2023-07-29 23:37:10 +05:30

121 lines
3.9 KiB
C#

using System;
using System.IO;
using System.Runtime.CompilerServices;
using System.Security.Cryptography;
using System.Text;
namespace Server.Algorithm;
public class Aes256
{
private const int KeyLength = 32;
private const int AuthKeyLength = 64;
private const int IvLength = 16;
private const int HmacSha256Length = 32;
private readonly byte[] _key;
private readonly byte[] _authKey;
private static readonly byte[] Salt = Encoding.ASCII.GetBytes("VenomRATByVenom");
public Aes256(string masterKey)
{
if (string.IsNullOrEmpty(masterKey))
{
throw new ArgumentException("masterKey can not be null or empty.");
}
using Rfc2898DeriveBytes rfc2898DeriveBytes = new Rfc2898DeriveBytes(masterKey, Salt, 50000);
_key = rfc2898DeriveBytes.GetBytes(32);
_authKey = rfc2898DeriveBytes.GetBytes(64);
}
public string Encrypt(string input)
{
return Convert.ToBase64String(Encrypt(Encoding.UTF8.GetBytes(input)));
}
public byte[] Encrypt(byte[] input)
{
if (input == null)
{
throw new ArgumentNullException("input can not be null.");
}
using MemoryStream memoryStream = new MemoryStream();
memoryStream.Position = 32L;
using (AesCryptoServiceProvider aesCryptoServiceProvider = new AesCryptoServiceProvider())
{
aesCryptoServiceProvider.KeySize = 256;
aesCryptoServiceProvider.BlockSize = 128;
aesCryptoServiceProvider.Mode = CipherMode.CBC;
aesCryptoServiceProvider.Padding = PaddingMode.PKCS7;
aesCryptoServiceProvider.Key = _key;
aesCryptoServiceProvider.GenerateIV();
using CryptoStream cryptoStream = new CryptoStream(memoryStream, aesCryptoServiceProvider.CreateEncryptor(), CryptoStreamMode.Write);
memoryStream.Write(aesCryptoServiceProvider.IV, 0, aesCryptoServiceProvider.IV.Length);
cryptoStream.Write(input, 0, input.Length);
cryptoStream.FlushFinalBlock();
using HMACSHA256 hMACSHA = new HMACSHA256(_authKey);
byte[] array = hMACSHA.ComputeHash(memoryStream.ToArray(), 32, memoryStream.ToArray().Length - 32);
memoryStream.Position = 0L;
memoryStream.Write(array, 0, array.Length);
}
return memoryStream.ToArray();
}
public string Decrypt(string input)
{
return Encoding.UTF8.GetString(Decrypt(Convert.FromBase64String(input)));
}
public byte[] Decrypt(byte[] input)
{
if (input == null)
{
throw new ArgumentNullException("input can not be null.");
}
using MemoryStream memoryStream = new MemoryStream(input);
using AesCryptoServiceProvider aesCryptoServiceProvider = new AesCryptoServiceProvider();
aesCryptoServiceProvider.KeySize = 256;
aesCryptoServiceProvider.BlockSize = 128;
aesCryptoServiceProvider.Mode = CipherMode.CBC;
aesCryptoServiceProvider.Padding = PaddingMode.PKCS7;
aesCryptoServiceProvider.Key = _key;
using (HMACSHA256 hMACSHA = new HMACSHA256(_authKey))
{
byte[] a = hMACSHA.ComputeHash(memoryStream.ToArray(), 32, memoryStream.ToArray().Length - 32);
byte[] array = new byte[32];
memoryStream.Read(array, 0, array.Length);
if (!AreEqual(a, array))
{
throw new CryptographicException("Invalid message authentication code (MAC).");
}
}
byte[] array2 = new byte[16];
memoryStream.Read(array2, 0, 16);
aesCryptoServiceProvider.IV = array2;
using CryptoStream cryptoStream = new CryptoStream(memoryStream, aesCryptoServiceProvider.CreateDecryptor(), CryptoStreamMode.Read);
byte[] array3 = new byte[memoryStream.Length - 16 + 1];
byte[] array4 = new byte[cryptoStream.Read(array3, 0, array3.Length)];
Buffer.BlockCopy(array3, 0, array4, 0, array4.Length);
return array4;
}
[MethodImpl(MethodImplOptions.NoInlining | MethodImplOptions.NoOptimization)]
private bool AreEqual(byte[] a1, byte[] a2)
{
bool result = true;
for (int i = 0; i < a1.Length; i++)
{
if (a1[i] != a2[i])
{
result = false;
}
}
return result;
}
}