在gRPC支持下，C#中的gRPC客户端不与gRPC服务器一起工作

Question

我在Golang中有一个gRPC服务器，它使用以下ServerOptions启用了mTLS：

// getServerOptions returns a list of GRPC server options.
// Current options are TLS certs and opencensus stats handler.
func (h *serviceHandler) getServerOptions() []grpc.ServerOption {
    tlsCer, err := tls.LoadX509KeyPair(tlsDir+"tls.crt", tlsDir+"tls.key")
    if err != nil {
        logger.WithError(err).Fatal("failed to generate credentials")
    }

    cfg := &tls.Config{
        Certificates: []tls.Certificate{tlsCer},
        ClientAuth:   tls.RequireAndVerifyClientCert,
        GetConfigForClient: func(*tls.ClientHelloInfo) (*tls.Config, error) {
            h.certMutex.RLock()
            defer h.certMutex.RUnlock()
            return &tls.Config{
                Certificates: []tls.Certificate{tlsCer},
                ClientAuth:   tls.RequireAndVerifyClientCert,
                ClientCAs:    h.caCertPool,
            }, nil
        },
    }
    // Add options for creds and OpenCensus stats handler to enable stats and tracing.
    return []grpc.ServerOption{grpc.Creds(credentials.NewTLS(cfg)), grpc.StatsHandler(&ocgrpc.ServerHandler{})}
}

该服务器对于Golang中的gRPC客户端运行良好，但对于以下gRPC c#客户端，在cert交换握手后失败。

        static async Task Main(string[] args)
        {
            string baseAddress = "x.x.x.x";
            var x509Cert = new X509Certificate2("client.pfx", "123");
            var client = CreateClientWithCert("https://" + baseAddress + ":443", x509Cert);

            try {
                var response = await client.PostAllocateAsync(new AllocationRequest {Namespace = "Default"});
                Console.Write(response.State.ToString());
            } 
            catch(RpcException e)
            {
                Console.WriteLine($"gRPC error: {e.Status.Detail}");
            }
            catch 
            {
                Console.WriteLine($"Unexpected error calling agones-allocator");
                throw;
            }
        }

        public static AllocationService.AllocationServiceClient CreateClientWithCert(
            string baseAddress,
            X509Certificate2 certificate)
        {

            var loggerFactory = LoggerFactory.Create(logging =>
            {
                logging.AddConsole();
                logging.SetMinimumLevel(LogLevel.Trace);
            });

            // Add client cert to the handler
            var handler = new HttpClientHandler();
            handler.ClientCertificates.Add(certificate);
            handler.ServerCertificateCustomValidationCallback = 
                HttpClientHandler.DangerousAcceptAnyServerCertificateValidator;

            // Create the gRPC channel
            var channel = GrpcChannel.ForAddress(baseAddress, new GrpcChannelOptions
            {
                HttpClient = new HttpClient(handler),
                LoggerFactory = loggerFactory,
            });

            return new AllocationService.AllocationServiceClient(channel);
        }
    }

下面是跟踪日志：

dbug: Grpc.Net.Client.Internal.GrpcCall[1]
      Starting gRPC call. Method type: 'Unary', URI: 'https://x.x.x.x/v1alpha1.AllocationService/PostAllocate'.
dbug: Grpc.Net.Client.Internal.GrpcCall[18]
      Sending message.
trce: Grpc.Net.Client.Internal.GrpcCall[21]
      Serialized 'V1Alpha1.AllocationRequest' to 9 byte message.
trce: Grpc.Net.Client.Internal.GrpcCall[19]
      Message sent.
fail: Grpc.Net.Client.Internal.GrpcCall[6]
      Error starting gRPC call.
System.Net.Http.HttpRequestException: An error occurred while sending the request.
 ---> System.IO.IOException: The response ended prematurely.
   at System.Net.Http.HttpConnection.FillAsync()
   at System.Net.Http.HttpConnection.ReadNextResponseHeaderLineAsync(Boolean foldedHeadersAllowed)
   at System.Net.Http.HttpConnection.SendAsyncCore(HttpRequestMessage request, CancellationToken cancellationToken)
   --- End of inner exception stack trace ---
   at System.Net.Http.HttpConnection.SendAsyncCore(HttpRequestMessage request, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.SendWithNtConnectionAuthAsync(HttpConnection connection, HttpRequestMessage request, Boolean doRequestAuth, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.SendWithRetryAsync(HttpRequestMessage request, Boolean doRequestAuth, CancellationToken cancellationToken)
   at System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
   at System.Net.Http.DiagnosticsHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
   at System.Net.Http.HttpClient.FinishSendAsyncUnbuffered(Task`1 sendTask, HttpRequestMessage request, CancellationTokenSource cts, Boolean disposeCts)
   at Grpc.Net.Client.Internal.GrpcCall`2.RunCall(HttpRequestMessage request)
dbug: Grpc.Net.Client.Internal.GrpcCall[8]
      gRPC call canceled.
fail: Grpc.Net.Client.Internal.GrpcCall[3]
      Call failed with gRPC error status. Status code: 'Internal', Message: 'Error starting gRPC call: An error occurred while sending the request.'.
dbug: Grpc.Net.Client.Internal.GrpcCall[4]
      Finished gRPC call.
gRPC error: Error starting gRPC call: An error occurred while sending the request.

有人能帮我理解一下失败的原因吗？同时使用SslCredentials和失败。出于隐私原因，x.x是IP的替代品。

Answer 1

我编写了一些样本码来再现这里报告的跨平台不兼容问题。

根本原因是在golang服务器中使用GetConfigForClient (在本例中用于刷新客户端CA证书)时，来自C#客户端的请求失败。然而，当它被VerifyPeerCertificate取代时，这个问题就得到了解决。