AU: Verify that the actual download size matches the size reported by Omaha.

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 120 matching lines @@
   if (writer_) {
     CHECK_EQ(writer_->Close(), 0) << errno;
     writer_ = NULL;
   }
   if (delegate_) {
     delegate_->SetDownloadStatus(false);  // Set to inactive.
   }
   ActionExitCode code =
       successful ? kActionCodeSuccess : kActionCodeDownloadTransferError;
   if (code == kActionCodeSuccess) {
-    // Make sure hash is correct
+    // Makes sure the hash and size are correct.
     omaha_hash_calculator_.Finalize();
     if (omaha_hash_calculator_.hash() != install_plan_.download_hash) {
       LOG(ERROR) << "Download of " << install_plan_.download_url
-                 << " failed. Expect hash " << install_plan_.download_hash
+                 << " 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;
     }
   }
 
   FlushLinuxCaches();
 
   // Write the path to the output pipe if we're successful.
   if (code == kActionCodeSuccess && HasOutputPipe())
     SetOutputObject(GetInputObject());
   processor_->ActionComplete(this, code);
 }
 
 };  // namespace {}