python-authentication-failures.mdc

---
description: Detect and prevent identification and authentication failures in Python applications as defined in OWASP Top 10:2021-A07
globs: *.py, *.ini, *.cfg, *.yml, *.yaml, *.json, *.toml
alwaysApply: false
---
 # Python Identification and Authentication Failures Standards (OWASP A07:2021)

This rule enforces security best practices to prevent identification and authentication failures in Python applications, as defined in OWASP Top 10:2021-A07.

<rule>
name: python_authentication_failures
description: Detect and prevent identification and authentication failures in Python applications as defined in OWASP Top 10:2021-A07
filters:
  - type: file_extension
    pattern: "\\.(py|ini|cfg|yml|yaml|json|toml)$"
  - type: file_path
    pattern: ".*"

actions:
  - type: enforce
    conditions:
      # Pattern 1: Weak password validation
      - pattern: "password\\s*=\\s*['\"][^'\"]{1,7}['\"]|min_length\\s*=\\s*[1-7]"
        message: "Weak password policy detected. Passwords should be at least 8 characters long and include complexity requirements."
        
      # Pattern 2: Hardcoded credentials
      - pattern: "(username|user|login|password|passwd|pwd|secret|api_key|apikey|token)\\s*=\\s*['\"][^'\"]+['\"]"
        message: "Hardcoded credentials detected. Store sensitive credentials in environment variables or a secure vault."
        
      # Pattern 3: Missing password hashing
      - pattern: "password\\s*=\\s*request\\.form\\[\\'password\\'\\]|password\\s*=\\s*request\\.POST\\.get\\(\\'password\\'\\)"
        message: "Storing or comparing plain text passwords detected. Always hash passwords before storage or comparison."
        
      # Pattern 4: Insecure password hashing
      - pattern: "hashlib\\.md5\\(|hashlib\\.sha1\\(|hashlib\\.sha224\\("
        message: "Insecure hashing algorithm detected. Use strong hashing algorithms like bcrypt, Argon2, or PBKDF2."
        
      # Pattern 5: Missing brute force protection
      - pattern: "@app\\.route\\(['\"]\\/(login|signin|authenticate)['\"]"
        message: "Authentication endpoint detected without rate limiting or brute force protection. Implement account lockout or rate limiting."
        
      # Pattern 6: Insecure session management
      - pattern: "session\\[\\'user_id\\'\\]\\s*=|session\\[\\'authenticated\\'\\]\\s*=\\s*True"
        message: "Session management detected. Ensure proper session security with secure cookies, proper expiration, and rotation."
        
      # Pattern 7: Missing CSRF protection in authentication
      - pattern: "form\\s*=\\s*FlaskForm|class\\s+\\w+Form\\(\\s*FlaskForm\\s*\\)|class\\s+\\w+Form\\(\\s*Form\\s*\\)"
        message: "Form handling detected. Ensure CSRF protection is enabled for all authentication forms."
        
      # Pattern 8: Insecure remember me functionality
      - pattern: "remember_me|remember_token|stay_logged_in"
        message: "Remember me functionality detected. Ensure secure implementation with proper expiration and refresh mechanisms."
        
      # Pattern 9: Insecure password reset
      - pattern: "@app\\.route\\(['\"]\\/(reset-password|forgot-password|recover)['\"]"
        message: "Password reset functionality detected. Ensure secure implementation with time-limited tokens and proper user verification."
        
      # Pattern 10: Missing multi-factor authentication
      - pattern: "def\\s+login|def\\s+authenticate|def\\s+signin"
        message: "Authentication function detected. Consider implementing multi-factor authentication for sensitive operations."
        
      # Pattern 11: Insecure direct object reference in user management
      - pattern: "User\\.objects\\.get\\(id=|User\\.query\\.get\\(|get_user_by_id\\("
        message: "Direct user lookup detected. Ensure proper authorization checks before accessing user data."
        
      # Pattern 12: Insecure JWT implementation
      - pattern: "jwt\\.encode\\(|jwt\\.decode\\("
        message: "JWT usage detected. Ensure proper signing, validation, expiration, and refresh mechanisms for JWTs."
        
      # Pattern 13: Missing secure flag in cookies
      - pattern: "set_cookie\\([^,]+,[^,]+,[^,]*secure=False|set_cookie\\([^,]+,[^,]+(?!,\\s*secure=True)"
        message: "Cookie setting without secure flag detected. Set secure=True for all authentication cookies."
        
      # Pattern 14: Missing HTTP-only flag in cookies
      - pattern: "set_cookie\\([^,]+,[^,]+,[^,]*httponly=False|set_cookie\\([^,]+,[^,]+(?!,\\s*httponly=True)"
        message: "Cookie setting without httponly flag detected. Set httponly=True for all authentication cookies."
        
      # Pattern 15: Insecure default credentials
      - pattern: "DEFAULT_USERNAME|DEFAULT_PASSWORD|ADMIN_USERNAME|ADMIN_PASSWORD"
        message: "Default credential configuration detected. Remove default credentials from production code."

  - type: suggest
    message: |
      **Python Authentication Security Best Practices:**
      
      1. **Password Storage:**
         - Use strong hashing algorithms with salting
         - Implement proper work factors
         - Example with passlib:
           ```python
           from passlib.hash import argon2
           
           # Hash a password
           hashed_password = argon2.hash("user_password")
           
           # Verify a password
           is_valid = argon2.verify("user_password", hashed_password)
           ```
         - Example with Django:
           ```python
           from django.contrib.auth.hashers import make_password, check_password
           
           # Hash a password
           hashed_password = make_password("user_password")
           
           # Verify a password
           is_valid = check_password("user_password", hashed_password)
           ```
      
      2. **Password Policies:**
         - Enforce minimum length (at least 8 characters)
         - Require complexity (uppercase, lowercase, numbers, special characters)
         - Check against common passwords
         - Example with Django:
           ```python
           # settings.py
           AUTH_PASSWORD_VALIDATORS = [
               {
                   'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
                   'OPTIONS': {'min_length': 12}
               },
               {
                   'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
               },
               {
                   'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
               },
               {
                   'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
               },
           ]
           ```
      
      3. **Brute Force Protection:**
         - Implement account lockout after failed attempts
         - Use rate limiting for authentication endpoints
         - Example with Flask and Flask-Limiter:
           ```python
           from flask import Flask
           from flask_limiter import Limiter
           from flask_limiter.util import get_remote_address
           
           app = Flask(__name__)
           limiter = Limiter(
               app,
               key_func=get_remote_address,
               default_limits=["200 per day", "50 per hour"]
           )
           
           @app.route("/login", methods=["POST"])
           @limiter.limit("5 per minute")
           def login():
               # Login logic here
               pass
           ```
      
      4. **Multi-Factor Authentication:**
         - Implement MFA for sensitive operations
         - Use time-based one-time passwords (TOTP)
         - Example with pyotp:
           ```python
           import pyotp
           
           # Generate a secret key for the user
           secret = pyotp.random_base32()
           
           # Create a TOTP object
           totp = pyotp.TOTP(secret)
           
           # Verify a token
           is_valid = totp.verify(user_provided_token)
           ```
      
      5. **Secure Session Management:**
         - Use secure, HTTP-only cookies
         - Implement proper session expiration
         - Rotate session IDs after login
         - Example with Flask:
           ```python
           from flask import Flask, session
           
           app = Flask(__name__)
           app.config.update(
               SECRET_KEY='your-secret-key',
               SESSION_COOKIE_SECURE=True,
               SESSION_COOKIE_HTTPONLY=True,
               SESSION_COOKIE_SAMESITE='Lax',
               PERMANENT_SESSION_LIFETIME=timedelta(hours=1)
           )
           ```
      
      6. **CSRF Protection:**
         - Implement CSRF tokens for all forms
         - Validate tokens on form submission
         - Example with Flask-WTF:
           ```python
           from flask_wtf import FlaskForm, CSRFProtect
           from wtforms import StringField, PasswordField, SubmitField
           
           csrf = CSRFProtect(app)
           
           class LoginForm(FlaskForm):
               username = StringField('Username')
               password = PasswordField('Password')
               submit = SubmitField('Login')
           ```
      
      7. **Secure Password Reset:**
         - Use time-limited, single-use tokens
         - Send reset links to verified email addresses
         - Example implementation:
           ```python
           import secrets
           from datetime import datetime, timedelta
           
           def generate_reset_token(user_id):
               token = secrets.token_urlsafe(32)
               expiry = datetime.utcnow() + timedelta(hours=1)
               # Store token and expiry in database with user_id
               return token
           
           def verify_reset_token(token):
               # Retrieve token from database
               # Check if token exists and is not expired
               # If valid, return user_id
               pass
           ```
      
      8. **Secure JWT Implementation:**
         - Use strong signing keys
         - Include expiration claims
         - Validate all claims
         - Example with PyJWT:
           ```python
           import jwt
           from datetime import datetime, timedelta
           
           # Create a JWT
           payload = {
               'user_id': user.id,
               'exp': datetime.utcnow() + timedelta(hours=1),
               'iat': datetime.utcnow()
           }
           token = jwt.encode(payload, SECRET_KEY, algorithm='HS256')
           
           # Verify a JWT
           try:
               payload = jwt.decode(token, SECRET_KEY, algorithms=['HS256'])
               user_id = payload['user_id']
           except jwt.ExpiredSignatureError:
               # Token has expired
               pass
           except jwt.InvalidTokenError:
               # Invalid token
               pass
           ```
      
      9. **Secure Cookie Configuration:**
         - Set secure, HTTP-only, and SameSite flags
         - Example with Flask:
           ```python
           from flask import Flask, make_response
           
           app = Flask(__name__)
           
           @app.route('/set_cookie')
           def set_cookie():
               resp = make_response('Cookie set')
               resp.set_cookie(
                   'session_id', 
                   'value', 
                   secure=True, 
                   httponly=True, 
                   samesite='Lax',
                   max_age=3600
               )
               return resp
           ```
      
      10. **Credential Storage:**
          - Use environment variables or secure vaults
          - Never hardcode credentials
          - Example with python-dotenv:
            ```python
            import os
            from dotenv import load_dotenv
            
            load_dotenv()
            
            # Access credentials from environment variables
            db_user = os.environ.get('DB_USER')
            db_password = os.environ.get('DB_PASSWORD')
            ```

  - type: validate
    conditions:
      # Check 1: Proper password hashing
      - pattern: "argon2|bcrypt|pbkdf2|make_password|generate_password_hash"
        message: "Using secure password hashing algorithms."
      
      # Check 2: CSRF protection
      - pattern: "csrf|CSRFProtect|csrf_token|csrftoken"
        message: "CSRF protection is implemented."
      
      # Check 3: Secure cookie settings
      - pattern: "SESSION_COOKIE_SECURE\\s*=\\s*True|secure=True|httponly=True|samesite"
        message: "Secure cookie settings are configured."
      
      # Check 4: Rate limiting
      - pattern: "limiter\\.limit|RateLimitExceeded|rate_limit|throttle"
        message: "Rate limiting is implemented for authentication endpoints."

metadata:
  priority: high
  version: 1.0
  tags:
    - security
    - python
    - authentication
    - identity
    - owasp
    - language:python
    - framework:django
    - framework:flask
    - framework:fastapi
    - category:security
    - subcategory:authentication
    - standard:owasp-top10
    - risk:a07-identification-authentication-failures
  references:
    - "https://owasp.org/Top10/A07_2021-Identification_and_Authentication_Failures/"
    - "https://cheatsheetseries.owasp.org/cheatsheets/Authentication_Cheat_Sheet.html"
    - "https://cheatsheetseries.owasp.org/cheatsheets/Password_Storage_Cheat_Sheet.html"
    - "https://cheatsheetseries.owasp.org/cheatsheets/Credential_Stuffing_Prevention_Cheat_Sheet.html"
    - "https://docs.djangoproject.com/en/stable/topics/auth/passwords/"
    - "https://flask-login.readthedocs.io/en/latest/"
    - "https://fastapi.tiangolo.com/tutorial/security/"
</rule>