AWS IAM Identity Center

AWS IAM Identity Center, formerly known as AWS Single Sign-On (AWS SSO), addresses the complex challenge of managing access to multiple AWS accounts and applications by providing a centralized single sign-on (SSO) solution. This service allows you to create or connect your workforce identities once and manage their access centrally across all your AWS accounts and applications.

Technically, IAM Identity Center integrates with various identity sources such as Microsoft Active Directory, Microsoft Entra ID, Okta, and others, using standards-based protocols like SAML 2.0. This integration enables seamless authentication and authorization, allowing users to access AWS resources, applications, and even Amazon EC2 Windows instances with a single set of credentials. The architecture leverages the existing AWS Identity and Access Management (IAM) and AWS Organizations capabilities to manage fine-grained access to all accounts within an AWS Organization.

Operationally, IAM Identity Center streamlines user and group management by making identity information from your chosen identity source available centrally. This facilitates easier auditing and management of user access to AWS applications. However, it requires careful configuration, especially when managing access across multiple AWS accounts, to ensure consistent and secure access. For instance, administrators need to set up the appropriate SAML configurations, manage session durations (which default to 8 hours but can be adjusted), and handle trusted device settings to optimize the user experience.

Specifically, IAM Identity Center supports various security standards and is available in 21 regions globally, ensuring scalability and compliance. It also allows for role switching, enabling users to temporarily assume different permissions without needing to sign out and back in. This flexibility, however, comes with the need for careful role management to avoid unintended access privileges.