AWS federated access and identity services (for example, AWS Identity and Access Management [IAM], AWS IAM Identity Center [AWS Single Sign-On])

When it comes to managing access to AWS resources and services securely, AWS offers a suite of identity services to fit a variety of use cases. Federated access allows users from external systems to gain access to AWS resources without the need to create individual IAM users for each of them within AWS. This is particularly useful for organizations that want to manage user access centrally, often using their existing identity solutions, such as Active Directory or LDAP directories.

AWS Identity and Access Management (IAM)

AWS IAM is a foundational service that helps you securely control access to AWS services and resources. With IAM, you can create and manage AWS users and groups, and use permissions to allow and deny their access to AWS resources.

IAM allows you to:

• Create IAM users and assign them individual security credentials (like access keys, passwords, and multi-factor authentication devices).
• Create IAM roles for different scenarios, including federated user access. A role can be assumed by anyone who needs it and has the correct permissions.
• Manage permissions by creating policies in JSON format, which define what actions are allowed or denied on specific AWS resources.

AWS IAM Identity Center (Previously AWS Single Sign-On)

AWS IAM Identity Center simplifies the management of SSO access and user permissions to all of your AWS accounts in AWS Organizations. With IAM Identity Center, you can create SSO access to AWS SSO-integrated applications, such as Salesforce, Box, and Office 365.

Key features of IAM Identity Center include:

• The ability to manage SSO access and permissions to all your AWS accounts in AWS Organizations.
• Centralized management of federated access across multiple AWS accounts.
• Customizable identity synchronization which connects IAM Identity Center to external identity sources.
• A user portal where end users can find and access all their assigned AWS accounts, cloud applications, and custom applications in one place.

Integration with External Identity Providers

To enable federated access, both IAM and IAM Identity Center allow integration with external identity providers. Organizations can leverage their existing identity solutions (like Microsoft AD or LDAP) to permit users to access the AWS Management Console or call AWS APIs using their existing corporate credentials.

Examples of Federated Access Scenarios

1. Federating with a Corporate Directory: This allows users in an organization to use their corporate credentials to access the AWS Management Console or make programmatic calls to AWS APIs.
2. Single Sign-On to AWS accounts: With AWS IAM Identity Center, you can allow users to sign in once to a central portal and gain access to multiple AWS accounts and applications without needing to sign in again.
3. Cross-Account Access: You can use IAM roles to allow users who are authenticated in one AWS account to access resources in another AWS account.

IAM Policies and Permissions

IAM policies dictate the level of access a user or federated user has within AWS. These policies are written in JSON and consist of statements that declare the allowed or denied actions.

Here’s a very simple example policy that grants read-only access to Amazon S3:

{
“Version”: “2012-10-17”,
“Statement”: [
{
“Effect”: “Allow”,
“Action”: “s3:Get*”,
“Resource”: “*”
}
]
}

Considerations for Certification

When preparing for the AWS Certified Solutions Architect – Associate (SAA-C03) exam, it’s essential to understand federated access and identity services in depth. Specifically, you should be familiar with:

• The differences between IAM users, groups, roles, and policies.
• How to establish trust between AWS and third-party identity providers.
• Best practices for securing IAM and IAM Identity Center, including the principle of least privilege.
• How IAM Identity Center can be used to manage SSO and federated access.
• The process of integrating AWS IAM with external directories for federated user access.

In summary, AWS federated access and identity services like IAM and IAM Identity Center provide robust mechanisms for managing users and their permissions across AWS environments. Understanding how these services work is crucial for designing secure, efficient, and scalable systems on AWS, which is key for anyone preparing for the AWS Certified Solutions Architect – Associate exam.