pact-security-patterns

name

pact-security-patterns

description

Security best practices and threat mitigation patterns for PACT framework development. Use when: implementing authentication or authorization, handling API credentials, integrating external APIs, processing sensitive data (PII, financial, health), reviewing code for vulnerabilities, or enforcing SACROSANCT security rules. Triggers on: security audit, credential handling, OWASP, auth flows, encryption, data protection, backend proxy pattern, frontend credential exposure.

PACT Security Patterns

Security guidance for PACT development phases. This skill provides essential security patterns and links to detailed references for comprehensive implementation.

SACROSANCT Rules (Non-Negotiable)

These rules are ABSOLUTE and must NEVER be violated.

Rule 1: Credential Protection

NEVER ALLOW in version control:

• Actual API keys, tokens, passwords, or secrets
• Credentials in frontend code (VITE_, REACT_APP_, NEXT_PUBLIC_ prefixes)
• Real credential values in documentation or code examples
• Hardcoded secrets in any file committed to git

ONLY acceptable locations for actual credentials:

Location	Example	Security Level
.env files in .gitignore	API_KEY=sk-xxx	Development
Server-side process.env	process.env.API_KEY	Runtime
Deployment platform secrets	Railway, Vercel, AWS	Production
Secrets managers	Vault, AWS Secrets Manager	Enterprise

In Documentation - Always Use Placeholders:

# Configuration
Set your API key in `.env`:
API_KEY=your_api_key_here

Rule 2: Backend Proxy Pattern

WRONG:  Frontend --> External API (credentials in frontend)
CORRECT: Frontend --> Backend Proxy --> External API

Architecture Requirements:

• Frontend MUST NEVER have direct access to API credentials
• ALL API credentials MUST exist exclusively on server-side
• Frontend calls backend endpoints (/api/resource) without credentials
• Backend handles ALL authentication with external APIs
• Backend validates and sanitizes ALL requests from frontend

Verification Checklist:

# Build the application
npm run build

# Search for exposed credentials in bundle
grep -r "sk-" dist/assets/*.js
grep -r "api_key" dist/assets/*.js
grep -r "VITE_" dist/assets/*.js
# All above should return NO results

Quick Security Reference

Input Validation

Always validate on the server side:

// Express.js example
const { body, validationResult } = require('express-validator');

app.post('/api/user',
  body('email').isEmail().normalizeEmail(),
  body('name').trim().escape().isLength({ min: 1, max: 100 }),
  body('age').isInt({ min: 0, max: 150 }),
  (req, res) => {
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
      return res.status(400).json({ errors: errors.array() });
    }
    // Process validated input
  }
);

Output Encoding

Prevent XSS by encoding output:

// React (automatic encoding)
return <div>{userInput}</div>; // Safe - React escapes

// Dangerous - avoid unless absolutely necessary
return <div dangerouslySetInnerHTML={{__html: userInput}} />; // UNSAFE

// Node.js HTML response
const escapeHtml = (str) => str
  .replace(/&/g, '&amp;')
  .replace(/</g, '&lt;')
  .replace(/>/g, '&gt;')
  .replace(/"/g, '&quot;')
  .replace(/'/g, '&#039;');

SQL Injection Prevention

Always use parameterized queries:

// WRONG - SQL Injection vulnerable
const query = `SELECT * FROM users WHERE id = ${userId}`;

// CORRECT - Parameterized query
const query = 'SELECT * FROM users WHERE id = $1';
const result = await db.query(query, [userId]);

// ORM example (Prisma)
const user = await prisma.user.findUnique({
  where: { id: userId }  // Safe - Prisma handles escaping
});

Authentication Security

Password Storage:

const bcrypt = require('bcrypt');

// Hashing password
const saltRounds = 12;  // Minimum recommended
const hashedPassword = await bcrypt.hash(password, saltRounds);

// Verifying password
const isValid = await bcrypt.compare(password, hashedPassword);

Session Configuration:

app.use(session({
  secret: process.env.SESSION_SECRET,  // Strong, random secret
  resave: false,
  saveUninitialized: false,
  cookie: {
    secure: true,       // HTTPS only
    httpOnly: true,     // No JavaScript access
    sameSite: 'strict', // CSRF protection
    maxAge: 3600000     // 1 hour
  }
}));

Security Headers

Essential HTTP headers:

const helmet = require('helmet');

app.use(helmet({
  contentSecurityPolicy: {
    directives: {
      defaultSrc: ["'self'"],
      scriptSrc: ["'self'"],
      styleSrc: ["'self'", "'unsafe-inline'"],
      imgSrc: ["'self'", "data:", "https:"],
      connectSrc: ["'self'"],
      frameSrc: ["'none'"],
      objectSrc: ["'none'"]
    }
  },
  hsts: {
    maxAge: 31536000,
    includeSubDomains: true
  }
}));

Rate Limiting

Protect against abuse:

const rateLimit = require('express-rate-limit');

// General API rate limit
const apiLimiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15 minutes
  max: 100,
  message: { error: 'Too many requests, please try again later' }
});

// Stricter limit for auth endpoints
const authLimiter = rateLimit({
  windowMs: 60 * 60 * 1000, // 1 hour
  max: 5,
  message: { error: 'Too many login attempts' }
});

app.use('/api/', apiLimiter);
app.use('/api/auth/', authLimiter);

Security Checklist

Before any commit or deployment, verify:

Credential Protection

• No credentials in staged files (git diff --staged | grep -i "key\|secret\|password")
• .env files listed in .gitignore
• Placeholders used in all documentation
• No hardcoded API keys in source code

Architecture

• Frontend makes NO direct external API calls with credentials
• Backend proxy pattern implemented for all external integrations
• All credentials loaded from environment variables

Input/Output

• All user inputs validated server-side
• SQL queries use parameterized statements
• HTML output properly encoded
• File uploads validated for type and size

Authentication

• Passwords hashed with bcrypt (12+ rounds)
• Sessions configured with secure flags
• Authentication endpoints rate-limited
• JWT tokens have short expiration

Headers and Transport

• Security headers configured (use Helmet.js or equivalent)
• HTTPS enforced in production
• CORS configured restrictively

Detailed References

For comprehensive security guidance, see:

• OWASP Top 10 Mitigations: references/owasp-top-10.md

  • Detailed vulnerability descriptions
  • Code examples for each mitigation
  • Testing approaches

• Authentication Patterns: references/authentication-patterns.md

  • JWT implementation
  • Session management
  • OAuth 2.0 flows
  • Multi-factor authentication

• Data Protection: references/data-protection.md

  • Encryption at rest and in transit
  • PII handling requirements
  • GDPR compliance patterns
  • Key management