/// <summary>
/// 使用http tunnel检测代理状态
/// </summary>
/// <param name="webProxy">web代理</param>
/// <param name="targetAddress">目标地址，可以是http或https</param>
/// <param name="timeout">发送或等待数据的超时时间</param>
/// <exception cref="ArgumentNullException"></exception>
/// <returns></returns>
public static HttpStatusCode Validate(IWebProxy webProxy, Uri targetAddress, TimeSpan?timeout = null)
{
if (webProxy == null)
{
throw new ArgumentNullException(nameof(webProxy));
}
var httpProxy = webProxy as HttpProxy;
if (httpProxy == null)
{
httpProxy = HttpProxy.FromWebProxy(webProxy, targetAddress);
}
Socket socket = null;
try
{
var ascii = Encoding.GetEncoding("ASCII");
var host = Dns.GetHostEntry(httpProxy.Host);
socket = new Socket(host.AddressList[0].AddressFamily, SocketType.Stream, ProtocolType.Tcp);
if (timeout.HasValue)
{
socket.SendTimeout = (int)timeout.Value.TotalMilliseconds;
socket.ReceiveTimeout = (int)timeout.Value.TotalMilliseconds;
}
socket.Connect(new IPEndPoint(host.AddressList[0], httpProxy.Port));
var request = httpProxy.ToTunnelRequestString(targetAddress);
var sendBuffer = ascii.GetBytes(request);
socket.Send(sendBuffer);
var recvBuffer = new byte[150];
var length = socket.Receive(recvBuffer);
var response = ascii.GetString(recvBuffer, 0, length);
var statusCode =
int.Parse(Regex.Match(response, "(?<=HTTP/1.1 )\\d+", RegexOptions.IgnoreCase).Value);
return((HttpStatusCode)statusCode);
}
catch (Exception)
{
return(HttpStatusCode.ServiceUnavailable);
}
finally
{
socket?.Dispose();
}
}
public void FromWebProxyTest()
{
var target = new Uri("https://www.baidu.com/");
var p = new WebProxy("127.0.0.1", 5000)
{
Credentials = new NetworkCredential("abc", "123")
};
var proxy = HttpProxy.FromWebProxy(p, target);
Assert.True(proxy.Host == "127.0.0.1" && proxy.Port == 5000);
Assert.True(proxy.GetProxy(target) == new Uri("http://127.0.0.1:5000"));
Assert.True(proxy.UserName == "abc");
Assert.True(proxy.Password == "123");
Assert.True(((IWebProxy)proxy).Credentials.GetCredential(null, null).UserName == "abc");
Assert.True(((IWebProxy)proxy).Credentials.GetCredential(null, null).Password == "123");
}