# Security Documentation

## Overview

This document outlines the security features and practices implemented in the system.

## Authentication

Authentication is handled through the user accounts system. See `user-accounts.md` for details on:
- User registration
- Login/logout functionality 
- Password requirements
- Session management

## Database Security

1. **SQL Injection Prevention**
   - All database queries use prepared statements with parameterized queries
   - Input validation and sanitization
   - Use of PDO for database access

2. **Data Access Control**
   - User ownership verification on all operations
   - Permission checks before data access
   - Proper error handling to prevent information leakage

## Database Tables

The security system uses the following tables:

1. **Rate Limits (`rate_limit`)**
   - Tracks rate limiting for various operations
   - User and IP tracking
   - Operation type identification
   - Timestamp tracking
   - Attempt counting

2. **Security Events (`security_event`)**
   - Records security-related events
   - Event type and severity
   - User and IP information
   - Timestamp tracking
   - Event details storage

3. **Blocked IPs (`blocked_ip`)**
   - Manages IP blocking
   - Block reason tracking
   - Block duration
   - Administrator notes

## Data Protection

1. **Passwords**
   - Stored using secure hashing
   - Never stored or transmitted in plain text
   - Password reset functionality with secure tokens

2. **Session Security**
   - Session tokens properly generated and managed
   - Session timeout implementation
   - Protection against session fixation

3. **Input Validation**
   - Data validation on both client and server side
   - Protection against XSS attacks
   - Content type verification
   - Size limits on inputs

## Access Control

1. **Resource Protection**
   - User ownership verification for all resources
   - Permission checks before operations
   - Proper error handling for unauthorized access

2. **API Security**
   - Authentication required for API access
   - Rate limiting
   - Input validation
   - Error handling without information leakage

## Best Practices

1. **Code Security**
   - Use of prepared statements
   - Input validation and sanitization
   - Proper error handling
   - Secure configuration management

2. **Data Security**
   - User data protection
   - Secure storage practices
   - Access control implementation
   - Error handling without leaks

3. **Infrastructure Security**
   - Configuration security
   - Environment separation
   - Secure deployment practices
   - Regular security updates