public override byte [] ComputeHash(byte [] buffer)
{
byte [] tempBa = (byte [])buffer.Clone();
rgbInner = KeySetup(key, 0x36);
rgbOuter = KeySetup(key, 0x5C);
//SHA1CryptoServiceProvider scap = new SHA1CryptoServiceProvider();
byte [] in1 = PSHA1.ConcatBa(rgbInner, tempBa);
hash = mHashAlg.ComputeHash(in1);
byte [] in2 = PSHA1.ConcatBa(rgbOuter, hash);
hash = mHashAlg.ComputeHash(in2);
return(hash);
}
/// <summary>
/// Returns pseudo-random key bytes.
/// </summary>
/// <param name="cb">The number of pseudo-random key bytes to generate.</param>
/// <returns>A byte array filled with pseudo-random key bytes.</returns>
public override byte[] GetBytes(int cb)
{
//http://www.rsasecurity.com/rsalabs/node.asp?id=2127
byte [] P = Format.GetBytes(password);
HashAlgorithm ha = new HMACSHA1(P);
int hLen = 20; //HMACSHA1 out is 20 bytes
int L = cb / hLen;
int rem = cb % hLen;
if (rem != 0)
{
L = L + 1; //round up
}
int r = cb - (L - 1) * hLen;
byte [] outL = new byte[hLen * L];
int offsetL = 0;
for (int k = 0; k < L; k++)
{
byte[] icb = BitConverter.GetBytes(internalCount);
Array.Reverse(icb, 0, 4);
byte [] salt_icb = PSHA1.ConcatBa(salt, icb);
byte [] U = ha.ComputeHash(salt_icb);
byte[] T = U;
for (int i = 2; i <= iterations; i++)
{
U = ha.ComputeHash(U);
for (int j = 0; j < hLen; j++)
{
byte b1 = T[j];
byte b2 = U[j];
T[j] = (byte)(b1 ^ b2);
}
}
Array.Copy(T, 0, outL, offsetL, hLen);
offsetL = offsetL + hLen;
internalCount = internalCount + 1;
}
byte[] key = new byte[cb];
Array.Copy(outL, 0, key, 0, cb);
return(key);
}