private int j; // Key indexer
public RC2Transform(RC2 rc2Algo, bool encryption, byte[] key, byte[] iv)
: base(rc2Algo, encryption, iv)
{
#if ONLY_1_1
if (key == null)
{
throw new ArgumentNullException("key");
}
#endif
int t1 = rc2Algo.EffectiveKeySize;
if (key == null)
{
key = KeyBuilder.Key(rc2Algo.KeySize >> 3);
}
else
{
key = (byte[])key.Clone();
t1 = Math.Min(t1, key.Length << 3);
}
int t = key.Length;
if (!KeySizes.IsLegalKeySize(rc2Algo.LegalKeySizes, (t << 3)))
{
string msg = Locale.GetText("Key is too small ({0} bytes), it should be between {1} and {2} bytes long.",
t, 5, 16);
throw new CryptographicException(msg);
}
// Expand key into a byte array, then convert to word
// array since we always access the key in 16bit chunks.
byte[] L = new byte [128];
int t8 = ((t1 + 7) >> 3); // divide by 8
int tm = 255 % (2 << (8 + t1 - (t8 << 3) - 1));
for (int i = 0; i < t; i++)
{
L [i] = key [i];
}
for (int i = t; i < 128; i++)
{
L [i] = (byte)(pitable [(L [i - 1] + L [i - t]) & 0xff]);
}
L [128 - t8] = pitable [L [128 - t8] & tm];
for (int i = 127 - t8; i >= 0; i--)
{
L [i] = pitable [L [i + 1] ^ L [i + t8]];
}
K = new UInt16 [64];
int pos = 0;
for (int i = 0; i < 64; i++)
{
K [i] = (UInt16)(L [pos++] + (L [pos++] << 8));
}
}
public RC2Transform(RC2 rc2Algo, bool encryption, byte[] key, byte[] iv) : base(rc2Algo, encryption, iv)
{
int num = rc2Algo.EffectiveKeySize;
if (key == null)
{
key = KeyBuilder.Key(rc2Algo.KeySize >> 3);
}
else
{
key = (byte[])key.Clone();
num = Math.Min(num, key.Length << 3);
}
int num2 = key.Length;
if (!KeySizes.IsLegalKeySize(rc2Algo.LegalKeySizes, num2 << 3))
{
string text = Locale.GetText("Key is too small ({0} bytes), it should be between {1} and {2} bytes long.", new object[]
{
num2,
5,
16
});
throw new CryptographicException(text);
}
byte[] array = new byte[128];
int num3 = num + 7 >> 3;
int num4 = 255 % (2 << 8 + num - (num3 << 3) - 1);
for (int i = 0; i < num2; i++)
{
array[i] = key[i];
}
for (int j = num2; j < 128; j++)
{
array[j] = RC2Transform.pitable[(int)(array[j - 1] + array[j - num2] & byte.MaxValue)];
}
array[128 - num3] = RC2Transform.pitable[(int)array[128 - num3] & num4];
for (int k = 127 - num3; k >= 0; k--)
{
array[k] = RC2Transform.pitable[(int)(array[k + 1] ^ array[k + num3])];
}
this.K = new ushort[64];
int num5 = 0;
for (int l = 0; l < 64; l++)
{
this.K[l] = (ushort)((int)array[num5++] + ((int)array[num5++] << 8));
}
}
public bool ValidKeySize(int bitLength)
{
return(KeySizes.IsLegalKeySize(LegalKeySizesValue, bitLength));
}
