#!/usr/bin/env python3
"""
VULNERABLE CODE SAMPLES - FOR TESTING ONLY
==========================================
This file contains intentionally vulnerable code patterns.
DO NOT use this code in production!

This file demonstrates various security vulnerabilities that the
security checker should detect. Think of it as a "patient" for
our security "doctor" to diagnose.
"""

import os
import pickle
import hashlib
import random
import subprocess
import sqlite3
import yaml
from flask import Flask, request, redirect

app = Flask(__name__)

# ============================================================
# VULNERABILITY 1: SQL Injection
# Analogy: Like leaving your house key under the doormat
# ============================================================

def get_user_unsafe(username):
    """VULNERABLE: User input directly concatenated into SQL query."""
    conn = sqlite3.connect('users.db')
    cursor = conn.cursor()
    
    # BAD: String formatting in SQL query
    query = f"SELECT * FROM users WHERE username = '{username}'"
    cursor.execute(query)
    
    return cursor.fetchone()


def search_products_unsafe(search_term):
    """VULNERABLE: Another SQL injection example."""
    conn = sqlite3.connect('products.db')
    cursor = conn.cursor()
    
    # BAD: f-string in execute
    cursor.execute(f"SELECT * FROM products WHERE name LIKE '%{search_term}%'")
    
    return cursor.fetchall()


# ============================================================
# VULNERABILITY 2: Command Injection
# Analogy: Like letting a stranger operate your computer
# ============================================================

def ping_server_unsafe(hostname):
    """VULNERABLE: User input passed directly to shell command."""
    # BAD: os.system with user input
    os.system(f"ping -c 1 {hostname}")


def convert_file_unsafe(filename):
    """VULNERABLE: subprocess with shell=True and user input."""
    # BAD: shell=True with f-string
    subprocess.call(f"convert {filename} output.pdf", shell=True)


# ============================================================
# VULNERABILITY 3: Hardcoded Credentials
# Analogy: Writing your PIN on your credit card
# ============================================================

# BAD: Passwords in source code
DATABASE_PASSWORD = "SuperSecret123!"
API_KEY = "sk-1234567890abcdef1234567890abcdef"
SECRET_TOKEN = "my_very_secret_token_12345"

def connect_to_database():
    """VULNERABLE: Hardcoded password."""
    password = "AnotherHardcodedPass123"
    return f"mysql://user:{password}@localhost/db"


# ============================================================
# VULNERABILITY 4: Weak Password Hashing
# Analogy: Using a paper lock instead of a steel one
# ============================================================

def hash_password_weak(password):
    """VULNERABLE: Using MD5 for password hashing."""
    # BAD: MD5 is cryptographically broken
    return hashlib.md5(password.encode()).hexdigest()


def verify_password_sha1(password, stored_hash):
    """VULNERABLE: Using SHA1 for password hashing."""
    # BAD: SHA1 is not suitable for passwords
    return hashlib.sha1(password.encode()).hexdigest() == stored_hash


# ============================================================
# VULNERABILITY 5: Insecure Deserialization
# Analogy: Opening a package without checking what's inside
# ============================================================

def load_user_data_unsafe(data):
    """VULNERABLE: Deserializing untrusted data with pickle."""
    # BAD: pickle.loads on user-provided data
    return pickle.loads(data)


def load_config_unsafe(config_file):
    """VULNERABLE: yaml.load without SafeLoader."""
    with open(config_file) as f:
        # BAD: yaml.load without specifying Loader
        return yaml.load(f)


# ============================================================
# VULNERABILITY 6: Insecure Random Number Generation
# Analogy: Using predictable dice in a casino
# ============================================================

def generate_token_unsafe():
    """VULNERABLE: Using random module for security tokens."""
    # BAD: random.random is not cryptographically secure
    return ''.join([chr(int(random.random() * 26) + 65) for _ in range(32)])


def generate_session_id_unsafe():
    """VULNERABLE: Using random.randint for session IDs."""
    # BAD: Predictable session IDs
    return str(random.randint(100000, 999999))


# ============================================================
# VULNERABILITY 7: Path Traversal
# Analogy: A visitor who can access any room in your house
# ============================================================

def read_file_unsafe(filename):
    """VULNERABLE: User input used directly in file path."""
    # BAD: No path validation
    with open(f"/uploads/{filename}") as f:
        return f.read()


def serve_image_unsafe(image_name):
    """VULNERABLE: Path traversal in file operations."""
    # BAD: Could access ../../etc/passwd
    path = "/images/" + image_name
    with open(path, 'rb') as f:
        return f.read()


# ============================================================
# VULNERABILITY 8: XSS (Cross-Site Scripting)
# Analogy: Letting someone put their own signs in your store
# ============================================================

@app.route('/search')
def search_results_unsafe():
    """VULNERABLE: Reflected XSS vulnerability."""
    query = request.args.get('q', '')
    # BAD: User input rendered directly in HTML
    return f"<html><body>Results for: {query}</body></html>"


# ============================================================
# VULNERABILITY 9: Open Redirect
# Analogy: A sign that sends visitors anywhere they want
# ============================================================

@app.route('/redirect')
def redirect_unsafe():
    """VULNERABLE: Open redirect vulnerability."""
    # BAD: Unvalidated redirect URL
    next_url = request.args.get('next')
    return redirect(next_url)


# ============================================================
# VULNERABILITY 10: Debug Mode Enabled
# Analogy: Leaving your diary open on the coffee table
# ============================================================

# BAD: Debug mode in production
DEBUG = True
FLASK_DEBUG = True

if __name__ == '__main__':
    # BAD: Debug mode enabled
    app.run(debug=True, host='0.0.0.0')


# ============================================================
# VULNERABILITY 11: SSL Verification Disabled
# Analogy: Accepting any ID without checking if it's real
# ============================================================

import requests

def fetch_data_unsafe(url):
    """VULNERABLE: SSL verification disabled."""
    # BAD: verify=False allows MITM attacks
    response = requests.get(url, verify=False)
    return response.text


# ============================================================
# VULNERABILITY 12: Sensitive Data in Logs
# Analogy: Announcing credit card numbers over a loudspeaker
# ============================================================

import logging

def log_login_unsafe(username, password):
    """VULNERABLE: Logging sensitive information."""
    # BAD: Password logged in plaintext
    logging.info(f"Login attempt: username={username}, password={password}")


def log_payment_unsafe(card_number, cvv):
    """VULNERABLE: Logging credit card information."""
    # BAD: Credit card data in logs
    print(f"Processing payment: card={card_number}, cvv={cvv}")


# ============================================================
# VULNERABILITY 13: Hardcoded Encryption Key
# Analogy: Using the same lock combination as everyone else
# ============================================================

# BAD: Hardcoded encryption key
ENCRYPTION_KEY = b'ThisIsASecretKey1234567890123456'
AES_IV = b'InitializationV!'


def encrypt_unsafe(data):
    """VULNERABLE: Using hardcoded encryption key."""
    from Crypto.Cipher import AES
    # BAD: Hardcoded key used directly
    key = b'MySuperSecretKey1234567890123456'
    cipher = AES.new(key, AES.MODE_CBC, AES_IV)
    return cipher.encrypt(data)


# ============================================================
# VULNERABILITY 14: CORS Wildcard
# Analogy: Allowing anyone to pick up your mail
# ============================================================

@app.after_request
def add_cors_headers(response):
    """VULNERABLE: Permissive CORS configuration."""
    # BAD: Wildcard CORS allows any origin
    response.headers['Access-Control-Allow-Origin'] = '*'
    response.headers['Access-Control-Allow-Methods'] = '*'
    return response


# ============================================================
# VULNERABILITY 15: JWT Without Verification
# Analogy: Accepting any badge without checking if it's real
# ============================================================

import jwt

def decode_token_unsafe(token):
    """VULNERABLE: JWT decoded without verification."""
    # BAD: verify=False bypasses signature check
    return jwt.decode(token, verify=False)


def decode_with_none_alg(token):
    """VULNERABLE: Allowing 'none' algorithm."""
    # BAD: 'none' algorithm is insecure
    return jwt.decode(token, algorithms=['none'])