Security Guide

Security Guide

Overview

Security is a critical aspect of FLEXON. This guide covers security best practices, potential vulnerabilities, and mitigation strategies.

Data Security

1. Input Validation

public class SecurityValidator
{
    public void ValidateInput(byte[] data)
    {
        // Check size limits
        if (data.Length > MaxDataSize)
            throw new SecurityException("Data exceeds size limit");

        // Validate magic number
        if (!IsValidMagicNumber(data))
            throw new SecurityException("Invalid data format");

        // Check for malicious content
        if (ContainsMaliciousPatterns(data))
            throw new SecurityException("Potentially malicious content");
    }
}

2. Schema Validation

var schema = @"{
    'type': 'object',
    'properties': {
        'id': { 
            'type': 'string',
            'pattern': '^[A-Za-z0-9]+$'
        },
        'data': {
            'type': 'string',
            'maxLength': 1000
        }
    },
    'additionalProperties': false
}";

var options = new FlexonOptions
{
    EnableValidation = true,
    Schema = FlexonSchema.FromString(schema)
};

3. Sensitive Data Handling

public class SecureData : IDisposable
{
    private byte[] _sensitiveData;

    public void SetData(byte[] data)
    {
        _sensitiveData = data;
    }

    public void Dispose()
    {
        if (_sensitiveData != null)
        {
            Array.Clear(_sensitiveData, 0, _sensitiveData.Length);
            _sensitiveData = null;
        }
    }
}

Network Security

1. Transport Security

public class SecureTransport
{
    private readonly HttpClient _client;

    public SecureTransport()
    {
        var handler = new HttpClientHandler
        {
            SslProtocols = SslProtocols.Tls12 | SslProtocols.Tls13
        };
        _client = new HttpClient(handler);
    }

    public async Task SendSecurely(byte[] data, string endpoint)
    {
        using var content = new FlexonContent(data);
        await _client.PostAsync(endpoint, content);
    }
}

2. Authentication

public class SecureClient
{
    private readonly string _apiKey;
    private readonly IAuthenticationProvider _auth;

    public async Task<byte[]> GetSecureData()
    {
        var token = await _auth.GetTokenAsync();
        using var request = new HttpRequestMessage
        {
            Headers = { Authorization = new AuthenticationHeaderValue("Bearer", token) }
        };
        
        // Make request
    }
}

3. Rate Limiting

public class RateLimiter
{
    private readonly SemaphoreSlim _semaphore;
    private readonly Dictionary<string, TokenBucket> _buckets;

    public async Task<bool> AllowRequest(string clientId)
    {
        await _semaphore.WaitAsync();
        try
        {
            return _buckets[clientId].TryConsume();
        }
        finally
        {
            _semaphore.Release();
        }
    }
}

Cryptography

1. Encryption

public class FlexonEncryption
{
    private readonly byte[] _key;
    private readonly byte[] _iv;

    public byte[] Encrypt(byte[] data)
    {
        using var aes = Aes.Create();
        aes.Key = _key;
        aes.IV = _iv;

        using var encryptor = aes.CreateEncryptor();
        return encryptor.TransformFinalBlock(data, 0, data.Length);
    }

    public byte[] Decrypt(byte[] encrypted)
    {
        using var aes = Aes.Create();
        aes.Key = _key;
        aes.IV = _iv;

        using var decryptor = aes.CreateDecryptor();
        return decryptor.TransformFinalBlock(encrypted, 0, encrypted.Length);
    }
}

2. Hashing

public class FlexonHash
{
    public byte[] ComputeHash(byte[] data)
    {
        using var sha256 = SHA256.Create();
        return sha256.ComputeHash(data);
    }

    public bool VerifyHash(byte[] data, byte[] hash)
    {
        var computed = ComputeHash(data);
        return computed.SequenceEqual(hash);
    }
}

3. Key Management

public class KeyManager
{
    private readonly ISecretStore _secretStore;

    public async Task<byte[]> GetEncryptionKey(string keyId)
    {
        return await _secretStore.GetSecretAsync(keyId);
    }

    public async Task RotateKey(string keyId)
    {
        var newKey = GenerateKey();
        await _secretStore.SetSecretAsync(keyId, newKey);
    }

    private byte[] GenerateKey()
    {
        using var rng = new RNGCryptoServiceProvider();
        var key = new byte[32];
        rng.GetBytes(key);
        return key;
    }
}

Access Control

1. Permission System

public class PermissionManager
{
    public bool CheckPermission(string userId, string resource, string action)
    {
        var permissions = GetUserPermissions(userId);
        return permissions.Contains($"{resource}:{action}");
    }

    public void GrantPermission(string userId, string resource, string action)
    {
        var permissions = GetUserPermissions(userId);
        permissions.Add($"{resource}:{action}");
        SavePermissions(userId, permissions);
    }
}

2. Role-Based Access

public class RoleBasedAccess
{
    private readonly Dictionary<string, HashSet<string>> _rolePermissions;

    public bool HasPermission(string role, string permission)
    {
        return _rolePermissions.TryGetValue(role, out var permissions) &&
               permissions.Contains(permission);
    }
}

3. Audit Logging

public class AuditLogger
{
    private readonly ILogger _logger;

    public void LogAccess(string userId, string resource, string action)
    {
        _logger.LogInformation(
            "User {User} performed {Action} on {Resource}",
            userId, action, resource);
    }

    public void LogSecurityEvent(string eventType, string details)
    {
        _logger.LogWarning(
            "Security event {Type}: {Details}",
            eventType, details);
    }
}

Best Practices

1. General Security

• Validate all input
• Use encryption for sensitive data
• Implement proper access control
• Keep dependencies updated
• Follow security standards

2. Data Protection

• Clear sensitive data from memory
• Use secure random numbers
• Implement proper key management
• Regular security audits

3. Network Security

• Use TLS 1.2 or later
• Implement rate limiting
• Use proper authentication
• Monitor for attacks

4. Error Handling

• Don't expose sensitive information in errors
• Log security events
• Implement proper error recovery
• Monitor error patterns

Security Checklist

1. Input Validation

   • Schema validation
   • Size limits
   • Content validation

2. Data Protection

   • Encryption at rest
   • Secure key storage
   • Memory protection

3. Network Security

   • TLS configuration
   • Authentication
   • Rate limiting

4. Access Control

   • Permission system
   • Role-based access
   • Audit logging

5. Monitoring

   • Security logging
   • Error tracking
   • Performance monitoring