Beyond IAM access keys: Modern authentication approaches for AWS

When it comes to AWS authentication, relying on long-term credentials, such as AWS Identity and Access Management (IAM) access keys, introduces unnecessary risks; including potential credential exposure, unauthorized sharing, or theft. In this post, I present five common use cases where AWS customers traditionally use IAM access keys and present more secure alternatives that you should consider.

AWS CLI access: Embrace CloudShell

If you’re primarily using access keys for AWS Command Line Interface (AWS CLI) access, consider AWS CloudShell—a browser-based CLI that minimizes the need for local credential management while providing the same powerful CLI capabilities that you’re accustomed to.

AWS CLI with enhanced security: IAM Identity Center

If you need a more robust solution, AWS CLI v2 combined with AWS IAM Identity Center offers a superior authentication approach. This integration enables:

• Centralized user management
• Seamless multi-factor authentication (MFA) integration
• Enhanced security controls

Configuration is straightforward using the AWS CLI documentation, and MFA can be enabled following the IAM Identity Center MFA guide.

Local development: IDE integration

For developers working in local environments, modern integrated development environments (IDEs) such as Visual Studio Code, with AWS Toolkit support offer secure authentication through IAM Identity Center. This alleviates the need for static access keys while maintaining a smooth development experience. Learn more about AWS IDE integrations.

AWS compute services and CI/CD access

When your applications and automation pipelines need AWS resource access, whether running on AWS compute services (Amazon Elastic Compute Cloud (Amazon EC2), Amazon Elastic Container Service (Amazon ECS), or AWS Lambda) or through continuous integration and delivery (CI/CD) tools, IAM roles can provide the ideal solution. These roles automatically manage temporary credential rotation and follow security best practices.

• For AWS compute services: Use standard IAM roles with your compute resources. Review the EC2 IAM roles documentation for implementation details.
• For AWS-hosted CI/CD: When using AWS CodePipeline or AWS CodeBuild for example, use service-linked roles to manage permissions securely.
• For CI/CD tools self-hosted on Amazon EC2: If you’re running tools such as Jenkins or GitLab on AWS resources, use the instance profile roles the same as you would with other compute services.

For third-party CI/CD services (such as GitHub Actions, CircleCI, and so on), see External access requirements.

External access requirements

For scenarios involving third-party applications or on-premises workloads, AWS offers three methods:

• Third-party applications: Implement temporary security credentials through IAM roles instead of static access keys. Never use root account access keys. See third-party access documentation.
• On-premises workloads: Use AWS IAM Roles Anywhere to generate temporary credentials for non-AWS workloads. For more information, see Access for non AWS workloads.
• CI/CD software as a service (SaaS): For cloud-based CI/CD services, use OpenID Connect (OIDC) integration with IAM roles to minimize the need for long-term credentials. This allows your CI/CD pipelines to obtain temporary credentials through trust relationships. See the AWS OIDC provider documentation for implementation details.

Best practice: Principle of least privilege

Regardless of your authentication method, always implement the principle of least privilege. This helps make sure that users and applications have only the permissions they need. For guidance on crafting precise IAM policies, see Techniques for writing least privilege IAM policies.

Note: AWS also offers policy generation based on AWS CloudTrail logs, helping you create permission templates based on actual usage patterns. Learn about this feature in the IAM policy generation documentation.

Conclusion

As you’ve seen, there are numerous secure alternatives to IAM access keys that you can use to enhance your AWS authentication strategy while reducing security risks. By using tools such as CloudShell, IAM Identity Center, IDE integrations, IAM roles, and IAM Roles Anywhere, you can implement robust authentication mechanisms that align with modern security best practices.Key takeaways:

• Prefer temporary credentials over long-term access keys
• Choose the authentication method that best fits your use case
• Implement the principle of least privilege across all access methods
• Take advantage of the built-in tools provided by AWS for policy generation and management
• Regularly review and update your authentication methods as new solutions become available

By making these changes, you can not only improve your security posture but also streamline your authentication processes across your AWS environment. Start small by identifying your current IAM access key use cases and gradually transition to these more secure alternatives. Your future self—and your security team—will thank you.

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