docs: Update ADR-002 with OAuth-only focus and testing status [skip ci]
Major changes to ADR-002 (Vector Database Background Sync Authentication): 1. Reordered authentication tiers: - Tier 1: Service Account Token (client_credentials) - most compatible - Tier 2: Token Exchange with Impersonation - not implemented - Tier 3: Token Exchange with Delegation - implemented 2. Removed admin credentials fallback: - ADR now focuses exclusively on OAuth mode - Background sync unavailable without proper OAuth configuration - BasicAuth mode out of scope (credentials already available) 3. Clarified testing status: - Tier 1: Implemented but only manual tests exist - Tier 3: Implemented but only manual tests exist - Added TODO for automated integration tests 4. Removed "Offline Access with Refresh Tokens": - Documented as "Will Not Implement" - MCP protocol architecture prevents server from accessing refresh tokens - Violates OAuth security model (tokens must stay with client) 5. Simplified configuration: - Removed all admin credential references - OAuth-only environment variables - Automatic tier detection based on provider capabilities The ADR now accurately reflects that refresh tokens should never be shared between MCP client and server, following OAuth best practices and the FastMCP SDK architecture. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>
This commit is contained in:
Chris Coutinho
@@ -1,7 +1,7 @@
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# ADR-002: Vector Database Background Sync Authentication
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## Status
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Proposed
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Accepted - Tier 2 (Token Exchange) Implemented
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## Context
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@@ -39,27 +39,77 @@ We need an OAuth-native solution that maintains security while enabling backgrou
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## Decision
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We will implement a **tiered authentication strategy** that leverages OAuth standards with graceful fallback:
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We will implement a **tiered OAuth authentication strategy** for background operations in OAuth mode. When OAuth authentication is not configured or available, the background sync feature is not available.
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### Primary Strategy: OAuth-Based Authentication
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**Note**: This ADR applies only to **OAuth mode**. In BasicAuth mode (single-user deployments), credentials are already available via environment variables, and background operations work without additional configuration.
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**Tier 1: Offline Access with Refresh Tokens** (Preferred)
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- Request `offline_access` scope during OAuth client registration
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- Receive and securely store user refresh tokens
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- Background worker exchanges refresh tokens for access tokens as needed
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- Respects per-user permissions and provides full audit trail
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### Tier 1: Service Account Token (client_credentials) ✅ **IMPLEMENTED**
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**Tier 2: Token Exchange (RFC 8693)** (If supported)
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- Service account exchanges its token for user-scoped tokens on-demand
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- No token storage required
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- Only available if OIDC provider implements RFC 8693
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**Most Compatible Option** - Works with all OIDC providers supporting `client_credentials`
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### Fallback Strategy: Admin Credentials
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- MCP server obtains service account token via `client_credentials` grant
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- Background worker uses service account token directly
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- No user-specific delegation or impersonation
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- **Implementation**: `KeycloakOAuthClient.get_service_account_token()` (keycloak_oauth.py:341-395)
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- **Testing**: Manual test in `tests/manual/test_token_exchange.py`
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- **TODO**: Automated integration tests needed for both Keycloak and Nextcloud OIDC app
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**Tier 3: Admin BasicAuth** (Development/Simple Deployments)
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- Dedicated sync account with read-only permissions
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- Clear documentation of security implications
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- Recommended only for trusted environments
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**Trade-offs**:
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- ✅ Works with nearly all OIDC providers
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- ✅ Simple implementation and configuration
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- ✅ No additional provider features required
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- ❌ Service account needs broad permissions across users
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- ❌ Less granular audit trail (all actions attributed to service account)
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- ❌ No per-user permission enforcement
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### Tier 2: Token Exchange with Impersonation (RFC 8693) ⚠️ **NOT IMPLEMENTED**
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**Better Security** - Requires provider support for user impersonation
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- Service account exchanges token to impersonate specific users
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- Each background operation runs as the target user
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- Uses `requested_subject` parameter in token exchange
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- Per-user permission enforcement at API level
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**Requirements**:
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- OIDC provider supports RFC 8693 token exchange
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- Provider supports user impersonation (rare - requires Legacy Keycloak V1 with preview features)
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- Service account has impersonation permissions
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**Status**: ⚠️ Not implemented - Keycloak Standard V2 doesn't support impersonation
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**Reference**: See `docs/oauth-impersonation-findings.md` for investigation details
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### Tier 3: Token Exchange with Delegation (RFC 8693) ✅ **IMPLEMENTED**
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**Best Security** - Requires provider support for delegation with `act` claim
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- Service account exchanges token on behalf of users (delegation, not impersonation)
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- Token includes `act` claim showing service account as actor
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- API sees both the user (`sub`) and actor (`act`) in token
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- Full audit trail of delegated operations
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- **Implementation**: `KeycloakOAuthClient.exchange_token_for_user()` (keycloak_oauth.py:397-495)
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- **Testing**: Manual test in `tests/manual/test_token_exchange.py`
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- **Limitation**: Keycloak doesn't support `act` claim yet - [Issue #38279](https://github.com/keycloak/keycloak/issues/38279)
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**Requirements**:
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- OIDC provider supports RFC 8693 token exchange
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- Provider supports delegation with `act` claim (very rare)
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- Proper token exchange permissions configured
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**Current Implementation**: Internal-to-internal token exchange with audience modification (without `act` claim)
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### ❌ Will Not Implement
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**1. Offline Access with Refresh Tokens**
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- **MCP Protocol Architecture**: FastMCP SDK manages OAuth where MCP Client handles refresh tokens
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- **Security Model**: Refresh tokens must never be shared between client and server (OAuth best practice)
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- **Technical Impossibility**: MCP Server has no access to refresh tokens from the OAuth callback
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- **Alternative**: Token exchange provides similar benefits without violating OAuth security model
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**2. Admin Credentials Fallback**
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- **Out of Scope**: This ADR focuses on OAuth mode only
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- **Not Appropriate**: Admin credentials bypass OAuth security model
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- **BasicAuth Mode**: For single-user deployments needing background operations, use BasicAuth mode instead
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### Key Architectural Principles
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@@ -72,169 +122,9 @@ We will implement a **tiered authentication strategy** that leverages OAuth stan
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## Implementation Details
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### 1. Offline Access Flow (Tier 1)
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### 1. Service Account Token (Tier 1 - Primary) ✅ IMPLEMENTED
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#### 1.1 Client Registration
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```python
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# During OAuth client registration
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client_metadata = {
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"client_name": "Nextcloud MCP Server",
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"redirect_uris": ["http://localhost:8000/oauth/callback"],
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"grant_types": ["authorization_code", "refresh_token"],
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"scope": "openid profile email offline_access notes:read files:read ...",
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"token_type": "Bearer" # or "jwt"
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}
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```
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#### 1.2 Token Storage
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```python
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# Encrypted token storage
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class RefreshTokenStorage:
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"""Securely store and manage user refresh tokens"""
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def __init__(self, db_path: str, encryption_key: bytes):
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self.db = Database(db_path)
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self.cipher = Fernet(encryption_key)
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async def store_refresh_token(
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self,
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user_id: str,
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refresh_token: str,
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expires_at: int | None = None
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):
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"""Store encrypted refresh token for user"""
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encrypted_token = self.cipher.encrypt(refresh_token.encode())
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await self.db.execute(
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"INSERT OR REPLACE INTO refresh_tokens VALUES (?, ?, ?, ?)",
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(user_id, encrypted_token, expires_at, int(time.time()))
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)
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async def get_refresh_token(self, user_id: str) -> str | None:
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"""Retrieve and decrypt refresh token"""
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row = await self.db.fetch_one(
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"SELECT encrypted_token FROM refresh_tokens WHERE user_id = ?",
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(user_id,)
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)
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if row:
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return self.cipher.decrypt(row[0]).decode()
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return None
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```
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#### 1.3 Token Refresh Flow
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```python
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async def get_user_access_token(user_id: str) -> str:
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"""Exchange refresh token for fresh access token"""
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# Retrieve stored refresh token
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refresh_token = await token_storage.get_refresh_token(user_id)
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if not refresh_token:
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raise ValueError(f"No refresh token for user {user_id}")
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# Exchange for access token
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async with httpx.AsyncClient() as client:
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response = await client.post(
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token_endpoint,
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data={
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"grant_type": "refresh_token",
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"refresh_token": refresh_token
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},
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auth=(client_id, client_secret)
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)
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response.raise_for_status()
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token_data = response.json()
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# Store new refresh token if rotated
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if "refresh_token" in token_data:
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await token_storage.store_refresh_token(
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user_id,
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token_data["refresh_token"],
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token_data.get("refresh_expires_in")
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)
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return token_data["access_token"]
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```
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#### 1.4 Capturing Refresh Tokens
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**Challenge**: MCP protocol doesn't expose refresh tokens to server
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**Solution**: Intercept OAuth callback
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```python
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# Add route to MCP server
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@app.route("/oauth/callback")
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async def oauth_callback(request):
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"""Capture OAuth callback and store refresh token"""
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code = request.query_params.get("code")
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state = request.query_params.get("state")
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# Exchange authorization code for tokens
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token_response = await exchange_authorization_code(code)
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# Extract user info
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userinfo = await get_userinfo(token_response["access_token"])
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user_id = userinfo["sub"]
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# Store refresh token (if present)
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if "refresh_token" in token_response:
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await token_storage.store_refresh_token(
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user_id,
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token_response["refresh_token"],
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expires_at=token_response.get("refresh_expires_in")
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)
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logger.info(f"Stored refresh token for user: {user_id}")
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# Continue MCP OAuth flow
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return redirect_to_mcp_client(state, token_response)
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```
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### 2. Token Exchange Flow (Tier 2)
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#### 2.1 Capability Detection
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```python
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async def check_token_exchange_support(discovery_url: str) -> bool:
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"""Check if OIDC provider supports RFC 8693 token exchange"""
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async with httpx.AsyncClient() as client:
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response = await client.get(discovery_url)
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discovery = response.json()
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# Check for token exchange grant type
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grant_types = discovery.get("grant_types_supported", [])
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return "urn:ietf:params:oauth:grant-type:token-exchange" in grant_types
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```
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#### 2.2 Token Exchange Implementation
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```python
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async def exchange_for_user_token(
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service_token: str,
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user_id: str,
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scopes: list[str]
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) -> str:
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"""Exchange service token for user-scoped token"""
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async with httpx.AsyncClient() as client:
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response = await client.post(
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token_endpoint,
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data={
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"grant_type": "urn:ietf:params:oauth:grant-type:token-exchange",
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"subject_token": service_token,
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"subject_token_type": "urn:ietf:params:oauth:token-type:access_token",
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"requested_token_type": "urn:ietf:params:oauth:token-type:access_token",
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"resource": f"user:{user_id}",
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"scope": " ".join(scopes)
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},
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auth=(client_id, client_secret)
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)
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if response.status_code != 200:
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logger.warning(f"Token exchange failed: {response.status_code}")
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raise TokenExchangeNotSupportedError()
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return response.json()["access_token"]
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```
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#### 2.3 Service Account Token
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#### 1.1 Service Account Token Acquisition
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```python
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async def get_service_token() -> str:
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"""Get token for MCP server's service account"""
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@@ -252,7 +142,117 @@ async def get_service_token() -> str:
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return response.json()["access_token"]
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```
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### 3. Sync Worker with Tiered Authentication
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**Implementation**: `KeycloakOAuthClient.get_service_account_token()` (keycloak_oauth.py:341-395)
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**Usage**:
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```python
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# Background worker uses service account token directly
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service_token_data = await oauth_client.get_service_account_token(
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scopes=["notes:read", "files:read", "calendar:read"]
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)
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client = NextcloudClient.from_token(
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base_url=nextcloud_host,
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token=service_token_data["access_token"],
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username="service-account"
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)
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# All operations are performed as the service account
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notes = await client.notes.list_notes()
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```
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### 2. Token Exchange with Impersonation (Tier 2) ⚠️ NOT IMPLEMENTED
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This tier is documented for completeness but is not currently implemented due to lack of provider support.
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#### 2.1 Impersonation Flow (Conceptual)
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```python
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async def exchange_for_impersonated_user_token(
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service_token: str,
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target_user_id: str,
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scopes: list[str]
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) -> str:
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"""Exchange service token to impersonate specific user (NOT IMPLEMENTED)"""
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async with httpx.AsyncClient() as client:
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response = await client.post(
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token_endpoint,
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data={
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"grant_type": "urn:ietf:params:oauth:grant-type:token-exchange",
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"subject_token": service_token,
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"subject_token_type": "urn:ietf:params:oauth:token-type:access_token",
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"requested_token_type": "urn:ietf:params:oauth:token-type:access_token",
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"requested_subject": target_user_id, # Impersonate this user
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"audience": "nextcloud",
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"scope": " ".join(scopes)
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},
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auth=(client_id, client_secret)
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)
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response.raise_for_status()
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return response.json()["access_token"]
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```
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**Why Not Implemented**:
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- Keycloak Standard V2 doesn't support `requested_subject` parameter
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- Requires Legacy Keycloak V1 with preview features (not production-ready)
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- Very few OIDC providers support user impersonation via token exchange
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**See**: `docs/oauth-impersonation-findings.md` for detailed investigation
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### 3. Token Exchange with Delegation (Tier 3) ✅ IMPLEMENTED
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#### 3.1 Capability Detection
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```python
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async def check_token_exchange_support(discovery_url: str) -> bool:
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"""Check if OIDC provider supports RFC 8693 token exchange"""
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async with httpx.AsyncClient() as client:
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response = await client.get(discovery_url)
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discovery = response.json()
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# Check for token exchange grant type
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grant_types = discovery.get("grant_types_supported", [])
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return "urn:ietf:params:oauth:grant-type:token-exchange" in grant_types
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```
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#### 3.2 Delegation Token Exchange
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```python
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async def exchange_for_user_token(
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service_token: str,
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target_user_id: str,
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audience: str,
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scopes: list[str]
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) -> str:
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"""Exchange service token for user-scoped token via RFC 8693"""
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async with httpx.AsyncClient() as client:
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response = await client.post(
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token_endpoint,
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data={
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"grant_type": "urn:ietf:params:oauth:grant-type:token-exchange",
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"subject_token": service_token,
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"subject_token_type": "urn:ietf:params:oauth:token-type:access_token",
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"requested_token_type": "urn:ietf:params:oauth:token-type:access_token",
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"audience": audience, # Target resource server (e.g., "nextcloud")
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"scope": " ".join(scopes)
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},
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auth=(client_id, client_secret)
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)
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if response.status_code != 200:
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logger.warning(f"Token exchange failed: {response.status_code}")
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raise TokenExchangeNotSupportedError()
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return response.json()["access_token"]
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```
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**Implementation**: `KeycloakOAuthClient.exchange_token_for_user()` (keycloak_oauth.py:397-495)
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|
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**Note**: Full delegation with `act` claim requires provider support that is currently very rare. Keycloak tracking: [Issue #38279](https://github.com/keycloak/keycloak/issues/38279)
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### 4. Sync Worker with Tiered Authentication
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|
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```python
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# nextcloud_mcp_server/sync_worker.py
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@@ -261,76 +261,72 @@ class VectorSyncWorker:
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|
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def __init__(self):
|
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self.auth_method = None
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self.token_storage = None
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self.oauth_client = None # KeycloakOAuthClient or similar
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self.vector_service = None
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|
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async def initialize(self):
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"""Detect and configure authentication method"""
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|
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# Try Tier 1: Offline Access
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if os.getenv("ENABLE_OFFLINE_ACCESS") == "true":
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try:
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encryption_key = os.getenv("TOKEN_ENCRYPTION_KEY")
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self.token_storage = RefreshTokenStorage(
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db_path="tokens.db",
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encryption_key=base64.b64decode(encryption_key)
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)
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self.auth_method = "offline_access"
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logger.info("✓ Using offline_access authentication")
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return
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except Exception as e:
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logger.warning(f"Offline access unavailable: {e}")
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from nextcloud_mcp_server.auth.keycloak_oauth import KeycloakOAuthClient
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|
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# Try Tier 2: Token Exchange
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try:
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if await check_token_exchange_support(discovery_url):
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self.auth_method = "token_exchange"
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logger.info("✓ Using token exchange authentication (RFC 8693)")
|
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return
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self.oauth_client = KeycloakOAuthClient.from_env()
|
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await self.oauth_client.discover()
|
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|
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# Verify service account access (Tier 1)
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service_token = await self.oauth_client.get_service_account_token()
|
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logger.info("✓ Service account token acquired")
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# Check if token exchange is supported (Tier 2/3)
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if await check_token_exchange_support(self.oauth_client.discovery_url):
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self.auth_method = "token_exchange_delegation"
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logger.info(
|
||||
"✓ Token exchange supported (RFC 8693) - will use delegation for user-scoped operations"
|
||||
)
|
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else:
|
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self.auth_method = "service_account"
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logger.info(
|
||||
"ℹ Token exchange not supported - using service account token for all operations"
|
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)
|
||||
|
||||
except Exception as e:
|
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logger.warning(f"Token exchange unavailable: {e}")
|
||||
|
||||
# Fallback: Admin Credentials
|
||||
if os.getenv("NEXTCLOUD_USERNAME") and os.getenv("NEXTCLOUD_PASSWORD"):
|
||||
self.auth_method = "admin_basic"
|
||||
logger.warning(
|
||||
"⚠ Using admin BasicAuth authentication. "
|
||||
"Consider enabling offline_access for production."
|
||||
)
|
||||
return
|
||||
|
||||
raise RuntimeError("No authentication method available for sync worker")
|
||||
logger.error(f"Failed to initialize OAuth authentication: {e}")
|
||||
raise RuntimeError(
|
||||
"OAuth authentication is required for background sync. "
|
||||
"Either configure OIDC_CLIENT_ID/OIDC_CLIENT_SECRET with service account enabled, "
|
||||
"or use BasicAuth mode for single-user deployments."
|
||||
) from e
|
||||
|
||||
async def get_user_client(self, user_id: str) -> NextcloudClient:
|
||||
"""Get authenticated client for user based on auth method"""
|
||||
|
||||
if self.auth_method == "offline_access":
|
||||
# Exchange refresh token for access token
|
||||
access_token = await get_user_access_token(user_id)
|
||||
if self.auth_method == "token_exchange_delegation":
|
||||
# Tier 2/3: Get service token and exchange for user-scoped token
|
||||
service_token_data = await self.oauth_client.get_service_account_token()
|
||||
|
||||
user_token_data = await self.oauth_client.exchange_token_for_user(
|
||||
subject_token=service_token_data["access_token"],
|
||||
target_user_id=user_id,
|
||||
audience="nextcloud",
|
||||
scopes=["notes:read", "files:read", "calendar:read"]
|
||||
)
|
||||
|
||||
return NextcloudClient.from_token(
|
||||
base_url=nextcloud_host,
|
||||
token=access_token,
|
||||
token=user_token_data["access_token"],
|
||||
username=user_id
|
||||
)
|
||||
|
||||
elif self.auth_method == "token_exchange":
|
||||
# Get service token and exchange for user token
|
||||
service_token = await get_service_token()
|
||||
user_token = await exchange_for_user_token(
|
||||
service_token,
|
||||
user_id,
|
||||
scopes=["notes:read", "files:read"]
|
||||
)
|
||||
elif self.auth_method == "service_account":
|
||||
# Tier 1: Use service account token directly (no user scoping)
|
||||
service_token_data = await self.oauth_client.get_service_account_token()
|
||||
|
||||
return NextcloudClient.from_token(
|
||||
base_url=nextcloud_host,
|
||||
token=user_token,
|
||||
username=user_id
|
||||
token=service_token_data["access_token"],
|
||||
username="service-account"
|
||||
)
|
||||
|
||||
elif self.auth_method == "admin_basic":
|
||||
# Use admin credentials (fallback)
|
||||
return NextcloudClient.from_env()
|
||||
|
||||
raise RuntimeError(f"Unknown auth method: {self.auth_method}")
|
||||
|
||||
async def sync_user_content(self, user_id: str):
|
||||
@@ -370,14 +366,13 @@ class VectorSyncWorker:
|
||||
while True:
|
||||
try:
|
||||
# Get list of users to sync
|
||||
if self.auth_method == "admin_basic":
|
||||
# Admin can list all users
|
||||
admin_client = NextcloudClient.from_env()
|
||||
users = await admin_client.users.list_users()
|
||||
user_ids = [u.id for u in users]
|
||||
else:
|
||||
# OAuth methods: only sync users with stored tokens
|
||||
user_ids = await self.token_storage.get_all_user_ids()
|
||||
# Implementation depends on how you track authenticated users
|
||||
# Options:
|
||||
# - Audit logs of MCP authentication events
|
||||
# - MCP session history
|
||||
# - Configured user list
|
||||
# - If using service account with broad permissions: list all users
|
||||
user_ids = await self.get_active_users()
|
||||
|
||||
logger.info(f"Syncing content for {len(user_ids)} users")
|
||||
|
||||
@@ -452,40 +447,59 @@ async def nc_notes_semantic_search(
|
||||
|
||||
### 5. Security Implementation
|
||||
|
||||
#### 5.1 Token Encryption
|
||||
#### 5.1 Service Account Credentials Protection
|
||||
```python
|
||||
# Generate encryption key (store securely)
|
||||
from cryptography.fernet import Fernet
|
||||
|
||||
# On first setup
|
||||
encryption_key = Fernet.generate_key()
|
||||
# Store in environment or secrets manager
|
||||
# Store OAuth client credentials securely
|
||||
# NEVER commit to source control
|
||||
|
||||
# In production
|
||||
encryption_key = os.getenv("TOKEN_ENCRYPTION_KEY") # Base64-encoded Fernet key
|
||||
# Option 1: Environment variables (for development)
|
||||
export OIDC_CLIENT_ID="nextcloud-mcp-server"
|
||||
export OIDC_CLIENT_SECRET="<secure-secret>"
|
||||
|
||||
# Option 2: Secrets manager (for production)
|
||||
import boto3
|
||||
secrets = boto3.client('secretsmanager')
|
||||
secret = secrets.get_secret_value(SecretId='nextcloud-mcp-oauth')
|
||||
client_secret = json.loads(secret['SecretString'])['client_secret']
|
||||
|
||||
# Option 3: Encrypted storage (for self-hosted)
|
||||
from nextcloud_mcp_server.auth.refresh_token_storage import RefreshTokenStorage
|
||||
|
||||
storage = RefreshTokenStorage.from_env()
|
||||
await storage.initialize()
|
||||
|
||||
# Client credentials are encrypted at rest using Fernet
|
||||
client_data = await storage.get_oauth_client()
|
||||
```
|
||||
|
||||
#### 5.2 Token Rotation
|
||||
#### 5.2 Token Lifecycle Management
|
||||
```python
|
||||
async def rotate_refresh_token(user_id: str):
|
||||
"""Handle refresh token rotation"""
|
||||
async def manage_service_token_lifecycle():
|
||||
"""Cache and refresh service account tokens"""
|
||||
|
||||
old_refresh_token = await token_storage.get_refresh_token(user_id)
|
||||
# Cache service token (avoid repeated requests)
|
||||
cached_token = None
|
||||
token_expires_at = 0
|
||||
|
||||
# Exchange for new tokens
|
||||
response = await exchange_refresh_token(old_refresh_token)
|
||||
async def get_fresh_service_token() -> str:
|
||||
nonlocal cached_token, token_expires_at
|
||||
|
||||
if "refresh_token" in response:
|
||||
# Store new refresh token
|
||||
await token_storage.store_refresh_token(
|
||||
user_id,
|
||||
response["refresh_token"],
|
||||
expires_at=response.get("refresh_expires_in")
|
||||
)
|
||||
now = time.time()
|
||||
|
||||
# Securely delete old token
|
||||
await token_storage.delete_refresh_token(user_id, old_refresh_token)
|
||||
# Return cached token if still valid (with 5-minute buffer)
|
||||
if cached_token and now < (token_expires_at - 300):
|
||||
return cached_token
|
||||
|
||||
# Request new token
|
||||
token_data = await oauth_client.get_service_account_token()
|
||||
|
||||
cached_token = token_data["access_token"]
|
||||
token_expires_at = now + token_data.get("expires_in", 3600)
|
||||
|
||||
logger.info("Service account token refreshed")
|
||||
return cached_token
|
||||
|
||||
return get_fresh_service_token
|
||||
```
|
||||
|
||||
#### 5.3 Audit Logging
|
||||
@@ -517,17 +531,16 @@ async def audit_log(
|
||||
|
||||
#### 6.1 Environment Variables
|
||||
```bash
|
||||
# Tier 1: Offline Access
|
||||
ENABLE_OFFLINE_ACCESS=true
|
||||
TOKEN_ENCRYPTION_KEY=<base64-encoded-fernet-key>
|
||||
TOKEN_STORAGE_DB=/app/data/tokens.db
|
||||
# OAuth Configuration (Required for Background Sync in OAuth Mode)
|
||||
# Requires external OIDC provider with client_credentials support
|
||||
OIDC_DISCOVERY_URL=http://keycloak:8080/realms/nextcloud-mcp/.well-known/openid-configuration
|
||||
OIDC_CLIENT_ID=nextcloud-mcp-server
|
||||
OIDC_CLIENT_SECRET=<secure-secret>
|
||||
NEXTCLOUD_HOST=http://app:80
|
||||
|
||||
# Tier 2: Token Exchange (auto-detected)
|
||||
# No configuration needed - detected via OIDC discovery
|
||||
|
||||
# Tier 3: Admin Fallback
|
||||
NEXTCLOUD_USERNAME=sync-bot
|
||||
NEXTCLOUD_PASSWORD=<secure-password>
|
||||
# Tier selection is automatic:
|
||||
# - Tier 1 (service_account): Always available if client has service account enabled
|
||||
# - Tier 2/3 (token_exchange): Used if provider supports RFC 8693 token exchange
|
||||
|
||||
# Vector Database
|
||||
QDRANT_URL=http://qdrant:6333
|
||||
@@ -536,9 +549,31 @@ QDRANT_API_KEY=<api-key>
|
||||
# Sync Configuration
|
||||
SYNC_INTERVAL_SECONDS=300
|
||||
SYNC_BATCH_SIZE=100
|
||||
|
||||
# Note: For BasicAuth mode (single-user), background sync uses NEXTCLOUD_USERNAME/NEXTCLOUD_PASSWORD
|
||||
# This ADR focuses on OAuth mode only
|
||||
```
|
||||
|
||||
#### 6.2 Docker Compose
|
||||
#### 6.2 Keycloak Configuration (for Token Exchange)
|
||||
|
||||
**Client Settings** (`nextcloud-mcp-server`):
|
||||
```json
|
||||
{
|
||||
"clientId": "nextcloud-mcp-server",
|
||||
"serviceAccountsEnabled": true,
|
||||
"authorizationServicesEnabled": false,
|
||||
"attributes": {
|
||||
"token.exchange.grant.enabled": "true",
|
||||
"client.token.exchange.standard.enabled": "true"
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
**Service Account Roles**:
|
||||
- Assign appropriate Nextcloud roles/scopes to the service account
|
||||
- Configure token exchange permissions
|
||||
|
||||
#### 6.3 Docker Compose
|
||||
```yaml
|
||||
services:
|
||||
mcp-sync:
|
||||
@@ -546,20 +581,24 @@ services:
|
||||
command: ["python", "-m", "nextcloud_mcp_server.sync_worker"]
|
||||
environment:
|
||||
- NEXTCLOUD_HOST=http://app:80
|
||||
- ENABLE_OFFLINE_ACCESS=true
|
||||
- TOKEN_ENCRYPTION_KEY=${TOKEN_ENCRYPTION_KEY}
|
||||
|
||||
# External OIDC provider (Keycloak)
|
||||
- OIDC_DISCOVERY_URL=http://keycloak:8080/realms/nextcloud-mcp/.well-known/openid-configuration
|
||||
- OIDC_CLIENT_ID=nextcloud-mcp-server
|
||||
- OIDC_CLIENT_SECRET=${OIDC_CLIENT_SECRET}
|
||||
|
||||
# Vector database
|
||||
- QDRANT_URL=http://qdrant:6333
|
||||
# OAuth client credentials (for token refresh)
|
||||
- NEXTCLOUD_OIDC_CLIENT_ID=${NEXTCLOUD_OIDC_CLIENT_ID}
|
||||
- NEXTCLOUD_OIDC_CLIENT_SECRET=${NEXTCLOUD_OIDC_CLIENT_SECRET}
|
||||
- QDRANT_API_KEY=${QDRANT_API_KEY}
|
||||
volumes:
|
||||
- sync-tokens:/app/data
|
||||
- sync-data:/app/data # For OAuth client credential storage
|
||||
depends_on:
|
||||
- app
|
||||
- keycloak
|
||||
- qdrant
|
||||
|
||||
volumes:
|
||||
sync-tokens: # Persistent storage for encrypted tokens
|
||||
sync-data: # Persistent storage for encrypted OAuth client credentials
|
||||
```
|
||||
|
||||
## Consequences
|
||||
@@ -641,32 +680,37 @@ volumes:
|
||||
|
||||
#### Security Best Practices
|
||||
|
||||
1. **Token Encryption Key Management**
|
||||
1. **OAuth Client Secret Management**
|
||||
```bash
|
||||
# Generate secure key
|
||||
python -c "from cryptography.fernet import Fernet; print(Fernet.generate_key().decode())"
|
||||
|
||||
# Store in secrets manager (Vault, AWS Secrets Manager, etc.)
|
||||
# Or use environment variable with restricted permissions
|
||||
|
||||
# For self-hosted: Use encrypted storage
|
||||
# OAuth client credentials stored in SQLite with Fernet encryption
|
||||
# Encryption key: TOKEN_ENCRYPTION_KEY environment variable
|
||||
|
||||
# Generate encryption key:
|
||||
python -c "from cryptography.fernet import Fernet; print(Fernet.generate_key().decode())"
|
||||
```
|
||||
|
||||
2. **Token Storage Permissions**
|
||||
2. **Service Account Token Lifecycle**
|
||||
- Cache service tokens to minimize requests (with expiry buffer)
|
||||
- Automatically refresh expired tokens
|
||||
- Use short-lived tokens (provider default, typically 1 hour)
|
||||
- Monitor token request rates and failures
|
||||
|
||||
3. **Database Permissions (for Client Credential Storage)**
|
||||
```bash
|
||||
# Restrict database file permissions
|
||||
chmod 600 /app/data/tokens.db
|
||||
chown mcp-server:mcp-server /app/data/tokens.db
|
||||
```
|
||||
|
||||
3. **Token Rotation Schedule**
|
||||
- Refresh access tokens every 5 minutes (or token expiry)
|
||||
- Rotate refresh tokens on each use (if provider supports)
|
||||
- Revoke tokens on user logout/deauthorization
|
||||
|
||||
4. **Monitoring and Alerting**
|
||||
- Alert on token refresh failures
|
||||
- Alert on token exchange failures
|
||||
- Monitor for unusual access patterns
|
||||
- Track token age and rotation
|
||||
- Audit sync operations per user
|
||||
- Track service account token usage
|
||||
- Audit sync operations per user (if delegation supported)
|
||||
|
||||
### Future Enhancements
|
||||
|
||||
|
||||
Reference in New Issue
Block a user