Arquitetura de Segurança

🔒 Visão Geral da Segurança

O Payment Gateway implementa múltiplas camadas de segurança para garantir conformidade com PCI DSS, LGPD/GDPR e best practices da indústria de pagamentos.

🛡️ Modelo de Segurança em Camadas

┌─────────────────────────────────────────────────────────────────┐
│                       EDGE SECURITY                             │
│  WAF │ DDoS Protection │ Rate Limiting │ IP Filtering          │
└─────────────────────────────────────────────────────────────────┘
                               │
┌─────────────────────────────────────────────────────────────────┐
│                    NETWORK SECURITY                             │
│  TLS 1.3 │ mTLS │ VPN │ Private Networks │ Firewall Rules     │
└─────────────────────────────────────────────────────────────────┘
                               │
┌─────────────────────────────────────────────────────────────────┐
│                  APPLICATION SECURITY                           │
│  Authentication │ Authorization │ Input Validation │ CSRF      │
└─────────────────────────────────────────────────────────────────┘
                               │
┌─────────────────────────────────────────────────────────────────┐
│                     DATA SECURITY                               │
│  Encryption │ Tokenization │ PII Protection │ Audit Logging    │
└─────────────────────────────────────────────────────────────────┘

🔐 Autenticação e Autorização

1. JWT Authentication

// JWT payload structure
{
  "sub": "user_12345",
  "iat": 1640995200,
  "exp": 1641001200,
  "scope": ["payments:read", "payments:write"],
  "merchant_id": "merchant_67890",
  "role": "admin"
}

2. API Key Authentication

// API Key format: pk_live_1234567890abcdef
const validateApiKey = (apiKey) => {
  const [prefix, env, key] = apiKey.split('_');
  return {
    isValid: prefix === 'pk' && ['test', 'live'].includes(env),
    environment: env,
    merchantId: extractMerchantId(key)
  };
};

3. Role-Based Access Control (RBAC)

const PERMISSIONS = {
  'admin': ['*'],
  'merchant': ['payments:read', 'payments:write', 'webhooks:read'],
  'readonly': ['payments:read', 'analytics:read'],
  'webhook': ['webhooks:write']
};

🔒 Criptografia e Proteção de Dados

1. Encryption at Rest

// AES-256-GCM para dados sensíveis
const encryptSensitiveData = (data, key) => {
  const cipher = crypto.createCipher('aes-256-gcm', key);
  const iv = crypto.randomBytes(16);
  const encrypted = cipher.update(data, 'utf8', 'hex') + cipher.final('hex');
  const authTag = cipher.getAuthTag();
  
  return {
    encrypted,
    iv: iv.toString('hex'),
    authTag: authTag.toString('hex')
  };
};

2. Tokenização de Cartões

// PCI-compliant card tokenization
class CardTokenizer {
  tokenize(cardNumber) {
    const token = `tok_${crypto.randomUUID()}`;
    const encryptedCard = this.encrypt(cardNumber);
    
    // Store mapping in secure vault
    this.vault.store(token, encryptedCard);
    
    return token;
  }
  
  detokenize(token) {
    const encryptedCard = this.vault.retrieve(token);
    return this.decrypt(encryptedCard);
  }
}

3. PII Protection

// Automatic PII masking for logs
const maskPII = (data) => ({
  ...data,
  email: data.email?.replace(/(.{2}).*(@.*)/, '$1***$2'),
  phone: data.phone?.replace(/(\d{2})\d+(\d{2})/, '$1****$2'),
  cardNumber: data.cardNumber?.replace(/\d{12}(\d{4})/, '****-****-****-$1')
});

🛡️ Proteção contra Fraudes

1. Risk Scoring

class FraudDetector {
  calculateRiskScore(transaction) {
    let score = 0;
    
    // Velocity checks
    score += this.checkVelocity(transaction.customer_id);
    
    // Geolocation anomalies
    score += this.checkGeolocation(transaction.ip_address);
    
    // Device fingerprinting
    score += this.checkDevice(transaction.device_fingerprint);
    
    // Amount patterns
    score += this.checkAmountPatterns(transaction.amount);
    
    return Math.min(score, 100);
  }
}

2. Real-time Monitoring

// Real-time fraud detection rules
const FRAUD_RULES = {
  'velocity_check': {
    condition: 'transactions_per_hour > 10',
    action: 'flag_for_review',
    severity: 'medium'
  },
  'high_amount': {
    condition: 'amount > 5000 AND first_transaction = true',
    action: 'require_verification',
    severity: 'high'
  },
  'suspicious_location': {
    condition: 'country != merchant_country AND amount > 1000',
    action: 'decline',
    severity: 'high'
  }
};

🔍 Auditoria e Compliance

1. Audit Trail

-- Comprehensive audit log schema
CREATE TABLE audit_log (
  id UUID PRIMARY KEY,
  timestamp TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  user_id TEXT,
  action TEXT NOT NULL,
  resource_type TEXT NOT NULL,
  resource_id TEXT,
  old_values JSON,
  new_values JSON,
  ip_address INET,
  user_agent TEXT,
  success BOOLEAN DEFAULT true,
  error_message TEXT
);

2. PCI DSS Compliance

// PCI DSS Requirements Implementation
const PCI_CONTROLS = {
  // Requirement 1: Firewall configuration
  firewall: {
    implemented: true,
    rules: ['block_unused_ports', 'whitelist_ips', 'dmz_segmentation']
  },
  
  // Requirement 3: Protect stored cardholder data
  data_protection: {
    encryption: 'AES-256',
    tokenization: true,
    key_management: 'HSM'
  },
  
  // Requirement 8: Unique IDs and strong authentication
  authentication: {
    unique_ids: true,
    strong_passwords: true,
    two_factor: true
  }
};

3. LGPD/GDPR Compliance

// Data subject rights implementation
class DataPrivacy {
  async rightToAccess(userId) {
    return await this.exportUserData(userId);
  }
  
  async rightToErasure(userId) {
    // Anonymize instead of delete for compliance
    return await this.anonymizeUserData(userId);
  }
  
  async rightToPortability(userId) {
    const data = await this.exportUserData(userId);
    return this.formatAsJSON(data);
  }
}

🚨 Incident Response

1. Security Incident Classification

const INCIDENT_LEVELS = {
  'P0': {
    description: 'Data breach or system compromise',
    response_time: '15 minutes',
    escalation: ['CISO', 'CEO', 'Legal']
  },
  'P1': {
    description: 'Fraud detection or suspicious activity',
    response_time: '1 hour',
    escalation: ['Security Team', 'Operations']
  },
  'P2': {
    description: 'Security policy violation',
    response_time: '4 hours',
    escalation: ['Security Team']
  }
};

2. Automated Response

// Automated incident response
class IncidentResponse {
  async handleSecurityEvent(event) {
    // Immediate containment
    if (event.severity === 'high') {
      await this.isolateAffectedSystems(event.source);
      await this.notifySecurityTeam(event);
    }
    
    // Evidence collection
    await this.collectForensicData(event);
    
    // Stakeholder notification
    await this.notifyStakeholders(event);
    
    // Create incident ticket
    return await this.createIncidentTicket(event);
  }
}

🔐 Secrets Management

1. Environment-based Configuration

// Secure secrets management
const secrets = {
  development: {
    stripe_key: process.env.STRIPE_TEST_KEY,
    jwt_secret: process.env.JWT_SECRET_DEV
  },
  production: {
    stripe_key: vault.getSecret('stripe/live/api_key'),
    jwt_secret: vault.getSecret('jwt/production/secret')
  }
};

2. Key Rotation

// Automatic key rotation
class KeyRotation {
  async rotateJWTSecret() {
    const newSecret = crypto.randomBytes(32).toString('hex');
    
    // Update in vault
    await vault.updateSecret('jwt/secret', newSecret);
    
    // Graceful transition period
    await this.enableDualKeyValidation(newSecret);
    
    // Schedule old key deprecation
    setTimeout(() => this.deprecateOldKey(), 24 * 60 * 60 * 1000);
  }
}

📊 Security Metrics e Monitoring

1. Security KPIs

const SECURITY_METRICS = {
  'failed_login_attempts': {
    threshold: 100,
    window: '5m',
    action: 'alert_security_team'
  },
  'fraud_detection_rate': {
    target: '< 0.1%',
    measurement: 'daily',
    action: 'review_rules'
  },
  'cert_expiry_warning': {
    threshold: '30 days',
    frequency: 'daily',
    action: 'renew_certificate'
  }
};

2. Security Dashboard

<!-- Real-time security monitoring -->
<div class="security-dashboard">
  <div class="metric-card">
    <h3>Failed Logins (24h)</h3>
    <span class="metric-value">{{ failedLogins }}</span>
  </div>
  <div class="metric-card">
    <h3>Fraud Attempts Blocked</h3>
    <span class="metric-value">{{ fraudBlocked }}</span>
  </div>
  <div class="metric-card">
    <h3>Security Events</h3>
    <span class="metric-value">{{ securityEvents }}</span>
  </div>
</div>

🔧 Security Testing

1. Automated Security Scanning

# Security pipeline
security_scan:
  runs-on: ubuntu-latest
  steps:
    - name: SAST Scan
      uses: github/codeql-action/analyze
    - name: Dependency Scan
      run: npm audit --audit-level=moderate
    - name: Container Scan
      run: trivy image payment-gateway:latest

2. Penetration Testing

// Automated security testing
const securityTests = [
  'sql_injection',
  'xss_attacks',
  'csrf_protection',
  'authentication_bypass',
  'authorization_flaws',
  'sensitive_data_exposure'
];

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Última atualização: December 2024