Implemented screen notifying users about malformed HWID.

chrome/browser/chromeos/login/hwid_checker.cc

Index: chrome/browser/chromeos/login/hwid_checker.cc
diff --git a/chrome/browser/chromeos/login/hwid_checker.cc b/chrome/browser/chromeos/login/hwid_checker.cc
new file mode 100644
index 0000000000000000000000000000000000000000..4fec2f51214d22b2baab4555e14bbee799acb19d
--- /dev/null
+++ b/chrome/browser/chromeos/login/hwid_checker.cc
@@ -0,0 +1,64 @@
+// Copyright (c) 2013 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/hwid_checker.h"
+
+#include <cstdio>
+
+#include "base/chromeos/chromeos_version.h"
+#include "base/command_line.h"
+#include "base/logging.h"
+#include "chrome/browser/chromeos/system/statistics_provider.h"
+#include "chrome/common/chrome_switches.h"
+#include "third_party/re2/re2/re2.h"
+#include "third_party/zlib/zlib.h"
+
+namespace chromeos {
+
+std::string CalculateHWIDChecksum(const std::string& data) {
+  unsigned crc32_checksum = static_cast<unsigned>(crc32(
+      0,
+      reinterpret_cast<const Bytef*>(data.c_str()),
+      data.length()));
+  // We take four least significant decimal digits of CRC-32.
+  char checksum[5];
+  int snprintf_result =
+      snprintf(checksum, 5, "%04u", crc32_checksum % 10000);
+  LOG_ASSERT(snprintf_result == 4);
+  return checksum;
+}
+
+bool IsHWIDCorrect(const std::string& hwid) {
+  // TODO(dzhioev): add support of HWID v3 format.
+  std::string body;
+  std::string checksum;
+  if (!RE2::FullMatch(hwid, "([\\s\\S]*) (\\d{4})", &body, &checksum))
+    return false;
+  return CalculateHWIDChecksum(body) == checksum;
+}
+
+bool IsMachineHWIDCorrect() {
+#if !defined(GOOGLE_CHROME_BUILD)
+  return true;
+#endif
+  if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kTestType))
+    return true;
+  if (!base::chromeos::IsRunningOnChromeOS())
+    return true;
+  std::string hwid;
+  chromeos::system::StatisticsProvider* stats =
+      chromeos::system::StatisticsProvider::GetInstance();
+  if (!stats->GetMachineStatistic("hardware_class", &hwid)) {
+    LOG(ERROR) << "Couldn't get machine statistic 'hardware_class'.";
+    return false;
+  }
+  if (!chromeos::IsHWIDCorrect(hwid)) {
+    LOG(ERROR) << "Machine has malformed HWID '" << hwid << "'.";
+    return false;
+  }
+  return true;
+}
+
+} // namespace chromeos
+