Send the "Proxy-Connection: keep-alive" header with HTTP CONNECT...

net/http/http_network_transaction.cc

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/http/http_network_transaction.h"
 
 #include "base/scoped_ptr.h"
 #include "base/compiler_specific.h"
 #include "base/field_trial.h"
 #include "base/string_util.h"
@@ skipping 86 matching lines @@
   *request_headers += "\r\n";
 }
 
 // The HTTP CONNECT method for establishing a tunnel connection is documented
 // in draft-luotonen-web-proxy-tunneling-01.txt and RFC 2817, Sections 5.2 and
 // 5.3.
 void BuildTunnelRequest(const HttpRequestInfo* request_info,
                         const std::string& authorization_headers,
                         std::string* request_headers) {
   // RFC 2616 Section 9 says the Host request-header field MUST accompany all
-  // HTTP/1.1 requests.
-  *request_headers = StringPrintf("CONNECT %s HTTP/1.1\r\nHost: %s\r\n",
+  // HTTP/1.1 requests.  Add "Proxy-Connection: keep-alive" for compat with
+  // HTTP/1.0 proxies such as Squid (required for NTLM authentication).
+  *request_headers = StringPrintf(
+      "CONNECT %s HTTP/1.1\r\nHost: %s\r\nProxy-Connection: keep-alive\r\n",
       GetHostAndPort(request_info->url).c_str(),
       GetHostAndOptionalPort(request_info->url).c_str());
 
   if (!request_info->user_agent.empty())
     StringAppendF(request_headers, "User-Agent: %s\r\n",
                   request_info->user_agent.c_str());
 
   if (!authorization_headers.empty()) {
     *request_headers += authorization_headers;
   }
@@ skipping 1492 matching lines @@
     host_and_port = proxy_info_.proxy_server().host_and_port();
   } else {
     DCHECK(target == HttpAuth::AUTH_SERVER);
     host_and_port = GetHostAndPort(request_->url);
   }
   auth_info->host_and_port = ASCIIToWide(host_and_port);
   response_.auth_challenge = auth_info;
 }
 
 }  // namespace net