public TripleDESTransform (TripleDES algo, bool encryption, byte[] key, byte[] iv) : base (algo, encryption, iv)
{
if (key == null) {
key = GetStrongKey ();
}
// note: checking weak keys also checks valid key length
if (TripleDES.IsWeakKey (key)) {
string msg = Locale.GetText ("This is a known weak key.");
throw new CryptographicException (msg);
}
byte[] key1 = new byte [8];
byte[] key2 = new byte [8];
byte[] key3 = new byte [8];
DES des = DES.Create ();
Buffer.BlockCopy (key, 0, key1, 0, 8);
Buffer.BlockCopy (key, 8, key2, 0, 8);
if (key.Length == 16)
Buffer.BlockCopy (key, 0, key3, 0, 8);
else
Buffer.BlockCopy (key, 16, key3, 0, 8);
// note: some modes (like CFB) requires encryption when decrypting
if ((encryption) || (algo.Mode == CipherMode.CFB)) {
E1 = new DESTransform (des, true, key1, iv);
D2 = new DESTransform (des, false, key2, iv);
E3 = new DESTransform (des, true, key3, iv);
}
else {
D1 = new DESTransform (des, false, key3, iv);
E2 = new DESTransform (des, true, key2, iv);
D3 = new DESTransform (des, false, key1, iv);
}
}
internal static void Permutation(byte[] input, byte[] output, uint[] permTab, bool preSwap)
{
if (preSwap && BitConverter.IsLittleEndian)
{
DESTransform.BSwap(input);
}
int num = input[0] >> 4 << 1;
int num2 = 32 + ((int)(input[0] & 15) << 1);
uint num3 = permTab[num++] | permTab[num2++];
uint num4 = permTab[num] | permTab[num2];
int num5 = DESTransform.BLOCK_BYTE_SIZE << 1;
int i = 2;
int num6 = 1;
while (i < num5)
{
int num7 = (int)input[num6];
num = (i << 5) + (num7 >> 4 << 1);
num2 = (i + 1 << 5) + ((num7 & 15) << 1);
num3 |= (permTab[num++] | permTab[num2++]);
num4 |= (permTab[num] | permTab[num2]);
i += 2;
num6++;
}
if (preSwap || !BitConverter.IsLittleEndian)
{
output[0] = (byte)num3;
output[1] = (byte)(num3 >> 8);
output[2] = (byte)(num3 >> 16);
output[3] = (byte)(num3 >> 24);
output[4] = (byte)num4;
output[5] = (byte)(num4 >> 8);
output[6] = (byte)(num4 >> 16);
output[7] = (byte)(num4 >> 24);
}
else
{
output[0] = (byte)(num3 >> 24);
output[1] = (byte)(num3 >> 16);
output[2] = (byte)(num3 >> 8);
output[3] = (byte)num3;
output[4] = (byte)(num4 >> 24);
output[5] = (byte)(num4 >> 16);
output[6] = (byte)(num4 >> 8);
output[7] = (byte)num4;
}
}
// note: this method is garanteed to be called with a valid blocksize
// for both input and output
protected override void ECB(byte[] input, byte[] output)
{
DESTransform.Permutation(input, output, DESTransform.ipTab, false);
if (encrypt)
{
E1.ProcessBlock(output, output);
D2.ProcessBlock(output, output);
E3.ProcessBlock(output, output);
}
else
{
D1.ProcessBlock(output, output);
E2.ProcessBlock(output, output);
D3.ProcessBlock(output, output);
}
DESTransform.Permutation(output, output, DESTransform.fpTab, true);
}
public TripleDESTransform(TripleDES algo, bool encryption, byte[] key, byte[] iv) : base(algo, encryption, iv)
{
#if NET_2_0
if (key == null)
{
key = GetStrongKey();
}
#endif
// note: checking weak keys also checks valid key length
if (TripleDES.IsWeakKey(key))
{
string msg = Locale.GetText("This is a known weak key.");
throw new CryptographicException(msg);
}
byte[] key1 = new byte [8];
byte[] key2 = new byte [8];
byte[] key3 = new byte [8];
DES des = DES.Create();
Buffer.BlockCopy(key, 0, key1, 0, 8);
Buffer.BlockCopy(key, 8, key2, 0, 8);
if (key.Length == 16)
{
Buffer.BlockCopy(key, 0, key3, 0, 8);
}
else
{
Buffer.BlockCopy(key, 16, key3, 0, 8);
}
// note: some modes (like CFB) requires encryption when decrypting
if ((encryption) || (algo.Mode == CipherMode.CFB))
{
E1 = new DESTransform(des, true, key1, iv);
D2 = new DESTransform(des, false, key2, iv);
E3 = new DESTransform(des, true, key3, iv);
}
else
{
D1 = new DESTransform(des, false, key3, iv);
E2 = new DESTransform(des, true, key2, iv);
D3 = new DESTransform(des, false, key1, iv);
}
}
internal DESTransform(SymmetricAlgorithm symmAlgo, bool encryption, byte[] key, byte[] iv) : base(symmAlgo, encryption, iv)
{
byte[] array = null;
if (key == null)
{
key = DESTransform.GetStrongKey();
array = key;
}
if (DES.IsWeakKey(key) || DES.IsSemiWeakKey(key))
{
string text = Locale.GetText("This is a known weak, or semi-weak, key.");
throw new CryptographicException(text);
}
if (array == null)
{
array = (byte[])key.Clone();
}
this.keySchedule = new byte[DESTransform.KEY_BYTE_SIZE * 16];
this.byteBuff = new byte[DESTransform.BLOCK_BYTE_SIZE];
this.dwordBuff = new uint[DESTransform.BLOCK_BYTE_SIZE / 4];
this.SetKey(array);
}
public TripleDESTransform(TripleDES algo, bool encryption, byte[] key, byte[] iv) : base(algo, encryption, iv)
{
if (key == null)
{
key = TripleDESTransform.GetStrongKey();
}
if (TripleDES.IsWeakKey(key))
{
string text = Locale.GetText("This is a known weak key.");
throw new CryptographicException(text);
}
byte[] array = new byte[8];
byte[] array2 = new byte[8];
byte[] array3 = new byte[8];
DES symmAlgo = DES.Create();
Buffer.BlockCopy(key, 0, array, 0, 8);
Buffer.BlockCopy(key, 8, array2, 0, 8);
if (key.Length == 16)
{
Buffer.BlockCopy(key, 0, array3, 0, 8);
}
else
{
Buffer.BlockCopy(key, 16, array3, 0, 8);
}
if (encryption || algo.Mode == CipherMode.CFB)
{
this.E1 = new DESTransform(symmAlgo, true, array, iv);
this.D2 = new DESTransform(symmAlgo, false, array2, iv);
this.E3 = new DESTransform(symmAlgo, true, array3, iv);
}
else
{
this.D1 = new DESTransform(symmAlgo, false, array3, iv);
this.E2 = new DESTransform(symmAlgo, true, array2, iv);
this.D3 = new DESTransform(symmAlgo, false, array, iv);
}
}
public override void GenerateKey()
{
KeyValue = DESTransform.GetStrongKey();
}
protected override void ECB(byte[] input, byte[] output)
{
DESTransform.Permutation(input, output, DESTransform.ipTab, false);
this.ProcessBlock(output, this.byteBuff);
DESTransform.Permutation(this.byteBuff, output, DESTransform.fpTab, true);
}
