# Security Review - NGauge Backup SQL Module

## Current Security Measures

### 1. Access Control ✅
- **Authentication Required**: Only authenticated users (`roles => ['@']`) can access backup functionality
- **CSRF Protection**: All POST actions require valid CSRF token
- **Verb Filters**: HTTP methods are restricted (POST for destructive operations, GET for downloads)

### 2. Input Validation ✅
- Table names validated against actual database schema
- Filename sanitization to prevent path traversal
- Empty input checks

### 3. Path Security ✅
- Backups stored in configured directory
- Basename extraction prevents directory traversal
- File existence validation before operations

## Security Vulnerabilities & Recommendations

### 1. ⚠️ Data Encryption - CRITICAL
**Issue**: Backup files stored as plain SQL/compressed SQL
**Risk**: Sensitive data exposed if backups are compromised
**Solution**: Implement AES-256-GCM encryption with system-specific keys

### 2. ⚠️ Access Granularity
**Issue**: All authenticated users have full backup/restore access
**Risk**: Too broad permissions
**Recommendation**: Add role-based permissions (admin/backup-operator roles)

### 3. ⚠️ Audit Logging
**Issue**: Limited audit trail in BackupHistory
**Risk**: Cannot track who performed sensitive operations
**Recommendation**: Enhanced logging with user ID, IP, and operation details

### 4. ⚠️ File Download Security
**Issue**: Direct file serving without additional validation
**Risk**: Potential unauthorized access
**Recommendation**: Add download token/session validation

### 5. ⚠️ Backup Retention
**Issue**: Old backups may accumulate sensitive data
**Risk**: Data exposure over time
**Status**: Partially addressed with cleanup function
**Recommendation**: Enforce mandatory retention policies

### 6. ⚠️ SQL Injection
**Status**: ✅ Safe - Using prepared statements and schema validation
**Note**: Continue using Yii's Active Record and Query Builder

### 7. ⚠️ Command Injection
**Issue**: mysqldump/mysql commands constructed with user input
**Status**: ⚠️ Mitigated with escapeshellcmd/escapeshellarg
**Recommendation**: Additional validation of table names against whitelist

## Encryption Implementation Plan

### System-Specific Encryption
1. **Encryption Key Generation**:
   - Generate unique key based on system identifier (hostname + secret)
   - Allow manual key configuration for multi-system setups
   - Store key securely in module configuration or environment

2. **Encryption Process**:
   - Use OpenSSL with AES-256-GCM
   - Add authentication tag for integrity
   - Embed metadata (system ID, encryption version) in file header

3. **Authorized Systems**:
   - Primary system (creator) can always decrypt
   - Secondary system(s) configured via shared key
   - Metadata stored in encrypted header

4. **File Format**:
   ```
   [MAGIC_HEADER][VERSION][SYSTEM_ID][IV][AUTH_TAG][ENCRYPTED_DATA]
   ```

### Implementation Files
- `components/EncryptionManager.php` - Encryption/decryption logic
- `components/BackupManager.php` - Integration with backup/restore
- `migrations/` - Add encryption_key column to backup_history
- `Module.php` - Configuration for encryption settings

## Recommendations Priority

1. **High Priority**: Implement encryption (DONE in this update)
2. **Medium Priority**: Add role-based access control
3. **Medium Priority**: Enhanced audit logging
4. **Low Priority**: Download token validation
5. **Low Priority**: UI security headers (CSP, X-Frame-Options)

## Configuration Security

### Secure Module Configuration
```php
'db-backup' => [
    'class' => 'PortalPeople\NgaugeBackupSql\Module',
    'encryptionEnabled' => true,
    'encryptionKey' => getenv('DB_BACKUP_ENCRYPTION_KEY'), // From env, not hardcoded
    'authorizedSystems' => [
        'primary-server',
        'backup-server'
    ],
    'backupPath' => '/secure/backup/location', // Outside web root
],
```

### Environment Variables
```bash
DB_BACKUP_ENCRYPTION_KEY=base64:random_64_character_key_here
```

## Compliance Notes

- **GDPR**: Encrypted backups help with data protection requirements
- **PCI-DSS**: Encryption at rest for sensitive payment data
- **HIPAA**: Protected health information encryption requirements
- **SOC 2**: Data security and access controls

## Testing Checklist

- [ ] Encryption key generation and storage
- [ ] Backup encryption successful
- [ ] Restore decryption successful
- [ ] Cross-system restore with shared key
- [ ] Invalid key rejection
- [ ] Tampered file detection (via auth tag)
- [ ] Performance impact assessment
- [ ] Key rotation procedure
