byte[] Decrypt(byte[] encryptedData)
{
const int KEY_LEN = 0x100;
if (encryptedData.Length < KEY_LEN)
{
throw new ApplicationException("Invalid encrypted data length");
}
var decryptedData = new byte[encryptedData.Length - KEY_LEN];
var pkt = PublicKey.GetRawData(PublicKeyBase.ToPublicKeyToken(module.Assembly.PublicKey));
if (pkt == null || pkt.Length == 0)
{
pkt = new byte[8];
}
for (int i = 0, j = 0, ki = 0; i < decryptedData.Length; i++)
{
ki = (ki + 1) % (KEY_LEN - 1);
j = (j + encryptedData[ki] + pkt[i % 8]) % (KEY_LEN - 1);
var tmp = encryptedData[j];
encryptedData[j] = encryptedData[ki];
encryptedData[ki] = tmp;
decryptedData[i] = (byte)(encryptedData[KEY_LEN + i] ^ encryptedData[(encryptedData[j] + encryptedData[ki]) % (KEY_LEN - 1)]);
}
return(decryptedData);
}
