Question

我必须使用C＃的Socket类来加载网页。我今天设法学到了很多，我可以成功创建加载页面所需的GET请求。

但是现在我想使用HTTP代理。

我还学会了如何连接代理。

我现在遇到的问题是，一旦我连接起来，我该如何获得＆＃39; GET＆＃39;页面？

Socket s = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
s.Connect(proxyIP, proxyPort);
string connectMsg = "CONNECT " + proxyIPString + ":" + proxyPortString + " HTTP/1.1\r\n" +
                    "Proxy-Authorization: Basic " + base64ProxyCredentials + "\r\n" +
                    "\r\n";
byte[] msg = System.Text.Encoding.ASCII.GetBytes(connectMsg);
s.Send(msg);
string proxyConnectionResponseHeader = "";
while (!proxyConnectionResponseHeader.Contains("\r\n\r\n"))
{
    // read the header byte by byte, until \r\n\r\n
    byte[] buffer = new byte[1];
    s.Receive(buffer, 0, 1, 0);
    proxyConnectionResponseHeader += Encoding.ASCII.GetString(buffer);
}
if (!proxyConnectionResponseHeader.Contains("200 Connection established"))
{
    return /*some error*/;
}

此时，我已成功连接到代理。为什么以下内容会返回错误请求？

string request = "GET / HTTP/1.1\r\n" +
                "Host: whatismyipaddress.com\r\n" +
                "User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:41.0) Gecko/20100101 Firefox/41.0\r\n" +
                "Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8\r\n" +
                "Accept-Language: en-US,en;q=0.5\r\n" +
                "Accept-Encoding: gzip, deflate\r\n" +
                "Connection: keep-alive\r\n" +
                "\r\n";
msg = Encoding.ASCII.GetBytes(request);
s.Send(msg);
string getResponseHeader = "";
while (!getResponseHeader.Contains("\r\n\r\n"))
{
    // read the header byte by byte, until \r\n\r\n
    byte[] buffer = new byte[1];
    s.Receive(buffer, 0, 1, 0);
    getResponseHeader += Encoding.ASCII.GetString(buffer);
}

回复的标题似乎来自代理而不是＆＃39; whatismyipaddress.com＆＃39;

HTTP/1.0 400 Bad Request
Server: squid/3.1.19
Mime-Version: 1.0
Date: Sun, 04 Oct 2015 02:00:32 GMT
Content-Type: text/html
Content-Length: 3141
X-Squid-Error: ERR_INVALID_URL 0
Vary: Accept-Language
Content-Language: en
X-Cache: MISS from funky
X-Cache-Lookup: NONE from funky:<port>
Connection: close

编辑：或者我误解了使用代理的过程？

Answer 1

克莱门斯是对的。

我不需要做＆＃34; CONNECT＆＃34;，我只需要正常发出GET请求，除了通过授权。也使用绝对路径而不是相对路径。

string request = "GET http://whatismyipaddress.com/ HTTP/1.1\r\n" +
                 "Host: whatismyipaddress.com\r\n" +
                 "Proxy-Authorization: Basic " + base64ProxyCredentials + "\r\n" +
                 "User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:41.0) Gecko/20100101 Firefox/41.0\r\n" +
                 "Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8\r\n" +
                 "Accept-Language: en-US,en;q=0.5\r\n" +
                 "Accept-Encoding: gzip, deflate\r\n" +
                 "Connection: keep-alive\r\n" +
                 "\r\n";
msg = Encoding.ASCII.GetBytes(request);
s.Send(msg);

使用HTTP代理的套接字上的HTTP

1 个答案: