/// <exception cref="ArgumentException">Wrong length of IV.</exception>
public ICryptoTransform Create(CryptoDirection direction, Mode mode, byte[] iv)
{
if (iv.Length != BlockSize)
{
throw new ArgumentException("Wrong length of IV.");
}
InitRoundKey(direction);
switch (mode)
{
default:
case Mode.ECB:
if (direction == CryptoDirection.Encrypt)
{
return(new FROGEncryptTransform(_encryptRoundKeys));
}
else
{
return(new FROGDecryptTransform(_decryptRoundKeys));
}
case Mode.CBC:
return(CBC.Get(CreateNice(direction), iv, direction));
case Mode.CFB:
return(CFB.Get(CreateNice(CryptoDirection.Encrypt), iv, direction));
case Mode.OFB:
return(OFB.Get(CreateNice(CryptoDirection.Encrypt), iv, direction));
}
}
/// <summary>
/// Transforms the value.
/// </summary>
/// <param name="value">Value to transform.</param>
/// <param name="direction">Direction to transform.</param>
/// <exception cref="KeyNotFoundException">Thrown when the key is not declared.</exception>
/// <exception cref="VectorNotFoundException">Thrown when the initialisation vector is not declared.</exception>
/// <exception cref="InvalidFormatException">Thrown when either key or vector does not have a proper length.</exception>
/// <exception cref="ValueNotFoundException">Thrown when the value to transform is NULL or empty.</exception>
/// <returns>Returns the value transformed.</returns>
public string Transform(string value, CryptoDirection direction)
{
if (String.IsNullOrWhiteSpace(this.Key))
{
throw new KeyNotFoundException("Key has not been defined.");
}
if (this.Key.Length != 32)
{
throw new InvalidFormatException("Invalid key format.");
}
if (String.IsNullOrWhiteSpace(this.Vector))
{
throw new VectorNotFoundException("Vector has not been defined.");
}
if (this.Vector.Length != 16)
{
throw new InvalidFormatException("Invalid vector format.");
}
if (String.IsNullOrWhiteSpace(value))
{
throw new ValueNotFoundException("Value is NULL or empty.");
}
string transformed;
using (var aes = new AesManaged())
{
aes.Key = Encoding.UTF8.GetBytes(this.Key);
aes.IV = Encoding.UTF8.GetBytes(this.Vector);
var buffer = direction == CryptoDirection.Encrypt
? Encoding.UTF8.GetBytes(value)
: Convert.FromBase64String(value);
var transform = direction == CryptoDirection.Encrypt
? aes.CreateEncryptor(aes.Key, aes.IV)
: aes.CreateDecryptor(aes.Key, aes.IV);
using (var ms = direction == CryptoDirection.Encrypt ? new MemoryStream() : new MemoryStream(buffer))
using (var cs = new CryptoStream(ms, transform, direction == CryptoDirection.Encrypt
? CryptoStreamMode.Write
: CryptoStreamMode.Read))
{
if (direction == CryptoDirection.Encrypt)
{
cs.Write(buffer, 0, buffer.Length);
cs.FlushFinalBlock();
transformed = Convert.ToBase64String(ms.ToArray());
}
else
{
using (var sr = new StreamReader(cs))
{
transformed = sr.ReadToEnd();
}
}
}
}
return(transformed);
}
/// <summary>
/// Initializes a new instance of the <see cref="SelfMadeAes256Cryptor"/> class.
/// </summary>
/// <param name="key">The key.</param>
/// <param name="initializationVector">The initialization vector.</param>
/// <param name="cryptoDirection">The crypto direction.</param>
/// <exception cref="System.NotSupportedException">Key size must be 256 bit!</exception>
public SelfMadeAes256Cryptor(byte[] key, byte[] initializationVector, CryptoDirection cryptoDirection)
{
if (key.Length != AesConstants.KeySize256) throw new NotSupportedException("Key size must be 256 bit!");
_key = key;
_initializationVector = initializationVector;
_cryptoDirection = cryptoDirection;
_expandedKey = AesHelperMethods.CalculateExpandedKey(_key);
}
public static INiceCryptoTransform GetNice(ulong key56, CryptoDirection direction)
{
if (direction == CryptoDirection.Encrypt)
{
return(new DESEncryptTransform(key56));
}
else
{
return(new DESDecryptTransform(key56));
}
}
private void InitRoundKey(CryptoDirection direction)
{
if (direction == CryptoDirection.Encrypt && _encryptRoundKeys is null)
{
_encryptRoundKeys = GenerateKey(_key, CryptoDirection.Encrypt);
}
if (direction == CryptoDirection.Decrypt && _decryptRoundKeys is null)
{
_decryptRoundKeys = GenerateKey(_key, CryptoDirection.Decrypt);
}
}
public INiceCryptoTransform CreateNice(CryptoDirection direction)
{
InitRoundKey(direction);
if (direction == CryptoDirection.Encrypt)
{
return(new FROGEncryptTransform(_encryptRoundKeys));
}
else
{
return(new FROGDecryptTransform(_decryptRoundKeys));
}
}
/// <exception cref="ArgumentException">Wrong key length</exception>
public static INiceCryptoTransform GetNice(byte[] key, Size stateSize, CryptoDirection direction)
{
if (!IsValidKeyLength(key))
{
throw new ArgumentException("Wrong key length.");
}
if (direction == CryptoDirection.Encrypt)
{
return(new RijndaelEncryptTransform(stateSize, key));
}
else
{
return(new RijndaelDecryptTransform(stateSize, key));
}
}
public static ICryptoTransform Get(ulong key56, byte[] IV, Mode mode, CryptoDirection direction)
{
switch (mode)
{
default:
case Mode.ECB:
return(Get(key56, direction));
case Mode.CBC:
return(CBC.Get(GetNice(key56, direction), IV, direction));
case Mode.CFB:
return(CFB.Get(GetNice(key56, CryptoDirection.Encrypt), IV, direction));
case Mode.OFB:
return(OFB.Get(GetNice(key56, CryptoDirection.Encrypt), IV, direction));
}
}
/// <summary>
/// Процедура форматирования ключа
/// </summary>
private static byte[][][] FormatExpandedKey(byte[] expandedKey, CryptoDirection direction)
{
int bytesInKey = 288; // 16 + 256 + 16
byte[][][] result = new byte[8][][]; // indices: round, key(16, 256, 16), byteIndex
for (int i = 0; i < 8; i++)
{
// 1
byte[] key1 = new byte[16];
byte[] key2 = new byte[256];
byte[] key3 = new byte[16];
Array.Copy(expandedKey, i * bytesInKey, key1, 0, 16);
Array.Copy(expandedKey, i * bytesInKey + 16, key2, 0, 256);
Array.Copy(expandedKey, i * bytesInKey + 272, key3, 0, 16);
// 2
Format(key2);
if (direction == CryptoDirection.Decrypt)
{
key2 = Invert(key2);
}
// 3.a
Format(key3);
// 3.b
MakeSingleCycle(key3);
// 3.c
for (int j = 0; j < 16; j++)
{
if (key3[j] == j + 1)
{
key3[j] = (byte)((j + 2) % 16);
}
}
result[i] = new byte[3][]
{
key1, key2, key3
};
}
return(result);
}
private ICryptoTransform GetCrytoTransfomer(CryptoDirection direction, Byte[] key, Byte[] IV)
{
SymmetricAlgorithm algorithm = GetAlgorithm();
algorithm.Mode = CipherMode.CBC;
if (key == null)
{
key = algorithm.Key;
}
else
{
algorithm.Key = key;
}
if (IV == null)
{
IV = algorithm.IV;
}
else
{
algorithm.IV = IV;
}
switch (direction)
{
case CryptoDirection.Encrypt:
return(algorithm.CreateEncryptor());
break;
case CryptoDirection.Decrypt:
return(algorithm.CreateDecryptor());
break;
default:
throw new ArgumentException("Invalid Crypto Direction");
break;
}
}
/// <summary>
/// Key expansion procedure
/// </summary>
/// <returns>keys with indices: round index, key index (16b, 256b, 16b), byte in key index</returns>
private static byte[][][] GenerateKey(byte[] key, CryptoDirection direction)
{
// 1
byte[] keyExpanded = Expand(key, 2304);
// 2
byte[] masterKeyExpanded = Expand(_masterKey, 2304);
// 3
for (int i = 0; i < 2304; i++)
{
keyExpanded[i] = (byte)(keyExpanded[i] ^ masterKeyExpanded[i]);
}
// 4
byte[][][] preliminaryKey = FormatExpandedKey(keyExpanded, CryptoDirection.Encrypt);
// 5
byte[] iv = new byte[BlockSize];
Array.Copy(keyExpanded, iv, BlockSize);
iv[0] ^= (byte)key.Length;
byte[] result = TransformEmptyText(preliminaryKey, iv);
// 6
return(FormatExpandedKey(result, direction));
}
/// <exception cref="ArgumentException">Wrong length of IV</exception>
public static ICryptoTransform Get(INiceCryptoTransform transform, byte[] IV, CryptoDirection direction)
{
if (direction == CryptoDirection.Encrypt)
{
return(new CFBEncryptTransform(transform, IV));
}
else
{
return(new CFBDecryptTransform(transform, IV));
}
}
/// <summary>
/// Initializes a new instance of the <see cref="SelfMadeCaesarCryptor"/> class.
/// </summary>
/// <param name="key">The key.</param>
/// <param name="cryptoDirection">The crypto direction.</param>
public SelfMadeCaesarCryptor(int key, CryptoDirection cryptoDirection)
{
_key = key;
_cryptoDirection = cryptoDirection;
}
private ICryptoTransform GetCrytoTransfomer(CryptoDirection direction, Byte[] key, Byte[] IV)
{
SymmetricAlgorithm algorithm = GetAlgorithm();
algorithm.Mode = CipherMode.CBC;
if (key == null)
key = algorithm.Key;
else
algorithm.Key = key;
if (IV == null)
IV = algorithm.IV;
else
algorithm.IV = IV;
switch (direction)
{
case CryptoDirection.Encrypt:
return algorithm.CreateEncryptor();
break;
case CryptoDirection.Decrypt:
return algorithm.CreateDecryptor();
break;
default:
throw new ArgumentException("Invalid Crypto Direction");
break;
}
}
