src/chrome/browser/chromeos/login/auth/tpm_password_fetcher.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/chromeos/login/auth/tpm_password_fetcher.h"
   6
   7 #include "base/bind.h"
   8 #include "base/compiler_specific.h"
   9 #include "base/message_loop/message_loop.h"
  10 #include "chromeos/dbus/cryptohome_client.h"
  11 #include "chromeos/dbus/dbus_thread_manager.h"
  12
  13 namespace chromeos {
  14
  15 namespace {
  16
  17 // Interval between TPM password checks.
  18 const int kTpmCheckIntervalMs = 500;
  19
  20 }  // namespace
  21
  22 TpmPasswordFetcher::TpmPasswordFetcher(TpmPasswordFetcherDelegate* delegate)
  23     : weak_factory_(this),
  24       delegate_(delegate) {
  25   DCHECK(delegate_);
  26 }
  27
  28 TpmPasswordFetcher::~TpmPasswordFetcher() {
  29 }
  30
  31 void TpmPasswordFetcher::Fetch() {
  32   // Since this method is also called directly.
  33   weak_factory_.InvalidateWeakPtrs();
  34
  35   DBusThreadManager::Get()->GetCryptohomeClient()->TpmIsReady(
  36       base::Bind(&TpmPasswordFetcher::OnTpmIsReady,
  37                  weak_factory_.GetWeakPtr()));
  38 }
  39
  40 void TpmPasswordFetcher::OnTpmIsReady(DBusMethodCallStatus call_status,
  41                                       bool tpm_is_ready) {
  42   if (call_status == DBUS_METHOD_CALL_SUCCESS && tpm_is_ready) {
  43     DBusThreadManager::Get()->GetCryptohomeClient()->TpmGetPassword(
  44         base::Bind(&TpmPasswordFetcher::OnTpmGetPassword,
  45                    weak_factory_.GetWeakPtr()));
  46   } else {
  47     // Password hasn't been acquired, reschedule fetch.
  48     RescheduleFetch();
  49   }
  50 }
  51
  52 void TpmPasswordFetcher::OnTpmGetPassword(DBusMethodCallStatus call_status,
  53                                           const std::string& password) {
  54   if (call_status == DBUS_METHOD_CALL_SUCCESS) {
  55     if (password.empty()) {
  56       // For a fresh OOBE flow TPM is uninitialized,
  57       // ownership process is started at the EULA screen,
  58       // password is cleared after EULA is accepted.
  59       LOG(ERROR) << "TPM returned an empty password.";
  60     }
  61     delegate_->OnPasswordFetched(password);
  62   } else {
  63     // Password hasn't been acquired, reschedule fetch.
  64     RescheduleFetch();
  65   }
  66 }
  67
  68 void TpmPasswordFetcher::RescheduleFetch() {
  69   base::MessageLoop::current()->PostDelayedTask(
  70       FROM_HERE,
  71       base::Bind(&TpmPasswordFetcher::Fetch, weak_factory_.GetWeakPtr()),
  72       base::TimeDelta::FromMilliseconds(kTpmCheckIntervalMs));
  73 }
  74
  75 }  // namespace chromeos