与HttpClient异步NancyFX - 用于fbcdn的GetAsync返回403禁止？

注：我已经改变了这个问题很多，试图让它更多地指出问题。下面的评论不再反映这个问题。与HttpClient异步NancyFX - 用于fbcdn的GetAsync返回403禁止？

我试图从fbcdn得到这个图片：

https://scontent.xx.fbcdn.net/v/t1.0-1/c15.0.50.50/p50x50/10354686_10150004552801856_220367501106153455_n.jpg?oh=6c801f82cd5a32fd6e5a4258ce00a314&oe=589AAD2F

浏览器得到它就好了。这里是我的代码：

public class ReverseProxyController : NancyModule 
{ 
    public ReverseProxyController() 
    { 
     Get["/", true] = async (parameters, ct) => 
     { 
      var result = await GetResult(parameters, ct); 
      return result; 
     }; 
    } 

    private async Task<Response> GetResult(dynamic parameters, CancellationToken ct) 
    { 
     var client = new HttpClient(); 
     string url = Request.Query["url"].Value.ToString(); 
     if (url == null) return null; 

     client.DefaultRequestHeaders.Add("Access-Control-Allow-Origin", "*"); 
     client.DefaultRequestHeaders.Add("User-Agent", 
      "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.71 Safari/537.36"); 
     client.DefaultRequestHeaders.Add("Upgrade-Insecure-Requests", "1"); 
     client.DefaultRequestHeaders.Add("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8"); 
     client.DefaultRequestHeaders.Add("Accept-Encoding", "gzip, deflate, sdch, br"); 
     client.DefaultRequestHeaders.Add("Accept-Language", "en-US,en;q=0.8,ru;q=0.6"); 
     var response = await client.GetAsync(url, ct); 

     ct.ThrowIfCancellationRequested(); 


     switch (response.StatusCode) 
     { 
      case HttpStatusCode.OK: 
       var stream = await response.Content.ReadAsStreamAsync(); 

       return Response.FromStream(stream, response.Content.Headers.ContentType != null 
        ? response.Content.Headers.ContentType.ToString() 
        : "application/octet-stream"); 

      default: 
       return Response.AsText("\nError " + response.StatusCode); 
     } 
    } 
}

我每次都得到403 Forbidden响应。我认为添加标题会使它工作，但不行。

此代码适用于其他主机上的其他图像像这样的：

https://s-media-cache-ak0.pinimg.com/564x/ff/f0/c9/fff0c988a4516659d4009f60e0694cb6.jpg

来源

2016-10-29 richard

因此''Response.FromStream'和'Response.AsText'是从哪些库中获得的？或者他们在做什么？ – Jim

以及如果多数民众赞成没有问题，如果我测试其他代码，在这里工作正常200反应 – Jim

真的吗？使用fbcdn网址？ – richard

的问题是在URL检索来自Nancy的要求，不与HttpClient获取数据。

我假设你发送请求到南希这样的：

http://localhost/?url= ...

因此对于Facebook，这将是：

http://localhost/?url=https://scontent.xx.fbcdn.net/v/t1.0-1/c15.0.50.50/p50x50/10354686_10150004552801856_220367501106153455_n.jpg?oh=6c801f82cd5a32fd6e5a4258ce00a314&oe=589AAD2F

但对于这个URL string url = Request.Query["url"].Value.ToString();是不完整并丢失最后一部分（& oe = 589AAD2F），因此服务器响应Forbidden。

下面是简单的改变来演示该问题：

private async Task<Response> GetResult(dynamic parameters, CancellationToken ct) 
{ 
    var client = new HttpClient(); 
    var req = Request.Url.ToString(); 
    var queryStart = req.IndexOf("url="); 
    if (queryStart == -1) 
     return Nancy.HttpStatusCode.BadRequest; 

    var url = req.Substring(queryStart + 4); 
    if (string.IsNullOrEmpty(url)) 
     return Nancy.HttpStatusCode.BadRequest; 

    client.DefaultRequestHeaders.Add("Access-Control-Allow-Origin", "*"); 
    client.DefaultRequestHeaders.Add("User-Agent", 
     "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.71 Safari/537.36"); 
    client.DefaultRequestHeaders.Add("Upgrade-Insecure-Requests", "1"); 
    client.DefaultRequestHeaders.Add("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8"); 
    client.DefaultRequestHeaders.Add("Accept-Encoding", "gzip, deflate, sdch, br"); 
    client.DefaultRequestHeaders.Add("Accept-Language", "en-US,en;q=0.8,ru;q=0.6"); 
    var response = await client.GetAsync(url, ct); 

    ct.ThrowIfCancellationRequested(); 


    switch (response.StatusCode) 
    { 
     case System.Net.HttpStatusCode.OK: 
      var stream = await response.Content.ReadAsStreamAsync(); 

      return Response.FromStream(stream, response.Content.Headers.ContentType != null 
       ? response.Content.Headers.ContentType.ToString() 
       : "application/octet-stream"); 

     default: 
      return Response.AsText("\nError " + response.StatusCode); 
    } 
}

解决方案

事实上，我们可以事先将其发送编码的URL，南茜会自动解码的URL对我们来说，因此不需要改变任何服务器端。

这里是产生利用施加于

https://scontent.xx.fbcdn.net/v/t1.0-1/c15.0.50.50/p50x50/10354686_10150004552801856_220367501106153455_n.jpg?oh=6c801f82cd5a32fd6e5a4258ce00a314&oe=589AAD2F

结果HttpUtility.UrlEncode一个链接例如：

HTTPS％3A％2F％2fscontent.xx.fbcdn.net％2FV％2ft1.0- 1％2fc15.0.50.50％2fp50x50％2f10354686_10150004552801856_220367501106153455_n。JPG％3foh％3d6c801f82cd5a32fd6e5a4258ce00a314％26oe％3d589AAD2F

，并为这个特定链接的实际要求是：

http://localhost:9876/?url=https%3a%2f%2fscontent.xx.fbcdn.net%2fv%2ft1.0-1%2fc15.0.50.50%2fp50x50%2f10354686_10150004552801856_220367501106153455_n.jpg%3foh%3d6c801f82cd5a32fd6e5a4258ce00a314%26oe%3d589AAD2F

替代的解决方案

我在这个个人更喜欢POST完胜情况，所以这里是：

public class ReverseProxyController : NancyModule 
{ 
    class ProxyRequest 
    { 
     public string Url { get; set; } 
    } 

    public ReverseProxyController() 
    { 
     Post["/", true] = async (parameters, ct) => 
     { 
      var result = await GetResult(parameters, ct); 
      return result; 
     }; 
    } 

    private async Task<Response> GetResult(dynamic parameters, CancellationToken ct) 
    { 
     var pReq = this.Bind<ProxyRequest>(); 
     var url = pReq.Url; 
     if (string.IsNullOrEmpty(url)) 
      return null; 

     var client = new HttpClient(); 
     client.DefaultRequestHeaders.Add("Access-Control-Allow-Origin", "*"); 
     client.DefaultRequestHeaders.Add("User-Agent", 
      "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.71 Safari/537.36"); 
     client.DefaultRequestHeaders.Add("Upgrade-Insecure-Requests", "1"); 
     client.DefaultRequestHeaders.Add("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8"); 
     client.DefaultRequestHeaders.Add("Accept-Encoding", "gzip, deflate, sdch, br"); 
     client.DefaultRequestHeaders.Add("Accept-Language", "en-US,en;q=0.8,ru;q=0.6"); 
     var response = await client.GetAsync(url, ct); 

     ct.ThrowIfCancellationRequested(); 


     switch (response.StatusCode) 
     { 
      case System.Net.HttpStatusCode.OK: 
       var stream = await response.Content.ReadAsStreamAsync(); 

       return Response.FromStream(stream, response.Content.Headers.ContentType != null 
        ? response.Content.Headers.ContentType.ToString() 
        : "application/octet-stream"); 

      default: 
       return Response.AsText("\nError " + response.StatusCode); 
     } 
    } 
}

来源

2016-10-31 05:58:50 user3473830

这就是问题所在。在我看到这个答案之前我刚刚检查过，它最后一次缺少“＆oe = 589AAD2F”。 – richard

为什么南希会截断最后一个查询参数？ – richard

没关系...南希截断了它，因为南希标记网址的方式......它给我什么它认为是我想要的参数。有什么方法可以正确地格式化路线以获得我想要的？ – richard

作为控制台应用程序代码工作正常

static void Main(string[] args) 
    { 
     GetStuff(); 
     Console.ReadLine(); 
    } 

    private static async void GetStuff() 
    { 
     CancellationToken ct = new CancellationToken(); 
     var client = new HttpClient(); 
     //this is only a Simple Change to demonstrate the problem, and should not be considered as a proper solution 

     string url = "https://scontent.xx.fbcdn.net/v/t1.0-1/c15.0.50.50/p50x50/10354686_10150004552801856_220367501106153455_n.jpg?oh=6c801f82cd5a32fd6e5a4258ce00a314&oe=589AAD2F"; 
     if (url == null) return; 

     client.DefaultRequestHeaders.Add("Access-Control-Allow-Origin", "*"); 
     client.DefaultRequestHeaders.Add("User-Agent", 
      "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.71 Safari/537.36"); 
     client.DefaultRequestHeaders.Add("Upgrade-Insecure-Requests", "1"); 
     client.DefaultRequestHeaders.Add("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8"); 
     client.DefaultRequestHeaders.Add("Accept-Encoding", "gzip, deflate, sdch, br"); 
     client.DefaultRequestHeaders.Add("Accept-Language", "en-US,en;q=0.8,ru;q=0.6"); 
     var response = await client.GetAsync(url, ct); 

     ct.ThrowIfCancellationRequested(); 


     switch (response.StatusCode) 
     { 
      case System.Net.HttpStatusCode.OK: 
       var stream = await response.Content.ReadAsStreamAsync(); 


       break; 
      default: 
       break; 
     } 
    }

我得到一个OK 200返回消息。是否使用其他图像可能需要登录信息？

来源

2016-10-31 06:27:02

与HttpClient异步NancyFX - 用于fbcdn的GetAsync返回403禁止？

回答

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