Make downloads.download() respect host permissions

chrome/browser/download/download_extension_api.cc

 // Copyright (c) 2012 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 "chrome/browser/download/download_extension_api.h"
 
 #include <algorithm>
 #include <cctype>
 #include <iterator>
 #include <set>
@@ skipping 363 matching lines @@
   std::string url;
   iodata_.reset(new IOData());
   EXTENSION_FUNCTION_VALIDATE(args_->GetDictionary(0, &options));
   EXTENSION_FUNCTION_VALIDATE(options->GetString(kUrlKey, &url));
   iodata_->url = GURL(url);
   if (!iodata_->url.is_valid()) {
     error_ = download_extension_errors::kInvalidURLError;
     return false;
   }
 
+  // The host permissions should not be why e.g. data, filesystem URLs don't
+  // work.
+  if ((iodata_->url.SchemeIs("http") ||

[Mihai Parparita -not on Chrome, 2012/05/01 20:08:31]

Why do you have these scheme checks? HasHostPermission (despite the name) also
checks schemes.

[benjhayden, 2012/05/01 20:19:12]

HasHostPermission() *disallows* schemes other than these, but download() should
*allow* them. Extensions should be able to "download" data: and filesystem:
URLs.

[Mihai Parparita -not on Chrome, 2012/05/01 20:53:12]

Then I'd rather have those be explicitly listed (i.e. making the check into
!url.SchemeIs("data") && !url.SchemeIs("filesystem") &&
!GetExtension()->HasHostPermission(url)). Otherwise you risk allowing unknown
schemes (e.g. your current code allows downloads from the chrome:// scheme,
which doesn't seem wise).

[benjhayden, 2012/05/02 14:40:18]

Done.

+       iodata_->url.SchemeIs("https") ||
+       iodata_->url.SchemeIs("ftp") ||
+       iodata_->url.SchemeIs("file") ||
+       iodata_->url.SchemeIs("chrome-extension")) &&
+      !GetExtension()->HasHostPermission(iodata_->url)) {
+    error_ = download_extension_errors::kInvalidURLError;
+    return false;
+  }
+
   if (options->HasKey(kFilenameKey)) {
     EXTENSION_FUNCTION_VALIDATE(options->GetString(
         kFilenameKey, &iodata_->filename));
     if (!ValidateFilename(iodata_->filename)) {
       error_ = download_extension_errors::kGenericError;
       return false;
     }
   }
 
   if (options->HasKey(kSaveAsKey)) {
@@ skipping 681 matching lines @@
   ListValue args;
   args.Append(arg);
   std::string json_args;
   base::JSONWriter::Write(&args, &json_args);
   profile_->GetExtensionEventRouter()->DispatchEventToRenderers(
       event_name,
       json_args,
       profile_,
       GURL());
 }