This PR fixes multiple OAuth-related issues:
## Unified OAuth Callback
- Consolidated `/oauth/callback-nextcloud` and `/oauth/login-callback` into single `/oauth/callback` endpoint
- Flow type determined by session lookup via state parameter (no query params in redirect_uri)
- Fixes redirect_uri validation issues with IdPs requiring exact match
- Legacy endpoints kept as aliases for backwards compatibility
## PKCE Implementation
- Implemented PKCE (RFC 7636) for Flow 2 (resource provisioning)
- Generate code_verifier and code_challenge
- Store code_verifier in session storage
- Retrieve and use in token exchange
- Fixed PKCE for browser login (integrated mode)
- Previously only worked for external IdP (Keycloak)
- Now works for both Nextcloud OIDC and external IdP
## Login Elicitation Fixes (ADR-006)
- Fixed elicitation URL to route through MCP server endpoint
- Changed from direct Nextcloud URL to `/oauth/authorize-nextcloud`
- Ensures PKCE is properly handled by server
- Fixed login detection after OAuth flow completes
- Look up refresh token by state parameter instead of user_id
- Works even when Flow 1 token not present
- Added `get_refresh_token_by_provisioning_client_id()` method
## Session Authentication
- Fixed `/user/page` redirect loop
- Shared oauth_context with mounted browser_app
- SessionAuthBackend can now validate sessions correctly
## Tests
- Added comprehensive login elicitation test suite
- Updated scope authorization test expectations
- All 43 OAuth tests passing
## Files Changed
- `app.py`: Shared oauth_context, unified callback route
- `oauth_routes.py`: Unified callback, PKCE for Flow 2
- `browser_oauth_routes.py`: PKCE for integrated mode
- `oauth_tools.py`: Fixed elicitation URL generation
- `refresh_token_storage.py`: Added lookup by provisioning_client_id
- `test_login_elicitation.py`: New test suite
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Co-Authored-By: Claude <noreply@anthropic.com>
This commit completes the OAuth audience validation implementation per RFC 7519,
RFC 8707 (Resource Indicators), and RFC 9728 (Protected Resource Metadata).
## Key Changes
### OAuth Resource Parameters (RFC 8707)
- Add `resource` parameter to Flow 1 (MCP client auth) with MCP server audience
- Add `resource` parameter to Flow 2 (Nextcloud access) with Nextcloud audience
- Add `nextcloud_resource_uri` to oauth_context configuration
- Fix undefined variable error in starlette_lifespan
### PRM-Based Resource Discovery (RFC 9728)
- Update tests to fetch resource identifier from PRM endpoint
- Add fallback to hardcoded value if PRM fetch fails
- Demonstrate correct OAuth client implementation pattern
### ADR-005 Documentation Updates
- Update to reflect simplified RFC 7519 compliant implementation
- Document that MCP validates only its own audience (not Nextcloud's)
- Add section on OAuth resource parameters and PRM discovery
- Update implementation checklist to show completed items
- Mark status as "Implemented" with update date
## Implementation Details
The solution follows RFC 7519 Section 4.1.3: resource servers validate only
their own presence in the audience claim. This simplifies the logic while
maintaining security:
- MCP server validates MCP audience only
- Nextcloud independently validates its own audience
- No dual validation required at MCP layer
- Token reuse is allowed per RFC 8707 for multi-audience tokens
## Test Results
✅ test_mcp_oauth_server_connection - PASSED
✅ test_deck_board_view_permissions - PASSED
✅ test_prm_endpoint - PASSED
All OAuth flows now properly specify target resources, resulting in correct
audience validation throughout the system.
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Co-Authored-By: Claude <noreply@anthropic.com>
Implements Progressive Consent architecture with dual OAuth flows:
- Flow 1: Direct client authentication (aud: "mcp-server")
- Flow 2: Resource provisioning with refresh tokens
Components added:
- Client registry with validation (client_registry.py)
- Progressive token verifier (progressive_token_verifier.py)
- Token broker service integration
- Provisioning decorator for MCP tools
- OAuth provisioning tools (provision_nextcloud_access, etc.)
Configuration:
- Progressive Consent enabled by default (ENABLE_PROGRESSIVE_CONSENT=true)
- Client validation with pre-registered clients
- Audience separation framework
KNOWN ISSUE - Token Exchange Pattern Incorrect:
The current implementation does NOT properly implement token exchange.
MCP session tokens should be EXCHANGED for delegated Nextcloud tokens
during tool calls, not stored/reused. Critical corrections needed:
1. Session tokens: Flow 1 token → exchange → ephemeral Nextcloud token
- Generated on-demand per tool call
- Short-lived, not stored
- Scopes limited to tool requirements
2. Background tokens: Flow 2 refresh token → background Nextcloud token
- Only for offline/background jobs
- Potentially different scopes than session tokens
- Must NOT be used for MCP session tool calls
The token exchange mechanism needs to be implemented to properly
separate session-time delegation from background job authorization.
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Co-Authored-By: Claude <noreply@anthropic.com>
Implement dual OAuth flows for Progressive Consent architecture:
Flow 1 (Client Authentication):
- Client authenticates directly to IdP with its own client_id
- Server validates client_id against ALLOWED_MCP_CLIENTS whitelist
- Issues tokens with aud: "mcp-server" for MCP authentication only
- Progressive mode detected via ENABLE_PROGRESSIVE_CONSENT env var
Flow 2 (Resource Provisioning):
- New endpoints: /oauth/authorize-nextcloud, /oauth/callback-nextcloud
- MCP server acts as OAuth client for delegated Nextcloud access
- Stores master refresh tokens with flow_type and audience metadata
- Returns success HTML page after provisioning completion
Scope Authorization Updates:
- Added ProvisioningRequiredError for missing Flow 2 provisioning
- Decorator checks if Nextcloud scopes require provisioning in Progressive mode
- Validates token has Nextcloud scopes before allowing access
Storage Schema Enhancements:
- Added flow_type, is_provisioning, requested_scopes to oauth_sessions
- Enhanced store_oauth_session to support Progressive Consent metadata
- Maintains backward compatibility with hybrid flow
This completes the Progressive Consent implementation, enabling:
- Explicit user consent for resource access
- Stateless server by default (no automatic provisioning)
- Clear separation between authentication and resource access
- Defense in depth with audience-specific tokens
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