🔒 StudyFlow Security Policy

Status: ✅ v2.0 Production Ready | 🚧 v2.5 In Active Development
Version: 2.5.0 (In Development)
Last Updated: March 2, 2026

📋 Table of Contents

Supported Versions
Security Features
Authentication & Authorization
Data Protection
API Security
v2.5 Security Enhancements
Reporting a Vulnerability
Security Best Practices
Compliance

✅ Supported Versions

Currently supported versions with security updates:

Version	Status	Support Level	End of Support
2.5.x (Dev)	🚧 In Development	Active Development	TBA
2.0.x	✅ Current Stable	Full Support	June 2027
1.5.x	⚠️ Maintenance	Security Patches Only	December 2026
< 1.5	❌ Unsupported	No Support	Ended

Recommendation: Always use the latest stable version (currently 2.0.x) for production deployments.

🛡️ Security Features (v2.0)

1. Authentication System

JWT-Based Authentication:

Secure token generation with 24-hour expiration
HTTP-only cookie storage (XSS protection)
Token refresh mechanism
Automatic logout on inactivity

Password Security:

bcrypt hashing with salt rounds (12)
Minimum password requirements:
- At least 8 characters
- One uppercase letter
- One lowercase letter
- One number
- One special character
Password reset via secure email link (1-hour expiration)

Example Implementation:

// Backend/middleware/auth.middleware.js
const jwt = require('jsonwebtoken');

const authMiddleware = (req, res, next) => {
  const token = req.headers.authorization?.split(' ')[1];
  
  if (!token) {
    return res.status(401).json({ error: 'Authentication required' });
  }
  
  try {
    const decoded = jwt.verify(token, process.env.JWT_SECRET);
    req.userId = decoded.id;
    next();
  } catch (error) {
    return res.status(401).json({ error: 'Invalid or expired token' });
  }
};

2. Input Validation & Sanitization

Protection Against:

SQL Injection (MongoDB parameterized queries)
NoSQL Injection (input sanitization)
XSS Attacks (HTML escaping)
CSRF Attacks (CSRF tokens)

Validation Libraries:

express-validator for request validation
DOMPurify for HTML sanitization
validator.js for email/URL validation

Example:

// Backend/routes/auth.routes.js
const { body, validationResult } = require('express-validator');

router.post('/register', [
  body('email').isEmail().normalizeEmail(),
  body('password').isLength({ min: 8 }).isStrongPassword(),
  body('username').trim().isLength({ min: 3, max: 30 })
    .matches(/^[a-zA-Z0-9_]+$/)
], async (req, res) => {
  const errors = validationResult(req);
  if (!errors.isEmpty()) {
    return res.status(400).json({ errors: errors.array() });
  }
  // Process registration...
});

3. Rate Limiting

Protection Against:

Brute force attacks
DDoS attacks
API abuse

Limits:

// Backend/server.js
const rateLimit = require('express-rate-limit');

const limiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15 minutes
  max: 100, // Max 100 requests per window
  message: 'Too many requests, please try again later.'
});

const authLimiter = rateLimit({
  windowMs: 15 * 60 * 1000,
  max: 5, // Max 5 login attempts per 15 minutes
  skipSuccessfulRequests: true
});

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

4. CORS Configuration

Secure Cross-Origin Requests:

// Backend/server.js
const cors = require('cors');

app.use(cors({
  origin: process.env.FRONTEND_URL || 'https://studyflow.salahuddin.codes',
  credentials: true,
  methods: ['GET', 'POST', 'PUT', 'DELETE', 'PATCH'],
  allowedHeaders: ['Content-Type', 'Authorization']
}));

5. Environment Variables

Sensitive Data Protection:

All secrets stored in .env file (not committed)
Environment-specific configurations
Secure key management

Example .env:

# Never commit this file!
JWT_SECRET=your_super_secret_jwt_key_here_change_this
MONGO_URI=mongodb://localhost:27017/studyflow
BREVO_API_KEY=your_brevo_api_key
EMAIL_FROM=noreply@studyflow.com
FRONTEND_URL=https://studyflow.salahuddin.codes
NODE_ENV=production

🔐 Authentication & Authorization

Authentication Flow

Client                          Server                       Database
  │                               │                             │
  │──── POST /auth/register ────>│                             │
  │      (email, password)        │                             │
  │                               │─── Hash Password ─────────>│
  │                               │    (bcrypt, 12 rounds)      │
  │                               │<─── Store User ────────────│
  │                               │                             │
  │<─── JWT Token ───────────────│                             │
  │     (24h expiration)          │                             │
  │                               │                             │
  │──── GET /api/user/profile ──>│                             │
  │     Authorization: Bearer     │                             │
  │                               │─── Verify Token ──────────>│
  │                               │<─── User Data ─────────────│
  │<─── User Profile ────────────│                             │

Authorization Middleware

Role-Based Access Control (RBAC):

// Backend/middleware/admin.middleware.js
const adminMiddleware = (req, res, next) => {
  if (req.user.role !== 'admin') {
    return res.status(403).json({ 
      error: 'Access denied. Admin privileges required.' 
    });
  }
  next();
};

// Usage
router.delete('/api/admin/users/:id', 
  authMiddleware, 
  adminMiddleware, 
  adminController.deleteUser
);

Resource Ownership Verification:

// Ensure users can only access their own data
const ownershipMiddleware = (req, res, next) => {
  const resourceUserId = req.params.userId || req.body.userId;
  
  if (resourceUserId !== req.userId) {
    return res.status(403).json({ 
      error: 'Access denied. You can only access your own resources.' 
    });
  }
  next();
};

🗄️ Data Protection

Database Security

MongoDB Security Measures:

Authentication Required:

mongodb://username:password@host:port/database?authSource=admin

Connection Encryption:
- TLS/SSL enabled for production
- Certificate validation

Query Parameterization:

// ✅ SAFE - Parameterized query
const user = await User.findOne({ email: req.body.email });

// ❌ UNSAFE - Never do this
const user = await User.findOne({
  $where: `this.email == "${req.body.email}"`
});

Data Encryption

Encryption at Rest:

MongoDB encryption enabled (Enterprise)
Sensitive fields encrypted (e.g., API keys)

Encryption in Transit:

HTTPS/TLS for all communications
Secure WebSocket connections (WSS)

Field-Level Encryption:

// Backend/models/User.js
const crypto = require('crypto');

userSchema.methods.encryptSensitiveData = function(data) {
  const cipher = crypto.createCipher('aes-256-cbc', process.env.ENCRYPTION_KEY);
  let encrypted = cipher.update(data, 'utf8', 'hex');
  encrypted += cipher.final('hex');
  return encrypted;
};

userSchema.methods.decryptSensitiveData = function(encrypted) {
  const decipher = crypto.createDecipher('aes-256-cbc', process.env.ENCRYPTION_KEY);
  let decrypted = decipher.update(encrypted, 'hex', 'utf8');
  decrypted += decipher.final('utf8');
  return decrypted;
};

Data Retention & Privacy

GDPR Compliance:

User data deletion on request
Data export functionality
Privacy policy and consent
Audit logs for data access

Data Anonymization:

// Anonymize user data for analytics
const anonymizedData = {
  userId: crypto.createHash('sha256').update(user._id.toString()).digest('hex'),
  totalSessions: user.totalSessions,
  // No PII included
};

🔒 API Security

Secure Headers

Helmet.js Configuration:

// Backend/server.js
const helmet = require('helmet');

app.use(helmet({
  contentSecurityPolicy: {
    directives: {
      defaultSrc: ["'self'"],
      styleSrc: ["'self'", "'unsafe-inline'"],
      scriptSrc: ["'self'"],
      imgSrc: ["'self'", "data:", "https:"],
    },
  },
  hsts: {
    maxAge: 31536000,
    includeSubDomains: true,
    preload: true
  },
  referrerPolicy: { policy: 'strict-origin-when-cross-origin' }
}));

Request Validation

Schema Validation:

// Backend/validators/taskValidator.js
const taskSchema = {
  title: {
    type: 'string',
    minLength: 1,
    maxLength: 200,
    required: true
  },
  subject: {
    type: 'string',
    pattern: '^[a-zA-Z0-9 ]+$'
  },
  priority: {
    type: 'string',
    enum: ['low', 'medium', 'high']
  }
};

API Key Management

Secure API Keys:

Stored in environment variables
Rotated regularly (every 90 days)
Scoped permissions
Usage monitoring

🚀 v2.5 Security Enhancements

1. WebSocket Security

Real-Time Communication Protection:

Authentication:

// Backend/websocket/socketAuth.js
const socketAuth = (socket, next) => {
  const token = socket.handshake.auth.token;
  
  try {
    const decoded = jwt.verify(token, process.env.JWT_SECRET);
    socket.userId = decoded.id;
    socket.userRole = decoded.role;
    next();
  } catch (error) {
    next(new Error('Authentication failed'));
  }
};

io.use(socketAuth);

Room Authorization:

// Verify user is member of study group before joining room
socket.on('joinRoom', async (roomId) => {
  const isMember = await Group.exists({
    _id: roomId,
    'members.userId': socket.userId
  });
  
  if (!isMember) {
    socket.emit('error', { message: 'Access denied to this room' });
    return;
  }
  
  socket.join(roomId);
});

Message Validation:

// Sanitize and validate all incoming messages
socket.on('sendMessage', async (data) => {
  // Validate message format
  if (!data.message || typeof data.message !== 'string') {
    return socket.emit('error', { message: 'Invalid message format' });
  }
  
  // Sanitize HTML
  const sanitizedMessage = DOMPurify.sanitize(data.message);
  
  // Rate limiting (max 10 messages per minute)
  const messageCount = await redis.incr(`msg_count:${socket.userId}`);
  await redis.expire(`msg_count:${socket.userId}`, 60);
  
  if (messageCount > 10) {
    return socket.emit('error', { message: 'Rate limit exceeded' });
  }
  
  // Broadcast message
  io.to(data.roomId).emit('newMessage', {
    userId: socket.userId,
    message: sanitizedMessage,
    timestamp: Date.now()
  });
});

2. Redis Security

Secure Caching Layer:

Connection Security:

// Backend/config/redis.js
const redis = require('redis');

const client = redis.createClient({
  host: process.env.REDIS_HOST,
  port: process.env.REDIS_PORT,
  password: process.env.REDIS_PASSWORD,
  tls: process.env.NODE_ENV === 'production' ? {} : undefined,
  db: 0
});

// Enable ACL (Access Control Lists)
// Only allow specific commands for each connection type

Data Encryption:

// Encrypt sensitive data before caching
const cacheUserData = async (userId, data) => {
  const encrypted = encrypt(JSON.stringify(data));
  await redis.set(`user:${userId}`, encrypted, 'EX', 3600);
};

const getCachedUserData = async (userId) => {
  const encrypted = await redis.get(`user:${userId}`);
  if (!encrypted) return null;
  return JSON.parse(decrypt(encrypted));
};

3. File Upload Security

Cloudinary/S3 Integration:

Upload Validation:

// Backend/middleware/fileUpload.js
const multer = require('multer');
const path = require('path');

const upload = multer({
  limits: {
    fileSize: 5 * 1024 * 1024, // 5MB max
  },
  fileFilter: (req, file, cb) => {
    // Allow only specific file types
    const allowedTypes = /jpeg|jpg|png|pdf|docx/;
    const extname = allowedTypes.test(
      path.extname(file.originalname).toLowerCase()
    );
    const mimetype = allowedTypes.test(file.mimetype);
    
    if (extname && mimetype) {
      return cb(null, true);
    }
    cb(new Error('Invalid file type'));
  }
});

// Virus scanning (ClamAV integration)
const scanFile = async (fileBuffer) => {
  const NodeClam = require('clamscan');
  const clamscan = await new NodeClam().init();
  const { isInfected } = await clamscan.scanBuffer(fileBuffer);
  return !isInfected;
};

router.post('/upload', upload.single('file'), async (req, res) => {
  // Scan file for viruses
  const safe = await scanFile(req.file.buffer);
  if (!safe) {
    return res.status(400).json({ error: 'File contains malware' });
  }
  
  // Upload to Cloudinary
  const result = await cloudinary.uploader.upload(req.file.path, {
    folder: 'studyflow/notes',
    resource_type: 'auto',
    access_control: [{ access_type: 'token' }]
  });
  
  res.json({ url: result.secure_url });
});

4. Enhanced Logging & Monitoring

Audit Logs:

// Backend/models/AuditLog.js
const auditLogSchema = new mongoose.Schema({
  userId: { type: mongoose.Schema.Types.ObjectId, ref: 'User' },
  action: { 
    type: String, 
    enum: ['login', 'logout', 'data_export', 'data_delete', 'settings_change']
  },
  ipAddress: String,
  userAgent: String,
  metadata: mongoose.Schema.Types.Mixed,
  timestamp: { type: Date, default: Date.now }
});

// Middleware to log all sensitive operations
const auditMiddleware = (action) => async (req, res, next) => {
  req.on('finish', async () => {
    await AuditLog.create({
      userId: req.userId,
      action: action,
      ipAddress: req.ip,
      userAgent: req.get('user-agent'),
      metadata: {
        method: req.method,
        path: req.path,
        statusCode: res.statusCode
      }
    });
  });
  next();
};

Security Monitoring:

// Backend/services/securityMonitor.js
const monitor = {
  // Detect suspicious login patterns
  checkSuspiciousLogin: async (userId, ipAddress) => {
    const recentLogins = await AuditLog.find({
      userId,
      action: 'login',
      timestamp: { $gte: Date.now() - 3600000 } // Last hour
    });
    
    const uniqueIPs = new Set(recentLogins.map(log => log.ipAddress));
    
    // Alert if multiple IPs in short time
    if (uniqueIPs.size > 3) {
      await sendSecurityAlert(userId, 'Multiple login locations detected');
    }
  },
  
  // Detect brute force attempts
  checkBruteForce: async (ipAddress) => {
    const failedAttempts = await redis.get(`failed_login:${ipAddress}`);
    if (failedAttempts > 10) {
      // Block IP temporarily
      await redis.set(`blocked_ip:${ipAddress}`, '1', 'EX', 3600);
      return true;
    }
    return false;
  }
};

5. Two-Factor Authentication (2FA)

Coming in v2.5:

// Backend/utils/2fa.js
const speakeasy = require('speakeasy');
const QRCode = require('qrcode');

const enable2FA = async (userId) => {
  const secret = speakeasy.generateSecret({
    name: `StudyFlow (${user.email})`
  });
  
  const qrCodeUrl = await QRCode.toDataURL(secret.otpauth_url);
  
  // Save secret to user (encrypted)
  await User.findByIdAndUpdate(userId, {
    'twoFA.secret': encrypt(secret.base32),
    'twoFA.enabled': false // Enable after verification
  });
  
  return { qrCodeUrl, secret: secret.base32 };
};

const verify2FA = (secret, token) => {
  return speakeasy.totp.verify({
    secret: decrypt(secret),
    encoding: 'base32',
    token: token,
    window: 2 // Allow 2 time steps for clock drift
  });
};

6. Content Security Policy (CSP)

Enhanced CSP for v2.5:

// More strict CSP with nonce-based script loading
app.use((req, res, next) => {
  const nonce = crypto.randomBytes(16).toString('base64');
  res.locals.nonce = nonce;
  
  res.setHeader('Content-Security-Policy', `
    default-src 'self';
    script-src 'self' 'nonce-${nonce}' https://cdn.jsdelivr.net;
    style-src 'self' 'unsafe-inline';
    img-src 'self' data: https://res.cloudinary.com;
    connect-src 'self' wss://studyflow.salahuddin.codes;
    font-src 'self' data:;
    frame-src 'none';
    object-src 'none';
  `.replace(/\s{2,}/g, ' ').trim());
  
  next();
});

🚨 Reporting a Vulnerability

How to Report

If you discover a security vulnerability in StudyFlow, please follow responsible disclosure:

📧 Email: security@studyflow.salahuddin.codes
🔒 PGP Key: Available upon request
⏱️ Response Time: Within 48 hours

What to Include

Description of the vulnerability
Steps to reproduce the issue
Potential impact assessment
Suggested fix (if any)
Your contact information

Our Commitment

✅ Acknowledge receipt within 48 hours
✅ Provide regular updates (at least weekly)
✅ Credit you in release notes (if desired)
✅ Fix critical vulnerabilities within 7 days
✅ Fix high-severity issues within 30 days
✅ Maintain confidentiality until patch is released

Hall of Fame

We recognize security researchers who help make StudyFlow safer:

Researcher	Vulnerability	Severity	Date
Your name here	-	-	-

📘 Security Best Practices

For Developers

Never Commit Secrets:

# Add to .gitignore
.env
.env.local
.env.production
config/secrets.js

Regular Dependency Updates:

# Check for vulnerabilities
npm audit

# Fix automatically
npm audit fix

# Update dependencies
npm update

Use Security Linters:

# ESLint security plugin
npm install --save-dev eslint-plugin-security

# Add to .eslintrc.js
plugins: ['security'],
extends: ['plugin:security/recommended']

Code Review Checklist:
- No hardcoded credentials
- Input validation on all endpoints
- Authorization checks present
- Sensitive data encrypted
- Error messages don't leak information
- Rate limiting applied

For Users

Strong Passwords:
- Use unique passwords for StudyFlow
- Enable 2FA when available (v2.5)
- Never share credentials
Secure Your Account:
- Log out on shared devices
- Review login history regularly
- Report suspicious activity
Data Privacy:
- Review privacy settings
- Export your data regularly
- Be cautious with third-party integrations

✅ Compliance

Standards & Regulations

GDPR (General Data Protection Regulation):

✅ Right to access data
✅ Right to data portability
✅ Right to erasure ("right to be forgotten")
✅ Consent management
✅ Data breach notification (within 72 hours)

CCPA (California Consumer Privacy Act):

✅ Disclosure of data collection
✅ Opt-out of data sales (we don't sell data)
✅ Data deletion requests

OWASP Top 10 (2021):

✅ A01: Broken Access Control → Role-based access, ownership verification
✅ A02: Cryptographic Failures → bcrypt, TLS/SSL, encryption
✅ A03: Injection → Parameterized queries, input validation
✅ A04: Insecure Design → Security by design principles
✅ A05: Security Misconfiguration → Helmet.js, secure headers
✅ A06: Vulnerable Components → Regular dependency updates
✅ A07: Authentication Failures → JWT, rate limiting, 2FA (v2.5)
✅ A08: Software Integrity → Package verification, SRI
✅ A09: Logging Failures → Comprehensive audit logs
✅ A10: SSRF → URL validation, allowlist

Security Certifications

Planned:

SOC 2 Type II (2026)
ISO 27001 (2027)
HIPAA Compliance (if handling health data)

Team: Salah Uddin Kader & Sohana Rahman
Status: ✅ v2.0 Production Ready | 🚧 v2.5 In Active Development
Version: 2.5.0 (In Development)
Last Updated: March 2, 2026

v2.5 Security Additions:

🔐 WebSocket authentication and authorization
🗄️ Redis security with ACL and encryption
📁 Secure file upload with virus scanning
📊 Enhanced audit logging and monitoring
🔑 Two-factor authentication (2FA)
🛡️ Stricter Content Security Policy

Security is not a product, but a process. 🔒

Security: salahuddingfx/Study-Flow

Security

SECURITY.md