private static RequestSetClientDHParams SerializeRequest(TClientDHInnerData clientDhInnerData, AesKeyData aesKeyData)
{
var dhInnerDataBuffer = Serializer.Serialize(clientDhInnerData);
byte[] innerData;
try
{
Serializer.Serialize(clientDhInnerData);
innerData = dhInnerDataBuffer.ToArray();
}
finally
{
dhInnerDataBuffer.SafeRelease();
}
var hashsum = Sha1Helper.ComputeHashsum(innerData);
var answerWithHash = hashsum.Concat(innerData).ToArray();
var encryptedAnswer = AES.EncryptAes(aesKeyData, answerWithHash);
return(new RequestSetClientDHParams
{
EncryptedDataAsBinary = encryptedAnswer,
Nonce = clientDhInnerData.Nonce,
ServerNonce = clientDhInnerData.ServerNonce
});
}
public static RequestSetClientDHParams GetRequest(TServerDHParamsOk serverDhParams, byte[] newNonce, out byte[] clientAgree, out int serverTime)
{
AesHelper.ComputeAesParameters(newNonce, serverDhParams.ServerNonce, out var aesKeyData);
var dhInnerData = DeserializeResponse(serverDhParams, aesKeyData);
serverTime = dhInnerData.ServerTime;
var p = new BigInteger(1, dhInnerData.DhPrimeAsBinary);
var g = BigInteger.ValueOf(dhInnerData.G);
var dhParameters = new DHParameters(p, g);
KeyGenerationParameters kgp = new DHKeyGenerationParameters(new SecureRandom(), dhParameters);
var keyGen = GeneratorUtilities.GetKeyPairGenerator("DH");
keyGen.Init(kgp);
var clientKeyPair = keyGen.GenerateKeyPair();
var publicKey = ((DHPublicKeyParameters)clientKeyPair.Public);
var y = new BigInteger(1, dhInnerData.GAAsBinary);
Guard.That(y).IsValidDhPublicKey(dhParameters.P);
var serverPublicKey = new DHPublicKeyParameters(y, dhParameters);
var clientKeyAgree = AgreementUtilities.GetBasicAgreement("DH");
clientKeyAgree.Init(clientKeyPair.Private);
clientAgree = clientKeyAgree.CalculateAgreement(serverPublicKey).ToByteArrayUnsigned();
var clientDhInnerData = new TClientDHInnerData
{
RetryId = 0,
Nonce = serverDhParams.Nonce,
ServerNonce = serverDhParams.ServerNonce,
GBAsBinary = publicKey.Y.ToByteArray()
};
return(SerializeRequest(clientDhInnerData, aesKeyData));
}
