AU: Verify delta payload signature and signed hash.

download_action.cc

 // Copyright (c) 2010 The Chromium OS 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 "update_engine/download_action.h"
 #include <errno.h>
 #include <algorithm>
 #include <string>
 #include <vector>
 #include <glib.h>
@@ skipping 132 matching lines @@
     if (omaha_hash_calculator_.hash() != install_plan_.download_hash) {
       LOG(ERROR) << "Download of " << install_plan_.download_url
                  << " failed. Expected hash " << install_plan_.download_hash
                  << " but got hash " << omaha_hash_calculator_.hash();
       code = kActionCodeDownloadHashMismatchError;
     } else if (bytes_received_ != install_plan_.size) {
       LOG(ERROR) << "Download of " << install_plan_.download_url
                  << " failed. Expected size " << install_plan_.size
                  << " but got size " << bytes_received_;
       code = kActionCodeDownloadSizeMismatchError;
+    } else if (!install_plan_.is_full_update &&
+               !delta_performer_->VerifyPayload("")) {
+      LOG(ERROR) << "Download of " << install_plan_.download_url
+                 << " failed due to payload verification error.";
+      code = kActionCodeDownloadPayloadVerificationError;
     }
   }
 
   FlushLinuxCaches();
 
   // Write the path to the output pipe if we're successful.
   if (code == kActionCodeSuccess && HasOutputPipe())
     SetOutputObject(GetInputObject());
   processor_->ActionComplete(this, code);
 }
 
 };  // namespace {}