user authentication

Authentication is essential for security in enterprise environments, protecting sensitive data and resources from unauthorized access. Kerberos authentication is utilized for Amazon Aurora PostgreSQL-Compatible Edition with AWS Directory Service for Microsoft Active Directory, particularly through the pg_ad_mapping extension, which enhances access control management. Aurora PostgreSQL supports multiple authentication methods, including password authentication, AWS Identity and Access Management (IAM) database authentication, and Kerberos authentication. By default, password authentication is enabled, while IAM and Kerberos can be used independently. Users are assigned specific roles based on the authentication method: rds_iam for IAM, rds_ad for Kerberos, and no specific roles for password authentication. Kerberos authentication integrates with Microsoft Active Directory, allowing centralized authentication and single sign-on (SSO) capabilities. With versions 14.10 and 15.5, Aurora PostgreSQL introduced the pg_ad_mapping extension, which allows administrators to manage access through Active Directory (AD) security groups instead of provisioning individual users. This extension checks AD group memberships upon user login and assigns corresponding database roles, prioritizing roles based on assigned weights. The pg_ad_mapping extension includes functions such as pgadmap_set_mapping to add mappings between AD security groups and database roles, pgadmap_read_mapping to list existing mappings, and pgadmap_reset_mapping to delete or reset mappings. To deploy the solution, a CloudFormation stack is used to create necessary resources, including an AWS Managed Microsoft AD server, an Aurora PostgreSQL database cluster, and a Windows EC2 instance. Users can be added to AD groups, and roles can be mapped to facilitate access management. Security best practices for Aurora PostgreSQL include using IAM policies for resource management, implementing security groups for database access control, utilizing encryption for data protection, and employing Transport Layer Security (TLS) for secure connections. For auditing, the pg_stat_gssapi view can be used to identify authenticated users, and enabling the log_connections parameter will log session establishments, including AD user identities.