连接尝试:(抛出异常的点)

private readonly ClientWebSocket _socket;

public ApiConnection()
{
    _socket = new ClientWebSocket();
}

public async Task Connect()
{
    // the uri is like: wss://example.com/ws
    await _socket.ConnectAsync(new Uri(_settings.WebSocketUrl),CancellationToken.None);

    if (_socket.State == WebSocketState.Open)
        Console.WriteLine("connected.");
}

异常堆栈：

System.Net.WebSockets.WebSocketException (0x80004005): Unable to connect to the remote server ---> System.Security.Authentication.AuthenticationException: The remote certificate is invalid according to the validation procedure.
         at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
         at System.Net.Security.SslState.StartSendAuthResetSignal(ProtocolToken message,AsyncProtocolRequest asyncRequest,ExceptionDispatchInfo exception)
         at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message,AsyncProtocolRequest asyncRequest)
         at System.Net.Security.SslState.StartSendBlob(Byte[] incoming,Int32 count,AsyncProtocolRequest asyncRequest)
         at System.Net.Security.SslState.ProcessReceivedBlob(Byte[] buffer,AsyncProtocolRequest asyncRequest)
         at System.Net.Security.SslState.StartReadFrame(Byte[] buffer,Int32 readBytes,AsyncProtocolRequest asyncRequest)
         at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer,AsyncProtocolRequest asyncRequest)
         at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message,AsyncProtocolRequest asyncRequest)
         at System.Net.Security.SslState.PartialFrameCallback(AsyncProtocolRequest asyncRequest)
      --- End of stack trace from prevIoUs location where exception was thrown ---
         at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
         at System.Net.Security.SslState.InternalEndProcessAuthentication(LazyAsyncResult lazyResult)
         at System.Net.Security.SslState.EndProcessAuthentication(IAsyncResult result)
         at System.Net.Security.SslStream.EndAuthenticateAsClient(IAsyncResult asyncResult)
         at System.Threading.Tasks.TaskFactory`1.FromAsyncCoreLogic(IAsyncResult iar,Func`2 endFunction,Action`1 endAction,Task`1 promise,Boolean requiresSynchronization)
      --- End of stack trace from prevIoUs location where exception was thrown ---
         at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
         at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
         at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
         at System.Net.WebSockets.WebSocketHandle.IoUs location where exception was thrown ---
         at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
         at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
         at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
         at System.Net.WebSockets.ClientWebSocket.IoUs location where exception was thrown ---
         at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
         at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
         at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
         at System.Runtime.CompilerServices.TaskAwaiter.GetResult()

目标websocket服务器在Ubuntu上的Nginx代理后面运行.我认为问题依赖于客户端,因为如果代码在Windows上执行,一切正常.

我还尝试将CA证书导入Raspians“证书库”.没有运气.

更新：
http连接(ws：//)也适用于linux.看来,WebSocketClient不信任我的LetsEncrypt证书？