ZeroTrustKerberosLink Identity Federation Architecture¶
Overview¶
This document provides a detailed architectural overview of how ZeroTrustKerberosLink enables secure identity federation between enterprise Kerberos authentication systems and AWS Identity and Access Management (IAM). The architecture implements Zero Trust principles while providing a seamless authentication experience for users.
Identity Federation Flow¶
The following diagram illustrates the end-to-end identity federation flow from user authentication via Kerberos to AWS service access:
┌─────────────────┐ ┌───────────────────────────────────────┐ ┌───────────────────┐
│ │ │ │ │ │
│ Enterprise │ │ ZeroTrustKerberosLink │ │ AWS │
│ Environment │ │ │ │ Environment │
│ │ │ │ │ │
└────────┬────────┘ └─────────────────┬─────────────────────┘ └─────────┬─────────┘
│ │ │
│ │ │
┌────────▼────────┐ ┌────────────────▼──────────────────┐ ┌─────────▼─────────┐
│ │ │ │ │ │
│ User with │ 1 │ │ │ │
│ Kerberos ├────►│ Authentication Gateway │ │ │
│ Credentials │ │ │ │ │
│ │ │ │ │ │
└────────┬────────┘ └────────────────┬──────────────────┘ │ │
│ │ │ │
│ │ │ │
│ ┌────────────────▼──────────────────┐ │ │
│ │ │ │ │
│ │ Kerberos Ticket Validator │ │ │
│ │ │ │ │
│ └────────────────┬──────────────────┘ │ │
│ │ │ │
│ │ 2 │ │
│ ┌────────────────▼──────────────────┐ │ │
│ │ │ │ │
│ │ Identity Attribute Service │ │ │
│ │ │ │ │
│ └────────────────┬──────────────────┘ │ │
│ │ │ │
│ │ 3 │ │
│ ┌────────────────▼──────────────────┐ │ │
│ │ │ │ │
│ │ Role Mapping Engine │ │ │
│ │ │ │ │
│ └────────────────┬──────────────────┘ │ │
│ │ │ │
│ │ 4 │ │
│ ┌────────────────▼──────────────────┐ │ │
│ │ │ │ │
│ │ Policy Decision Point │ │ │
│ │ │ │ │
│ └────────────────┬──────────────────┘ │ │
│ │ │ │
│ │ 5 │ │
│ ┌────────────────▼──────────────────┐ ┌─────────▼─────────┐
│ │ │ 6 │ │
│ │ AWS STS Client ├────►│ AWS STS │
│ │ │ │ │
│ └────────────────┬──────────────────┘ └─────────┬─────────┘
│ │ │
│ │ 7 │
│ ┌────────────────▼──────────────────┐ ┌─────────▼─────────┐
│ │ │ │ │
│ │ Credential Management Service │◄────┤ Temporary AWS │
│ │ │ │ Credentials │
│ └────────────────┬──────────────────┘ │ │
│ │ └─────────┬─────────┘
│ │ 8 │
┌────────▼────────┐ ┌────────────────▼──────────────────┐ │
│ │ │ │ │
│ User with │◄────┤ Secure Credential Delivery │ │
│ AWS Access │ 9 │ │ │
│ │ │ │ │
└────────┬────────┘ └────────────────┬──────────────────┘ │
│ │ │
│ 10 │ │
│ │ │
┌────────▼────────┐ │ ┌───────────▼─────────┐
│ │ │ │ │
│ AWS Service │ │ │ AWS IAM │
│ Access │◄─────────────────────┼───────────────────────┤ Authorization │
│ │ │ │ │
└─────────────────┘ │ └─────────────────────┘
│
│
┌──────────▼─────────────┐
│ │
│ Continuous Session │
│ Monitoring │
│ │
└────────────────────────┘
Process Flow Description¶
The identity federation process follows these steps:
1. User Authentication¶
The user initiates authentication using their Kerberos credentials. This can occur through: - Web-based authentication portal - Command-line interface - Integrated application authentication
The authentication request is directed to the ZeroTrustKerberosLink Authentication Gateway.
2. Kerberos Ticket Validation¶
The Kerberos Ticket Validator component: - Validates the Kerberos ticket with the enterprise KDC (Key Distribution Center) - Verifies ticket integrity and authenticity - Checks ticket expiration and validity - Extracts the user principal name and other attributes
3. Identity Attribute Resolution¶
The Identity Attribute Service: - Queries enterprise directory services (Active Directory, LDAP) for additional user attributes - Retrieves group memberships, roles, and other authorization-relevant attributes - Normalizes attributes for consistent processing - Enriches the user identity context
4. Role Mapping¶
The Role Mapping Engine: - Maps the authenticated Kerberos principal to appropriate AWS IAM roles - Applies mapping rules based on user attributes and group memberships - Determines the scope of access (which AWS accounts and services) - Applies time-based and context-based restrictions
5. Policy Evaluation¶
The Policy Decision Point: - Evaluates access policies against the user's identity and context - Applies additional restrictions based on environmental factors - Determines the final set of permissions - Creates a structured authorization decision
6. AWS STS Integration¶
The AWS STS Client: - Requests temporary AWS credentials from AWS Security Token Service (STS) - Uses appropriate AWS STS API calls based on the role mapping - Implements AssumeRole, AssumeRoleWithSAML, or AssumeRoleWithWebIdentity as appropriate - Includes proper session tags for attribution and context
7. Credential Issuance¶
AWS STS issues temporary security credentials that include: - Access key ID - Secret access key - Session token - Expiration time
8. Credential Management¶
The Credential Management Service: - Securely stores temporary credentials - Manages credential lifecycle - Handles credential rotation - Implements secure credential destruction
9. Credential Delivery¶
The Secure Credential Delivery component: - Delivers credentials to the user through secure channels - Configures AWS SDK or CLI with the credentials - Sets up appropriate credential profiles - Provides clear usage instructions
10. AWS Service Access¶
The user can now access AWS services: - Using temporary credentials with limited permissions - Subject to continuous monitoring and verification - With time-limited access - According to the principle of least privilege
Security Controls¶
The identity federation architecture implements multiple security controls:
Authentication Controls¶
- Multi-factor Authentication: Optional additional authentication factors
- Certificate Validation: Verification of certificate validity and trust chains
- Ticket Integrity Verification: Cryptographic verification of Kerberos tickets
- Authentication Strength Evaluation: Assessment of authentication strength
Authorization Controls¶
- Fine-grained Access Control: Precise control over resource access
- Least Privilege Enforcement: Minimal necessary permissions
- Time-based Restrictions: Limitations on when access is permitted
- Context-aware Authorization: Consideration of environmental factors
Monitoring Controls¶
- Session Monitoring: Real-time monitoring of active sessions
- Anomaly Detection: Identification of unusual access patterns
- Comprehensive Logging: Detailed logging of all federation activities
- Alert Generation: Automated alerts for suspicious activities
Cryptographic Controls¶
- Strong Encryption: Protection of all sensitive data
- Secure Key Management: Proper handling of cryptographic keys
- Secure Communication: Encrypted channels for all communications
- Credential Protection: Safeguarding of temporary credentials
AWS IAM Integration¶
ZeroTrustKerberosLink integrates with AWS IAM through the following mechanisms:
AWS STS API Integration¶
- AssumeRole: Used when mapping to specific IAM roles
- AssumeRoleWithSAML: Used with SAML-based federation
- AssumeRoleWithWebIdentity: Used with web identity providers
- GetFederationToken: Used for federated user access
IAM Role Configuration¶
- Trust Relationships: Properly configured trust policies
- Permission Boundaries: Limits on maximum permissions
- Session Policies: Dynamic restrictions on sessions
- Session Tags: Contextual information in session
Temporary Credential Management¶
- Short Lifetimes: Brief validity periods for credentials
- Automatic Rotation: Regular renewal of credentials
- Secure Storage: Protection of credentials at rest
- Secure Transmission: Protection of credentials in transit
Deployment Scenarios¶
ZeroTrustKerberosLink supports multiple deployment scenarios:
On-premises Deployment¶
- ZeroTrustKerberosLink deployed within enterprise network
- Direct connectivity to Kerberos infrastructure
- Secure connection to AWS via Direct Connect or VPN
- Full control over all components
AWS VPC Deployment¶
- ZeroTrustKerberosLink deployed within AWS VPC
- Secure connection to on-premises Kerberos via Direct Connect or VPN
- Internal AWS network connectivity
- Cloud-native deployment model
Hybrid Deployment¶
- Components distributed across on-premises and AWS
- Authentication components near Kerberos infrastructure
- AWS integration components near AWS services
- Optimized for performance and security
Security Considerations¶
The identity federation architecture addresses several security considerations:
Trust Establishment¶
- Verification of all trust relationships
- Validation of trust chains
- Explicit trust configuration
- Regular trust verification
Credential Protection¶
- Secure handling of all credentials
- Minimal credential lifetime
- Secure credential storage
- Proper credential destruction
Attack Surface Reduction¶
- Minimal network exposure
- Limited service interfaces
- Strong boundary controls
- Defense in depth
Monitoring and Detection¶
- Comprehensive activity logging
- Real-time monitoring
- Anomaly detection
- Incident response integration
Conclusion¶
The ZeroTrustKerberosLink identity federation architecture provides a secure bridge between enterprise Kerberos authentication and AWS IAM. By implementing Zero Trust principles and strong security controls, it enables organizations to leverage AWS services while maintaining their existing authentication infrastructure and security posture.
For more detailed information about the implementation or deployment options, please contact our security team at security@zerotrustkerberoslink.com.