cros: Added policies for screen unlock.

chrome/browser/chromeos/login/quick_unlock/pin_storage.cc

 // Copyright 2016 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/quick_unlock/pin_storage.h"
 
 #include "base/base64.h"
 #include "base/strings/string_util.h"
 #include "chrome/browser/chromeos/login/quick_unlock/quick_unlock_utils.h"
 #include "chrome/common/pref_names.h"
@@ skipping 19 matching lines @@
   return salt;
 }
 
 // Computes the hash for |pin| and |salt|.
 std::string ComputeSecret(const std::string& pin, const std::string& salt) {
   Key key(pin);
   key.Transform(Key::KEY_TYPE_SALTED_PBKDF2_AES256_1234, salt);
   return key.GetSecret();
 }
 
+base::TimeDelta QuickUnlockPasswordConfirmationFrequencyFrequencyToTimeDelta(

[pastarmovj, 2016/11/04 10:33:03]

nit: Do you need the word Frequency twice in this name?

[sammiequon, 2016/11/06 17:52:52]

Done.

+    QuickUnlockPasswordConfirmationFrequency frequency) {
+  switch (frequency) {
+    case QuickUnlockPasswordConfirmationFrequency::SIX_HOURS:
+      return base::TimeDelta::FromHours(6);
+    case QuickUnlockPasswordConfirmationFrequency::TWELVE_HOURS:
+      return base::TimeDelta::FromHours(12);
+    case QuickUnlockPasswordConfirmationFrequency::DAY:
+      return base::TimeDelta::FromDays(1);
+    case QuickUnlockPasswordConfirmationFrequency::WEEK:
+      return base::TimeDelta::FromDays(7);
+  }
+  NOTREACHED();
+  return base::TimeDelta();
+}
+
 }  // namespace
 
 // static
-const base::TimeDelta PinStorage::kStrongAuthTimeout =
-    base::TimeDelta::FromHours(24);
-
-// static
 void PinStorage::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterStringPref(prefs::kQuickUnlockPinSalt, "",
                                user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
   registry->RegisterStringPref(prefs::kQuickUnlockPinSecret, "",
                                user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
 }
 
 PinStorage::PinStorage(PrefService* pref_service)
     : pref_service_(pref_service) {}
 
 PinStorage::~PinStorage() {}
 
 void PinStorage::MarkStrongAuth() {
   last_strong_auth_ = base::Time::Now();
   ResetUnlockAttemptCount();
 }
 
 bool PinStorage::HasStrongAuth() const {
-  return !last_strong_auth_.is_null();
+  if (last_strong_auth_.is_null())
+    return false;
+
+  QuickUnlockPasswordConfirmationFrequency strong_auth_interval =
+      static_cast<QuickUnlockPasswordConfirmationFrequency>(
+          pref_service_->GetInteger(prefs::kQuickUnlockTimeout));
+  base::TimeDelta strong_auth_timeout =
+      QuickUnlockPasswordConfirmationFrequencyFrequencyToTimeDelta(
+          strong_auth_interval);
+
+  return TimeSinceLastStrongAuth() < strong_auth_timeout;
 }
 
 base::TimeDelta PinStorage::TimeSinceLastStrongAuth() const {
   DCHECK(!last_strong_auth_.is_null());
   return base::Time::Now() - last_strong_auth_;
 }
 
 void PinStorage::AddUnlockAttempt() {
   ++unlock_attempt_count_;
 }
@@ skipping 23 matching lines @@
   return pref_service_->GetString(prefs::kQuickUnlockPinSalt);
 }
 
 std::string PinStorage::PinSecret() const {
   return pref_service_->GetString(prefs::kQuickUnlockPinSecret);
 }
 
 bool PinStorage::IsPinAuthenticationAvailable() const {
   const bool exceeded_unlock_attempts =
       unlock_attempt_count() >= kMaximumUnlockAttempts;
-  const bool has_strong_auth =
-      HasStrongAuth() && TimeSinceLastStrongAuth() < kStrongAuthTimeout;
 
-  return IsQuickUnlockEnabled() && IsPinSet() && has_strong_auth &&
+  return IsPinUnlockEnabled(pref_service_) && IsPinSet() && HasStrongAuth() &&
          !exceeded_unlock_attempts;
 }
 
 bool PinStorage::TryAuthenticatePin(const std::string& pin) {
   if (!IsPinAuthenticationAvailable())
     return false;
 
   AddUnlockAttempt();
   return ComputeSecret(pin, PinSalt()) == PinSecret();
 }
 
 }  // namespace chromeos