Merge pull request #279 from sheyman546/docs/auth-refresh-strategy-clean

Docs/auth refresh strategy clean

Author: greatest0fallt1me

CREATE_PR.txt

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+Go to this URL to create the Pull Request:
+
+https://github.com/sheyman546/Callora-Backend/compare/main...feature/stellar-error-normalization
+
+Steps:
+1. Click the link above
+2. Review the changes 
+3. Click "Create pull request"
+4. Title: "chore(backend): normalize soroban rpc errors into stable api error codes"
+5. Copy description from PR_ERROR_NORMALIZATION.md
+6. Create PR
+
+Branch is ready: feature/stellar-error-normalization

PR_LINK.txt

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+# Refresh Token Strategy Implementation
+
+## Summary
+
+This PR implements a comprehensive refresh token strategy for the Callora Backend, addressing issue #232. The implementation enhances security by supporting long-lived refresh tokens with short-lived access tokens, enabling secure token rotation and immediate revocation capabilities.
+
+## Changes Made
+
+### 🔐 Core Implementation
+- **RefreshTokenService**: Secure token generation, validation, and management
+- **RefreshTokenRepository**: Database operations for token storage and retrieval
+- **AuthController**: REST endpoints for token refresh, revocation, and management
+- **Auth Routes**: Express routes with proper validation and middleware
+
+### 🗄️ Database Schema
+- Added `refresh_tokens` table with proper indexing and constraints
+- Includes fields for token hashing, expiration tracking, and revocation status
+- Optimized for performance with composite indexes
+
+### 📝 Documentation
+- Comprehensive documentation in `docs/auth-refresh-strategy.md`
+- Security considerations and best practices
+- Migration strategy and configuration guidelines
+
+### 🧪 Testing
+- Unit tests for RefreshTokenService covering all scenarios
+- Integration tests for API endpoints with mock repository
+- Security tests for edge cases and attack vectors
+
+## Security Features
+
+### 🔒 Token Security
+- **SHA-256 Hashing**: Refresh tokens stored as secure hashes
+- **Token Validation**: Multiple layers of verification (signature, type, claims)
+- **Hash Verification**: Prevents token substitution attacks
+- **Timing-Safe Comparison**: Prevents timing attacks
+
+### 🛡️ Protection Mechanisms
+- **Token Expiration**: Configurable expiry times (15m access, 7d refresh)
+- **Revocation Support**: Individual and bulk token revocation
+- **Rate Limiting**: Token usage tracking and cleanup
+- **Maximum Tokens**: Limit of 5 active refresh tokens per user
+
+### 🔍 Monitoring & Logging
+- Comprehensive logging for security events
+- Token usage tracking with timestamps
+- Failed attempt monitoring
+- Security violation alerts
+
+## API Endpoints
+
+### POST /auth/refresh
+Refresh an access token using a valid refresh token
+```json
+Request: { "refreshToken": "eyJhbGciOiJIUzI1NiJ9..." }
+Response: { "accessToken": "eyJhbGciOiJIUzI1NiJ9...", "tokenType": "Bearer" }
+```
+
+### POST /auth/revoke
+Revoke a specific refresh token
+```json
+Request: { "refreshToken": "eyJhbGciOiJIUzI1NiJ9..." }
+Response: { "message": "Token revoked successfully" }
+```
+
+### POST /auth/revoke-all
+Revoke all refresh tokens for authenticated user
+```json
+Response: { "message": "All tokens revoked successfully" }
+```
+
+### GET /auth/tokens
+Get token information for authenticated user
+```json
+Response: { "activeRefreshTokens": 2, "maxAllowedTokens": 5 }
+```
+
+## Configuration
+
+### Environment Variables
+```bash
+JWT_SECRET=your-super-secret-key
+ACCESS_TOKEN_EXPIRY=15m
+REFRESH_TOKEN_EXPIRY=7d
+MAX_REFRESH_TOKENS_PER_USER=5
+```
+
+## Migration Strategy
+
+### Phase 1: Infrastructure
+- Deploy database migration
+- Update backend services
+- Maintain backward compatibility
+
+### Phase 2: Client Integration
+- Update clients to handle token pairs
+- Implement automatic token refresh
+- Add token revocation handling
+
+### Phase 3: Full Rollout
+- Enable refresh token flow for all clients
+- Monitor for issues and performance
+- Cleanup legacy authentication
+
+## Testing Results
+
+### ✅ Unit Tests
+- Token creation and validation
+- Refresh token flow
+- Security validations
+- Error handling
+
+### ✅ Integration Tests
+- API endpoint functionality
+- Database operations
+- Security scenarios
+- Edge cases
+
+### ✅ Security Tests
+- Token substitution attacks
+- Token enumeration prevention
+- Revoked token rejection
+- Expired token handling
+
+## Performance Impact
+
+### Database
+- Minimal overhead with proper indexing
+- Efficient token lookup and cleanup
+- Optimized for concurrent access
+
+### Memory
+- Efficient token hashing and validation
+- Minimal memory footprint
+- Proper cleanup of expired tokens
+
+### Network
+- Reduced authentication frequency
+- Smaller access tokens for API calls
+- Efficient token refresh mechanism
+
+## Backward Compatibility
+
+- Existing 24-hour JWT tokens continue to work
+- Gradual migration path available
+- No breaking changes to current API
+- Optional refresh token usage
+
+## Security & Data Integrity Notes
+
+### 🔐 Security Assumptions
+- JWT secret is properly secured and rotated
+- Database access is properly restricted
+- Client-side token storage follows security best practices
+- Network communication uses HTTPS
+
+### 🛡️ Data Integrity
+- All tokens are cryptographically signed
+- Token hashes prevent tampering
+- Database constraints ensure data consistency
+- Audit trail for token operations
+
+### ⚠️ Risk Mitigations
+- Token revocation for compromised tokens
+- Rate limiting prevents abuse
+- Comprehensive logging for monitoring
+- Security testing for attack vectors
+
+## Future Enhancements
+
+1. **Token Rotation**: Implement refresh token rotation
+2. **Device Management**: Track tokens by device/browser
+3. **Anomaly Detection**: AI-powered usage analysis
+4. **Multi-factor Refresh**: Additional verification for sensitive ops
+5. **Token Scoping**: Different permissions for different tokens
+
+## Files Changed
+
+- `src/types/auth.ts` - Added refresh token interfaces
+- `src/services/refreshTokenService.ts` - Core token service
+- `src/repositories/refreshTokenRepository.ts` - Database operations
+- `src/controllers/authController.ts` - API endpoints
+- `src/routes/authRoutes.ts` - Express routes
+- `src/services/refreshTokenService.test.ts` - Unit tests
+- `tests/integration/refreshToken.test.ts` - Integration tests
+- `docs/auth-refresh-strategy.md` - Documentation
+- `migrations/add_refresh_tokens.sql` - Database schema
+
+## Testing Commands
+
+```bash
+# Run unit tests
+npm test src/services/refreshTokenService.test.ts
+
+# Run integration tests
+npm test tests/integration/refreshToken.test.ts
+
+# Run all auth-related tests
+npm test -- --testNamePattern="refresh|auth"
+
+# Type checking
+npm run typecheck
+
+# Linting
+npm run lint
+```
+
+## Checklist
+
+- [x] Comprehensive refresh token implementation
+- [x] Security best practices followed
+- [x] Full test coverage
+- [x] Database migration provided
+- [x] Documentation complete
+- [x] Backward compatibility maintained
+- [x] Performance considerations addressed
+- [x] Security testing completed
+- [x] Error handling robust
+- [x] Logging and monitoring included
+
+---
+
+**Security Note**: This implementation follows OWASP JWT security guidelines and industry best practices for token-based authentication systems.