Welcome back to the Day 6 of PG18 Hacktober and we’re amazed at the security features that were added in PG18, no wonder PostgreSQL is The World’s Most Advanced Open Source Relational Database and one of the most vibrant FOSS communities.
Here’s our final blog on the Security features focussing on OAuth Authorization/Authentication . If you haven’t read our remaining blog post on Security features . They are available below:
- Secure Password Hashing with SHA-2 Algorithms
- Richer SSL/TLS configuration options in PostgreSQL
- FIPS mode validation
PostgreSQL 18 marks a significant milestone in database security and authentication by introducing native OAuth 2.0 support. This feature aligns PostgreSQL with modern identity management and Single Sign-On (SSO) practices, allowing secure token-based authentication instead of relying solely on traditional password-based methods.
OAuth 2.0 is a widely adopted authorization framework that enables third-party applications to access protected resources on behalf of a user using access tokens (bearer tokens). PostgreSQL 18 implements this standard by allowing clients to authenticate using these bearer tokens issued by external Identity Providers (IdPs), such as Google, Microsoft Entra, Keycloak, Auth0, or Okta.
Instead of sending a password, the client presents an OAuth bearer token, which PostgreSQL verifies through a pluggable validator module before mapping the authenticated identity to a database role. This integration allows organizations to unify their database authentication with existing centralized identity providers, simplifying user management and improving security.
What does the documentation says?
OAuth 2.0 is an industry-standard framework, defined in RFC 6749, to enable third-party applications to obtain limited access to a protected resource.
In order for validation to happen server side a new framework for plugging in OAuth validation modules is added. As validation is implementation specific, with no default specified in the standard, PostgreSQL does not ship with one built-in. Each pg_hba entry can specify a specific validator or be left blank for the validator installed as default.
This feature enables a range of authentication scenarios like:
- Single Sign-On (SSO) for database access
- Centralized user management through your existing identity provider
- Token-based authentication that eliminates password storage in applications
- Fine-grained access control through OAuth scopes
PostgreSQL validates tokens but doesn’t issue them, that’s handled by your OAuth provider (Google, Microsoft Azure AD, Keycloak, Auth0, etc.).
Security Benefits
- Eliminates Password Storage: Since authentication uses short-lived tokens, there’s no need to store database-specific passwords in applications, reducing attack surfaces.
- Centralized User Management: Leverages enterprise IdPs for unified user lifecycle management — onboarding, offboarding, and access control.
- Supports Modern Standards: PostgreSQL 18 implements OAuth following industry standards such as RFC 6749 , ensuring compatibility and security assurances.
- Encrypted Communications: OAuth token validation requires HTTPS endpoints, reinforcing secure token exchange.
- Deprecation of md5 Password Authentication: Reflecting the emphasis on stronger authentication, PostgreSQL 18 starts the deprecation of older
md5authentication, recommending SCRAM or OAuth-based methods instead.
Summary
PostgreSQL 18’s native OAuth 2.0 authentication feature ushers in a modern, secure, and flexible way of handling database authentication, aligning with current enterprise identity practices. By allowing token-based authentication via existing IdPs, PostgreSQL simplifies credential management, boosts security and enables smoother integration into identity-driven architectures.
For database administrators and developers implementing PostgreSQL in enterprise environments, leveraging OAuth authentication reduces password management overhead and enhances overall system security.
The next blog will cover how to configure this feature — stay tuned for more updates!