public byte[] processHandleAuth_Request(byte[] data)
{
// RSA version check
byte[] neededRSAV = { 0x04, 0x00, 0x00, 0x00 };
byte[] packetRSAV = new byte[4];
// In this packet, RSA starts at offset 3
ArrayUtils.copy(data, 3, packetRSAV, 0, 4);
if (!ArrayUtils.equal(neededRSAV, packetRSAV))
{
throw new AuthException("Invalid RSA version");
}
// Get RSA encrypted blob from the data
byte [] blob = new byte[128];
ArrayUtils.copy(data, 44, blob, 0, 128);
Output.OptWriteLine("-> Encrypted blob received.");
// Get RSA decrypted blob
byte[] decryptedBlob = rsa.decryptWithPrivkey(blob);
Output.OptWriteLine("-> Blob decoded.");
// Copy the Auth TF key from decoded blob.
byte [] tfKey = new byte[16];
ArrayUtils.copy(decryptedBlob, 7, tfKey, 0, 16);
tf.setIV(blankIV);
tf.setKey(tfKey);
// Create the challenge
challenge = new byte[] { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
byte[] criptedChallenge = new byte[16];
tf.encrypt(challenge, criptedChallenge);
md5edChallenge = md5.digest(challenge); // Rajko said this
Output.OptWriteLine(" --> Client TF key: " + StringUtils.bytesToString(tfKey));
Output.OptWriteLine(" --> MD5(challenge): " + StringUtils.bytesToString(md5edChallenge));
Output.OptWriteLine(" --> Twofished(challenge): " + StringUtils.bytesToString(criptedChallenge));
// Copy the encrypted thing to the global variable "Challenge"
ArrayUtils.copy(criptedChallenge, 0, challenge, 0, 16);
int nameLength = decryptedBlob.Length - 30;
byte[] nameB = new byte[nameLength];
ArrayUtils.copy(decryptedBlob, 29, nameB, 0, nameLength);
// Set WorldList username
wl.setUsername(StringUtils.charBytesToString(nameB));
Output.OptWriteLine("-> User login: " + wl.getUsername());
byte[] a = new byte [18];
a[0] = 0x11; // Size
a[1] = 0x09; // Answer opcode
ArrayUtils.copy(criptedChallenge, 0, a, 2, 16);
return(a);
}