.
Type a name for the file.
Choose Commit file.
Now follow the same steps to add a file in a different branch. (In our example repository, that’s the branch named test-branch.) You should be able to add a file to both branches regardless of whether you’re signed in as Arnav or Mary.
Let’s change that.
Create a conditional policy in IAM
You’re going to create a policy in IAM that will deny API actions if certain conditions are met. We want to prevent users with this policy applied from updating a branch named master, but we don’t want to prevent them from viewing the branch, cloning the repository, or creating pull requests that will merge to that branch. For this reason, we want to pick and choose our APIs carefully. Looking at the Permissions Reference, the logical permissions for this are:
GitPush
PutFile
MergePullRequestByFastForward
Now’s the time to think about what else you might want this policy to do. For example, because we don’t want users with this policy to make changes to this branch, we probably don’t want them to be able to delete it either, right? So let’s add one more permission:
DeleteBranch
The branch in which we want to deny these actions is master. The repository in which the branch resides is MyDemoRepo. We’re going to need more than just the repository name, though. We need the repository ARN. Fortunately, that’s easy to find. Just go to the AWS CodeCommit console, choose the repository, and choose Settings. The repository ARN is displayed on the General tab.
Now we’re ready to create a policy. 1. Open the IAM console at https://console.aws.amazon.com/iam/. Make sure you’re signed in with the account that has sufficient permissions to create policies, and not as Arnav or Mary. 2. In the navigation pane, choose Policies, and then choose Create policy. 3. Choose JSON, and then paste in the following:
You’ll notice a few things here. First, change the repository ARN to the ARN for your repository and include the repository name. Second, if you want to restrict access to a branch with a name different from our example, master, change that reference too.
Now let’s talk about this policy and what it does. You might be wondering why we’re using a Git reference (refs/heads) value instead of just the branch name. The answer lies in how Git references things, and how AWS CodeCommit, as a Git-based repository service, implements its APIs. A branch in Git is a simple pointer (reference) to the SHA-1 value of the head commit for that branch.
You might also be wondering about the second part of the condition, the nullification language. This is necessary because of the way git push and git-receive-pack work. Without going into too many technical details, when you attempt to push a change from a local repo to AWS CodeCommit, an initial reference call is made to AWS CodeCommit without any branch information. AWS CodeCommit evaluates that initial call to ensure that:
a) You’re authorized to make calls.
b) A repository exists with the name specified in the initial call. If you left that null out of the policy, users with that policy would be unable to complete any pushes from their local repos to the AWS CodeCommit remote repository at all, regardless of which branch they were trying to push their commits to.
Could you write a policy in such a way that the null is not required? Of course. IAM policy language is flexible. There’s an example of how to do this in the AWS CodeCommit User Guide, if you’re curious. But for the purposes of this blog post, let’s continue with this policy as written.
So what have we essentially said in this policy? We’ve asked IAM to deny the relevant CodeCommit permissions if the request is made to the resource MyDemoRepo and it meets the following condition: the reference is to refs/heads/master. Otherwise, the deny does not apply.
I’m sure you’re wondering if this policy has to be constrained to a specific repository resource like MyDemoRepo. After all, it would be awfully convenient if a single policy could apply to all branches in any repository in an AWS account, particularly since the default branch in any repository is initially the master branch. Good news! Simply replace the ARN with an *, and your policy will affect ALL branches named master in every AWS CodeCommit repository in your AWS account. Make sure that this is really what you want, though. We suggest you start by limiting the scope to just one repository, and then changing things when you’ve tested it and are happy with how it works.
When you’re sure you’ve modified the policy for your environment, choose Review policy to validate it. Give this policy a name, such as DenyChangesToMaster, provide a description of its purpose, and then choose Create policy.
Now that you have a policy, it’s time to apply and test it.
Apply the policy to a group
In theory, you could apply the policy you just created directly to any IAM user, but that really doesn’t scale well. You should apply this policy to a group, if you use IAM groups to manage users, or to a role, if your users assume a role when interacting with AWS resources.
In the IAM console, choose Groups, and then choose Developers.
On the Permissions tab, choose Attach Policy.
Choose DenyChangesToMaster, and then choose Attach policy.
Your groups now have a critical difference: users in the Developers group have an additional policy applied that restricts their actions in the master branch. In other words, Mary can continue to add files, push commits, and merge pull requests in the master branch, but Arnav cannot.
Figure 2: Two example groups in IAM, one with an additional policy applied that will prevent users in this group from making changes to the master branch
Test it out. Sign in as Arnav, and do the following:
On the Dashboard page, from the list of repositories, choose MyDemoRepo.
In the Code view, choose the branch named master.
Choose Add file, and then choose Create file, just as you did before. Provide some text, and then add the file name and your user information.
Choose Commit file.
This time you’ll see an error after choosing Commit file. It’s not a pretty message, but at the very end, you’ll see a telling phrase: “explicit deny”. That’s the policy in action. You, as Arnav, are explicitly denied PutFile, which prevents you from adding a file to the master branch. You’ll see similar results if you try other actions denied by that policy, such as deleting the master branch.
Stay signed in as Arnav, but this time add a file to test-branch. You should be able to add a file without seeing any errors. You can create a branch based on the master branch, add a file to it, and create a pull request that will merge to the master branch, all just as before. However, you cannot perform denied actions on that master branch.
Sign out as Arnav and sign in as Mary. You’ll see that as that IAM user, you can add and edit files in the master branch, merge pull requests to it, and even, although we don’t recommend this, delete it.
Conclusion
You can use conditional statements in policies in IAM to refine how users interact with your AWS CodeCommit repositories. This blog post showed how to use such a policy to prevent users from making changes to a branch named master. There are many other options. We hope this blog post will encourage you to experiment with AWS CodeCommit, IAM policies, and permissions. If you have any questions or suggestions, we’d love to hear from you.
AWS Glue is a fully managed extract, transform, and load (ETL) service that makes it easier to prepare and load your data for analytics. You can create and run an ETL job with a few clicks on the AWS Management Console. Just point AWS Glue to your data store. AWS Glue discovers your data and stores the associated metadata (for example, a table definition and schema) in the AWS Glue Data Catalog.
AWS Glue has native connectors to data sources using JDBC drivers, either on AWS or elsewhere, as long as there is IP connectivity. In this post, we demonstrate how to connect to data sources that are not natively supported in AWS Glue today. We walk through connecting to and running ETL jobs against two such data sources, IBM DB2 and SAP Sybase. However, you can use the same process with any other JDBC-accessible database.
AWS Glue data sources
AWS Glue natively supports the following data stores by using the JDBC protocol:
One of the fastest growing architectures deployed on AWS is the data lake. The ETL processes that are used to ingest, clean, transform, and structure data are critically important for this architecture. Having the flexibility to interoperate with a broader range of database engines allows for a quicker adoption of the data lake architecture.
For data sources that AWS Glue doesn’t natively support, such as IBM DB2, Pivotal Greenplum, SAP Sybase, or any other relational database management system (RDBMS), you can import custom database connectors from Amazon S3 into AWS Glue jobs. In this case, the connection to the data source must be made from the AWS Glue script to extract the data, rather than using AWS Glue connections. To learn more, see Providing Your Own Custom Scripts in the AWS Glue Developer Guide.
Setting up an ETL job for an IBM DB2 data source
The first example demonstrates how to connect the AWS Glue ETL job to an IBM DB2 instance, transform the data from the source, and store it in Apache Parquet format in Amazon S3. To successfully create the ETL job using an external JDBC driver, you must define the following:
The S3 location of the job script
The S3 location of the temporary directory
The S3 location of the JDBC driver
The S3 location of the Parquet data (output)
The IAM role for the job
By default, AWS Glue suggests bucket names for the scripts and the temporary directory using the following format:
Keep in mind that having the AWS Glue job and S3 buckets in the same AWS Region helps save on cross-Region data transfer fees. For this post, we will work in the US East (Ohio) Region (us-east-2).
Creating the IAM role
The next step is to set up the IAM role that the ETL job will use:
Sign in to the AWS Management Console, and search for IAM:
On the IAM console, choose Roles in the left navigation pane.
Choose Create role. The role type of trusted entity must be an AWS service, specifically AWS Glue.
Choose Next: Permissions.
Search for the AWSGlueServiceRole policy, and select it.
Search again, now for the SecretsManagerReadWrite This policy allows the AWS Glue job to access database credentials that are stored in AWS Secrets Manager.
CAUTION: This policy is open and is being used for testing purposes only. You should create a custom policy to narrow the access just to the secrets that you want to use in the ETL job.
Select this policy, and choose Next: Review.
Give your role a name, for example, GluePermissions, and confirm that both policies were selected.
Choose Create role.
Now that you have created the IAM role, it’s time to upload the JDBC driver to the defined location in Amazon S3. For this example, we will use the DB2 driver, which is available on the IBM Support site.
Storing database credentials
It is a best practice to store database credentials in a safe store. In this case, we use AWS Secrets Manager to securely store credentials. Follow these steps to create those credentials:
Open the console, and search for Secrets Manager.
In the AWS Secrets Manager console, choose Store a new secret.
Under Select a secret type, choose Other type of secrets.
In the Secret key/value, set one row for each of the following parameters:
db_username
db_password
db_url (for example, jdbc:db2://10.10.12.12:50000/SAMPLE)
db_table
driver_name (ibm.db2.jcc.DB2Driver)
output_bucket: (for example, aws-glue-data-output-1234567890-us-east-2/User)
Choose Next.
For Secret name, use DB2_Database_Connection_Info.
Choose Next.
Keep the Disable automatic rotation check box selected.
Choose Next.
Choose Store.
Adding a job in AWS Glue
The next step is to author the AWS Glue job, following these steps:
In the AWS Management Console, search for AWS Glue.
In the navigation pane on the left, choose Jobs under the ETL
Choose Add job.
Fill in the basic Job properties:
Give the job a name (for example, db2-job).
Choose the IAM role that you created previously (GluePermissions).
For This job runs, choose A new script to be authored by you.
For ETL language, choose Python.
In the Script libraries and job parameters section, choose the location of your JDBC driver for Dependent jars path.
Choose Next.
On the Connections page, choose Next
On the summary page, choose Save job and edit script. This creates the job and opens the script editor.
In the editor, replace the existing code with the following script. Important: Line 47 of the script corresponds to the mapping of the fields in the source table to the destination, dropping of the null fields to save space in the Parquet destination, and finally writing to Amazon S3 in Parquet format.
Choose the black X on the right side of the screen to close the editor.
Running the ETL job
Now that you have created the job, the next step is to execute it as follows:
On the Jobs page, select your new job. On the Action menu, choose Run job, and confirm that you want to run the job. Wait a few moments as it finishes the execution.
After the job shows as Succeeded, choose Logs to read the output of the job.
In the output of the job, you will find the result of executing the df.printSchema() and the message with the df.count().
Also, if you go to your output bucket in S3, you will find the Parquet result of the ETL job.
Using AWS Glue, you have created an ETL job that connects to an existing database using an external JDBC driver. It enables you to execute any transformation that you need.
Setting up an ETL job for an SAP Sybase data source
In this section, we describe how to create an AWS Glue ETL job against an SAP Sybase data source. The process mentioned in the previous section works for a Sybase data source with a few changes required in the job:
While creating the job, choose the correct jar for the JDBC dependency.
In the script, change the reference to the secret to be used from AWS Secrets Manager:
After you successfully execute the new ETL job, the output contains the same type of information that was generated with the DB2 data source.
Note that each of these JDBC drivers has its own nuances and different licensing terms that you should be aware of before using them.
Maximizing JDBC read parallelism
Something to keep in mind while working with big data sources is the memory consumption. In some cases, “Out of Memory” errors are generated when all the data is read into a single executor. One approach to optimize this is to rely on the parallelism on read that you can implement with Apache Spark and AWS Glue. To learn more, see the Apache Spark SQL module.
You can use the following options:
partitionColumn: The name of an integer column that is used for partitioning.
lowerBound: The minimum value of partitionColumn that is used to decide partition stride.
upperBound: The maximum value of partitionColumn that is used to decide partition stride.
numPartitions: The number of partitions. This, along with lowerBound (inclusive) and upperBound (exclusive), form partition strides for generated WHERE clause expressions used to split the partitionColumn When unset, this defaults to SparkContext.defaultParallelism.
Those options specify the parallelism of the table read. lowerBound and upperBound decide the partition stride, but they don’t filter the rows in the table. Therefore, Spark partitions and returns all rows in the table. For example:
It’s important to be careful with the number of partitions because too many partitions could also result in Spark crashing your external database systems.
Conclusion
Using the process described in this post, you can connect to and run AWS Glue ETL jobs against any data source that can be reached using a JDBC driver. This includes new generations of common analytical databases like Greenplum and others.
You can improve the query efficiency of these datasets by using partitioning and pushdown predicates. For more information, see Managing Partitions for ETL Output in AWS Glue. This technique opens the door to moving data and feeding data lakes in hybrid environments.
Kapil Shardha is a Technical Account Manager and supports enterprise customers with their AWS adoption. He has background in infrastructure automation and DevOps.
William Torrealba is an AWS Solutions Architect supporting customers with their AWS adoption. He has background in Application Development, High Available Distributed Systems, Automation, and DevOps.
Mozilla has released Firefox 60. From the release notes: “Firefox 60 offers something for everyone and a little something extra for everyone who deploys Firefox in an enterprise environment. This release includes changes that give you more content and more ways to customize your New Tab/Firefox Home. It also introduces support for the Web Authentication API, which means you can log in to websites in Firefox with USB tokens like YubiKey. Firefox 60 also brings a new policy engine and Group Policy support for enterprise deployments. For more info about why and how to use Firefox in the enterprise, see this blog post.”
We have a new resource available to help you meet a requirement for physically-separated infrastructure using logical separation in the AWS cloud. Our latest guide, Logical Separation: An Evaluation of the U.S. Department of Defense Cloud Security Requirements for Sensitive Workloads outlines how AWS meets the U.S. Department of Defense’s (DoD) stringent physical separation requirement by pioneering a three-pronged logical separation approach that leverages virtualization, encryption, and deploying compute to dedicated hardware.
This guide will help you understand logical separation in the cloud and demonstrates its advantages over a traditional physical separation model. Embracing this approach can help organizations confidently meet or exceed security requirements found in traditional on-premises environments, while also providing increased security control and flexibility.
Logical Separation is the second guide in the AWS Government Handbook Series, which examines cybersecurity policy initiatives and identifies best practices.
If you have questions or want to learn more, contact your account executive or AWS Support.
Last month, Wired published a long article about Ray Ozzie and his supposed new scheme for adding a backdoor in encrypted devices. It’s a weird article. It paints Ozzie’s proposal as something that “attains the impossible” and “satisfies both law enforcement and privacy purists,” when (1) it’s barely a proposal, and (2) it’s essentially the same key escrow scheme we’ve been hearing about for decades.
Basically, each device has a unique public/private key pair and a secure processor. The public key goes into the processor and the device, and is used to encrypt whatever user key encrypts the data. The private key is stored in a secure database, available to law enforcement on demand. The only other trick is that for law enforcement to use that key, they have to put the device in some sort of irreversible recovery mode, which means it can never be used again. That’s basically it.
I have no idea why anyone is talking as if this were anything new. Severalcryptographershavealreadyexplained why this key escrow scheme is no better than any other key escrow scheme. The short answer is (1) we won’t be able to secure that database of backdoor keys, (2) we don’t know how to build the secure coprocessor the scheme requires, and (3) it solves none of the policy problems around the whole system. This is the typical mistake non-cryptographers make when they approach this problem: they think that the hard part is the cryptography to create the backdoor. That’s actually the easy part. The hard part is ensuring that it’s only used by the good guys, and there’s nothing in Ozzie’s proposal that addresses any of that.
I worry that this kind of thing is damaging in the long run. There should be some rule that any backdoor or key escrow proposal be a fully specified proposal, not just some cryptography and hand-waving notions about how it will be used in practice. And before it is analyzed and debated, it should have to satisfy some sort of basic security analysis. Otherwise, we’ll be swatting pseudo-proposals like this one, while those on the other side of this debate become increasingly convinced that it’s possible to design one of these things securely.
Already people are using the National Academies report on backdoors for law enforcement as evidence that engineers are developing workable and secure backdoors. Writing in Lawfare, Alan Z. Rozenshtein claims that the report — and a related New York Timesstory — “undermine the argument that secure third-party access systems are so implausible that it’s not even worth trying to develop them.” Susan Landau effectively corrects this misconception, but the damage is done.
Here’s the thing: it’s not hard to design and build a backdoor. What’s hard is building the systems — both technical and procedural — around them. Here’s Rob Graham:
He’s only solving the part we already know how to solve. He’s deliberately ignoring the stuff we don’t know how to solve. We know how to make backdoors, we just don’t know how to secure them.
A bunch of us cryptographers have already explained why we don’t think this sort of thing will work in the foreseeable future. We write:
Exceptional access would force Internet system developers to reverse “forward secrecy” design practices that seek to minimize the impact on user privacy when systems are breached. The complexity of today’s Internet environment, with millions of apps and globally connected services, means that new law enforcement requirements are likely to introduce unanticipated, hard to detect security flaws. Beyond these and other technical vulnerabilities, the prospect of globally deployed exceptional access systems raises difficult problems about how such an environment would be governed and how to ensure that such systems would respect human rights and the rule of law.
The reason so few of us are willing to bet on massive-scale key escrow systems is that we’ve thought about it and we don’t think it will work. We’ve looked at the threat model, the usage model, and the quality of hardware and software that exists today. Our informed opinion is that there’s no detection system for key theft, there’s no renewability system, HSMs are terrifically vulnerable (and the companies largely staffed with ex-intelligence employees), and insiders can be suborned. We’re not going to put the data of a few billion people on the line an environment where we believe with high probability that the system will fail.
Many companies across the globe use Amazon DynamoDB to store and query historical user-interaction data. DynamoDB is a fast NoSQL database used by applications that need consistent, single-digit millisecond latency.
Often, customers want to turn their valuable data in DynamoDB into insights by analyzing a copy of their table stored in Amazon S3. Doing this separates their analytical queries from their low-latency critical paths. This data can be the primary source for understanding customers’ past behavior, predicting future behavior, and generating downstream business value. Customers often turn to DynamoDB because of its great scalability and high availability. After a successful launch, many customers want to use the data in DynamoDB to predict future behaviors or provide personalized recommendations.
DynamoDB is a good fit for low-latency reads and writes, but it’s not practical to scan all data in a DynamoDB database to train a model. In this post, I demonstrate how you can use DynamoDB table data copied to Amazon S3 by AWS Data Pipeline to predict customer behavior. I also demonstrate how you can use this data to provide personalized recommendations for customers using Amazon SageMaker. You can also run ad hoc queries using Amazon Athena against the data. DynamoDB recently released on-demand backups to create full table backups with no performance impact. However, it’s not suitable for our purposes in this post, so I chose AWS Data Pipeline instead to create managed backups are accessible from other services.
To do this, I describe how to read the DynamoDB backup file format in Data Pipeline. I also describe how to convert the objects in S3 to a CSV format that Amazon SageMaker can read. In addition, I show how to schedule regular exports and transformations using Data Pipeline. The sample data used in this post is from Bank Marketing Data Set of UCI.
The solution that I describe provides the following benefits:
Separates analytical queries from production traffic on your DynamoDB table, preserving your DynamoDB read capacity units (RCUs) for important production requests
Automatically updates your model to get real-time predictions
Optimizes for performance (so it doesn’t compete with DynamoDB RCUs after the export) and for cost (using data you already have)
Makes it easier for developers of all skill levels to use Amazon SageMaker
All code and data set in this post are available in this .zip file.
Solution architecture
The following diagram shows the overall architecture of the solution.
The steps that data follows through the architecture are as follows:
Data Pipeline regularly copies the full contents of a DynamoDB table as JSON into an S3
Exported JSON files are converted to comma-separated value (CSV) format to use as a data source for Amazon SageMaker.
Amazon SageMaker renews the model artifact and update the endpoint.
The converted CSV is available for ad hoc queries with Amazon Athena.
Data Pipeline controls this flow and repeats the cycle based on the schedule defined by customer requirements.
Building the auto-updating model
This section discusses details about how to read the DynamoDB exported data in Data Pipeline and build automated workflows for real-time prediction with a regularly updated model.
Find the automation_script.sh file and edit it for your environment. For example, you need to replace 's3://<your bucket>/<datasource path>/' with your own S3 path to the data source for Amazon ML. In the script, the text enclosed by angle brackets—< and >—should be replaced with your own path.
Upload the json-serde-1.3.6-SNAPSHOT-jar-with-dependencies.jar file to your S3 path so that the ADD jar command in Apache Hive can refer to it.
For this solution, the banking.csv should be imported into a DynamoDB table.
Export a DynamoDB table
To export the DynamoDB table to S3, open the Data Pipeline console and choose the Export DynamoDB table to S3 template. In this template, Data Pipeline creates an Amazon EMR cluster and performs an export in the EMRActivity activity. Set proper intervals for backups according to your business requirements.
One core node(m3.xlarge) provides the default capacity for the EMR cluster and should be suitable for the solution in this post. Leave the option to resize the cluster before running enabled in the TableBackupActivity activity to let Data Pipeline scale the cluster to match the table size. The process of converting to CSV format and renewing models happens in this EMR cluster.
For a more in-depth look at how to export data from DynamoDB, see Export Data from DynamoDB in the Data Pipeline documentation.
Add the script to an existing pipeline
After you export your DynamoDB table, you add an additional EMR step to EMRActivity by following these steps:
Open the Data Pipeline console and choose the ID for the pipeline that you want to add the script to.
For Actions, choose Edit.
In the editing console, choose the Activities category and add an EMR step using the custom script downloaded in the previous section, as shown below.
Paste the following command into the new step after the data upload step:
The element #{output.directoryPath} references the S3 path where the data pipeline exports DynamoDB data as JSON. The path should be passed to the script as an argument.
The bash script has two goals, converting data formats and renewing the Amazon SageMaker model. Subsequent sections discuss the contents of the automation script.
Automation script: Convert JSON data to CSV with Hive
We use Apache Hive to transform the data into a new format. The Hive QL script to create an external table and transform the data is included in the custom script that you added to the Data Pipeline definition.
When you run the Hive scripts, do so with the -e option. Also, define the Hive table with the 'org.openx.data.jsonserde.JsonSerDe' row format to parse and read JSON format. The SQL creates a Hive EXTERNAL table, and it reads the DynamoDB backup data on the S3 path passed to it by Data Pipeline.
Note: You should create the table with the “EXTERNAL” keyword to avoid the backup data being accidentally deleted from S3 if you drop the table.
The full automation script for converting follows. Add your own bucket name and data source path in the highlighted areas.
After creating an external table, you need to read data. You then use the INSERT OVERWRITE DIRECTORY ~ SELECT command to write CSV data to the S3 path that you designated as the data source for Amazon SageMaker.
Depending on your requirements, you can eliminate or process the columns in the SELECT clause in this step to optimize data analysis. For example, you might remove some columns that have unpredictable correlations with the target value because keeping the wrong columns might expose your model to “overfitting” during the training. In this post, customer_id columns is removed. Overfitting can make your prediction weak. More information about overfitting can be found in the topic Model Fit: Underfitting vs. Overfitting in the Amazon ML documentation.
Automation script: Renew the Amazon SageMaker model
After the CSV data is replaced and ready to use, create a new model artifact for Amazon SageMaker with the updated dataset on S3. For renewing model artifact, you must create a new training job. Training jobs can be run using the AWS SDK ( for example, Amazon SageMaker boto3 ) or the Amazon SageMaker Python SDK that can be installed with “pip install sagemaker” command as well as the AWS CLI for Amazon SageMaker described in this post.
In addition, consider how to smoothly renew your existing model without service impact, because your model is called by applications in real time. To do this, you need to create a new endpoint configuration first and update a current endpoint with the endpoint configuration that is just created.
#!/bin/bash
## Define variable
REGION=$2
DTTIME=`date +%Y-%m-%d-%H-%M-%S`
ROLE="<your AmazonSageMaker-ExecutionRole>"
# Select containers image based on region.
case "$REGION" in
"us-west-2" )
IMAGE="174872318107.dkr.ecr.us-west-2.amazonaws.com/linear-learner:latest"
;;
"us-east-1" )
IMAGE="382416733822.dkr.ecr.us-east-1.amazonaws.com/linear-learner:latest"
;;
"us-east-2" )
IMAGE="404615174143.dkr.ecr.us-east-2.amazonaws.com/linear-learner:latest"
;;
"eu-west-1" )
IMAGE="438346466558.dkr.ecr.eu-west-1.amazonaws.com/linear-learner:latest"
;;
*)
echo "Invalid Region Name"
exit 1 ;
esac
# Start training job and creating model artifact
TRAINING_JOB_NAME=TRAIN-${DTTIME}
S3OUTPUT="s3://<your bucket name>/model/"
INSTANCETYPE="ml.m4.xlarge"
INSTANCECOUNT=1
VOLUMESIZE=5
aws sagemaker create-training-job --training-job-name ${TRAINING_JOB_NAME} --region ${REGION} --algorithm-specification TrainingImage=${IMAGE},TrainingInputMode=File --role-arn ${ROLE} --input-data-config '[{ "ChannelName": "train", "DataSource": { "S3DataSource": { "S3DataType": "S3Prefix", "S3Uri": "s3://<your bucket name>/<datasource path>/", "S3DataDistributionType": "FullyReplicated" } }, "ContentType": "text/csv", "CompressionType": "None" , "RecordWrapperType": "None" }]' --output-data-config S3OutputPath=${S3OUTPUT} --resource-config InstanceType=${INSTANCETYPE},InstanceCount=${INSTANCECOUNT},VolumeSizeInGB=${VOLUMESIZE} --stopping-condition MaxRuntimeInSeconds=120 --hyper-parameters feature_dim=20,predictor_type=binary_classifier
# Wait until job completed
aws sagemaker wait training-job-completed-or-stopped --training-job-name ${TRAINING_JOB_NAME} --region ${REGION}
# Get newly created model artifact and create model
MODELARTIFACT=`aws sagemaker describe-training-job --training-job-name ${TRAINING_JOB_NAME} --region ${REGION} --query 'ModelArtifacts.S3ModelArtifacts' --output text `
MODELNAME=MODEL-${DTTIME}
aws sagemaker create-model --region ${REGION} --model-name ${MODELNAME} --primary-container Image=${IMAGE},ModelDataUrl=${MODELARTIFACT} --execution-role-arn ${ROLE}
# create a new endpoint configuration
CONFIGNAME=CONFIG-${DTTIME}
aws sagemaker create-endpoint-config --region ${REGION} --endpoint-config-name ${CONFIGNAME} --production-variants VariantName=Users,ModelName=${MODELNAME},InitialInstanceCount=1,InstanceType=ml.m4.xlarge
# create or update the endpoint
STATUS=`aws sagemaker describe-endpoint --endpoint-name ServiceEndpoint --query 'EndpointStatus' --output text --region ${REGION} `
if [[ $STATUS -ne "InService" ]] ;
then
aws sagemaker create-endpoint --endpoint-name ServiceEndpoint --endpoint-config-name ${CONFIGNAME} --region ${REGION}
else
aws sagemaker update-endpoint --endpoint-name ServiceEndpoint --endpoint-config-name ${CONFIGNAME} --region ${REGION}
fi
Grant permission
Before you execute the script, you must grant proper permission to Data Pipeline. Data Pipeline uses the DataPipelineDefaultResourceRole role by default. I added the following policy to DataPipelineDefaultResourceRole to allow Data Pipeline to create, delete, and update the Amazon SageMaker model and data source in the script.
After you deploy a model into production using Amazon SageMaker hosting services, your client applications use this API to get inferences from the model hosted at the specified endpoint. This approach is useful for interactive web, mobile, or desktop applications.
Following, I provide a simple Python code example that queries against Amazon SageMaker endpoint URL with its name (“ServiceEndpoint”) and then uses them for real-time prediction.
Data Pipeline exports DynamoDB table data into S3. The original JSON data should be kept to recover the table in the rare event that this is needed. Data Pipeline then converts JSON to CSV so that Amazon SageMaker can read the data.Note: You should select only meaningful attributes when you convert CSV. For example, if you judge that the “campaign” attribute is not correlated, you can eliminate this attribute from the CSV.
Train the Amazon SageMaker model with the new data source.
When a new customer comes to your site, you can judge how likely it is for this customer to subscribe to your new product based on “predictedScores” provided by Amazon SageMaker.
If the new user subscribes your new product, your application must update the attribute “y” to the value 1 (for yes). This updated data is provided for the next model renewal as a new data source. It serves to improve the accuracy of your prediction. With each new entry, your application can become smarter and deliver better predictions.
Running ad hoc queries using Amazon Athena
Amazon Athena is a serverless query service that makes it easy to analyze large amounts of data stored in Amazon S3 using standard SQL. Athena is useful for examining data and collecting statistics or informative summaries about data. You can also use the powerful analytic functions of Presto, as described in the topic Aggregate Functions of Presto in the Presto documentation.
With the Data Pipeline scheduled activity, recent CSV data is always located in S3 so that you can run ad hoc queries against the data using Amazon Athena. I show this with example SQL statements following. For an in-depth description of this process, see the post Interactive SQL Queries for Data in Amazon S3 on the AWS News Blog.
Creating an Amazon Athena table and running it
Simply, you can create an EXTERNAL table for the CSV data on S3 in Amazon Athena Management Console.
=== Table Creation ===
CREATE EXTERNAL TABLE datasource (
age int,
job string,
marital string ,
education string,
default string,
housing string,
loan string,
contact string,
month string,
day_of_week string,
duration int,
campaign int,
pdays int ,
previous int ,
poutcome string,
emp_var_rate double,
cons_price_idx double,
cons_conf_idx double,
euribor3m double,
nr_employed double,
y int
)
ROW FORMAT DELIMITED
FIELDS TERMINATED BY ',' ESCAPED BY '\\' LINES TERMINATED BY '\n'
LOCATION 's3://<your bucket name>/<datasource path>/';
The following query calculates the correlation coefficient between the target attribute and other attributes using Amazon Athena.
=== Sample Query ===
SELECT corr(age,y) AS correlation_age_and_target,
corr(duration,y) AS correlation_duration_and_target,
corr(campaign,y) AS correlation_campaign_and_target,
corr(contact,y) AS correlation_contact_and_target
FROM ( SELECT age , duration , campaign , y ,
CASE WHEN contact = 'telephone' THEN 1 ELSE 0 END AS contact
FROM datasource
) datasource ;
Conclusion
In this post, I introduce an example of how to analyze data in DynamoDB by using table data in Amazon S3 to optimize DynamoDB table read capacity. You can then use the analyzed data as a new data source to train an Amazon SageMaker model for accurate real-time prediction. In addition, you can run ad hoc queries against the data on S3 using Amazon Athena. I also present how to automate these procedures by using Data Pipeline.
You can adapt this example to your specific use case at hand, and hopefully this post helps you accelerate your development. You can find more examples and use cases for Amazon SageMaker in the video AWS 2017: Introducing Amazon SageMaker on the AWS website.
Yong Seong Lee is a Cloud Support Engineer for AWS Big Data Services. He is interested in every technology related to data/databases and helping customers who have difficulties in using AWS services. His motto is “Enjoy life, be curious and have maximum experience.”
Today, I’m pleased to announce that, as of April 24th 2018, the AWS IoT Analytics service is generally available. Customers can use IoT Analytics to clean, process, encrich, store, and analyze their connected device data at scale. AWS IoT Analytics is now available in US East (N. Virginia), US West (Oregon), US East (Ohio), and EU (Ireland). In November of last year, my colleague Tara Walker wrote an excellent post that walks through some of the features of the AWS IoT Analytics service and Ben Kehoe (an AWS Community Hero and Research Scientist at iRobot) spoke at AWS Re:Invent about replacing iRobot’s existing “rube goldberg machine” for forwarding data into an elasticsearch cluster with AWS IoT Analytics.
Iterating on customer feedback received during the service preview the AWS IoT Analytics team has added a number of new features including the ability to ingest data from external souces using the BatchPutMessage API, the ability to set a data retention policy on stored data, the ability to reprocess existing data, preview pipeline results, and preview messages from channels with the SampleChannelData API.
Let’s cover the core concepts of IoT Analytics and then walk through an example.
AWS IoT Analytics Concepts
AWS IoT Analytics can be broken down into a few simple concepts. For data preparation customers have: Channels, Pipelines, and Data Stores. For analyzing data customers have: Datasets and Notebooks.
Data Preparation
Channels are the entry point into IoT Analytics and they collect data from an existing IoT Core MQTT topic or from external sources that send messages to the channel using the Ingestion API. Channels are elastically scalable and consume messages in Binary or JSON format. Channels also immutably store raw device data for easily reprocessing using different logic if your needs change.
Pipelines consume messages from channels and allow you to process messages with steps, called activities, such as filtering on attributes, transforming the content of the message by adding or remvoing fields, invoking lambda functions for complex transformations and adding data from external data sources, or even enriching the messages with data from IoT Core. Pipelines output their data to a Data Store.
Data Stores are a queryable IoT-optimized data storage solution for the output of your pipelines. Data stores support custom retention periods to optimize costs. When a customer queries a Data Store the result is put into a Dataset.
Data Analytics
Datasets are similar to a view in a SQL database. Customers create a dataset by running a query against a data store. Data sets can be generated manually or on a recurring schedule.
Notebooks are Amazon SageMaker hosted Jupyter notebooks that let customers analyze their data with custom code and even build or train ML models on the data. IoT Analytics offers several notebook templates with pre-authored models for common IoT use cases such as Predictive Maintenance, Anomaly Detection, Fleet Segmentation, and Forecasting.
Additionally, you can use IoT analytics as a data source for Amazon QuickSight for easy visualizations of your data. You can find pricing information for each of these services on the AWS IoT Analytics Pricing Page.
IoT Analytics Walkthrough
While this walkthrough uses the console everything shown here is equally easy to do with the CLI. When we first navigate to the console we have a helpful guide telling us to build a channel, pipeline, and a data store: Our first step is to create a channel. I already have some data into an MQTT channel with IoT core so I’ll select that channel. First we’ll name the channel and select a retention period.
Now, I’ll select my IoT Core topic and grab the data. I can also post messages directly into the channel with the PutMessages APIs.
Now that I have a channel my next step is to create a pipeline. To do this I’ll select “Create a pipeline from this channel” from the “Actions” drop down.
Now, I’ll walk through the pipeline wizard giving my pipeline a name and a source.
I’ll select which of the message attributes the pipeline should expect. This can draw from the channel with the sampling API and guess at which attributes are needed or I could upload a specification in JSON.
Next I define the pipeline activities. If I’m dealing with binary data I need a lambda function to first deserialize the message into JSON so the other filter functions can operate on it. I can create filters, calculate attributes based on other attributes, and I can also enrich the message with metadata from IoT core registry.
For now I just want to filter out some messages and make a small transform with a Lambda function.
Finally, I choose or create a data store to output the results of my pipeline.
Now that I have a data store, I can create a view of that data by creating a data set.
I’ll just select all the data from the data store for this dataset but I could also select individual attributes as needed.
I have a data set! I can adjust the cron expression in the schedule to re-run this as frequently or infrequently as I wish.
If I want to create a model from my data I can create a SageMaker powered Jupyter notebook. There are a few templates that are great starting points like anomaly detection or output forecasting.
Here you can see an example of the anomaly detection notebook.
Finally, if I want to create simple visualizations of my data I can use QuickSight to bring in an IoT Analytics data set.
Let Us Know
I’m excited to see what customers build with AWS IoT Analytics. My colleagues on the IoT teams are eager to hear your feedback about the service so please let us know in the comments or on Twitter what features you want to see.
AWS Config enables continuous monitoring of your AWS resources, making it simple to assess, audit, and record resource configurations and changes. AWS Config does this through the use of rules that define the desired configuration state of your AWS resources. AWS Config provides a number of AWS managed rules that address a wide range of security concerns such as checking if you encrypted your Amazon Elastic Block Store (Amazon EBS) volumes, tagged your resources appropriately, and enabled multi-factor authentication (MFA) for root accounts. You can also create custom rules to codify your compliance requirements through the use of AWS Lambda functions.
In this post we’ll show you how to use AWS Config to monitor our Amazon Simple Storage Service (S3) bucket ACLs and policies for violations which allow public read or public write access. If AWS Config finds a policy violation, we’ll have it trigger an Amazon CloudWatch Event rule to trigger an AWS Lambda function which either corrects the S3 bucket ACL, or notifies you via Amazon Simple Notification Service (Amazon SNS) that the policy is in violation and allows public read or public write access. We’ll show you how to do this in five main steps.
Enable AWS Config to monitor Amazon S3 bucket ACLs and policies for compliance violations.
Create an IAM Role and Policy that grants a Lambda function permissions to read S3 bucket policies and send alerts through SNS.
Create and configure a CloudWatch Events rule that triggers the Lambda function when AWS Config detects an S3 bucket ACL or policy violation.
Create a Lambda function that uses the IAM role to review S3 bucket ACLs and policies, correct the ACLs, and notify your team of out-of-compliance policies.
Verify the monitoring solution.
Note: This post assumes your compliance policies require the buckets you monitor not allow public read or write access. If you have intentionally open buckets serving static content, for example, you can use this post as a jumping-off point for a solution tailored to your needs.
At the end of this post, we provide an AWS CloudFormation template that implements the solution outlined. The template enables you to deploy the solution in multiple regions quickly.
Important: The use of some of the resources deployed, including those deployed using the provided CloudFormation template, will incur costs as long as they are in use. AWS Config Rules incur costs in each region they are active.
Architecture
Here’s an architecture diagram of what we’ll implement:
Figure 1: Architecture diagram
Step 1: Enable AWS Config and Amazon S3 Bucket monitoring
The following steps demonstrate how to set up AWS Config to monitor Amazon S3 buckets.
If this is your first time using AWS Config, select Get started. If you’ve already used AWS Config, select Settings.
In the Settings page, under Resource types to record, clear the All resources checkbox. In the Specific types list, select Bucket under S3.
Figure 2: The Settings dialog box showing the “Specific types” list
Choose the Amazon S3 bucket for storing configuration history and snapshots. We’ll create a new Amazon S3 bucket.
Figure 3: Creating an S3 bucket
If you prefer to use an existing Amazon S3 bucket in your account, select the Choose a bucket from your account radio button and, using the dropdown, select an existing bucket.
Figure 4: Selecting an existing S3 bucket
Under Amazon SNS topic, check the box next to Stream configuration changes and notifications to an Amazon SNS topic, and then select the radio button to Create a topic.
Alternatively, you can choose a topic that you have previously created and subscribed to.
Figure 5: Selecting a topic that you’ve previously created and subscribed to
If you created a new SNS topic you need to subscribe to it to receive notifications. We’ll cover this in a later step.
Under AWS Config role, choose Create a role (unless you already have a role you want to use). We’re using the auto-suggested role name.
Figure 6: Creating a role
Select Next.
Configure Amazon S3 bucket monitoring rules:
On the AWS Config rules page, search for S3 and choose the s3-bucket-publice-read-prohibited and s3-bucket-public-write-prohibited rules, then click Next.
Figure 7: AWS Config rules dialog
On the Review page, select Confirm. AWS Config is now analyzing your Amazon S3 buckets, capturing their current configurations, and evaluating the configurations against the rules we selected.
If you created a new Amazon SNS topic, open the Amazon SNS Management Console and locate the topic you created:
Figure 8: Amazon SNS topic list
Copy the ARN of the topic (the string that begins with arn:) because you’ll need it in a later step.
Select the checkbox next to the topic, and then, under the Actions menu, select Subscribe to topic.
Select Email as the protocol, enter your email address, and then select Create subscription.
After several minutes, you’ll receive an email asking you to confirm your subscription for notifications for this topic. Select the link to confirm the subscription.
Step 2: Create a Role for Lambda
Our Lambda will need permissions that enable it to inspect and modify Amazon S3 bucket ACLs and policies, log to CloudWatch Logs, and publishing to an Amazon SNS topic. We’ll now set up a custom AWS Identity and Access Management (IAM) policy and role to support these actions and assign them to the Lambda function we’ll create in the next section.
In the AWS Management Console, under Services, select IAM to access the IAM Console.
Create a policy with the following permissions, or copy the following policy:
Select Lambda from the list of services that will use this role.
Select the check box next to the policy you created previously, and then select Next: Review
Name your role, give it a description, and then select Create Role. In this example, we’re naming the role LambdaS3PolicySecuringRole.
Step 3: Create and Configure a CloudWatch Rule
In this section, we’ll create a CloudWatch Rule to trigger the Lambda function when AWS Config determines that your Amazon S3 buckets are non-compliant.
In the AWS Management Console, under Services, select CloudWatch.
On the left-hand side, under Events, select Rules.
Click Create rule.
In Step 1: Create rule, under Event Source, select the dropdown list and select Build custom event pattern.
Copy the following pattern and paste it into the text box:
The pattern matches events generated by AWS Config when it checks the Amazon S3 bucket for public accessibility.
We’ll add a Lambda target later. For now, select your Amazon SNS topic created earlier, and then select Configure details.
Figure 9: The “Create rule” dialog
Give your rule a name and description. For this example, we’ll name ours AWSConfigFoundOpenBucket
Click Create rule.
Step 4: Create a Lambda Function
In this section, we’ll create a new Lambda function to examine an Amazon S3 bucket’s ACL and bucket policy. If the bucket ACL is found to allow public access, the Lambda function overwrites it to be private. If a bucket policy is found, the Lambda function creates an SNS message, puts the policy in the message body, and publishes it to the Amazon SNS topic we created. Bucket policies can be complex, and overwriting your policy may cause unexpected loss of access, so this Lambda function doesn’t attempt to alter your policy in any way.
Get the ARN of the Amazon SNS topic created earlier.
In the AWS Management Console, under Services, select Lambda to go to the Lambda Console.
From the Dashboard, select Create Function. Or, if you were taken directly to the Functions page, select the Create Function button in the upper-right.
On the Create function page:
Choose Author from scratch.
Provide a name for the function. We’re using AWSConfigOpenAccessResponder.
The Lambda function we’ve written is Python 3.6 compatible, so in the Runtime dropdown list, select Python 3.6.
Under Role, select Choose an existing role. Select the role you created in the previous section, and then select Create function.
Figure 10: The “Create function” dialog
We’ll now add a CloudWatch Event based on the rule we created earlier.
In the Add triggers section, select CloudWatch Events. A CloudWatch Events box should appear connected to the left side of the Lambda Function and have a note that states Configuration required.
Figure 11: CloudWatch Events in the “Add triggers” section
From the Rule dropdown box, choose the rule you created earlier, and then select Add.
Scroll up to the Designer section and select the name of your Lambda function.
Delete the default code and paste in the following code:
import boto3
from botocore.exceptions import ClientError
import json
import os
ACL_RD_WARNING = "The S3 bucket ACL allows public read access."
PLCY_RD_WARNING = "The S3 bucket policy allows public read access."
ACL_WRT_WARNING = "The S3 bucket ACL allows public write access."
PLCY_WRT_WARNING = "The S3 bucket policy allows public write access."
RD_COMBO_WARNING = ACL_RD_WARNING + PLCY_RD_WARNING
WRT_COMBO_WARNING = ACL_WRT_WARNING + PLCY_WRT_WARNING
def policyNotifier(bucketName, s3client):
try:
bucketPolicy = s3client.get_bucket_policy(Bucket = bucketName)
# notify that the bucket policy may need to be reviewed due to security concerns
sns = boto3.client('sns')
subject = "Potential compliance violation in " + bucketName + " bucket policy"
message = "Potential bucket policy compliance violation. Please review: " + json.dumps(bucketPolicy['Policy'])
# send SNS message with warning and bucket policy
response = sns.publish(
TopicArn = os.environ['TOPIC_ARN'],
Subject = subject,
Message = message
)
except ClientError as e:
# error caught due to no bucket policy
print("No bucket policy found; no alert sent.")
def lambda_handler(event, context):
# instantiate Amazon S3 client
s3 = boto3.client('s3')
resource = list(event['detail']['requestParameters']['evaluations'])[0]
bucketName = resource['complianceResourceId']
complianceFailure = event['detail']['requestParameters']['evaluations'][0]['annotation']
if(complianceFailure == ACL_RD_WARNING or complianceFailure == PLCY_RD_WARNING):
s3.put_bucket_acl(Bucket = bucketName, ACL = 'private')
elif(complianceFailure == PLCY_RD_WARNING or complianceFailure == PLCY_WRT_WARNING):
policyNotifier(bucketName, s3)
elif(complianceFailure == RD_COMBO_WARNING or complianceFailure == WRT_COMBO_WARNING):
s3.put_bucket_acl(Bucket = bucketName, ACL = 'private')
policyNotifier(bucketName, s3)
return 0 # done
Scroll down to the Environment variables section. This code uses an environment variable to store the Amazon SNS topic ARN.
For the key, enter TOPIC_ARN.
For the value, enter the ARN of the Amazon SNS topic created earlier.
Under Execution role, select Choose an existing role, and then select the role created earlier from the dropdown.
Leave everything else as-is, and then, at the top, select Save.
Step 5: Verify it Works
We now have the Lambda function, an Amazon SNS topic, AWS Config watching our Amazon S3 buckets, and a CloudWatch Rule to trigger the Lambda function if a bucket is found to be non-compliant. Let’s test them to make sure they work.
We have an Amazon S3 bucket, myconfigtestbucket that’s been created in the region monitored by AWS Config, as well as the associated Lambda function. This bucket has no public read or write access set in an ACL or a policy, so it’s compliant.
Figure 12: The “Config Dashboard”
Let’s change the bucket’s ACL to allow public listing of objects:
Figure 13: Screen shot of “Permissions” tab showing Everyone granted list access
After saving, the bucket now has public access. After several minutes, the AWS Config Dashboard notes that there is one non-compliant resource:
Figure 14: The “Config Dashboard” shown with a non-compliant resource
In the Amazon S3 Console, we can see that the bucket no longer has public listing of objects enabled after the invocation of the Lambda function triggered by the CloudWatch Rule created earlier.
Figure 15: The “Permissions” tab showing list access no longer allowed
Notice that the AWS Config Dashboard now shows that there are no longer any non-compliant resources:
Figure 16: The “Config Dashboard” showing zero non-compliant resources
Now, let’s try out the Amazon S3 bucket policy check by configuring a bucket policy that allows list access:
Figure 17: A bucket policy that allows list access
A few minutes after setting this bucket policy on the myconfigtestbucket bucket, AWS Config recognizes the bucket is no longer compliant. Because this is a bucket policy rather than an ACL, we publish a notification to the SNS topic we created earlier that lets us know about the potential policy violation:
Figure 18: Notification about potential policy violation
Knowing that the policy allows open listing of the bucket, we can now modify or delete the policy, after which AWS Config will recognize that the resource is compliant.
Conclusion
In this post, we demonstrated how you can use AWS Config to monitor for Amazon S3 buckets with open read and write access ACLs and policies. We also showed how to use Amazon CloudWatch, Amazon SNS, and Lambda to overwrite a public bucket ACL, or to alert you should a bucket have a suspicious policy. You can use the CloudFormation template to deploy this solution in multiple regions quickly. With this approach, you will be able to easily identify and secure open Amazon S3 bucket ACLs and policies. Once you have deployed this solution to multiple regions you can aggregate the results using an AWS Config aggregator. See this post to learn more.
If you have feedback about this blog post, submit comments in the Comments section below. If you have questions about this blog post, start a new thread on the AWS Config forum or contact AWS Support.
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The Internet of Things (IoT) has precipitated to an influx of connected devices and data that can be mined to gain useful business insights. If you own an IoT device, you might want the data to be uploaded seamlessly from your connected devices to the cloud so that you can make use of cloud storage and the processing power to perform sophisticated analysis of data. To upload the data to the AWS Cloud, devices must pass authentication and authorization checks performed by the respective AWS services. The standard way of authenticating AWS requests is the Signature Version 4 algorithm that requires the caller to have an access key ID and secret access key. Consequently, you need to hardcode the access key ID and the secret access key on your devices. Alternatively, you can use the built-in X.509 certificate as the unique device identity to authenticate AWS requests.
AWS IoT has introduced the credentials provider feature that allows a caller to authenticate AWS requests by having an X.509 certificate. The credentials provider authenticates a caller using an X.509 certificate, and vends a temporary, limited-privilege security token. The token can be used to sign and authenticate any AWS request. Thus, the credentials provider relieves you from having to manage and periodically refresh the access key ID and secret access key remotely on your devices.
In the process of retrieving a security token, you use AWS IoT to create a thing (a representation of a specific device or logical entity), register a certificate, and create AWS IoT policies. You also configure an AWS Identity and Access Management (IAM) role and attach appropriate IAM policies to the role so that the credentials provider can assume the role on your behalf. You also make an HTTP-over-Transport Layer Security (TLS) mutual authentication request to the credentials provider that uses your preconfigured thing, certificate, policies, and IAM role to authenticate and authorize the request, and obtain a security token on your behalf. You can then use the token to sign any AWS request using Signature Version 4.
In this blog post, I explain the AWS IoT credentials provider design and then demonstrate the end-to-end process of retrieving a security token from AWS IoT and using the token to write a temperature and humidity record to a specific Amazon DynamoDB table.
Note: This post assumes you are familiar with AWS IoT and IAM to perform steps using the AWS CLI and OpenSSL. Make sure you are running the latest version of the AWS CLI.
Overview of the credentials provider workflow
The following numbered diagram illustrates the credentials provider workflow. The diagram is followed by explanations of the steps.
To explain the steps of the workflow as illustrated in the preceding diagram:
The AWS IoT device uses the AWS SDK or custom client to make an HTTPS request to the credentials provider for a security token. The request includes the device X.509 certificate for authentication.
The credentials provider forwards the request to the AWS IoT authentication and authorization module to verify the certificate and the permission to request the security token.
If the certificate is valid and has permission to request a security token, the AWS IoT authentication and authorization module returns success. Otherwise, it returns failure, which goes back to the device with the appropriate exception.
If assuming the role succeeds, AWS STS returns a temporary, limited-privilege security token to the credentials provider.
The credentials provider returns the security token to the device.
The AWS SDK on the device uses the security token to sign an AWS request with AWS Signature Version 4.
The requested service invokes IAM to validate the signature and authorize the request against access policies attached to the preconfigured IAM role.
If IAM validates the signature successfully and authorizes the request, the request goes through.
In another solution, you could configure an AWS Lambda rule that ingests your device data and sends it to another AWS service. However, in applications that require the uploading of large files such as videos or aggregated telemetry to the AWS Cloud, you may want your devices to be able to authenticate and send data directly to the AWS service of your choice. The credentials provider enables you to do that.
Outline of the steps to retrieve and use security token
Perform the following steps as part of this solution:
Create an AWS IoT thing: Start by creating a thing that corresponds to your home thermostat in the AWS IoT thing registry database. This allows you to authenticate the request as a thing and use thing attributes as policy variables in AWS IoT and IAM policies.
Register a certificate: Create and register a certificate with AWS IoT, and attach it to the thing for successful device authentication.
Create and configure an IAM role: Create an IAM role to be assumed by the service on behalf of your device. I illustrate how to configure a trust policy and an access policy so that AWS IoT has permission to assume the role, and the token has necessary permission to make requests to DynamoDB.
Create a role alias: Create a role alias in AWS IoT. A role alias is an alternate data model pointing to an IAM role. The credentials provider request must include a role alias name to indicate which IAM role to assume for obtaining a security token from AWS STS. You may update the role alias on the server to point to a different IAM role and thus make your device obtain a security token with different permissions.
Attach a policy: Create an authorization policy with AWS IoT and attach it to the certificate to control which device can assume which role aliases.
Request a security token: Make an HTTPS request to the credentials provider and retrieve a security token and use it to sign a DynamoDB request with Signature Version 4.
Use the security token to sign a request: Use the retrieved token to sign a request to DynamoDB and successfully write a temperature and humidity record from your home thermostat in a specific table. Thus, starting with an X.509 certificate on your home thermostat, you can successfully upload your thermostat record to DynamoDB and use it for further analysis. Before the availability of the credentials provider, you could not do this.
Deploy the solution
1. Create an AWS IoT thing
Register your home thermostat in the AWS IoT thing registry database by creating a thing type and a thing. You can use the AWS CLI with the following command to create a thing type. The thing type allows you to store description and configuration information that is common to a set of things.
Now, you need to have a Certificate Authority (CA) certificate, sign a device certificate using the CA certificate, and register both certificates with AWS IoT before your device can authenticate to AWS IoT. If you do not already have a CA certificate, you can use OpenSSL to create a CA certificate, as described in Use Your Own Certificate. To register your CA certificate with AWS IoT, follow the steps on Registering Your CA Certificate.
You then have to create a device certificate signed by the CA certificate and register it with AWS IoT, which you can do by following the steps on Creating a Device Certificate Using Your CA Certificate. Save the certificate and the corresponding key pair; you will use them when you request a security token later. Also, remember the password you provide when you create the certificate.
Run the following command in the AWS CLI to attach the device certificate to your thing so that you can use thing attributes in policy variables.
If the attach-thing-principal command succeeds, the output is empty.
3. Configure an IAM role
Next, configure an IAM role in your AWS account that will be assumed by the credentials provider on behalf of your device. You are required to associate two policies with the role: a trust policy that controls who can assume the role, and an access policy that controls which actions can be performed on which resources by assuming the role.
The following trust policy grants the credentials provider permission to assume the role. Put it in a text document and save the document with the name, trustpolicyforiot.json.
The following access policy allows DynamoDB operations on the table that has the same name as the thing name that you created in Step 1, MyHomeThermostat, by using credentials-iot:ThingName as a policy variable. I explain after Step 5 about using thing attributes as policy variables. Put the following policy in a text document and save the document with the name, accesspolicyfordynamodb.json.
Finally, run the following command in the AWS CLI to attach the access policy to your role.
aws iam attach-role-policy --role-name dynamodb-access-role --policy-arn arn:aws:iam::<your_aws_account_id>:policy/accesspolicyfordynamodb
If the attach-role-policy command succeeds, the output is empty.
Configure the PassRole permissions
The IAM role that you have created must be passed to AWS IoT to create a role alias, as described in Step 4. The user who performs the operation requires iam:PassRole permission to authorize this action. You also should add permission for the iam:GetRole action to allow the user to retrieve information about the specified role. Create the following policy to grant iam:PassRole and iam:GetRole permissions. Name this policy, passrolepermission.json.
Now, run the following command to attach the policy to the user.
aws iam attach-user-policy --policy-arn arn:aws:iam::<your_aws_account_id>:policy/passrolepermission --user-name <user_name>
If the attach-user-policy command succeeds, the output is empty.
4. Create a role alias
Now that you have configured the IAM role, you will create a role alias with AWS IoT. You must provide the following pieces of information when creating a role alias:
RoleAlias: This is the primary key of the role alias data model and hence a mandatory attribute. It is a string; the minimum length is 1 character, and the maximum length is 128 characters.
RoleArn: This is the Amazon Resource Name (ARN) of the IAM role you have created. This is also a mandatory attribute.
CredentialDurationSeconds: This is an optional attribute specifying the validity (in seconds) of the security token. The minimum value is 900 seconds (15 minutes), and the maximum value is 3,600 seconds (60 minutes); the default value is 3,600 seconds, if not specified.
Run the following command in the AWS CLI to create a role alias. Use the credentials of the user to whom you have given the iam:PassRole permission.
You created and registered a certificate with AWS IoT earlier for successful authentication of your device. Now, you need to create and attach a policy to the certificate to authorize the request for the security token.
Let’s say you want to allow a thing to get credentials for the role alias, Thermostat-dynamodb-access-role-alias, with thing owner Alice, thing type thermostat, and the thing attached to a principal. The following policy, with thing attributes as policy variables, achieves these requirements. After this step, I explain more about using thing attributes as policy variables. Put the policy in a text document, and save it with the name, alicethermostatpolicy.json.
If the attach-policy command succeeds, the output is empty.
You have completed all the necessary steps to request an AWS security token from the credentials provider!
Using thing attributes as policy variables
Before I show how to request a security token, I want to explain more about how to use thing attributes as policy variables and the advantage of using them. As a prerequisite, a device must provide a thing name in the credentials provider request.
Thing substitution variables in AWS IoT policies
AWS IoT Simplified Permission Management allows you to associate a connection with a specific thing, and allow the thing name, thing type, and other thing attributes to be available as substitution variables in AWS IoT policies. You can write a generic AWS IoT policy as in alicethermostatpolicy.json in Step 5, attach it to multiple certificates, and authorize the connection as a thing. For example, you could attach alicethermostatpolicy.json to certificates corresponding to each of the thermostats you have that you want to assume the role alias, Thermostat-dynamodb-access-role-alias, and allow operations only on the table with the name that matches the thing name. For more information, see the full list of thing policy variables.
Thing substitution variables in IAM policies
You also can use the following three substitution variables in the IAM role’s access policy (I used credentials-iot:ThingName in accesspolicyfordynamodb.json in Step 3):
credentials-iot:ThingName
credentials-iot:ThingTypeName
credentials-iot:AwsCertificateId
When the device provides the thing name in the request, the credentials provider fetches these three variables from the database and adds them as context variables to the security token. When the device uses the token to access DynamoDB, the variables in the role’s access policy are replaced with the corresponding values in the security token. Note that you also can use credentials-iot:AwsCertificateId as a policy variable; AWS IoT returns certificateId during registration.
6. Request a security token
Make an HTTPS request to the credentials provider to fetch a security token. You have to supply the following information:
Certificate and key pair: Because this is an HTTP request over TLS mutual authentication, you have to provide the certificate and the corresponding key pair to your client while making the request. Use the same certificate and key pair that you used during certificate registration with AWS IoT.
RoleAlias: Provide the role alias (in this example, Thermostat-dynamodb-access-role-alias) to be assumed in the request.
ThingName: Provide the thing name that you created earlier in the AWS IoT thing registry database. This is passed as a header with the name, x-amzn-iot-thingname. Note that the thing name is mandatory only if you have thing attributes as policy variables in AWS IoT or IAM policies.
Run the following command in the AWS CLI to obtain your AWS account-specific endpoint for the credentials provider. See the DescribeEndpoint API documentation for further details.
Note that if you are on Mac OS X, you need to export your certificate to a .pfx or .p12 file before you can pass it in the https request. Use OpenSSL with the following command to convert the device certificate from .pem to .pfx format. Remember the password because you will need it subsequently in a curl command.
Now, make an HTTPS request to the credentials provider to fetch a security token. You may use your preferred HTTP client for the request. I use curl in the following examples.
This command returns a security token object that has an accessKeyId, a secretAccessKey, a sessionToken, and an expiration. The following is sample output of the curl command.
Create a DynamoDB table called MyHomeThermostat in your AWS account. You will have to choose the hash (partition key) and the range (sort key) while creating the table to uniquely identify a record. Make the hash the serial_number of the thermostat and the range the timestamp of the record. Create a text file with the following JSON to put a temperature and humidity record in the table. Name the file, item.json.
You can use the accessKeyId, secretAccessKey, and sessionToken retrieved from the output of the curl command to sign a request that writes the temperature and humidity record to the DynamoDB table. Use the following commands to accomplish this.
In this blog post, I demonstrated how to retrieve a security token by using an X.509 certificate and then writing an item to a DynamoDB table by using the security token. Similarly, you could run applications on surveillance cameras or sensor devices that exchange the X.509 certificate for an AWS security token and use the token to upload video streams to Amazon Kinesis or telemetry data to Amazon CloudWatch.
If you have comments about this blog post, submit them in the “Comments” section below. If you have questions about or issues implementing this solution, start a new thread on the AWS IoT forum.
– Ramkishore
The collective thoughts of the interwebz
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