private static byte[] CreateKMSV5ResponseBytes(KMSV5Response responsev5)
{
using (MemoryStream stream = new MemoryStream())
{
using (BinaryWriter binaryWriter = new BinaryWriter(stream))
{
binaryWriter.Write(responsev5.BodyLength);
binaryWriter.Write(responsev5.Unknown);
binaryWriter.Write(responsev5.BodyLength2);
binaryWriter.Write(responsev5.Version);
binaryWriter.Write(responsev5.Salt);
binaryWriter.Write(responsev5.Encrypted);
binaryWriter.Write(responsev5.Padding);
binaryWriter.Flush();
stream.Position = 0;
return stream.ToArray();
}
}
}
public byte[] HandleRequest(byte[] kmsRequestData)
{
KMSV5Request kmsv5Request = CreateKMSV5Request(kmsRequestData);
byte[] decrypted = DecryptV5(kmsv5Request);
byte[] decryptedSalt = decrypted.Take(16).ToArray();
byte[] decryptedRequest = decrypted.Skip(16).ToArray();
byte[] responseBytes = Server.ExecuteKMSServerLogic(decryptedRequest, Logger);
byte[] randomSalt = Guid.NewGuid().ToByteArray();
byte[] randomSaltHash = GetSHA265Hash(randomSalt);
byte[] randomStuff = new byte[16];
for (int i = 0; i < 16; i++)
{
randomStuff[i] = (byte)(decryptedSalt[i] ^ kmsv5Request.Salt[i] ^ randomSalt[i]);
}
byte[] responsedata = responseBytes.Concat(randomStuff).Concat(randomSaltHash).ToArray();
byte[] encryptedResponseData = EncryptV5(responsedata, kmsv5Request.Salt);
KMSV5Response kmsResponse = new KMSV5Response { Version = kmsv5Request.Version, Salt = kmsv5Request.Salt, Encrypted = encryptedResponseData };
byte[] encryptedResponse = CreateKMSV5ResponseBytes(kmsResponse);
return encryptedResponse;
}