components/proximity_auth/cryptauth/cryptauth_enrollment_manager.cc

   1 // Copyright 2015 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 "components/proximity_auth/cryptauth/cryptauth_enrollment_manager.h"
   6
   7 #include "base/prefs/pref_registry_simple.h"
   8 #include "base/prefs/pref_service.h"
   9 #include "base/time/clock.h"
  10 #include "base/time/time.h"
  11 #include "components/proximity_auth/cryptauth/cryptauth_enroller.h"
  12 #include "components/proximity_auth/cryptauth/pref_names.h"
  13 #include "components/proximity_auth/cryptauth/secure_message_delegate.h"
  14 #include "components/proximity_auth/cryptauth/sync_scheduler_impl.h"
  15 #include "components/proximity_auth/logging/logging.h"
  16
  17 namespace proximity_auth {
  18
  19 namespace {
  20
  21 // The number of days that an enrollment is valid. Note that we try to refresh
  22 // the enrollment well before this time elapses.
  23 const int kValidEnrollmentPeriodDays = 45;
  24
  25 // The normal period between successful enrollments in days.
  26 const int kEnrollmentRefreshPeriodDays = 30;
  27
  28 // A more aggressive period between enrollments to recover when the last
  29 // enrollment fails, in minutes. This is a base time that increases for each
  30 // subsequent failure.
  31 const int kEnrollmentBaseRecoveryPeriodMinutes = 10;
  32
  33 // The bound on the amount to jitter the period between enrollments.
  34 const double kEnrollmentMaxJitterRatio = 0.2;
  35
  36 }  // namespace
  37
  38 CryptAuthEnrollmentManager::CryptAuthEnrollmentManager(
  39     scoped_ptr<base::Clock> clock,
  40     scoped_ptr<CryptAuthEnrollerFactory> enroller_factory,
  41     const std::string& user_public_key,
  42     const std::string& user_private_key,
  43     const cryptauth::GcmDeviceInfo& device_info,
  44     PrefService* pref_service)
  45     : clock_(clock.Pass()),
  46       enroller_factory_(enroller_factory.Pass()),
  47       user_public_key_(user_public_key),
  48       user_private_key_(user_private_key),
  49       device_info_(device_info),
  50       pref_service_(pref_service),
  51       weak_ptr_factory_(this) {
  52 }
  53
  54 CryptAuthEnrollmentManager::~CryptAuthEnrollmentManager() {
  55 }
  56
  57 // static
  58 void CryptAuthEnrollmentManager::RegisterPrefs(PrefRegistrySimple* registry) {
  59   registry->RegisterBooleanPref(
  60       prefs::kCryptAuthEnrollmentIsRecoveringFromFailure, false);
  61   registry->RegisterDoublePref(
  62       prefs::kCryptAuthEnrollmentLastEnrollmentTimeSeconds, 0.0);
  63   registry->RegisterIntegerPref(prefs::kCryptAuthEnrollmentReason,
  64                                 cryptauth::INVOCATION_REASON_UNKNOWN);
  65 }
  66
  67 void CryptAuthEnrollmentManager::Start() {
  68   bool is_recovering_from_failure =
  69       pref_service_->GetBoolean(
  70           prefs::kCryptAuthEnrollmentIsRecoveringFromFailure) ||
  71       !IsEnrollmentValid();
  72
  73   base::Time last_successful_enrollment = GetLastEnrollmentTime();
  74   base::TimeDelta elapsed_time_since_last_sync =
  75       clock_->Now() - last_successful_enrollment;
  76
  77   scheduler_ = CreateSyncScheduler();
  78   scheduler_->Start(elapsed_time_since_last_sync,
  79                     is_recovering_from_failure
  80                         ? SyncScheduler::Strategy::AGGRESSIVE_RECOVERY
  81                         : SyncScheduler::Strategy::PERIODIC_REFRESH);
  82 }
  83
  84 void CryptAuthEnrollmentManager::AddObserver(Observer* observer) {
  85   observers_.AddObserver(observer);
  86 }
  87
  88 void CryptAuthEnrollmentManager::RemoveObserver(Observer* observer) {
  89   observers_.RemoveObserver(observer);
  90 }
  91
  92 void CryptAuthEnrollmentManager::ForceEnrollmentNow(
  93     cryptauth::InvocationReason invocation_reason) {
  94   // We store the invocation reason in a preference so that it can persist
  95   // across browser restarts. If the sync fails, the next retry should still use
  96   // this original reason instead of INVOCATION_REASON_FAILURE_RECOVERY.
  97   pref_service_->SetInteger(prefs::kCryptAuthEnrollmentReason,
  98                             invocation_reason);
  99   scheduler_->ForceSync();
 100 }
 101
 102 bool CryptAuthEnrollmentManager::IsEnrollmentValid() const {
 103   base::Time last_enrollment_time = GetLastEnrollmentTime();
 104   return !last_enrollment_time.is_null() &&
 105          (clock_->Now() - last_enrollment_time) <
 106              base::TimeDelta::FromDays(kValidEnrollmentPeriodDays);
 107 }
 108
 109 base::Time CryptAuthEnrollmentManager::GetLastEnrollmentTime() const {
 110   return base::Time::FromDoubleT(pref_service_->GetDouble(
 111       prefs::kCryptAuthEnrollmentLastEnrollmentTimeSeconds));
 112 }
 113
 114 base::TimeDelta CryptAuthEnrollmentManager::GetTimeToNextAttempt() const {
 115   return scheduler_->GetTimeToNextSync();
 116 }
 117
 118 bool CryptAuthEnrollmentManager::IsEnrollmentInProgress() const {
 119   return scheduler_->GetSyncState() ==
 120          SyncScheduler::SyncState::SYNC_IN_PROGRESS;
 121 }
 122
 123 bool CryptAuthEnrollmentManager::IsRecoveringFromFailure() const {
 124   return scheduler_->GetStrategy() ==
 125          SyncScheduler::Strategy::AGGRESSIVE_RECOVERY;
 126 }
 127
 128 void CryptAuthEnrollmentManager::OnEnrollmentFinished(bool success) {
 129   if (success) {
 130     pref_service_->SetDouble(
 131         prefs::kCryptAuthEnrollmentLastEnrollmentTimeSeconds,
 132         clock_->Now().ToDoubleT());
 133     pref_service_->SetInteger(prefs::kCryptAuthEnrollmentReason,
 134                               cryptauth::INVOCATION_REASON_UNKNOWN);
 135   }
 136
 137   pref_service_->SetBoolean(prefs::kCryptAuthEnrollmentIsRecoveringFromFailure,
 138                             !success);
 139
 140   sync_request_->OnDidComplete(success);
 141   cryptauth_enroller_.reset();
 142   sync_request_.reset();
 143   FOR_EACH_OBSERVER(Observer, observers_, OnEnrollmentFinished(success));
 144 }
 145
 146 scoped_ptr<SyncScheduler> CryptAuthEnrollmentManager::CreateSyncScheduler() {
 147   return make_scoped_ptr(new SyncSchedulerImpl(
 148       this, base::TimeDelta::FromDays(kEnrollmentRefreshPeriodDays),
 149       base::TimeDelta::FromMinutes(kEnrollmentBaseRecoveryPeriodMinutes),
 150       kEnrollmentMaxJitterRatio, "CryptAuth Enrollment"));
 151 }
 152
 153 void CryptAuthEnrollmentManager::OnSyncRequested(
 154     scoped_ptr<SyncScheduler::SyncRequest> sync_request) {
 155   FOR_EACH_OBSERVER(Observer, observers_, OnEnrollmentStarted());
 156
 157   sync_request_ = sync_request.Pass();
 158   cryptauth_enroller_ = enroller_factory_->CreateInstance();
 159
 160   cryptauth::InvocationReason invocation_reason =
 161       cryptauth::INVOCATION_REASON_UNKNOWN;
 162
 163   int reason_stored_in_prefs =
 164       pref_service_->GetInteger(prefs::kCryptAuthEnrollmentReason);
 165
 166   if (cryptauth::InvocationReason_IsValid(reason_stored_in_prefs) &&
 167       reason_stored_in_prefs != cryptauth::INVOCATION_REASON_UNKNOWN) {
 168     invocation_reason =
 169         static_cast<cryptauth::InvocationReason>(reason_stored_in_prefs);
 170   } else if (GetLastEnrollmentTime().is_null()) {
 171     invocation_reason = cryptauth::INVOCATION_REASON_INITIALIZATION;
 172   } else if (!IsEnrollmentValid()) {
 173     invocation_reason = cryptauth::INVOCATION_REASON_EXPIRATION;
 174   } else if (scheduler_->GetStrategy() ==
 175              SyncScheduler::Strategy::PERIODIC_REFRESH) {
 176     invocation_reason = cryptauth::INVOCATION_REASON_PERIODIC;
 177   } else if (scheduler_->GetStrategy() ==
 178              SyncScheduler::Strategy::AGGRESSIVE_RECOVERY) {
 179     invocation_reason = cryptauth::INVOCATION_REASON_FAILURE_RECOVERY;
 180   }
 181
 182   PA_LOG(INFO) << "Making enrollment with reason: " << invocation_reason;
 183   cryptauth_enroller_->Enroll(
 184       user_public_key_, user_private_key_, device_info_, invocation_reason,
 185       base::Bind(&CryptAuthEnrollmentManager::OnEnrollmentFinished,
 186                  weak_ptr_factory_.GetWeakPtr()));
 187 }
 188
 189 }  // namespace proximity_auth