Fix for Proxy server authentication without credentials available.

net/http/http_auth.cc

 // Copyright (c) 2010 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_auth.h"
 
 #include <algorithm>
 
 #include "base/basictypes.h"
 #include "base/string_util.h"
@@ skipping 13 matching lines @@
     const HttpResponseHeaders* headers,
     Target target,
     const GURL& origin,
     const std::set<std::string>& disabled_schemes,
     const BoundNetLog& net_log,
     scoped_ptr<HttpAuthHandler>* handler) {
   DCHECK(http_auth_handler_factory);
 
   // A connection-based authentication scheme must continue to use the
   // existing handler object in |*handler|.
-  if (handler->get() && (*handler)->is_connection_based()) {
+  if (handler->get() && (*handler)->is_connection_based() &&
+      (disabled_schemes.find((*handler)->scheme()) == disabled_schemes.end())) {
     const std::string header_name = GetChallengeHeaderName(target);
     std::string challenge;
     void* iter = NULL;
     while (headers->EnumerateHeader(&iter, header_name, &challenge)) {
       ChallengeTokenizer props(challenge.begin(), challenge.end());
       if (LowerCaseEqualsASCII(props.scheme(), (*handler)->scheme().c_str()) &&
           (*handler)->InitFromChallenge(&props, target, origin, net_log))
         return;
     }
   }
 
   // Choose the challenge whose authentication handler gives the maximum score.
   scoped_ptr<HttpAuthHandler> best;
   const std::string header_name = GetChallengeHeaderName(target);
   std::string cur_challenge;
   void* iter = NULL;
   while (headers->EnumerateHeader(&iter, header_name, &cur_challenge)) {
     scoped_ptr<HttpAuthHandler> cur;
     int rv = http_auth_handler_factory->CreateAuthHandlerFromString(
         cur_challenge, target, origin, net_log, &cur);
     if (rv != OK) {
       LOG(WARNING) << "Unable to create AuthHandler. Status: "
                    << ErrorToString(rv) << " Challenge: " << cur_challenge;
       continue;
     }
-    if (cur.get() && (!best.get() || best->score() < cur->score())) {
-      if (disabled_schemes.find(cur->scheme()) == disabled_schemes.end())
-        best.swap(cur);
-    }
+    if (cur.get() && (!best.get() || best->score() < cur->score()) &&
+        (disabled_schemes.find(cur->scheme()) == disabled_schemes.end()))
+      best.swap(cur);
   }
   handler->swap(best);
 }
 
 void HttpAuth::ChallengeTokenizer::Init(std::string::const_iterator begin,
                                         std::string::const_iterator end) {
   // The first space-separated token is the auth-scheme.
   // NOTE: we are more permissive than RFC 2617 which says auth-scheme
   // is separated by 1*SP.
   StringTokenizer tok(begin, end, HTTP_LWS);
@@ skipping 98 matching lines @@
   }
 }
 
 // static
 std::string HttpAuth::GetAuthTargetString(
     HttpAuth::Target target) {
   return target == HttpAuth::AUTH_PROXY ? "proxy" : "server";
 }
 
 }  // namespace net