Commit Graph

17 Commits

Author SHA1 Message Date
Chris Coutinho e331544cee feat: Implement RFC 8693 token exchange for Keycloak (ADR-002 Tier 2)
Implements OAuth 2.0 Token Exchange (RFC 8693) enabling the MCP server to
exchange service account tokens for user-scoped tokens. This provides an
alternative to refresh tokens for background operations.

**Core Implementation:**
- Added `get_service_account_token()` method to KeycloakOAuthClient for
  client_credentials grant
- Added `exchange_token_for_user()` method implementing RFC 8693 token exchange
- Fixed Fernet encryption key handling in RefreshTokenStorage (was incorrectly
  base64 decoding already-encoded keys)
- Updated OAuth configuration to support offline_access scope and refresh token
  storage infrastructure

**Keycloak Configuration:**
- Enabled `serviceAccountsEnabled` in realm-export.json
- Added `token.exchange.grant.enabled` attribute
- Added `client.token.exchange.standard.enabled` attribute (required for
  Keycloak 26.2+ Standard Token Exchange V2)
- Fresh Keycloak imports now correctly enable token exchange

**Docker Compose:**
- Added TOKEN_ENCRYPTION_KEY and ENABLE_OFFLINE_ACCESS environment variables
- Created oauth-tokens volume for refresh token storage
- Configured both mcp-oauth and mcp-keycloak services

**Testing & Documentation:**
- Added tests/manual/test_token_exchange.py - Validates complete RFC 8693 flow
- Added tests/manual/test_nextcloud_impersonate.py - Documents session-based
  impersonation limitations
- Added docs/oauth-impersonation-findings.md - Comprehensive investigation
  findings and resolution documentation

**Verified Working:**
 Service account token acquisition (client_credentials grant)
 RFC 8693 token exchange for internal-to-internal tokens
 Exchanged tokens validate with Nextcloud APIs
 Keycloak 26.4.2 Standard Token Exchange V2 support

**Known Limitations:**
- User impersonation (requested_subject) requires Keycloak Legacy V1 with
  preview features
- Cross-client token exchange limited to same realm
- Refresh token storage infrastructure ready but unused (MCP protocol limitation)

Dependencies: aiosqlite>=0.20.0

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>
2025-11-02 22:03:19 +01:00
Chris Coutinho f34366a260 feat: Add Keycloak OAuth provider support with refresh token storage
Implements Keycloak as an external OIDC provider following ADR-002
architecture for background job authentication using offline_access.

## Features

- Keycloak OAuth provider with PKCE and offline_access support
- Refresh token storage with Fernet encryption
- Token verifier for both JWT and opaque tokens
- Multi-client validation (realm-level trust)
- Sample configuration for Keycloak integration

## Implementation

### OAuth Provider (keycloak_oauth.py)
- Authorization Code Flow with PKCE
- Refresh token exchange
- OIDC discovery endpoint support
- Token validation with JWKS

### Token Storage (refresh_token_storage.py)
- Encrypted storage using Fernet symmetric encryption
- SQLite backend for persistence
- Token rotation support
- Per-user token management

### Token Verifier Updates
- Support both JWT (self-encoded) and opaque tokens
- JWKS-based JWT signature verification
- Introspection endpoint fallback for opaque tokens
- Scope extraction from both token types

### Configuration
- .env.keycloak.sample: Example configuration with Keycloak URLs
- docs/keycloak-multi-client-validation.md: Realm-level validation documentation
- app-hooks/post-installation/10-install-user_oidc-app.sh: Updated dependencies

## Architecture Notes

- MCP Server is a protected resource (requires OAuth)
- MCP Client initiates OAuth flow and shares refresh tokens
- Refresh tokens enable background operations without admin credentials
- Supports future token exchange delegation when Keycloak implements it

## References

- ADR-002: Vector Database Background Sync Authentication
- RFC 6749: OAuth 2.0 (offline_access, refresh tokens)
- RFC 7517: JSON Web Key (JWK)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>
2025-11-02 22:03:19 +01:00
Chris Coutinho 415b1c901b docs: Parse available scopes from registered tools and update docs 2025-10-25 21:16:40 +02:00
Chris Coutinho 50b69a2531 fix: Add support for RFC 7592 client registration and deletion 2025-10-24 19:19:27 +02:00
Chris Coutinho 8e0a4d8ce5 feat(auth): Add support for client registration deletion 2025-10-24 18:54:24 +02:00
Chris Coutinho 1e877f17f7 test: Replace persistent OAuth client cache with session-scoped fixtures
Remove file-based caching of OAuth client credentials and implement automatic
client lifecycle management for test fixtures.

Changes:
- Add RFC 7592 client deletion function in auth/client_registration.py
- Remove cache_file parameter from _create_oauth_client_with_scopes helper
- Update all OAuth credential fixtures to use yield/finalizer pattern
- Add automatic client cleanup at end of test session (best-effort)
- Remove persistent .nextcloud_oauth_*.json cache files

Benefits:
- No persistent cache files cluttering repository
- Fresh OAuth clients created for each test session via DCR
- Automatic cleanup attempts (RFC 7592 DELETE endpoint)
- Cleaner test environment with proper fixture lifecycle

Note: Client deletion may fail due to Nextcloud authentication middleware
(logged as warning). The key improvement is removing persistent cache files.
OAuth clients may accumulate in Nextcloud but can be cleaned manually.
2025-10-24 08:11:22 +02:00
Chris Coutinho d452684535 feat: Split read/write scopes into app:read/write scopes 2025-10-24 04:38:49 +02:00
Chris Coutinho bdb0e17401 chore: Add logging to token introspection 2025-10-23 21:18:14 +02:00
Chris Coutinho e9a16c43b5 refactor: Update JWT client to use DCR, re-enable tool filtering 2025-10-23 09:33:06 +02:00
Chris Coutinho e48f5f3f30 feat(server): Add support for custom OIDC scopes and permissions via JWTs 2025-10-23 08:37:36 +02:00
Chris Coutinho c069d78f80 feat: Initialize JWT-scoped tools 2025-10-22 06:21:16 +02:00
Chris Coutinho 63b898c0e3 chore: Update logs 2025-10-20 22:57:18 +02:00
Chris Coutinho 3ad9198f36 fix(oauth): Remove the option to force_register new clients 2025-10-15 16:27:22 +02:00
Chris Coutinho 13e4915e38 test: Remove unused pytest fixtures 2025-10-14 01:23:39 +02:00
Chris Coutinho f58a9883a6 test: Fix oauth2 token extract from starlette requests 2025-10-14 01:23:37 +02:00
Chris Coutinho 33b962a7fc test: Setup interactive browser test 2025-10-14 01:23:30 +02:00
Chris Coutinho 4d7e4b9a4b feat(server): Experimental support for OAuth2/OIDC authentication 2025-10-14 01:22:15 +02:00