Обновить Program.cs

Program.cs

@@ -63,6 +63,7 @@ class Program
 
     static async Task HandleHttp(NetworkStream clientStream, HttpRequestData req)
     {
+        DefaultProxyCredentials = CredentialCache.DefaultCredentials
         var handler = new SocketsHttpHandler
         {
             UseProxy = true,
@@ -111,8 +112,8 @@ class Program
 
     // ================= CONNECT =================
 
-    static async Task HandleConnect(NetworkStream clientStream, string target)
-    {
+static async Task HandleConnect(NetworkStream clientStream, string target)
+{
     var parts = target.Split(':');
     string host = parts[0];
     int port = int.Parse(parts[1]);
@@ -125,25 +126,32 @@ class Program
 
     var upstreamStream = upstream.GetStream();
 
-        // CONNECT к upstream
+    // CONNECT к upstream proxy
     string connectReq =
-            $"CONNECT {host}:{port} HTTP/1.1\r\nHost: {host}:{port}\r\n\r\n";
+        $"CONNECT {host}:{port} HTTP/1.1\r\n" +
+        $"Host: {host}:{port}\r\n" +
+        $"Proxy-Connection: Keep-Alive\r\n\r\n";
 
     await upstreamStream.WriteAsync(Encoding.ASCII.GetBytes(connectReq));
 
-        // читаем ответ от upstream
-        var buffer = new byte[8192];
-        int read = await upstreamStream.ReadAsync(buffer);
+    // читаем ответ upstream полностью до \r\n\r\n
+    var resp = await ReadHeaders(upstreamStream);
 
-        // отвечаем клиенту что туннель открыт
+    if (!resp.HeadersRaw.Contains("200"))
+    {
+        await clientStream.WriteAsync(Encoding.ASCII.GetBytes("HTTP/1.1 502 Bad Gateway\r\n\r\n"));
+        return;
+    }
+
+    // говорим клиенту ОК
     await clientStream.WriteAsync(Encoding.ASCII.GetBytes("HTTP/1.1 200 Connection Established\r\n\r\n"));
 
-        // двунаправленный туннель
-        var t1 = upstreamStream.CopyToAsync(clientStream);
-        var t2 = clientStream.CopyToAsync(upstreamStream);
+    // туннель
+    var t1 = Pump(upstreamStream, clientStream);
+    var t2 = Pump(clientStream, upstreamStream);
 
     await Task.WhenAny(t1, t2);
-    }
+}
 
     // ================= AUTH =================
 
@@ -233,80 +241,96 @@ class WinHttpProxy : IWebProxy
     public bool IsBypassed(Uri host) => false;
 }
 
+using System.Runtime.InteropServices;
+
 static class WinHttpHelper
 {
     [DllImport("winhttp.dll", SetLastError = true)]
-    static extern bool WinHttpGetIEProxyConfigForCurrentUser(
-        out WINHTTP_CURRENT_USER_IE_PROXY_CONFIG config);
+    static extern IntPtr WinHttpOpen(string agent, int accessType, string proxy, string bypass, int flags);
+
+    [DllImport("winhttp.dll", SetLastError = true)]
+    static extern bool WinHttpGetProxyForUrl(
+        IntPtr hSession,
+        string url,
+        ref WINHTTP_AUTOPROXY_OPTIONS options,
+        out WINHTTP_PROXY_INFO proxyInfo);
+
+    [DllImport("winhttp.dll")]
+    static extern bool WinHttpCloseHandle(IntPtr handle);
 
     public static Uri GetProxyForUrl(Uri url)
     {
-        if (!WinHttpGetIEProxyConfigForCurrentUser(out var cfg))
-            return url;
+        IntPtr session = WinHttpOpen("proxy", 0, null, null, 0);
 
-        string proxy = PtrToString(cfg.lpszProxy);
+        var options = new WINHTTP_AUTOPROXY_OPTIONS
+        {
+            dwFlags = 0x00000001 | 0x00000002, // AUTO_DETECT + CONFIG_URL
+            dwAutoDetectFlags = 0x00000001 | 0x00000002 // DHCP + DNS_A
+        };
 
-        if (string.IsNullOrWhiteSpace(proxy))
-            return url;
+        if (WinHttpGetProxyForUrl(session, url.ToString(), ref options, out var info))
+        {
+            string proxy = PtrToString(info.lpszProxy);
 
-        string selectedProxy = ParseProxy(proxy, url.Scheme);
-
-        if (string.IsNullOrEmpty(selectedProxy))
-            return url;
-
-        return new Uri(NormalizeProxy(selectedProxy));
+            if (!string.IsNullOrEmpty(proxy))
+            {
+                var first = proxy.Split(';')[0];
+                return new Uri(Normalize(first));
+            }
         }
 
-    // ===== helpers =====
+        WinHttpCloseHandle(session);
+        return url; // direct fallback
+    }
 
     static string PtrToString(IntPtr ptr)
     {
-        if (ptr == IntPtr.Zero)
-            return null;
-
+        if (ptr == IntPtr.Zero) return null;
         return Marshal.PtrToStringUni(ptr);
     }
 
-    static string ParseProxy(string proxy, string scheme)
+    static string Normalize(string proxy)
     {
-        // варианты:
-        // "proxy:8080"
-        // "http=proxy:8080;https=proxy2:8080"
-
-        if (!proxy.Contains("="))
-            return proxy;
-
-        var entries = proxy.Split(';', StringSplitOptions.RemoveEmptyEntries);
-
-        foreach (var entry in entries)
-        {
-            var parts = entry.Split('=', 2);
-            if (parts.Length != 2)
-                continue;
-
-            if (parts[0].Equals(scheme, StringComparison.OrdinalIgnoreCase))
-                return parts[1];
-        }
-
-        // fallback — берём первый
-        return entries[0].Split('=')[1];
-    }
-
-    static string NormalizeProxy(string proxy)
-    {
-        if (!proxy.StartsWith("http://") && !proxy.StartsWith("https://"))
+        if (!proxy.StartsWith("http"))
             return "http://" + proxy;
-
         return proxy;
     }
 
-    // ===== struct =====
-
-    struct WINHTTP_CURRENT_USER_IE_PROXY_CONFIG
+    struct WINHTTP_AUTOPROXY_OPTIONS
     {
-        public bool fAutoDetect;
+        public int dwFlags;
+        public int dwAutoDetectFlags;
         public IntPtr lpszAutoConfigUrl;
+        public IntPtr lpvReserved;
+        public int dwReserved;
+        public bool fAutoLogonIfChallenged;
+    }
+
+    struct WINHTTP_PROXY_INFO
+    {
+        public int dwAccessType;
         public IntPtr lpszProxy;
         public IntPtr lpszProxyBypass;
     }
 }
+
+static async Task Pump(Stream from, Stream to)
+{
+    var buffer = ArrayPool<byte>.Shared.Rent(8192);
+
+    try
+    {
+        while (true)
+        {
+            int read = await from.ReadAsync(buffer);
+            if (read <= 0) break;
+
+            await to.WriteAsync(buffer.AsMemory(0, read));
+        }
+    }
+    catch { }
+    finally
+    {
+        ArrayPool<byte>.Shared.Return(buffer);
+    }
+}