public static byte[] HandlePepperLogin(ref PepperInit Init, byte[] Packet)
{
if (Packet.Length >= 32)
{
++Init.State;
Array.Copy(Packet, Init.ClientPublicKey = new byte[32], 32);
Blake2BHasher Blake2B = new Blake2BHasher();
Blake2B.Update(Init.ClientPublicKey);
Blake2B.Update(Init.ServerPublicKey);
byte[] C = new byte[Packet.Length - 16];
Array.Copy(Packet, 32, C, 16, Packet.Length - 32);
Curve25519Xsalsa20Poly1305.CryptoBoxBeforenm(Init.SharedKey = new byte[32], Init.ClientPublicKey, PepperFactory.PublicKeys[Init.KeyVersion]);
if (Curve25519Xsalsa20Poly1305.CryptoBoxAfternm(C, C, Blake2B.Finish(), Init.SharedKey) == 0)
{
byte[] Sk = new byte[24];
Array.Copy(C, 32, Sk, 0, 24);
for (int I = 0; I < 24; I++)
{
if (Sk[I] != Init.SessionKey[I])
{
Logging.Error(typeof(PepperCrypto), "HandlePepperLogin() - Session Key is not valid.");
return(null);
}
}
Array.Copy(C, 56, Init.Nonce = new byte[24], 0, 24);
byte[] Decrypted = new byte[C.Length - 80];
Array.Copy(C, 80, Decrypted, 0, Decrypted.Length);
return(Decrypted);
}
Logging.Error(typeof(PepperCrypto), "HandlePepperLogin() - Unable to handle pepper login. curve25519xsalsa20poly1305.crypto_box_afternm != 0.");
}
return(null);
}
/// <summary>
/// Encryptes the login response message.
/// </summary>
public static byte[] SendPepperLoginResponse(ref PepperInit Init, out IEncrypter SendEncrypter, out IEncrypter ReceiveEncrypter, byte[] Data)
{
++Init.State;
Blake2BHasher Blake2 = new Blake2BHasher();
Blake2.Update(Init.Nonce);
Blake2.Update(Init.ClientPublicKey);
Blake2.Update(Init.ServerPublicKey);
byte[] M = new byte[Data.Length + 88];
byte[] SendNonce = new byte[24];
byte[] SecretKey = new byte[32];
XorShift.NextBytes(SendNonce);
XorShift.NextBytes(SecretKey);
SendEncrypter = new PepperEncrypter(SendNonce, SecretKey);
ReceiveEncrypter = new PepperEncrypter(Init.Nonce, SecretKey);
Buffer.BlockCopy(SendNonce, 0, M, 32, 24);
Buffer.BlockCopy(SecretKey, 0, M, 56, 32);
Buffer.BlockCopy(Data, 0, M, 88, Data.Length);
if (Curve25519Xsalsa20Poly1305.CryptoBoxAfternm(M, M, Blake2.Finish(), Init.SharedKey) == 0)
{
byte[] Encrypted = new byte[M.Length - 16];
Buffer.BlockCopy(M, 16, Encrypted, 0, M.Length - 16);
return(Encrypted);
}
Logging.Error(typeof(PepperCrypto), "Unable de send pepper login response.");
return(null);
}