Use better fallback URLs when calling AVScanFile().

content/browser/download/quarantine_win.cc

 // Copyright 2016 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 "content/browser/download/quarantine.h"
 
 #include <windows.h>
 
 #include <cguid.h>
 #include <objbase.h>
@@ skipping 137 matching lines @@
 // Typical |save_result| values:
 //   S_OK   : The file was okay. If any viruses were found, they were cleaned.
 //   E_FAIL : Virus infected.
 //   INET_E_SECURITY_PROBLEM : The file was blocked due to security policy.
 //
 // Any other return value indicates an unexpected error during the scan.
 //
 // |full_path| : is the path to the downloaded file. This should be the final
 //               path of the download. Must be present.
 // |source_url|: the source URL for the download. If empty, the source will
-//               not be set.
+//               be set to 'about:internet'.
+// |referrer_url|: the referrer URL for the download. If empty, the referrer
+//               will not be set.
 // |client_guid|: the GUID to be set in the IAttachmentExecute client slot.
 //                Used to identify the app to the system AV function.
 //                If GUID_NULL is passed, no client GUID is set.
 // |save_result|: Receives the result of invoking IAttachmentExecute::Save().
 bool InvokeAttachmentServices(const base::FilePath& full_path,
                               const std::string& source_url,
+                              const std::string& referrer_url,
                               const GUID& client_guid,
                               HRESULT* save_result) {
   base::win::ScopedComPtr<IAttachmentExecute> attachment_services;
   HRESULT hr = attachment_services.CreateInstance(CLSID_AttachmentServices);
   *save_result = S_OK;
 
   if (FAILED(hr)) {
     // The thread must have COM initialized.
     DCHECK_NE(CO_E_NOTINITIALIZED, hr);
     RecordAttachmentServicesResult(
         AttachmentServicesResult::NO_ATTACHMENT_SERVICES);
     return false;
   }
 
   hr = attachment_services->SetClientGuid(client_guid);
   if (FAILED(hr)) {
     RecordAttachmentServicesResult(
         AttachmentServicesResult::FAILED_TO_SET_PARAMETER);
     return false;
   }
 
   hr = attachment_services->SetLocalPath(full_path.value().c_str());
   if (FAILED(hr)) {
     RecordAttachmentServicesResult(
         AttachmentServicesResult::FAILED_TO_SET_PARAMETER);
     return false;
   }
 
-  // Note: SetSource looks like it needs to be called, even if empty.
-  // Docs say it is optional, but it appears not calling it at all sets
-  // a zone that is too restrictive.
-  hr = attachment_services->SetSource(base::UTF8ToWide(source_url).c_str());
+  hr = attachment_services->SetSource(
+      source_url.empty() ? L"about:internet"
+                         : base::UTF8ToWide(source_url).c_str());
   if (FAILED(hr)) {
     RecordAttachmentServicesResult(
         AttachmentServicesResult::FAILED_TO_SET_PARAMETER);
     return false;
   }
 
+  // Only set referrer if one is present. Also, the source_url is authoritative
+  // for determining the relative danger of |full_path|. So not going to
+  // consider it fatal if setting the referrer fails.
+  if (!referrer_url.empty())
+    attachment_services->SetReferrer(base::UTF8ToWide(referrer_url).c_str());
+
   {
     // This method has been known to take longer than 10 seconds in some
     // instances.
     SCOPED_UMA_HISTOGRAM_LONG_TIMER("Download.AttachmentServices.Duration");
     *save_result = attachment_services->Save();
   }
   RecordAttachmentServicesSaveResult(full_path, *save_result);
   return true;
 }
 
@@ skipping 66 matching lines @@
   //
   // If the file is still there, then the error could be due to Windows
   // Attachment Services not being available or some other error during the AES
   // invocation. In either case, we don't surface the error to the user.
   if (!base::PathExists(file))
     return FailedSaveResultToQuarantineResult(save_result);
   return QuarantineFileResult::OK;
 }
 
 }  // namespace content