如何忽略c#signalr客户端中的https证书警告？

Question

我正在尝试使用无效证书连接到SignalR服务器.不出所料我收到以下错误:

    System.Net.Http.HttpRequestException : An error occurred while sending the request.
----> System.Net.WebException : The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel.
  ----> System.Security.Authentication.AuthenticationException : The remote certificate is invalid according to the validation procedure.

使用正常的.Net,HttpClient您可以使用WebRequestHandler具有ServerCertificateValidationCallback委托的构造它,允许您更改证书验证行为.SignalR HttpClient似乎没有这个.

Answer 1

你应该为ServerCertificateValidationCallback事件注册一个方法.

此代码只注册一个匿名方法,该方法在触发事件时返回true.

ServicePointManager.ServerCertificateValidationCallback +=
                  (sender, certificate, chain, sslPolicyErrors) => true;

小心,这是一个全球性的环境.所以所有ssl/tls请求signalr或http都将使用此设置.

Answer 2

我相信我已经找到了一种似乎有效但不像通常推荐的 ServicePointManager.ServerCertificateValidationCallback 方法那样具有全局性的方法。我首先创建 SignalR“DefaultHttpClient”类的子类，如下所示：

class CustomHttpClient : DefaultHttpClient
    {
        private readonly System.Net.Security.RemoteCertificateValidationCallback _serverCertificateValidationCallback;

        public CustomHttpClient (System.Net.Security.RemoteCertificateValidationCallback serverCertificateValidationCallback) : base()
        {
            this._serverCertificateValidationCallback = serverCertificateValidationCallback;
        }

        protected override HttpMessageHandler CreateHandler()
        {
            var rv = base.CreateHandler() as WebRequestHandler;
            if (this._serverCertificateValidationCallback != null)
                rv.ServerCertificateValidationCallback = this._serverCertificateValidationCallback;
            return rv;
        }
    }

现在，当我在 HubConnection 实例上调用“Start”时，我可以使用我的自定义 HttpClient 实现，如下所示：

var hubConnection = new HubConnection("my server url");
var myHub = hubConnection.CreateHubProxy("my hub name");
hubConnection.Start(new CustomHttpClient((sender, certificate, chain, sslPolicyErrors) =>
                {
                    //put some validation logic here if you want to.
                    return true;
                }));

这应该允许您按照您认为合适的方式验证服务器证书，但将范围保持在当前 HubConnection，而不是影响来自您的应用程序的所有 HTTP 流量。