public static void EncryptDecrypt(byte[][] adpcm, CriAdxKey key, int encryptionType, int frameSize)
{
for (int i = 0; i < adpcm.Length; i++)
{
EncryptDecryptChannel(adpcm[i], key, encryptionType, frameSize, i, adpcm.Length);
}
}
public static void EncryptDecryptChannel(byte[] adpcm, CriAdxKey key, int encryptionType, int frameSize, int channelNum, int channelCount)
{
int xor = key.Seed;
int frameCount = adpcm.Length.DivideByRoundUp(frameSize);
for (int i = 0; i < channelNum; i++)
{
xor = (xor * key.Mult + key.Inc) & 0x7fff;
}
for (int i = 0; i < frameCount; i++)
{
int pos = i * frameSize;
if (FrameNotEmpty(adpcm, pos, frameSize))
{
adpcm[pos] ^= (byte)(xor >> 8);
if (encryptionType == 9)
{
adpcm[pos] &= 0x1f;
}
adpcm[pos + 1] ^= (byte)xor;
}
for (int c = 0; c < channelCount; c++)
{
xor = (xor * key.Mult + key.Inc) & 0x7fff;
}
}
}
private static bool TestKey(CriAdxKey key, int encryptionType, ushort[] scales)
{
int validationMask = encryptionType == 8 ? 0xE000 : 0x1000;
int xorMask = 0x7fff;
int xor = key.Seed;
foreach (ushort scale in scales)
{
if (((scale ^ xor) & validationMask) != 0 && scale != 0)
{
return(false);
}
xor = (xor * key.Mult + key.Inc) & xorMask;
}
return(true);
}
