# BankPro Security Updates & Best Practices

## Overview
This document outlines all security fixes applied to the BankPro banking system and guidelines for secure deployment and operation.

## 🔒 Security Fixes Applied

### 1. SQL Injection Prevention
**Issue**: Direct string concatenation in SQL queries allowed attackers to inject malicious SQL code.

**Files Fixed**:
- `admin/viewwire-trans.php`
- `admin/view-domtrans.php`
- `admin/view-trans.php`
- `admin/viewcrypto-trans.php`
- `admin/viewloan-trans.php`
- `admin/viewwithdraw.php`
- `include/userClass.php`

**Solution**: 
- Implemented parameterized queries using PDO prepared statements
- All database queries now use bound parameters (`:param_name`)
- Input validation before queries
- Example:
```php
// BEFORE (VULNERABLE)
$sql = "SELECT * FROM users WHERE id = '$id'";

// AFTER (SECURE)
$sql = "SELECT * FROM users WHERE id = :id";
$stmt = $conn->prepare($sql);
$stmt->execute([':id' => $id]);
```

### 2. CSRF Protection
**Issue**: No Cross-Site Request Forgery tokens in forms.

**Solution**:
- Implemented CSRF token generation and validation
- SecurityUtils::generateCSRFToken() generates unique tokens per session
- SecurityUtils::verifyCSRFToken() validates tokens
- All POST requests now require CSRF token verification

**Usage in Forms**:
```html
<form method="POST">
    <?php echo SecurityUtils::getCSRFField(); ?>
    <!-- form fields -->
</form>
```

### 3. Input Validation
**Issue**: Insufficient input validation using only htmlspecialchars/htmlentities.

**Solution**:
- Created comprehensive SecurityUtils class with type-specific validators
- Implemented validators for:
  - Email (RFC-compliant)
  - Passwords (strength requirements: 8+ chars, uppercase, lowercase, number, special char)
  - Phone numbers (US format validation)
  - Numeric values (with min/max constraints)
  - Strings (length limits, HTML encoding)
  - Account numbers (length and format validation)

**Usage**:
```php
$email = SecurityUtils::validateInput($email, 'email');
$password = SecurityUtils::validateInput($password, 'password');
$phone = SecurityUtils::validateInput($phone, 'phone');
$amount = SecurityUtils::validateInput($amount, 'numeric');
```

### 4. Authentication & Authorization
**Issue**: No session validation or role-based access control.

**Solution**:
- Added session validation on all protected pages
- Role-based access control (RBAC) checks
- Session timeout enforcement (30 minutes)
- Session hijacking prevention via:
  - User-Agent validation
  - IP address verification (optional)
  - Periodic session ID regeneration
  - Secure session cookies (HTTPOnly, Secure, SameSite)

**Example**:
```php
if (!isset($_SESSION['user_id']) || !isset($_SESSION['user_role'])) {
    header('Location: ./login.php');
    exit('Unauthorized access');
}

if ($_SESSION['user_role'] !== 'admin') {
    header('Location: ../index.php');
    exit('Access denied');
}
```

### 5. HTTPS Enforcement
**Issue**: No enforcement of HTTPS; credentials could be transmitted in plain text.

**Solution**:
- Added HTTPS enforcement in config.php
- Security headers implemented:
  - X-Content-Type-Options: nosniff
  - X-Frame-Options: DENY
  - X-XSS-Protection: 1; mode=block
  - Strict-Transport-Security
  - Content-Security-Policy
  - Referrer-Policy

### 6. Password Security
**Issue**: Weak password hashing and no strength requirements.

**Solution**:
- Upgraded to bcrypt with cost=12 for higher security
- Implemented password strength validation:
  - Minimum 8 characters
  - Must contain uppercase letter
  - Must contain lowercase letter
  - Must contain number
  - Must contain special character (!@#$%^&*)
- SecurityUtils::hashPassword() and SecurityUtils::verifyPassword()

### 7. Error Handling
**Issue**: Database errors exposed to users, revealing system details.

**Solution**:
- Errors logged to files instead of displayed
- User-friendly error messages
- Production mode hides detailed errors
- All errors properly logged for debugging

### 8. Rate Limiting
**Issue**: No protection against brute force attacks.

**Solution**:
- Implemented rate limiting for sensitive operations
- SecurityUtils::isRateLimited() checks action frequency
- Configurable limits and time windows
- Applied to password resets, login attempts, etc.

### 9. Security Logging
**Issue**: No audit trail for security events.

**Solution**:
- Created security event logging system
- SecurityUtils::logSecurityEvent() logs:
  - Failed login attempts
  - Unauthorized access attempts
  - Password resets
  - Transaction modifications
  - Session security violations
- Logs stored in `/include/security_logs/` directory

### 10. Database Configuration
**Issue**: Hardcoded database credentials in source code.

**Solution**:
- Changed to environment variables:
```php
define("DB_HOST", getenv('DB_HOST') ?: 'localhost');
define("DB_USER", getenv('DB_USER') ?: '');
define("DB_PASS", getenv('DB_PASS') ?: '');
define("DB_NAME", getenv('DB_NAME') ?: '');
```
- Use `.env` file or server environment variables in production
- PDO connection with proper error modes

---

## 📋 Deployment Checklist

### Before Production Deployment:

1. **Environment Configuration**
   - [ ] Set environment variables for database credentials
   - [ ] Update WEB_URL to use HTTPS with your domain
   - [ ] Set WEB_TITLE to your bank name
   - [ ] Update WEB_EMAIL to valid support email

2. **Database Setup**
   - [ ] Ensure database uses UTF-8 charset (utf8mb4)
   - [ ] Create necessary tables
   - [ ] Set restrictive database user permissions
   - [ ] Enable database backups

3. **File Permissions**
   - [ ] Set 750 permissions on `/include/security_logs/`
   - [ ] Ensure logs directory is writable
   - [ ] Protect `.env` file (if used)
   - [ ] Set 644 permissions on PHP files

4. **Server Configuration**
   - [ ] Enable HTTPS/SSL certificate
   - [ ] Configure HSTS header
   - [ ] Disable directory listing
   - [ ] Enable `display_errors = Off` in php.ini (production)
   - [ ] Configure error logging
   - [ ] Set session.cookie_secure = 1
   - [ ] Set session.cookie_httponly = 1
   - [ ] Set session.cookie_samesite = Strict

5. **Security Testing**
   - [ ] Test all CSRF protections
   - [ ] Verify SQL injection is prevented
   - [ ] Test authentication/authorization
   - [ ] Verify HTTPS enforcement
   - [ ] Check security headers
   - [ ] Test rate limiting
   - [ ] Verify session timeout

6. **Monitoring**
   - [ ] Set up log monitoring for `/include/security_logs/`
   - [ ] Configure alerts for suspicious activities
   - [ ] Monitor failed login attempts
   - [ ] Track unauthorized access attempts

---

## 🔐 Password Policy

Enforce this password policy to all users:

**Minimum Requirements:**
- 8 characters minimum
- At least one uppercase letter (A-Z)
- At least one lowercase letter (a-z)
- At least one number (0-9)
- At least one special character (!@#$%^&*)

**Examples of Strong Passwords:**
- `SecureBank#2024`
- `MyPassword@123`
- `Bank$ecure456`

**Examples of Weak Passwords:**
- `password123` (no uppercase or special char)
- `Pass` (too short)
- `PASSWORD123` (no lowercase)

---

## 📝 Security Headers Explained

The following security headers are now sent with every response:

| Header | Value | Purpose |
|--------|-------|---------|
| X-Content-Type-Options | nosniff | Prevents MIME-type sniffing |
| X-Frame-Options | DENY | Prevents clickjacking attacks |
| X-XSS-Protection | 1; mode=block | Enables XSS filter |
| Strict-Transport-Security | max-age=31536000 | Enforces HTTPS for 1 year |
| Content-Security-Policy | Self + specific sources | Prevents inline script execution |
| Referrer-Policy | strict-origin-when-cross-origin | Controls referrer information |

---

## 🔄 Session Security

**Session Timeout:**
- Inactivity timeout: 30 minutes
- Sessions regenerate: Every 10 minutes
- User-Agent validation: Enabled
- IP validation: Optional (disabled by default to avoid issues)

**To Enable IP Validation:**
In `session.php`, uncomment the IP validation section:
```php
if (!isset($_SESSION['IP_ADDRESS'])) {
    $_SESSION['IP_ADDRESS'] = $_SERVER['REMOTE_ADDR'];
} else if ($_SESSION['IP_ADDRESS'] !== $_SERVER['REMOTE_ADDR']) {
    // Logout user
}
```

---

## 🚀 Using SecurityUtils Class

### CSRF Protection
```php
// Generate CSRF token
$token = SecurityUtils::generateCSRFToken();

// Get CSRF field for forms
echo SecurityUtils::getCSRFField();

// Verify CSRF token
if (!SecurityUtils::verifyCSRFToken($_POST['csrf_token'] ?? '')) {
    die('CSRF validation failed');
}
```

### Input Validation
```php
// Email validation
$email = SecurityUtils::validateInput($_POST['email'], 'email');

// Phone validation
$phone = SecurityUtils::validateInput($_POST['phone'], 'phone');

// Numeric validation with min/max
$amount = SecurityUtils::validateInput($_POST['amount'], 'numeric', 255);

// String validation with length limit
$name = SecurityUtils::validateInput($_POST['name'], 'string', 100);

// Password validation
$password = $_POST['password'] ?? '';
$validation = SecurityUtils::validatePassword($password);
if (!$validation['valid']) {
    echo "Error: " . $validation['message'];
}
```

### Password Hashing
```php
// Hash password
$hash = SecurityUtils::hashPassword($password);

// Verify password
if (SecurityUtils::verifyPassword($password, $hash)) {
    // Password correct
}
```

### Rate Limiting
```php
// Check if action is rate limited (5 attempts per 5 minutes)
if (SecurityUtils::isRateLimited('login', 5, 300)) {
    die('Too many login attempts. Try again later.');
}
```

### Security Logging
```php
// Log security event
SecurityUtils::logSecurityEvent('LOGIN_FAILURE', [
    'email' => $email,
    'ip' => $_SERVER['REMOTE_ADDR'],
    'reason' => 'Invalid credentials'
]);
```

### Output Sanitization
```php
// Safe output
echo SecurityUtils::sanitizeOutput($user_input);
// or
echo sanitize($user_input); // shorthand
```

---

## 🔧 Maintenance

### Regular Tasks

1. **Weekly**
   - Review security logs for suspicious activities
   - Check for failed login attempts

2. **Monthly**
   - Update password requirements
   - Review access logs
   - Test backup restoration

3. **Quarterly**
   - Security audit
   - Penetration testing
   - Update dependencies/libraries

4. **Annually**
   - Full security assessment
   - Compliance audit (PCI-DSS if handling cards)
   - Security training for staff

---

## 📞 Incident Response

If a security incident occurs:

1. **Immediate Actions**
   - Isolate affected systems
   - Enable detailed logging
   - Preserve evidence
   - Notify management

2. **Investigation**
   - Review security logs
   - Check access patterns
   - Identify affected data
   - Determine attack vector

3. **Containment**
   - Reset compromised passwords
   - Update access controls
   - Patch vulnerabilities
   - Monitor for re-exploitation

4. **Recovery**
   - Restore from clean backups
   - Verify system integrity
   - Test all functionality
   - Monitor for anomalies

5. **Post-Incident**
   - Notify affected users
   - Document lessons learned
   - Update security policies
   - Implement preventive measures

---

## ⚖️ Compliance

### PCI-DSS (if handling credit cards)
- Ensure all data is encrypted in transit and at rest
- Implement access controls and authentication
- Monitor and test security regularly
- Maintain security policy

### GDPR (if serving EU users)
- Obtain consent for data collection
- Implement data subject rights
- Conduct privacy impact assessments
- Maintain privacy documentation

### Other Standards
- Comply with local banking regulations
- Follow OWASP guidelines
- Implement industry best practices

---

## 📚 Additional Resources

- OWASP Top 10: https://owasp.org/Top10/
- PHP Security: https://www.php.net/manual/en/security.php
- PDO Documentation: https://www.php.net/manual/en/book.pdo.php
- NIST Cybersecurity Framework: https://www.nist.gov/cyberframework/

---

## 📞 Support

For security issues or questions:
1. Review this documentation
2. Check SecurityUtils class documentation
3. Test in development environment first
4. Contact security team for assistance

---

**Last Updated**: December 29, 2025
**Version**: 2.0 (Security Hardened)
