private static byte[] DecryptV6(KMSV6Request kmsRequest)
{
byte[] iv = kmsRequest.Salt;
byte[] encrypted = kmsRequest.Salt.Concat(kmsRequest.EncryptedRequest).ToArray();
return(AesCrypt.DecryptAesCbc(encrypted, AesCrypt.V6RoundKeys, iv));
}
private static byte[] DecryptV6(KMSV6Request kmsRequest)
{
byte[] iv = kmsRequest.Salt;
byte[] encrypted = kmsRequest.Salt.Concat(kmsRequest.EncryptedRequest).ToArray();
return(DecryptAESV6(encrypted, iv));
}
private static KMSV6Request CreateKMSV6Request(byte[] kmsRequestData)
{
KMSV6Request kmsRequest = new KMSV6Request();
using (MemoryStream stream = new MemoryStream(kmsRequestData))
{
using BinaryReader binaryReader = new BinaryReader(stream);
kmsRequest.BodyLength1 = binaryReader.ReadUInt32();
kmsRequest.BodyLength2 = binaryReader.ReadUInt32();
kmsRequest.Version = binaryReader.ReadUInt32();
kmsRequest.Salt = binaryReader.ReadBytes(16);
kmsRequest.EncryptedRequest = binaryReader.ReadBytes(kmsRequestData.Length - 8 - 4 - 16);
}
return(kmsRequest);
}
public byte[] HandleRequest(byte[] kmsRequestData)
{
KMSV6Request kmsv6Request = CreateKMSV6Request(kmsRequestData);
byte[] decrypted = DecryptV6(kmsv6Request);
byte[] decryptedSalt = decrypted.Take(16).ToArray();
byte[] decryptedRequest = decrypted.Skip(16).ToArray();
byte[] responseBytes = Server.ExecuteKMSServerLogic(decryptedRequest, Logger);
byte[] xorRequestSalt = new byte[16];
for (int i = 0; i < 16; i++)
{
xorRequestSalt[i] = (byte)(decryptedSalt[i] ^ kmsv6Request.Salt[i]);
}
byte[] randomSalt = Guid.NewGuid().ToByteArray();
byte[] randomSaltHash = GetSHA256Hash(randomSalt);
for (int i = 0; i < 16; i++)
{
randomSalt[i] ^= xorRequestSalt[i];
}
// Get KMS Hardware ID
byte[] hardwareID;
string hexString = KMSEmulator.KMSServer.Settings.DefaultKMSHWID;
if ((hexString.Length) % 2 != 0)
{
hardwareID = new byte[] { 0x36, 0x4F, 0x46, 0x3A, 0x88, 0x63, 0xD3, 0x5F };
}
else
{
byte[] hexAsBytes = new byte[hexString.Length / 2];
for (int index = 0; index < hexAsBytes.Length; index++)
{
string byteValue = hexString.Substring(index * 2, 2);
hexAsBytes[index] = byte.Parse(byteValue, NumberStyles.HexNumber, CultureInfo.InvariantCulture);
}
hardwareID = hexAsBytes;
}
hardwareID = hardwareID.Reverse().ToArray();
byte[] responseSalt = Guid.NewGuid().ToByteArray();
byte[] decryptedResponseSalt = DecryptAESV6(responseSalt, responseSalt);
byte[] responsedata = responseBytes.Concat(randomSalt).Concat(randomSaltHash).Concat(hardwareID).Concat(xorRequestSalt).ToArray();
byte[] hmacKey = GetHmacKey(BitConverter.ToUInt64(decryptedRequest, 84));
byte[] xorResponseSalt = new byte[16];
for (int i = 0; i < 16; i++)
{
xorResponseSalt[i] = (byte)(responseSalt[i] ^ decryptedResponseSalt[i]);
}
byte[] encryptedResponseData = EncryptV6(responsedata.Concat(GetHmacSha256(hmacKey, xorResponseSalt.Concat(responsedata).ToArray()).Skip(16)).ToArray(), responseSalt);
KMSV6Response kmsResponse = new KMSV6Response {
Version = kmsv6Request.Version, Salt = responseSalt, Encrypted = encryptedResponseData
};
byte[] encryptedResponse = CreateKMSV6ResponseBytes(kmsResponse);
return(encryptedResponse);
}
