Implemented a comprehensive secure authentication mechanism for inter-node
cluster communication with the following features:
1. Global Cluster Secret (GCS)
- Auto-generated cryptographically secure random secret (256-bit)
- Configurable via YAML config file
- Shared across all cluster nodes for authentication
2. Cluster Authentication Middleware
- Validates X-Cluster-Secret and X-Node-ID headers
- Applied to all cluster endpoints (/members/*, /merkle_tree/*, /kv_range)
- Comprehensive logging of authentication attempts
3. Authenticated HTTP Client
- Custom HTTP client with cluster auth headers
- TLS support with configurable certificate verification
- Protocol-aware (http/https based on TLS settings)
4. Secure Bootstrap Endpoint
- New /auth/cluster-bootstrap endpoint
- Protected by JWT authentication with admin scope
- Allows new nodes to securely obtain cluster secret
5. Updated Cluster Communication
- All gossip protocol requests include auth headers
- All Merkle tree sync requests include auth headers
- All data replication requests include auth headers
6. Configuration
- cluster_secret: Shared secret (auto-generated if not provided)
- cluster_tls_enabled: Enable TLS for inter-node communication
- cluster_tls_cert_file: Path to TLS certificate
- cluster_tls_key_file: Path to TLS private key
- cluster_tls_skip_verify: Skip TLS verification (testing only)
This implementation addresses the security vulnerability of unprotected
cluster endpoints and provides a flexible, secure approach to protecting
internal cluster communication while allowing for automated node bootstrapping.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
- Removed all duplicate Server methods from main.go (630 lines)
- Fixed import conflicts and unused imports
- main.go reduced from 3,298 to 340 lines (89% reduction)
- Clean modular structure with server package handling all server functionality
- Achieved clean build with no compilation errors
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
- Create auth/jwt.go with JWT token management
- Create auth/permissions.go with permission checking logic
- Create auth/storage.go with storage key utilities
- Create auth/auth.go with main authentication service
- Create auth/middleware.go with auth and rate limit middleware
- Update main.go to import auth package and use auth.* functions
- Add authService to Server struct
Major auth functionality now separated into dedicated package.
Build tested and verified working.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
- Move defaultConfig() and loadConfig() functions to config package
- Remove unused yaml import from main.go
- Clean separation of configuration logic
- Update main() to use config.Load()
Reduced main.go from ~3650 to ~3570 lines
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
- Move 300+ lines of type definitions to types package
- Update all type references throughout main.go
- Extract all structs: StoredValue, User, Group, APIToken, etc.
- Include all API request/response types
- Move permission constants and configuration types
- Maintain zero functional changes
Reduced main.go from ~3990 to ~3650 lines
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
- Move all SHA3-512 hashing functions to utils package
- Update import statements and function calls
- Maintain zero functional changes
- First step in systematic main.go refactoring
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
Implemented feature toggles for:
- Authentication system (auth_enabled)
- Tamper-evident logging (tamper_logging_enabled)
- Clustering/gossip (clustering_enabled)
- Rate limiting (rate_limiting_enabled)
- Revision history (revision_history_enabled)
All features are enabled by default to maintain backward compatibility.
When disabled, features are gracefully skipped to reduce overhead.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
This massive enhancement transforms KVS from a basic distributed key-value store
into a production-ready enterprise database system with comprehensive authentication,
authorization, data management, and security features.
PHASE 2.1: CORE AUTHENTICATION & AUTHORIZATION
• Complete JWT-based authentication system with SHA3-512 security
• User and group management with CRUD APIs (/api/users, /api/groups)
• POSIX-inspired 12-bit ACL permission model (Owner/Group/Others: CDWR)
• Token management system with configurable expiration (default 1h)
• Authorization middleware with resource-level permission checking
• SHA3-512 hashing utilities for secure credential storage
PHASE 2.2: ADVANCED DATA MANAGEMENT
• ZSTD compression system with configurable levels (1-19, default 3)
• TTL support with resource metadata and automatic expiration
• 3-version revision history system with automatic rotation
• JSON size validation with configurable limits (default 1MB)
• Enhanced storage utilities with compression/decompression
• Resource metadata tracking (owner, group, permissions, timestamps)
PHASE 2.3: ENTERPRISE SECURITY & OPERATIONS
• Per-user rate limiting with sliding window algorithm
• Tamper-evident logging with cryptographic signatures (SHA3-512)
• Automated backup scheduling using cron (default: daily at midnight)
• ZSTD-compressed database snapshots with automatic cleanup
• Configurable backup retention policies (default: 7 days)
• Backup status monitoring API (/api/backup/status)
TECHNICAL ADDITIONS
• New dependencies: JWT v4, crypto/sha3, zstd compression, cron v3
• Extended configuration system with comprehensive Phase 2 settings
• API endpoints: 13 new endpoints for authentication, management, monitoring
• Storage patterns: user:<uuid>, group:<uuid>, token:<hash>, ratelimit:<user>:<window>
• Revision history: data:<key>:rev:[1-3] with metadata integration
• Tamper logs: log:<timestamp>:<uuid> with permanent retention
BACKWARD COMPATIBILITY
• All existing APIs remain fully functional
• Existing Merkle tree replication system unchanged
• New features can be disabled via configuration
• Migration-ready design for upgrading existing deployments
This implementation adds 1,500+ lines of sophisticated enterprise code while
maintaining the distributed, eventually-consistent architecture. The system
now supports multi-tenant deployments, compliance requirements, and
production-scale operations.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
Features completed:
- Sophisticated conflict resolution with majority vote system
- Oldest node tie-breaker for even cluster scenarios
- Two-phase conflict resolution (majority vote → oldest node)
- Comprehensive logging for conflict resolution decisions
- Member querying for distributed voting
- Graceful fallback to oldest node rule when no quorum available
Technical implementation:
- resolveConflict() function implementing full design specification
- resolveByOldestNode() for 2-node scenarios and tie-breaking
- queryMemberForData() for distributed consensus gathering
- Detailed logging of vote counts, winners, and decision rationale
Configuration improvements:
- Updated .gitignore for data directories and build artifacts
- Test configurations for 3-node cluster setup
- Faster sync intervals for development/testing
The KVS now fully implements the design specification:
✅ Hierarchical key-value storage with BadgerDB
✅ HTTP REST API with full CRUD operations
✅ Gossip protocol for membership discovery
✅ Eventual consistency with timestamp-based resolution
✅ Sophisticated conflict resolution (majority vote + oldest node)
✅ Gradual bootstrapping for new nodes
✅ Operational modes (normal, read-only, syncing)
✅ Structured logging with configurable levels
✅ YAML configuration with auto-generation
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
Features added:
- Gossip protocol for member discovery and failure detection
- Random peer selection with 1-3 peers per round (1-2 minute intervals)
- Member health tracking (5-minute timeout, 10-minute cleanup)
- Regular 5-minute data synchronization between peers
- Gradual bootstrapping for new nodes joining cluster
- Background sync routines with proper context cancellation
- Conflict detection for timestamp collisions (resolution pending)
- Full peer-to-peer communication via HTTP endpoints
- Automatic stale member cleanup and failure detection
Endpoints added:
- POST /members/gossip - for peer member list exchange
The cluster now supports:
- Decentralized membership management
- Automatic node discovery through gossip
- Data replication with eventual consistency
- Bootstrap process via seed nodes
- Operational mode transitions (syncing -> normal)
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
