Federated access with identity providers is a crucial security concept in AWS that allows users to access AWS resources using credentials from external identity systems, eliminating the need to create individual IAM users for everyone.
Identity federation enables organizations to leverage existing…Federated access with identity providers is a crucial security concept in AWS that allows users to access AWS resources using credentials from external identity systems, eliminating the need to create individual IAM users for everyone.
Identity federation enables organizations to leverage existing identity management systems like Microsoft Active Directory, SAML 2.0 compliant providers, or social identity providers such as Google, Facebook, and Amazon. This approach follows the principle of single sign-on (SSO), where users authenticate once with their corporate or social credentials and gain access to AWS resources.
AWS supports several federation mechanisms:
1. **SAML 2.0 Federation**: Enterprises can integrate their existing identity providers (IdPs) that support SAML 2.0 with AWS. Users authenticate against the corporate IdP, receive a SAML assertion, and exchange it for temporary AWS credentials through AWS STS (Security Token Service).
2. **Web Identity Federation**: Mobile and web applications can use OpenID Connect (OIDC) providers like Google or Facebook. Amazon Cognito is the recommended service for this, handling token exchange and providing temporary credentials.
3. **AWS IAM Identity Center**: This service provides centralized access management across multiple AWS accounts and applications, supporting both SAML and OIDC protocols.
The federation process typically involves:
- User authenticates with the identity provider
- IdP returns a token or assertion
- Application calls AWS STS AssumeRoleWithSAML or AssumeRoleWithWebIdentity
- STS returns temporary credentials (access key, secret key, session token)
- User accesses AWS resources using these temporary credentials
Key benefits include enhanced security through temporary credentials, reduced administrative overhead, centralized user management, and compliance with organizational authentication policies. Developers should understand IAM roles for federation, trust policies, and how to properly configure identity provider integration for the certification exam.
Federated Access with Identity Providers - AWS Developer Associate Guide
Why Federated Access is Important
Federated access is crucial for enterprise environments where organizations need to allow users to access AWS resources using their existing corporate credentials. Instead of creating separate IAM users for every employee, federation enables single sign-on (SSO) capabilities, reducing administrative overhead and improving security by centralizing identity management.
What is Federated Access?
Federated access allows external identities from identity providers (IdPs) to obtain temporary AWS credentials. Users authenticate with their organization's identity system and receive temporary security credentials to access AWS services.
Key components include: - Identity Provider (IdP): The trusted system that authenticates users (e.g., Active Directory, Okta, Google) - Security Token Service (STS): AWS service that issues temporary credentials - SAML 2.0: Industry standard protocol for exchanging authentication data - OpenID Connect (OIDC): Modern authentication protocol built on OAuth 2.0 - Web Identity Federation: Allows users to sign in via social identity providers
How Federated Access Works
SAML 2.0 Federation Flow: 1. User authenticates with corporate IdP 2. IdP returns SAML assertion 3. Application calls AWS STS AssumeRoleWithSAML 4. STS validates assertion and returns temporary credentials 5. User accesses AWS resources with temporary credentials
Web Identity Federation Flow: 1. User authenticates with web IdP (Amazon, Facebook, Google, or OIDC provider) 2. IdP returns authentication token 3. Application calls STS AssumeRoleWithWebIdentity 4. STS returns temporary credentials 5. User accesses AWS resources
Amazon Cognito Flow (Recommended for mobile/web apps): 1. User authenticates with IdP 2. Token exchanged with Cognito Identity Pool 3. Cognito provides temporary AWS credentials 4. User accesses AWS resources
Key AWS Services and APIs
- AWS STS APIs: - AssumeRole: For cross-account access - AssumeRoleWithSAML: For SAML-based federation - AssumeRoleWithWebIdentity: For web identity federation - GetFederationToken: For custom federation broker
- Amazon Cognito: - User Pools: User directory for authentication - Identity Pools: Provides temporary AWS credentials
- IAM Identity Center (formerly AWS SSO): - Centralized SSO for multiple AWS accounts - Integrates with external IdPs
IAM Roles for Federation
Federated users assume IAM roles to gain permissions. The role's trust policy must specify: - The identity provider ARN - Conditions for assuming the role - The federated principal type
Exam Tips: Answering Questions on Federated Access with Identity Providers
Key Patterns to Recognize:
1. Corporate SSO scenarios: When questions mention Active Directory, LDAP, or corporate credentials accessing AWS, think SAML 2.0 federation or IAM Identity Center
2. Mobile/Web app authentication: When questions involve mobile apps or web applications with social login, think Amazon Cognito first, then Web Identity Federation
3. Cognito vs Web Identity Federation: AWS recommends Cognito over calling AssumeRoleWithWebIdentity for mobile apps. Cognito handles token refresh and provides additional features
4. Temporary credentials: All federation methods provide temporary credentials, never permanent access keys
5. Custom Identity Broker: For non-SAML compatible IdPs, use GetFederationToken or AssumeRole with a custom broker
Common Exam Scenarios:
- Scenario: Company wants employees to use corporate credentials for AWS Console access Answer: SAML 2.0 federation with AssumeRoleWithSAML or IAM Identity Center
- Scenario: Mobile app needs to access S3 using Facebook login Answer: Amazon Cognito Identity Pools
- Scenario: Thousands of users need temporary access, cannot create IAM users Answer: Federation with identity provider
Remember These Key Points:
- Cognito Identity Pools support both authenticated and unauthenticated access - SAML assertions have a maximum duration of 12 hours - IAM roles used for federation require trust policies specifying the IdP - Web Identity Federation supports Amazon, Facebook, Google, and any OIDC-compatible IdP - Federation eliminates the need to distribute long-term AWS credentials