root/chrome/browser/chromeos/policy/device_cloud_policy_manager_chromeos.cc

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DEFINITIONS

This source file includes following definitions.
  1. GetMachineStatistic
  2. GetMachineFlag
  3. local_state_
  4. Connect
  5. StartEnrollment
  6. CancelEnrollment
  7. GetDeviceRequisition
  8. SetDeviceRequisition
  9. ShouldAutoStartEnrollment
  10. CanExitEnrollment
  11. GetForcedEnrollmentDomain
  12. Shutdown
  13. OnStoreLoaded
  14. RegisterPrefs
  15. GetMachineID
  16. GetMachineModel
  17. GetCurrentDeviceStateKey
  18. CreateClient
  19. EnrollmentCompleted
  20. StartIfManaged
  21. StartConnection
  22. InitalizeRequisition
  23. GetRestoreMode
  24. GetDeviceStateKeys

// Copyright (c) 2012 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/policy/device_cloud_policy_manager_chromeos.h"

#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/command_line.h"
#include "base/port.h"
#include "base/prefs/pref_registry_simple.h"
#include "base/prefs/pref_service.h"
#include "base/strings/string_number_conversions.h"
#include "base/time/time.h"
#include "chrome/browser/browser_process.h"
#include "chrome/browser/chromeos/attestation/attestation_policy_observer.h"
#include "chrome/browser/chromeos/login/enrollment/auto_enrollment_controller.h"
#include "chrome/browser/chromeos/login/startup_utils.h"
#include "chrome/browser/chromeos/policy/device_cloud_policy_store_chromeos.h"
#include "chrome/browser/chromeos/policy/enrollment_handler_chromeos.h"
#include "chrome/browser/chromeos/policy/enterprise_install_attributes.h"
#include "chrome/browser/chromeos/policy/server_backed_device_state.h"
#include "chrome/common/chrome_content_client.h"
#include "chrome/common/pref_names.h"
#include "chromeos/chromeos_constants.h"
#include "chromeos/chromeos_switches.h"
#include "chromeos/system/statistics_provider.h"
#include "components/policy/core/common/cloud/cloud_policy_constants.h"
#include "components/policy/core/common/cloud/cloud_policy_store.h"
#include "components/policy/core/common/cloud/device_management_service.h"
#include "components/policy/core/common/cloud/system_policy_request_context.h"
#include "content/public/browser/browser_thread.h"
#include "crypto/sha2.h"
#include "policy/proto/device_management_backend.pb.h"
#include "url/gurl.h"

using content::BrowserThread;

namespace em = enterprise_management;

namespace policy {

namespace {

// Overridden no requisition value.
const char kNoRequisition[] = "none";

// Overridden no requisition value.
const char kRemoraRequisition[] = "remora";

// These are the machine serial number keys that we check in order until we
// find a non-empty serial number. The VPD spec says the serial number should be
// in the "serial_number" key for v2+ VPDs. However, legacy devices used a
// different key to report their serial number, which we fall back to if
// "serial_number" is not present.
//
// Product_S/N is still special-cased due to inconsistencies with serial
// numbers on Lumpy devices: On these devices, serial_number is identical to
// Product_S/N with an appended checksum. Unfortunately, the sticker on the
// packaging doesn't include that checksum either (the sticker on the device
// does though!). The former sticker is the source of the serial number used by
// device management service, so we prefer Product_S/N over serial number to
// match the server.
//
// TODO(mnissler): Move serial_number back to the top once the server side uses
// the correct serial number.
const char* kMachineInfoSerialNumberKeys[] = {
  "Product_S/N",    // Lumpy/Alex devices
  "serial_number",  // VPD v2+ devices
  "Product_SN",     // Mario
  "sn",             // old ZGB devices (more recent ones use serial_number)
};

// Fetches a machine statistic value from StatisticsProvider, returns an empty
// string on failure.
std::string GetMachineStatistic(const std::string& key) {
  std::string value;
  chromeos::system::StatisticsProvider* provider =
      chromeos::system::StatisticsProvider::GetInstance();
  if (!provider->GetMachineStatistic(key, &value))
    return std::string();

  return value;
}

// Gets a machine flag from StatisticsProvider, returns the given
// |default_value| if not present.
bool GetMachineFlag(const std::string& key, bool default_value) {
  bool value = default_value;
  chromeos::system::StatisticsProvider* provider =
      chromeos::system::StatisticsProvider::GetInstance();
  if (!provider->GetMachineFlag(key, &value))
    return default_value;

  return value;
}

}  // namespace

const int
DeviceCloudPolicyManagerChromeOS::kDeviceStateKeyTimeQuantumPower;

const int
DeviceCloudPolicyManagerChromeOS::kDeviceStateKeyFutureQuanta;

DeviceCloudPolicyManagerChromeOS::DeviceCloudPolicyManagerChromeOS(
    scoped_ptr<DeviceCloudPolicyStoreChromeOS> store,
    const scoped_refptr<base::SequencedTaskRunner>& task_runner,
    const scoped_refptr<base::SequencedTaskRunner>& background_task_runner,
    EnterpriseInstallAttributes* install_attributes)
    : CloudPolicyManager(
          PolicyNamespaceKey(dm_protocol::kChromeDevicePolicyType,
                             std::string()),
          store.get(),
          task_runner,
          BrowserThread::GetMessageLoopProxyForThread(BrowserThread::FILE),
          BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO)),
      device_store_(store.Pass()),
      background_task_runner_(background_task_runner),
      install_attributes_(install_attributes),
      device_management_service_(NULL),
      local_state_(NULL) {}

DeviceCloudPolicyManagerChromeOS::~DeviceCloudPolicyManagerChromeOS() {}

void DeviceCloudPolicyManagerChromeOS::Connect(
    PrefService* local_state,
    DeviceManagementService* device_management_service,
    scoped_ptr<CloudPolicyClient::StatusProvider> device_status_provider) {
  CHECK(!device_management_service_);
  CHECK(device_management_service);
  CHECK(local_state);

  local_state_ = local_state;
  device_management_service_ = device_management_service;
  device_status_provider_ = device_status_provider.Pass();

  InitalizeRequisition();
  StartIfManaged();
}

void DeviceCloudPolicyManagerChromeOS::StartEnrollment(
    const std::string& auth_token,
    bool is_auto_enrollment,
    const AllowedDeviceModes& allowed_device_modes,
    const EnrollmentCallback& callback) {
  CHECK(device_management_service_);
  core()->Disconnect();

  enrollment_handler_.reset(
      new EnrollmentHandlerChromeOS(
          device_store_.get(), install_attributes_, CreateClient(),
          background_task_runner_, auth_token,
          install_attributes_->GetDeviceId(), is_auto_enrollment,
          GetDeviceRequisition(), GetCurrentDeviceStateKey(),
          allowed_device_modes,
          base::Bind(&DeviceCloudPolicyManagerChromeOS::EnrollmentCompleted,
                     base::Unretained(this), callback)));
  enrollment_handler_->StartEnrollment();
}

void DeviceCloudPolicyManagerChromeOS::CancelEnrollment() {
  if (enrollment_handler_.get()) {
    enrollment_handler_.reset();
    StartIfManaged();
  }
}

std::string DeviceCloudPolicyManagerChromeOS::GetDeviceRequisition() const {
  std::string requisition;
  const PrefService::Preference* pref = local_state_->FindPreference(
      prefs::kDeviceEnrollmentRequisition);
  if (!pref->IsDefaultValue())
    pref->GetValue()->GetAsString(&requisition);

  if (requisition == kNoRequisition)
    requisition.clear();

  return requisition;
}

void DeviceCloudPolicyManagerChromeOS::SetDeviceRequisition(
    const std::string& requisition) {
  if (local_state_) {
    if (requisition.empty()) {
      local_state_->ClearPref(prefs::kDeviceEnrollmentRequisition);
      local_state_->ClearPref(prefs::kDeviceEnrollmentAutoStart);
      local_state_->ClearPref(prefs::kDeviceEnrollmentCanExit);
    } else {
      local_state_->SetString(prefs::kDeviceEnrollmentRequisition, requisition);
      if (requisition == kNoRequisition) {
        local_state_->ClearPref(prefs::kDeviceEnrollmentAutoStart);
        local_state_->ClearPref(prefs::kDeviceEnrollmentCanExit);
      } else {
        local_state_->SetBoolean(prefs::kDeviceEnrollmentAutoStart, true);
        local_state_->SetBoolean(prefs::kDeviceEnrollmentCanExit, false);
      }
    }
  }
}

bool DeviceCloudPolicyManagerChromeOS::ShouldAutoStartEnrollment() const {
  std::string restore_mode = GetRestoreMode();
  if (restore_mode == kDeviceStateRestoreModeReEnrollmentRequested ||
      restore_mode == kDeviceStateRestoreModeReEnrollmentEnforced) {
    return true;
  }

  if (local_state_->HasPrefPath(prefs::kDeviceEnrollmentAutoStart))
    return local_state_->GetBoolean(prefs::kDeviceEnrollmentAutoStart);

  return GetMachineFlag(chromeos::system::kOemIsEnterpriseManagedKey, false);
}

bool DeviceCloudPolicyManagerChromeOS::CanExitEnrollment() const {
  if (GetRestoreMode() == kDeviceStateRestoreModeReEnrollmentEnforced)
    return false;

  if (local_state_->HasPrefPath(prefs::kDeviceEnrollmentCanExit))
    return local_state_->GetBoolean(prefs::kDeviceEnrollmentCanExit);

  return GetMachineFlag(chromeos::system::kOemCanExitEnterpriseEnrollmentKey,
                        true);
}

std::string
DeviceCloudPolicyManagerChromeOS::GetForcedEnrollmentDomain() const {
  const base::DictionaryValue* device_state_dict =
      local_state_->GetDictionary(prefs::kServerBackedDeviceState);
  std::string management_domain;
  device_state_dict->GetString(kDeviceStateManagementDomain,
                               &management_domain);
  return management_domain;
}

void DeviceCloudPolicyManagerChromeOS::Shutdown() {
  CloudPolicyManager::Shutdown();
  device_status_provider_.reset();
}

void DeviceCloudPolicyManagerChromeOS::OnStoreLoaded(CloudPolicyStore* store) {
  CloudPolicyManager::OnStoreLoaded(store);

  if (!enrollment_handler_.get())
    StartIfManaged();
}

// static
void DeviceCloudPolicyManagerChromeOS::RegisterPrefs(
    PrefRegistrySimple* registry) {
  registry->RegisterStringPref(prefs::kDeviceEnrollmentRequisition,
                               std::string());
  registry->RegisterBooleanPref(prefs::kDeviceEnrollmentAutoStart, false);
  registry->RegisterBooleanPref(prefs::kDeviceEnrollmentCanExit, true);
  registry->RegisterDictionaryPref(prefs::kServerBackedDeviceState);
}

// static
std::string DeviceCloudPolicyManagerChromeOS::GetMachineID() {
  std::string machine_id;
  chromeos::system::StatisticsProvider* provider =
      chromeos::system::StatisticsProvider::GetInstance();
  for (size_t i = 0; i < arraysize(kMachineInfoSerialNumberKeys); i++) {
    if (provider->GetMachineStatistic(kMachineInfoSerialNumberKeys[i],
                                      &machine_id) &&
        !machine_id.empty()) {
      break;
    }
  }

  if (machine_id.empty())
    LOG(WARNING) << "Failed to get machine id.";

  return machine_id;
}

// static
std::string DeviceCloudPolicyManagerChromeOS::GetMachineModel() {
  return GetMachineStatistic(chromeos::system::kHardwareClassKey);
}

// static
std::string DeviceCloudPolicyManagerChromeOS::GetCurrentDeviceStateKey() {
  std::vector<std::string> state_keys;
  if (GetDeviceStateKeys(base::Time::Now(), &state_keys) &&
      !state_keys.empty()) {
    // The key for the current time is always the first one.
    return state_keys[0];
  }

  return std::string();
}

scoped_ptr<CloudPolicyClient> DeviceCloudPolicyManagerChromeOS::CreateClient() {
  scoped_refptr<net::URLRequestContextGetter> request_context =
      new SystemPolicyRequestContext(
          g_browser_process->system_request_context(), GetUserAgent());

  scoped_ptr<CloudPolicyClient> client(
      new CloudPolicyClient(GetMachineID(), GetMachineModel(),
                            kPolicyVerificationKeyHash,
                            USER_AFFILIATION_NONE,
                            device_status_provider_.get(),
                            device_management_service_,
                            request_context));

  // Set state keys to upload immediately after creation so the first policy
  // fetch submits them to the server.
  if (chromeos::AutoEnrollmentController::GetMode() ==
      chromeos::AutoEnrollmentController::MODE_FORCED_RE_ENROLLMENT) {
    std::vector<std::string> state_keys;
    if (GetDeviceStateKeys(base::Time::Now(), &state_keys))
      client->SetStateKeysToUpload(state_keys);
  }

  return client.Pass();
}

void DeviceCloudPolicyManagerChromeOS::EnrollmentCompleted(
    const EnrollmentCallback& callback,
    EnrollmentStatus status) {
  if (status.status() == EnrollmentStatus::STATUS_SUCCESS)
    StartConnection(enrollment_handler_->ReleaseClient());
  else
    StartIfManaged();

  enrollment_handler_.reset();
  if (!callback.is_null())
    callback.Run(status);
}

void DeviceCloudPolicyManagerChromeOS::StartIfManaged() {
  if (device_management_service_ &&
      local_state_ &&
      store()->is_initialized() &&
      store()->has_policy() &&
      !service()) {
    StartConnection(CreateClient());
  }
}

void DeviceCloudPolicyManagerChromeOS::StartConnection(
    scoped_ptr<CloudPolicyClient> client_to_connect) {
  core()->Connect(client_to_connect.Pass());
  core()->StartRefreshScheduler();
  core()->TrackRefreshDelayPref(local_state_,
                                prefs::kDevicePolicyRefreshRate);
  attestation_policy_observer_.reset(
      new chromeos::attestation::AttestationPolicyObserver(client()));
}

void DeviceCloudPolicyManagerChromeOS::InitalizeRequisition() {
  // OEM statistics are only loaded when OOBE is not completed.
  if (chromeos::StartupUtils::IsOobeCompleted())
    return;

  const PrefService::Preference* pref = local_state_->FindPreference(
      prefs::kDeviceEnrollmentRequisition);
  if (pref->IsDefaultValue()) {
    std::string requisition =
        GetMachineStatistic(chromeos::system::kOemDeviceRequisitionKey);

    if (!requisition.empty()) {
      local_state_->SetString(prefs::kDeviceEnrollmentRequisition,
                              requisition);
      if (requisition == kRemoraRequisition) {
        local_state_->SetBoolean(prefs::kDeviceEnrollmentAutoStart, true);
        local_state_->SetBoolean(prefs::kDeviceEnrollmentCanExit, false);
      } else {
        local_state_->SetBoolean(
            prefs::kDeviceEnrollmentAutoStart,
            GetMachineFlag(chromeos::system::kOemIsEnterpriseManagedKey,
                           false));
        local_state_->SetBoolean(
            prefs::kDeviceEnrollmentCanExit,
            GetMachineFlag(chromeos::system::kOemCanExitEnterpriseEnrollmentKey,
                           false));
      }
    }
  }
}

std::string DeviceCloudPolicyManagerChromeOS::GetRestoreMode() const {
  const base::DictionaryValue* device_state_dict =
      local_state_->GetDictionary(prefs::kServerBackedDeviceState);
  std::string restore_mode;
  device_state_dict->GetString(kDeviceStateRestoreMode, &restore_mode);
  return restore_mode;
}

// static
bool DeviceCloudPolicyManagerChromeOS::GetDeviceStateKeys(
    const base::Time& timestamp,
    std::vector<std::string>* state_keys) {
  state_keys->clear();

  std::string disk_serial_number =
      GetMachineStatistic(chromeos::system::kDiskSerialNumber);
  if (disk_serial_number.empty()) {
    LOG(ERROR) << "Missing disk serial number";
    return false;
  }

  std::string machine_id = GetMachineID();
  if (machine_id.empty())
    return false;

  // Tolerate missing group code keys, some old devices may not have it.
  std::string group_code_key =
      GetMachineStatistic(chromeos::system::kOffersGroupCodeKey);

  // Get the current time in quantized form.
  int64 quantum_size = GG_INT64_C(1) << kDeviceStateKeyTimeQuantumPower;
  int64 quantized_time =
      (timestamp - base::Time::UnixEpoch()).InSeconds() & ~(quantum_size - 1);
  for (int i = 0; i < kDeviceStateKeyFutureQuanta; ++i) {
    state_keys->push_back(crypto::SHA256HashString(
        crypto::SHA256HashString(group_code_key) +
        crypto::SHA256HashString(disk_serial_number) +
        crypto::SHA256HashString(machine_id) +
        crypto::SHA256HashString(base::Int64ToString(quantized_time))));
    quantized_time += quantum_size;
  }

  return true;
}

}  // namespace policy

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