AU: Verify source rootfs/kernel hashes before applying delta.

delta_diff_generator.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/delta_diff_generator.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <inttypes.h>
 #include <sys/stat.h>
@@ skipping 593 matching lines @@
                                                    &block_size));
     size = static_cast<int64_t>(block_count) * block_size;
   }
   TEST_AND_RETURN_FALSE(size > 0);
   info->set_size(size);
   OmahaHashCalculator hasher;
   TEST_AND_RETURN_FALSE(hasher.UpdateFile(partition, size) == size);
   TEST_AND_RETURN_FALSE(hasher.Finalize());
   const vector<char>& hash = hasher.raw_hash();
   info->set_hash(hash.data(), hash.size());
+  LOG(INFO) << "hash: " << hasher.hash();
   return true;
 }
 
 bool InitializePartitionInfos(const string& old_kernel,
                               const string& new_kernel,
                               const string& old_rootfs,
                               const string& new_rootfs,
                               DeltaArchiveManifest* manifest) {
-  if (!old_kernel.empty()) {
-    TEST_AND_RETURN_FALSE(
-        InitializePartitionInfo(true,
-                                old_kernel,
-                                manifest->mutable_old_kernel_info()));
-  }
+  // TODO(petkov): Generate the old kernel info when we stop generating full
+  // updates for the kernel partition.
   TEST_AND_RETURN_FALSE(
       InitializePartitionInfo(true,
                               new_kernel,
                               manifest->mutable_new_kernel_info()));
   if (!old_rootfs.empty()) {
     TEST_AND_RETURN_FALSE(
         InitializePartitionInfo(false,
                                 old_rootfs,
                                 manifest->mutable_old_rootfs_info()));
   }
@@ skipping 874 matching lines @@
 
   LOG(INFO) << "All done. Successfully created delta file.";
   return true;
 }
 
 const char* const kBsdiffPath = "/usr/bin/bsdiff";
 const char* const kBspatchPath = "/usr/bin/bspatch";
 const char* const kDeltaMagic = "CrAU";
 
 };  // namespace chromeos_update_engine