public void KDF()
{
// Decrypt packet salt
if (ecmID != prevEcmID)
{
byte[] saltHmacKey = sha1.ComputeHash(F4FOldMethod.AppendBuf(sessionKey, packetIV));
if (debug)
{
Program.DebugLog("SaltHmacKey : " + Hexlify(saltHmacKey));
}
shaSalt.Key = saltHmacKey;
saltAesKey = F4FOldMethod.BlockCopy(shaSalt.ComputeHash(hmacData1), 0, 16);
if (debug)
{
Program.DebugLog("SaltAesKey : " + Hexlify(saltAesKey));
}
prevEcmID = ecmID;
}
if (debug)
{
Program.DebugLog("EncryptedSalt: " + Hexlify(packetSalt));
}
byte[] decryptedSalt = AesDecrypt(packetSalt, saltAesKey, packetIV);
if (decryptedSalt == null)
{
Program.Quit("<c:Red>Error ocurred while decription salt of fagment.");
}
if (debug)
{
Program.DebugLog("DecryptedSalt: " + Hexlify(decryptedSalt));
}
decryptBytes = F4FOldMethod.ReadInt32(ref decryptedSalt, 0);
if (debug)
{
Program.DebugLog("DecryptBytes : " + decryptBytes);
}
byte[] decryptedSalt2 = F4FOldMethod.BlockCopy(decryptedSalt, 4, 16);
if (debug)
{
Program.DebugLog("DecryptedSalt: " + Hexlify(decryptedSalt2));
}
// Generate final packet decryption key
byte[] finalHmacKey = sha1.ComputeHash(decryptedSalt2);
if (debug)
{
Program.DebugLog("FinalHmacKey : " + Hexlify(finalHmacKey));
}
finalsha.Key = finalHmacKey;
packetKey = F4FOldMethod.BlockCopy(finalsha.ComputeHash(hmacData2), 0, 16);
if (debug)
{
Program.DebugLog("PacketKey : " + Hexlify(packetKey));
}
}
