cros: Implement cryptohome backend for pin.

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

Index: chrome/browser/chromeos/login/quick_unlock/pin_storage.cc
diff --git a/chrome/browser/chromeos/login/quick_unlock/pin_storage.cc b/chrome/browser/chromeos/login/quick_unlock/pin_storage.cc
deleted file mode 100644
index 4afc6de7cf2b789dda1e7f6bcb369a54611064cd..0000000000000000000000000000000000000000
--- a/chrome/browser/chromeos/login/quick_unlock/pin_storage.cc
+++ /dev/null
@@ -1,103 +0,0 @@
-// 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"
-#include "chromeos/login/auth/key.h"
-#include "components/prefs/pref_registry_simple.h"
-#include "components/prefs/pref_service.h"
-#include "crypto/random.h"
-
-namespace chromeos {
-namespace quick_unlock {
-
-namespace {
-
-const int kSaltByteSize = 16;
-
-// Returns a new salt of length |kSaltByteSize|.
-std::string CreateSalt() {
-  // The salt needs to be base64 encoded because the pref service requires a
-  // UTF8 string.
-  std::string salt;
-  crypto::RandBytes(base::WriteInto(&salt, kSaltByteSize + 1), kSaltByteSize);
-  base::Base64Encode(salt, &salt);
-  DCHECK(!salt.empty());
-  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();
-}
-
-}  // namespace
-
-// static
-void PinStorage::RegisterProfilePrefs(PrefRegistrySimple* registry) {
-  registry->RegisterStringPref(prefs::kQuickUnlockPinSalt, "");
-  registry->RegisterStringPref(prefs::kQuickUnlockPinSecret, "");
-}
-
-PinStorage::PinStorage(PrefService* pref_service)
-    : pref_service_(pref_service) {}
-
-PinStorage::~PinStorage() {}
-
-void PinStorage::AddUnlockAttempt() {
-  ++unlock_attempt_count_;
-}
-
-void PinStorage::ResetUnlockAttemptCount() {
-  unlock_attempt_count_ = 0;
-}
-
-bool PinStorage::IsPinSet() const {
-  return !PinSalt().empty() && !PinSecret().empty();
-}
-
-void PinStorage::SetPin(const std::string& pin) {
-  const std::string salt = CreateSalt();
-  const std::string secret = ComputeSecret(pin, salt);
-
-  pref_service_->SetString(prefs::kQuickUnlockPinSalt, salt);
-  pref_service_->SetString(prefs::kQuickUnlockPinSecret, secret);
-}
-
-void PinStorage::RemovePin() {
-  pref_service_->SetString(prefs::kQuickUnlockPinSalt, "");
-  pref_service_->SetString(prefs::kQuickUnlockPinSecret, "");
-}
-
-std::string PinStorage::PinSalt() const {
-  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;
-
-  return IsPinEnabled(pref_service_) && IsPinSet() && !exceeded_unlock_attempts;
-}
-
-bool PinStorage::TryAuthenticatePin(const std::string& pin) {
-  if (!IsPinAuthenticationAvailable())
-    return false;
-
-  AddUnlockAttempt();
-  return ComputeSecret(pin, PinSalt()) == PinSecret();
-}
-
-}  // namespace quick_unlock
-}  // namespace chromeos