Question

我正在尝试连接到外部 IP 地址，但我位于公司防火墙之后，因此我需要通过代理进行连接。

我用 curl 运行了一个测试：

"msg": "the field 'args' has an invalid value ({u'current_storage_type': u'{{ imported_config.content|b64decode |from_json |json_query(jmesquery) }}'}), and could not be converted to an dict.The error was: Expecting property name enclosed in double quotes: line 3 column 1 (char 17)\

但我无法在 C# 中复制上述 cUrl 命令：

curl -v https://IP_ADDRESS_OF_EXTERNAL_CLIENT:6125 -x http://MyComparyProxyAddress.com:8080 -U MYUSERNAME:MYPASSWORD

我不断从我的公司代理处获取以下信息：

private static Socket CreateTunnelThruProxy(string destIP, int destPort)
        {
            string destUriWithPort = $"{destIP}:{destPort}";
            UriBuilder uriBuilder = new UriBuilder(destUriWithPort);
            Uri destUri = uriBuilder.Uri;

            var proxy = new WebProxy("http://MyComparyProxyAddress.com", 8080);
            proxy.UseDefaultCredentials = false;
            proxy.Credentials = new NetworkCredential("MYUSERNAME", "MYPASSWORD");
            WebRequest.DefaultWebProxy = proxy;

            IWebProxy webProxy = WebRequest.DefaultWebProxy;

            try
            {
                if (webProxy.IsBypassed(destUri))
                    return null;
            }
            catch (PlatformNotSupportedException)
            {
                // .NET Core doesn't support IWebProxy.IsBypassed
                // (because .NET Core doesn't have access to Windows-specific services, of course)
                return null;
            }

            Uri proxyUri = webProxy.GetProxy(destUri);
            if (proxyUri == null)
                return null;

            IPAddress[] proxyEntry = Dns.GetHostAddresses(proxyUri.Host);
            int iPort = proxyUri.Port;
            IPAddress address = proxyEntry.First(a => a.AddressFamily == AddressFamily.InterNetwork);
            IPEndPoint proxyEndPoint = new IPEndPoint(address, iPort);
            Socket socketThruProxy = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            socketThruProxy.Connect(proxyEndPoint);

            string proxyMsg = $"CONNECT {destIP}:{destPort} HTTP/1.1 \n\n";
            byte[] buffer = Encoding.ASCII.GetBytes(proxyMsg);
            byte[] buffer12 = new byte[50000];
            socketThruProxy.Send(buffer, buffer.Length, 0);
            int msg = socketThruProxy.Receive(buffer12, 50000, 0);
            string data;
            data = Encoding.ASCII.GetString(buffer12);
            int index = data.IndexOf("200");

            if (index < 0)
                throw new ApplicationException(
                    $"Connection failed to {destUriWithPort} through proxy server {proxyUri.ToString()}.");

            return socketThruProxy;
        }

我可以清楚地看到 webProxy 对象包含我设置的凭据，与 cUrl 使用的凭据相同。

我在尝试简单调用时也遇到同样的错误：

HTTP/1.1 407 Proxy Authentication Required
Proxy-Authenticate: NEGOTIATE
Proxy-Authenticate: NTLM
Proxy-Authenticate: BASIC realm="ztb"
Cache-Control: no-cache
Pragma: no-cache
Content-Type: text/html; charset=utf-8
Proxy-Connection: close
Connection: close
Content-Length: 797

<HTML><HEAD>
<TITLE>Access Denied</TITLE>
</HEAD>
<BODY>
<body bgcolor="#FFFFEA">
<blockquote>
<TABLE border=0 cellPadding=1 width="80%">
<TR><TD>
<FONT face="Verdana">
<big>Access Denied (authentication_failed)</big>
<BR>
<BR>
</FONT>
</TD></TR>
<TR><TD>
<FONT face="Verdana">
Your credentials could not be authenticated: "Credentials are missing.". You will not be permitted access until your credentials can be verified.
</FONT>
</TD></TR>
<TR><TD>
<FONT face="Verdana">
This is typically caused by an incorrect username and/or password, but could also be caused by network problems.
</FONT>
</TD></TR>
<TR><TD>
<FONT face="Verdana" SIZE=2>
<BR>
For assistance, contact your Tech Desk . PXFFM25
</FONT>
</TD></TR>
</TABLE>
</blockquote>
</FONT>
</BODY></HTML>

而不是按照上面的代码片段手动设置凭据。所以看起来我的凭据没有被考虑......

有什么想法吗？

Answer 1

我之前尝试过这个场景，它通过创建一个继承 IWebProxy 的自定义代理类来配合我

public class MyProxy : IWebProxy
    {
        public ICredentials Credentials
        {
            get { return new NetworkCredential("your username","your password"); }
            set { }
        }

        public Uri GetProxy(Uri destination)
        {
            return new Uri("http://MyComparyProxyAddress.com:8080");
        }

        public bool IsBypassed(Uri host)
        {
            return false;
        }
    }

并在应用程序配置文件中将这部分添加到配置节点中

  <system.net>
    <defaultProxy enabled="true" useDefaultCredentials="false">
      <module type="yournamespace.MyProxy, your assembly name" />
    </defaultProxy>
  </system.net>

Answer 2

如果可以的话，我会将其添加为评论，但是添加域有帮助吗？过去，当我进行身份验证时，我必须确保域是正确的。每Network Credential docs

有一个接受域的构造函数，或者您可以将其设置为属性。

Answer 3

不要尝试在您的代码中修复此问题。使用本地代理（如 https://github.com/genotrance/px）向企业代理提供您的用户凭据。否则有一天你会在源代码管理中找到一个开发者密码。

Answer 4

我的一个项目遇到了这个问题，该公司使用了防火墙（准确地说是 Barracuda's firewall）。我尝试设置 WebProxy 并设置了机器代理，但没有运气。

我是这样解决的：

我已要求安全团队将 IP 以及将用于该服务的端口列入白名单。因此不会阻止任何传出或传入连接。然后，从应用程序中，我像这样在 web.config 中设置了代理：

<system.net>
    <defaultProxy>
        <proxy usesystemdefault="False" proxyaddress="http://proxy_ip" bypassonlocal="False" />
    </defaultProxy>
</system.net>

此外，在运行应用程序的服务器上设置了相同的代理。

这使事情按预期进行。

一周左右后，服务突然停止。当我检查与 Fiddler 的连接时，它显示 API 被重定向到另一台服务器（不同的 IP），防火墙阻止了它。因此，我要求安全团队也将其列入白名单，该服务又重新上线了。

Answer 5

这可以通过以下方式完成：

 if (IsProxyProvided(settings))
            {
                IPAddress[] proxyEntry = Dns.GetHostAddresses(settings.ProxyHost);
                IPAddress address = proxyEntry.First(a => a.AddressFamily == AddressFamily.InterNetwork);
                IPEndPoint proxyEndPoint = new IPEndPoint(address, settings.ProxyPort);
                socket.Connect(proxyEndPoint);

                if (AreProxyCredntialsProvided(settings))
                {
                    var basicAuthBase64 = Convert.ToBase64String(
                        Encoding.GetEncoding("ISO-8859-1").GetBytes($"{settings.ProxyUserName}:{settings.ProxyUserNamePassword}"));
                    var proxyMessage = $"Proxy-Authorization: {string.Format("Basic {0}", basicAuthBase64)} \r\n";
                    var keepAlive = "Connection: keep-alive\r\n";
                    var request = $"CONNECT {endpoint.Address}:{endpoint.Port} HTTP/1.1 \r\n" + proxyMessage + keepAlive + "\r\n";
                    byte[] buffer = Encoding.ASCII.GetBytes(request);
                    socket.Send(buffer, buffer.Length, 0);
                }
            }

感谢遇到类似问题的 Victor Victor Stone here

使用用户名通过公司代理连接

5 个答案: