Fixes an issue when the owner key is empty chrome would crash trying to access bogus memory.

chrome/browser/chromeos/login/owner_key_utils.cc

 // Copyright (c) 2011 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/chromeos/login/owner_key_utils.h"
 
 #include <limits>
 
 #include "base/file_path.h"
 #include "base/file_util.h"
@@ skipping 105 matching lines @@
     return false;
   }
   if (file_size > static_cast<int64>(std::numeric_limits<int>::max())) {
     LOG(ERROR) << key_file.value() << "is "
                << file_size << "bytes!!!  Too big!";
     return false;
   }
   int32 safe_file_size = static_cast<int32>(file_size);
 
   output->resize(safe_file_size);
+
+  if (safe_file_size == 0) {
+    LOG(WARNING) << "Public key file is empty. This seems wrong.";

[Mattias Nissler (ping if slow), 2012/05/21 16:30:34]

nit: Remove "This seems wrong.", it is redundant.

+    return false;
+  }
+
   // Get the key data off of disk
   int data_read = file_util::ReadFile(key_file,
                                       reinterpret_cast<char*>(&(output->at(0))),
                                       safe_file_size);
   return data_read == safe_file_size;
 }
 
 bool OwnerKeyUtilsImpl::Verify(const std::string& data,
                                const std::vector<uint8> signature,
                                const std::vector<uint8> public_key) {
@@ skipping 24 matching lines @@
 crypto::RSAPrivateKey* OwnerKeyUtilsImpl::FindPrivateKey(
     const std::vector<uint8>& key) {
   return crypto::RSAPrivateKey::FindFromPublicKeyInfo(key);
 }
 
 FilePath OwnerKeyUtilsImpl::GetOwnerKeyFilePath() {
   return FilePath(OwnerKeyUtilsImpl::kOwnerKeyFile);
 }
 
 }  // namespace chromeos