Strengthen Authentication Security and Remove Console Logging

[RUKAYAT-CODER]

The current implementation exposes sensitive information (e.g., tokens, emails) via console.log statements and lacks several production-grade security protections.

This update introduces secure logging, brute-force protection, token invalidation, session management with Redis, MFA support, and improved password security.

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🎯 Objectives

• Remove unsafe console.log statements
• Implement structured and secure logging
• Add token blacklisting on logout
• Protect against brute-force login attempts
• Implement Redis-backed session management
• Add multi-factor authentication (MFA) support
• Strengthen password hashing and validation policies

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🔧 Scope of Changes

1️⃣ Remove Console Logging

• Removed all console.log statements from auth.service.ts
• Replaced with structured logger (e.g., Logger service)
• Sensitive fields (tokens, passwords, emails) are:
  • Masked
  • Omitted from logs
  • Logged only when necessary (security/audit context)

✔ Prevents accidental credential/token exposure in production logs

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2️⃣ Token Blacklisting on Logout

• Implemented token blacklist store (Redis-backed)
• Access and refresh tokens are invalidated on logout
• Blacklisted tokens:
  • Cannot be reused
  • Expire automatically using TTL
• Middleware checks blacklist before validating JWT

✔ Ensures proper session termination

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3️⃣ Brute Force Protection

• Implemented login attempt tracking (per IP and per user)
• Configurable thresholds (e.g., 5 failed attempts)
• Temporary account/IP lockout after threshold exceeded
• Lockout duration configurable by environment
• Violations logged for monitoring

✔ Protects against credential stuffing and password guessing attacks

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4️⃣ Redis-Based Session Management

• Introduced centralized session store using Redis
• Each login creates a session record containing:
  • User ID
  • Device metadata (optional)
  • Token identifiers
  • Expiration timestamp
• Supports:
  • Single-session invalidation
  • Global logout
  • Session revocation
• Scales across distributed instances

✔ Enables proper stateful session control

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5️⃣ Multi-Factor Authentication (MFA)

• Added optional MFA flow
• Supports TOTP-based authentication (e.g., authenticator apps)
• MFA required:
  • After password verification
  • Before issuing final access token
• Secure secret storage
• Recovery flow supported (configurable)

✔ Adds additional authentication layer for high-security users

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6️⃣ Enhanced Password Security

• Strengthened password hashing using secure algorithm (e.g., bcrypt/argon2)
• Configurable hashing cost factor
• Enforced password validation rules:
  • Minimum length
  • Character complexity
  • Block common passwords (optional enhancement)
• Constant-time comparison used during validation

✔ Protects against weak passwords and hash cracking

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🧪 Testing

Added/updated tests covering:

• Successful login and logout flow
• Token blacklist enforcement
• Brute force lockout behavior
• Session creation and revocation
• MFA validation flow
• Password validation edge cases
• Logging behavior (no sensitive output)

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✅ Acceptance Criteria

• All console.log statements removed
• Proper structured logging implemented
• Token blacklisting enforced on logout
• Brute force protection implemented
• Redis-backed session management enabled
• MFA support added
• Enhanced password hashing and validation implemented
• Security-sensitive data no longer exposed in logs

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🔒 Security Impact

This PR significantly improves authentication security by:

• Eliminating sensitive log exposure
• Preventing token reuse after logout
• Mitigating brute-force attacks
• Enabling centralized session control
• Adding multi-factor authentication
• Strengthening password storage mechanisms

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📈 Operational Impact

• Redis dependency required for session + blacklist features
• Environment configuration updated for:
  • Lockout thresholds
  • Hash cost factor
  • MFA toggle
  • Redis connection
• Backward compatible with existing login flow (MFA optional)

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📝 Summary

This PR upgrades the authentication system to production-grade security standards by removing unsafe logging practices, introducing token invalidation, brute force protection, Redis-backed session control, MFA support, and stronger password security.

These improvements significantly reduce attack surface and align the authentication layer with modern security best practices.

close #36

[LaGodxy]

@RUKAYAT-CODER please fix the CI.

[RUKAYAT-CODER]

kindly check now for review