public byte[] IV(CMFHeader header, byte[] digest, int length)
{
byte[] buffer = new byte[length];
uint kidx, okidx;
kidx = okidx = (uint)(2 * digest[5]);
for (int i = 0; i != length; ++i)
{
buffer[i] = Keytable[SignedMod(kidx, 512)];
kidx += okidx % 13;
buffer[i] ^= digest[SignedMod(kidx + header.GetNonEncryptedMagic(), SHA1_DIGESTSIZE)];
}
return(buffer);
}
