使用 ASP.NET、C# 和身份验证的简单反向代理

Question

我正在尝试将自定义参数转发到 RESTful API 服务器并将代理响应返回到面向客户端的服务器。我不希望客户端能够访问或读取 API HTTP 请求/响应交互，因此我决定使用反向代理执行此操作。我转发请求并返回响应没有问题。问题在于身份验证。面向客户端的服务器总是希望重定向到登录页面，因为它不相信客户端已通过身份验证。我尝试过使用 HTTPS 和 HTTP，结果相似。

我研究这个问题已经有一段时间了，发现了各种各样的答案，但似乎都没有完全涵盖我的具体用例。我正在关注this example，这是最接近我特别需要的。但是，作者注释掉的凭据部分 (//request.Credentials = CredentialCache.DefaultCredentials;) 似乎并未涵盖我尝试实现的身份验证部分。请帮助我理解这个问题和解决方案。

这是我在控制器中使用的代码：

public ActionResult ProxyEndpoint(string custom_string, string another_custom_string)
{
    //Bunch of code here to grab the remoteUrl from AppConfig and do stuff to the parameters and store them in queryString, unnecessary to show here.

    //Here's the important bits:
    remoteUrl = remoteUrl + "?" + queryString; // create my remoteUrl
    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(remoteUrl);
    request.Credentials = CredentialCache.DefaultCredentials;
    // Also tried this to no avail:
    request.Credentials = CredentialCache.DefaultNetworkCredentials;
    return ProxyActionResult(request.GetResponse());
}

这是ProxyActionResult 类：

public class ProxyActionResult : ActionResult
{
    WebResponse _response;

    public ProxyActionResult(WebResponse response)
    {
        _response = response;
    }

    public override void ExecuteResult(ControllerContext controllerContext)
    {
        HttpContextBase httpContext = controllerContext.HttpContext;
        WebResponse response = _response;

        // Read the byte stream from the response:
        Stream responseStream = response.GetResponseStream();

        // Pulled this next piece from http://www.codeproject.com/Articles/7135/Simple-HTTP-Reverse-Proxy-with-ASP-NET-and-IIS
        // Seemed to fit our use case.
        if ((response.ContentType.ToLower().IndexOf("html") >= 0) || (response.ContentType.ToLower().IndexOf("javascript") >= 0))// || (response.ContentType.ToLower().IndexOf("image") >= 0))
        {
            //If the response is HTML Content, parse it like HTML:
            StreamReader readStream = new StreamReader(responseStream, Encoding.Default);

            String content;

            content = ParseHtmlResponse(readStream.ReadToEnd(), httpContext.Request.ApplicationPath);

            //Write the updated HTML to the client(and then close the response):
            httpContext.Response.Write(content);
            httpContext.Response.ContentType = response.ContentType;

            response.Close();
            httpContext.Response.End();
        }
        else
        {
            // If the response is not HTML Content, write the stream directly to the client:
            var buffer = new byte[1024];
            int bytes = 0;
            while ((bytes = responseStream.Read(buffer, 0, 1024)) > 0)
            {
                httpContext.Response.OutputStream.Write(buffer, 0, bytes);
            }
            // from http://www.dotnetperls.com/response-binarywrite
            httpContext.Response.ContentType = response.ContentType; // Set the appropriate content type of the response stream.
            // and close the stream:
            response.Close();
            httpContext.Response.End();
        }
        //throw new NotImplementedException();
    }
    // Debating whether we need this:
    public string ParseHtmlResponse(string html, string appPath)
    {
        html = html.Replace("\"/", "\"" + appPath + "/");
        html = html.Replace("'/", "'" + appPath + "/");
        html = html.Replace("=/", "=" + appPath + "/");
        return html;
    }

Answer 1

事实证明，反向代理代码没有任何问题。远程服务器是一个 ArcGIS OpenLayers API，它有一个设置为crossOrigin: anonymous。我把这个设置注释掉了，效果很好。

如果您遇到此特定 ArcGIS OpenLayers 问题，请查看文档： http://openlayers.org/en/v3.14.2/apidoc/ol.source.ImageWMS.html