public async Task <String> RetrieveDHSessionKey(String PublickKey)
{
String DecryptedServerNumber;
String readString = await ActivitySocket.read();
ReadObj = JsonParse.ReadObject(readString);
if (FingerPrint.Verification(ReadObj.getServerPrimeNumber(), PublickKey, ReadObj.getFingerPrint()))
{
if (MacAlgProvider.VerifyHMAC(ReadObj.getServerPrimeNumber(), SymmetricKey.StrKeyBase64,
ReadObj.getHmacHash()))
{
DecryptedServerNumber = AesEncryption.AES_Decrypt(ReadObj.getServerPrimeNumber(),
SymmetricKey.StrKeyBase64);
}
else
{
throw new Exception("Integrity of SymmetricKey canot verified");
}
}
else
{
throw new Exception("Integrity of RSA canot verified");
}
return(GeneratoreMachine.SessionDHGenerator(DecryptedServerNumber));
}
public async Task SendDHEncryptedMessage(String Message)
{
String encryptedMessage = (AesEncryption.AES_Encrypt(Message, sessionKey.SessionKey));
String HmacHash = MacAlgProvider.CreateHMAC(encryptedMessage, sessionKey.SessionKey);
WriteObj.setEncryptedMessage(encryptedMessage);
WriteObj.setHmacHash(HmacHash);
await ActivitySocket.send(JsonParse.WriteObject(WriteObj));
}
public async Task <String> ReceiveDHEncryptedMessage(String PublicKey)
{
ReadObj = JsonParse.ReadObject(await ActivitySocket.read());
if (FingerPrint.Verification(ReadObj.getEncryptedMessage(), PublicKey, ReadObj.getFingerPrint()))
{
if (MacAlgProvider.VerifyHMAC(ReadObj.getEncryptedMessage(), sessionKey.SessionKey,
ReadObj.getHmacHash()))
{
return(AesEncryption.AES_Decrypt(ReadObj.getEncryptedMessage(),
sessionKey.SessionKey));
}
else
{
throw new Exception("Integrity of SymmetricKey canot verified");
}
}
else
{
throw new Exception("Integrity of RSA canot verified");
}
}
public async Task StartDHSession()
{
String EncryptedClientNumber = AesEncryption.AES_Encrypt(GeneratoreMachine.GetClientPublicNumber(),
SymmetricKey.StrKeyBase64);
String HmacHash = MacAlgProvider.CreateHMAC(EncryptedClientNumber, SymmetricKey.StrKeyBase64);
WriteObj.setClientEncryptedPrimeNumber(EncryptedClientNumber);
WriteObj.setHmacHash(HmacHash);
WriteObj.setEncryptedSymetricClientKey(RsaEncryption.RsaEncrypt(
SymmetricKey.StrKeyBase64,
ReadObj.getRSAPublicKey())
);
String StringTOsentWithRsa = JsonParse.WriteObject(WriteObj);
await ActivitySocket.send(StringTOsentWithRsa);
}
