Integrating Assume Role in AWS Connectors for Secure Access

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In the world of AWS, managing secure access to resources is a top priority. One powerful feature that helps achieve this is the ability to "assume a role." This allows connectors, tools, or services that interact with AWS to temporarily acquire specific permissions without relying on permanent credentials. In this blog, we’ll explore what it means to assume a role, how to integrate it with AWS connectors, and why it’s a game-changer for security.

What does Assume Role mean in AWS?

In AWS, a role is an identity with permission policies that define what it can and cannot do. When a connector assumes a role, it uses the AWS Security Token Service (STS) to obtain temporary security credentials. These credentials grant access to AWS services for a limited time—typically one hour by default, though this can be adjusted.

This approach is particularly useful for connectors that need to perform tasks such as deploying resources, accessing S3 buckets, or managing EC2 instances. Instead of embedding long-term access keys, connectors can assume a role and use temporary credentials under the hood, thereby enhancing security and control.

Why use Assume Role with connectors?

Integrating the assume role command offers several advantages:

• Enhanced security: Temporary credentials expire, reducing the risk if they’re compromised.

• Least privilege: Roles can be tailored to grant only the permissions needed for a specific task.

• Flexibility: Connectors can assume different roles depending on the context or environment.

For example, an Amazon S3 connector might need to create a bucket or object. By assuming a role with bucket- and object-level permissions it avoids the need for broad, permanent access.

How to integrate Assume Role with AWS connectors

Follow these steps to configure AssumeRole for a connector.

Step 1: Create a role in AWS IAM

1. In the AWS Management Console, go to IAM > Roles > Create role.

2. Choose the trusted entity:

• For same-account access, select an AWS service (such as EC2 or Lambda).

• For cross-account access, select Another AWS account and enter the account ID.

3. Attach permission policies:

• Use predefined policies (e.g., AmazonS3FullAccess) or create a custom policy.

• Example: A policy that allows s3:PutObject or s3:GetObject.

4. Name the role (e.g., ConnectorDeploymentRole) and save it.

5. Copy the role’s Amazon Resource Name (ARN).

Step 2: Create a policy for assuming the role

Create an IAM policy that allows the sts:AssumeRole action for the role created in Step 1. This policy will be attached to a user or entity that needs to assume the role.

1. In IAM, go to Policies > Create policy.

2. Use the JSON editor to define a policy that allows sts:AssumeRole:

   {
       "Version": "2012-10-17",
       "Statement": [
           {
               "Sid": "AllowAssumeRole",
               "Effect": "Allow",
               "Action": "sts:AssumeRole",
               "Resource": "arn:aws:iam::123456789012:role/ConnectorDeploymentRole"
           }
       ]
   }

3. Name the policy (for example, AssumeConnectorRolePolicy) and save it.

Step 3: Create a user and attach the policy

1. In the IAM dashboard, go to Users > Add users.

2. Enter a username (for example, ConnectorUser) and create the user.

3. Skip adding permissions directly to the user (we’ll attach the policy next).

4. Create the user.

5. In the user’s details, go to Permissions > Add permissions > Attach existing policies directly.

6. Select the AssumeConnectorRolePolicy created in Step 2 and attach it.

Step 4: Generate Access Key ID and Secret Access Key

1. In the IAM dashboard, go to Users and select ConnectorUser.

2. Navigate to the Security credentials tab.

3. Under Access keys, click Create access key.

4. Choose Application running outside AWS or another relevant use case, then create the key.

5. Download or copy the Access Key ID and Secret Access Key. Store them securely, as they will be used by the connector.

For detailed information, see Obtaining connection values for Amazon EventBridge (as an example for Amazon EventBridge connector) on the IBM App Connect documentation page.

Security benefits and best practices

• Temporary Credentials: They expire (default: 1 hour), so set a duration that balances convenience and security.

• Least Privilege: Grant only the permissions required for the task.

Use case

Many organizations develop applications that require access to multiple AWS services to support complex workflows, such as data storage, compute operations, database queries, and real-time data streaming. Hardcoding long-term IAM user credentials in these applications is insecure and difficult to manage. It increases the risk of credential exposure and complicates rotation.

By using the AssumeRole command, an application can assume a role (for example, MultiServiceAccessRole) with permissions tailored for services such as:

• Amazon S3 (s3:PutObject)

• Amazon EC2 (ec2:RunInstances)

• Amazon RDS (rds:DescribeDBInstances)

• Amazon Kinesis (kinesis:PutRecord)

The application uses an IAM user’s access keys to call AssumeRole, obtaining temporary credentials that expire after a set duration. This ensures secure and controlled access to these services.

This approach is particularly valuable for applications such as a data processing pipeline, which might:

• Upload raw data to an S3 bucket

• Launch EC2 instances for computation

• Query metadata from an RDS database

• Stream processed results to Kinesis

Temporary credentials minimize security risks, as they are valid only for the session duration (for example, 1 hour). The role’s permissions can be finely tuned to allow only the necessary actions, adhering to the principle of least privilege. This setup simplifies credential management, enhances security, and supports seamless interaction with multiple AWS services.

Assume Role exchange flow

Conclusion

Integrating the assume role command with AWS connectors is a best practice for secure, temporary access to AWS services. Whether you’re automating deployments, managing cross-account access, or running data workflows, this approach reduces risk and aligns with modern cloud security principles. Start implementing role assumption today—your AWS environment will be safer for it!

Integrating the assume role command with AWS connectors is a best practice for secure, temporary access to AWS services. Whether you’re automating deployments, managing cross-account access, or running data workflows, this approach reduces risk and aligns with modern cloud security principles.

Start implementing role assumption today; your AWS environment will be safer for it.