public DtoSocketServerVerify VerifyServer()
{
var computerGuid = Context.Headers["computerGuid"];
var computer = new ServiceComputer().GetByGuid(computerGuid);
if (computer == null)
{
return(null);
}
var deviceCertEntity = new ServiceCertificate().GetCertificate(computer.CertificateId);
var deviceCert = new X509Certificate2(deviceCertEntity.PfxBlob, new EncryptionServices().DecryptText(deviceCertEntity.Password), X509KeyStorageFlags.Exportable);
//Calculate UNIX time
DateTime epochStart = new DateTime(1970, 01, 01, 0, 0, 0, 0, DateTimeKind.Utc);
TimeSpan timeSpan = DateTime.UtcNow - epochStart;
string requestTimeStamp = Convert.ToUInt64(timeSpan.TotalSeconds).ToString();
string nonce = Guid.NewGuid().ToString("N");
string signatureRawData = requestTimeStamp + nonce;
var csp = (RSACryptoServiceProvider)deviceCert.PrivateKey;
SHA1Managed sha1 = new SHA1Managed();
UnicodeEncoding encoding = new UnicodeEncoding();
byte[] data = encoding.GetBytes(signatureRawData);
byte[] hash = sha1.ComputeHash(data);
var signature = csp.SignHash(hash, CryptoConfig.MapNameToOID("SHA1"));
var serverVerification = new DtoSocketServerVerify();
serverVerification.nOnce = nonce;
serverVerification.Timestamp = requestTimeStamp;
serverVerification.signature = Convert.ToBase64String(signature);
return(serverVerification);
}
private bool isValidRequest(DtoSocketServerVerify verification)
{
if (isReplayRequest(verification.nOnce, verification.Timestamp))
{
Logger.Debug($"ID: {_logId} - Request appears to be a replay, denying {verification.nOnce} {verification.Timestamp}");
return(false);
}
var deviceThumbprint = new ServiceSetting().GetSetting("device_thumbprint");
var deviceCert = ServiceCertificate.GetCertificateFromStore(deviceThumbprint.Value, StoreName.My);
if (deviceCert == null)
{
Logger.Error("Could Not Find The Device Certificate For Signature Verification.");
return(false);
}
if (!ServiceCertificate.VerifySignature(deviceCert, Convert.FromBase64String(verification.signature), verification.Timestamp + verification.nOnce))
{
return(false);
}
return(true);
}
private bool VerifyServer(DtoSocketServerVerify verification)
{
return(true);
}
