TripleDesCipher
Implements 3DES cipher algorithm.
using System;
namespace Renci.SshNet.Security.Cryptography.Ciphers
{
public sealed class TripleDesCipher : DesCipher
{
private int[] _encryptionKey1;
private int[] _encryptionKey2;
private int[] _encryptionKey3;
private int[] _decryptionKey1;
private int[] _decryptionKey2;
private int[] _decryptionKey3;
public TripleDesCipher(byte[] key, CipherMode mode, CipherPadding padding)
: base(key, mode, padding)
{
}
public override int EncryptBlock(byte[] inputBuffer, int inputOffset, int inputCount, byte[] outputBuffer, int outputOffset)
{
if (inputOffset + base.BlockSize > inputBuffer.Length)
throw new ArgumentException("input buffer too short");
if (outputOffset + base.BlockSize > outputBuffer.Length)
throw new ArgumentException("output buffer too short");
if (_encryptionKey1 == null || _encryptionKey2 == null || _encryptionKey3 == null) {
byte[] array = new byte[8];
byte[] array2 = new byte[8];
Buffer.BlockCopy(base.Key, 0, array, 0, 8);
Buffer.BlockCopy(base.Key, 8, array2, 0, 8);
_encryptionKey1 = GenerateWorkingKey(true, array);
_encryptionKey2 = GenerateWorkingKey(false, array2);
if (base.Key.Length == 24) {
byte[] array3 = new byte[8];
Buffer.BlockCopy(base.Key, 16, array3, 0, 8);
_encryptionKey3 = GenerateWorkingKey(true, array3);
} else
_encryptionKey3 = _encryptionKey1;
}
byte[] array4 = new byte[base.BlockSize];
DesCipher.DesFunc(_encryptionKey1, inputBuffer, inputOffset, array4, 0);
DesCipher.DesFunc(_encryptionKey2, array4, 0, array4, 0);
DesCipher.DesFunc(_encryptionKey3, array4, 0, outputBuffer, outputOffset);
return base.BlockSize;
}
public override int DecryptBlock(byte[] inputBuffer, int inputOffset, int inputCount, byte[] outputBuffer, int outputOffset)
{
if (inputOffset + base.BlockSize > inputBuffer.Length)
throw new ArgumentException("input buffer too short");
if (outputOffset + base.BlockSize > outputBuffer.Length)
throw new ArgumentException("output buffer too short");
if (_decryptionKey1 == null || _decryptionKey2 == null || _decryptionKey3 == null) {
byte[] array = new byte[8];
byte[] array2 = new byte[8];
Buffer.BlockCopy(base.Key, 0, array, 0, 8);
Buffer.BlockCopy(base.Key, 8, array2, 0, 8);
_decryptionKey1 = GenerateWorkingKey(false, array);
_decryptionKey2 = GenerateWorkingKey(true, array2);
if (base.Key.Length == 24) {
byte[] array3 = new byte[8];
Buffer.BlockCopy(base.Key, 16, array3, 0, 8);
_decryptionKey3 = GenerateWorkingKey(false, array3);
} else
_decryptionKey3 = _decryptionKey1;
}
byte[] array4 = new byte[base.BlockSize];
DesCipher.DesFunc(_decryptionKey3, inputBuffer, inputOffset, array4, 0);
DesCipher.DesFunc(_decryptionKey2, array4, 0, array4, 0);
DesCipher.DesFunc(_decryptionKey1, array4, 0, outputBuffer, outputOffset);
return base.BlockSize;
}
protected override void ValidateKey()
{
int num = base.Key.Length * 8;
if ((num != 128 && num != 192) || 1 == 0)
throw new ArgumentException($"""{num}""");
}
}
}