// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/40285824): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif

#include "chromeos/ash/components/install_attributes/install_attributes.h"

#include <stddef.h>

#include <utility>

#include "base/files/file_util.h"
#include "base/functional/bind.h"
#include "base/functional/callback_helpers.h"
#include "base/location.h"
#include "base/logging.h"
#include "base/metrics/histogram_base.h"
#include "base/metrics/histogram_macros.h"
#include "base/notreached.h"
#include "base/path_service.h"
#include "base/system/sys_info.h"
#include "base/task/single_thread_task_runner.h"
#include "base/time/time.h"
#include "chromeos/ash/components/dbus/cryptohome/rpc.pb.h"
#include "chromeos/ash/components/dbus/device_management/device_management_interface.pb.h"
#include "chromeos/ash/components/dbus/device_management/install_attributes_util.h"
#include "chromeos/dbus/constants/dbus_paths.h"
#include "chromeos/dbus/tpm_manager/tpm_manager.pb.h"
#include "chromeos/dbus/tpm_manager/tpm_manager_client.h"
#include "components/policy/proto/install_attributes.pb.h"
#include "google_apis/gaia/gaia_auth_util.h"
#include "third_party/cros_system_api/dbus/service_constants.h"

namespace ash {

namespace {

InstallAttributes* g_install_attributes = nullptr;

// Calling SetForTesting sets this flag. This flag means that the production
// code which calls Initialize and Shutdown will have no effect - the test
// install attributes will remain in place until ShutdownForTesting is called.
bool g_using_install_attributes_for_testing = false;

// Number of TPM lock state query retries during consistency check.
const int kDbusRetryCount = 12;

// Interval of TPM lock state query retries during consistency check.
constexpr base::TimeDelta kDbusRetryInterval = base::Seconds(5);

std::string ReadMapKey(const std::map<std::string, std::string>& map,
                       const std::string& key) {
  std::map<std::string, std::string>::const_iterator entry = map.find(key);
  if (entry != map.end()) {
    return entry->second;
  }
  return std::string();
}

void WarnIfNonempty(const std::map<std::string, std::string>& map,
                    const std::string& key) {
  if (!ReadMapKey(map, key).empty()) {
    LOG(WARNING) << key << " expected to be empty.";
  }
}

}  // namespace

// static
void InstallAttributes::Initialize() {
  // Don't reinitialize if a specific instance has already been set for test.
  if (g_using_install_attributes_for_testing)
    return;

  DCHECK(!g_install_attributes);
  g_install_attributes = new InstallAttributes(InstallAttributesClient::Get());
  g_install_attributes->Init(base::PathService::CheckedGet(
      chromeos::dbus_paths::FILE_INSTALL_ATTRIBUTES));
}

// static
bool InstallAttributes::IsInitialized() {
  return g_install_attributes;
}

// static
void InstallAttributes::Shutdown() {
  if (g_using_install_attributes_for_testing)
    return;

  DCHECK(g_install_attributes);
  delete g_install_attributes;
  g_install_attributes = nullptr;
}

// static
InstallAttributes* InstallAttributes::Get() {
  DCHECK(g_install_attributes);
  return g_install_attributes;
}

// static
void InstallAttributes::SetForTesting(InstallAttributes* test_instance) {
  DCHECK(!g_install_attributes);
  DCHECK(!g_using_install_attributes_for_testing);
  g_install_attributes = test_instance;
  g_using_install_attributes_for_testing = true;
}

// static
void InstallAttributes::ShutdownForTesting() {
  DCHECK(g_using_install_attributes_for_testing);
  // Don't delete the test instance, we are not the owner.
  g_install_attributes = nullptr;
  g_using_install_attributes_for_testing = false;
}

InstallAttributes::InstallAttributes(
    InstallAttributesClient* userdataauth_client)
    : install_attributes_client_(userdataauth_client) {}

InstallAttributes::~InstallAttributes() = default;

void InstallAttributes::Init(const base::FilePath& cache_file) {
  DCHECK(!device_locked_);

  // Mark the consistency check as running to ensure that LockDevice() is
  // blocked, but wait for the cryptohome service to be available before
  // actually calling TriggerConsistencyCheck().
  consistency_check_running_ = true;
  install_attributes_client_->WaitForServiceToBeAvailable(
      base::BindOnce(&InstallAttributes::OnCryptohomeServiceInitiallyAvailable,
                     weak_ptr_factory_.GetWeakPtr()));

  if (!base::PathExists(cache_file)) {
    LOG_IF(WARNING, base::SysInfo::IsRunningOnChromeOS())
        << "Install attributes missing, first sign in";
    return;
  }

  device_locked_ = true;

  char buf[16384];
  int len = base::ReadFile(cache_file, buf, sizeof(buf));
  if (len == -1 || len >= static_cast<int>(sizeof(buf))) {
    PLOG(ERROR) << "Failed to read " << cache_file.value();
    return;
  }

  cryptohome::SerializedInstallAttributes install_attrs_proto;
  if (!install_attrs_proto.ParseFromArray(buf, len)) {
    LOG(ERROR) << "Failed to parse install attributes cache.";
    return;
  }

  std::map<std::string, std::string> attr_map;
  for (const auto& entry : install_attrs_proto.attributes()) {
    // The protobuf values contain terminating null characters, so we have to
    // sanitize the value here.
    attr_map.emplace(entry.name(), std::string(entry.value().c_str()));
  }

  DecodeInstallAttributes(attr_map);
}

void InstallAttributes::ReadImmutableAttributes(base::OnceClosure callback) {
  if (device_locked_) {
    std::move(callback).Run();
    return;
  }

  // Get Install Attributes Status to know if it's ready.
  install_attributes_client_->InstallAttributesGetStatus(
      device_management::InstallAttributesGetStatusRequest(),
      base::BindOnce(&InstallAttributes::ReadAttributesIfReady,
                     weak_ptr_factory_.GetWeakPtr(), std::move(callback)));
}

void InstallAttributes::ReadAttributesIfReady(
    base::OnceClosure callback,
    std::optional<device_management::InstallAttributesGetStatusReply> reply) {
  base::ScopedClosureRunner callback_runner(std::move(callback));

  // Can't proceed if the call failed.
  if (!reply.has_value()) {
    return;
  }

  // Can't proceed if not ready.
  if (reply->state() == ::device_management::InstallAttributesState::UNKNOWN ||
      reply->state() ==
          ::device_management::InstallAttributesState::TPM_NOT_OWNED) {
    return;
  }

  registration_mode_ = policy::DEVICE_MODE_NOT_SET;
  // TODO(b/183608597): Migrate this to check reply->state() to avoid the
  // blocking calls below.
  if (!install_attributes_util::InstallAttributesIsInvalid() &&
      !install_attributes_util::InstallAttributesIsFirstInstall()) {
    device_locked_ = true;

    static const char* const kEnterpriseAttributes[] = {
        kAttrEnterpriseDeviceId, kAttrEnterpriseDomain, kAttrEnterpriseRealm,
        kAttrEnterpriseMode,     kAttrEnterpriseOwned,
    };
    std::map<std::string, std::string> attr_map;
    for (size_t i = 0; i < std::size(kEnterpriseAttributes); ++i) {
      std::string value;
      if (install_attributes_util::InstallAttributesGet(
              kEnterpriseAttributes[i], &value))
        attr_map[kEnterpriseAttributes[i]] = value;
    }

    DecodeInstallAttributes(attr_map);
  }
}

void InstallAttributes::SetBlockDevmodeInTpm(
    bool block_devmode,
    chromeos::DBusMethodCallback<
        device_management::SetFirmwareManagementParametersReply> callback) {
  DCHECK(!callback.is_null());
  DCHECK(!device_locked_);

  device_management::SetFirmwareManagementParametersRequest request;
  // Set the flags, according to enum FirmwareManagementParametersFlags from
  // rpc.proto if devmode is blocked.
  if (block_devmode) {
    request.mutable_fwmp()->set_flags(
        cryptohome::DEVELOPER_DISABLE_BOOT |
        cryptohome::DEVELOPER_DISABLE_CASE_CLOSED_DEBUGGING_UNLOCK);
  }

  install_attributes_client_->SetFirmwareManagementParameters(
      request, std::move(callback));
}

void InstallAttributes::LockDevice(policy::DeviceMode device_mode,
                                   const std::string& domain,
                                   const std::string& realm,
                                   const std::string& device_id,
                                   LockResultCallback callback) {
  CHECK((device_mode == policy::DEVICE_MODE_ENTERPRISE && !domain.empty() &&
         realm.empty() && !device_id.empty()) ||
        (device_mode == policy::DEVICE_MODE_DEMO && !domain.empty() &&
         realm.empty() && !device_id.empty()));
  DCHECK(callback);
  CHECK_EQ(device_lock_running_, false);

  // Check for existing lock first.
  if (device_locked_) {
    if (device_mode != registration_mode_) {
      LOG(ERROR) << "Trying to re-lock with wrong mode: device_mode: "
                 << device_mode
                 << ", registration_mode: " << registration_mode_;
      std::move(callback).Run(LOCK_WRONG_MODE);
      return;
    }

    if (domain != registration_domain_ || realm != registration_realm_ ||
        device_id != registration_device_id_) {
      LOG(ERROR) << "Trying to re-lock with non-matching parameters.";
      std::move(callback).Run(LOCK_WRONG_DOMAIN);
      return;
    }

    // Already locked in the right mode, signal success.
    std::move(callback).Run(LOCK_SUCCESS);
    return;
  }

  // In case the consistency check is still running, postpone the device locking
  // until it has finished.  This should not introduce additional delay since
  // device locking must wait for TPM initialization anyways.
  if (consistency_check_running_) {
    CHECK(post_check_action_.is_null());
    post_check_action_ = base::BindOnce(
        &InstallAttributes::LockDevice, weak_ptr_factory_.GetWeakPtr(),
        device_mode, domain, realm, device_id, std::move(callback));
    return;
  }

  device_lock_running_ = true;
  // Get Install Attributes Status to know if it's ready.
  install_attributes_client_->InstallAttributesGetStatus(
      device_management::InstallAttributesGetStatusRequest(),
      base::BindOnce(&InstallAttributes::LockDeviceIfAttributesIsReady,
                     weak_ptr_factory_.GetWeakPtr(), device_mode, domain, realm,
                     device_id, std::move(callback)));
}

void InstallAttributes::LockDeviceIfAttributesIsReady(
    policy::DeviceMode device_mode,
    const std::string& domain,
    const std::string& realm,
    const std::string& device_id,
    LockResultCallback callback,
    std::optional<device_management::InstallAttributesGetStatusReply> reply) {
  if (!reply.has_value() ||
      reply->state() == ::device_management::InstallAttributesState::UNKNOWN ||
      reply->state() ==
          ::device_management::InstallAttributesState::TPM_NOT_OWNED) {
    device_lock_running_ = false;
    std::move(callback).Run(LOCK_NOT_READY);
    return;
  }

  // Clearing the TPM password seems to be always a good deal. At this point
  // install attributes is ready, which implies TPM readiness as well.
  chromeos::TpmManagerClient::Get()->ClearStoredOwnerPassword(
      ::tpm_manager::ClearStoredOwnerPasswordRequest(),
      base::BindOnce(&InstallAttributes::OnClearStoredOwnerPassword,
                     weak_ptr_factory_.GetWeakPtr()));

  // Make sure we really have a working InstallAttrs.
  if (install_attributes_util::InstallAttributesIsInvalid()) {
    LOG(ERROR) << "Install attributes invalid.";
    device_lock_running_ = false;
    std::move(callback).Run(LOCK_BACKEND_INVALID);
    return;
  }

  if (!install_attributes_util::InstallAttributesIsFirstInstall()) {
    LOG(ERROR) << "Install attributes already installed.";
    device_lock_running_ = false;
    std::move(callback).Run(LOCK_ALREADY_LOCKED);
    return;
  }

  // Set values in the InstallAttrs.
  std::string mode = GetDeviceModeString(device_mode);
  if (!install_attributes_util::InstallAttributesSet(kAttrEnterpriseOwned,
                                                     "true") ||
      !install_attributes_util::InstallAttributesSet(kAttrEnterpriseMode,
                                                     mode) ||
      !install_attributes_util::InstallAttributesSet(kAttrEnterpriseDomain,
                                                     domain) ||
      !install_attributes_util::InstallAttributesSet(kAttrEnterpriseRealm,
                                                     realm) ||
      !install_attributes_util::InstallAttributesSet(kAttrEnterpriseDeviceId,
                                                     device_id)) {
    LOG(ERROR) << "Failed writing attributes.";
    device_lock_running_ = false;
    std::move(callback).Run(LOCK_SET_ERROR);
    return;
  }

  if (!install_attributes_util::InstallAttributesFinalize() ||
      install_attributes_util::InstallAttributesIsFirstInstall()) {
    LOG(ERROR) << "Failed locking.";
    device_lock_running_ = false;
    std::move(callback).Run(LOCK_FINALIZE_ERROR);
    return;
  }

  ReadImmutableAttributes(
      base::BindOnce(&InstallAttributes::OnReadImmutableAttributes,
                     weak_ptr_factory_.GetWeakPtr(), device_mode, domain, realm,
                     device_id, std::move(callback)));
}

void InstallAttributes::OnReadImmutableAttributes(policy::DeviceMode mode,
                                                  const std::string& domain,
                                                  const std::string& realm,
                                                  const std::string& device_id,
                                                  LockResultCallback callback) {
  device_lock_running_ = false;

  if (registration_mode_ != mode || registration_domain_ != domain ||
      registration_realm_ != realm || registration_device_id_ != device_id) {
    LOG(ERROR) << "Locked data doesn't match.";
    std::move(callback).Run(LOCK_READBACK_ERROR);
    return;
  }

  std::move(callback).Run(LOCK_SUCCESS);
}

bool InstallAttributes::IsEnterpriseManaged() const {
  if (!device_locked_) {
    return false;
  }
  return registration_mode_ == policy::DEVICE_MODE_ENTERPRISE ||
         registration_mode_ == policy::DEVICE_MODE_DEMO;
}

bool InstallAttributes::IsCloudManaged() const {
  if (!device_locked_) {
    return false;
  }
  return registration_mode_ == policy::DEVICE_MODE_ENTERPRISE ||
         registration_mode_ == policy::DEVICE_MODE_DEMO;
}

bool InstallAttributes::IsDeviceInDemoMode() const {
  bool is_demo_device_mode =
      registration_mode_ == policy::DeviceMode::DEVICE_MODE_DEMO;
  bool is_demo_device_domain = registration_domain_ == policy::kDemoModeDomain;

  // We check device mode and domain to allow for dev/test
  // setup that is done by manual enrollment into demo domain. Device mode is
  // not set to DeviceMode::DEVICE_MODE_DEMO then.
  return is_demo_device_mode || is_demo_device_domain;
}

void InstallAttributes::TriggerConsistencyCheck(int dbus_retries) {
  chromeos::TpmManagerClient::Get()->GetTpmNonsensitiveStatus(
      ::tpm_manager::GetTpmNonsensitiveStatusRequest(),
      base::BindOnce(&InstallAttributes::OnTpmStatusComplete,
                     weak_ptr_factory_.GetWeakPtr(), dbus_retries));
}

void InstallAttributes::OnTpmStatusComplete(
    int dbus_retries_remaining,
    const ::tpm_manager::GetTpmNonsensitiveStatusReply& reply) {
  if (reply.status() != ::tpm_manager::STATUS_SUCCESS &&
      dbus_retries_remaining) {
    LOG(WARNING) << "Failed to get tpm status reply; status: "
                 << reply.status();
    base::SingleThreadTaskRunner::GetCurrentDefault()->PostDelayedTask(
        FROM_HERE,
        base::BindOnce(&InstallAttributes::TriggerConsistencyCheck,
                       weak_ptr_factory_.GetWeakPtr(),
                       dbus_retries_remaining - 1),
        kDbusRetryInterval);
    return;
  }

  base::HistogramBase::Sample32 state;
  // If we get the TPM status successfully, we are interested if install
  // attributes file exists (device_locked_), if the device is enrolled
  // (registration_mode_) and if the TPM is locked, meaning the TPM password
  // is deleted so the value from result is empty.
  if (reply.status() == ::tpm_manager::STATUS_SUCCESS) {
    const bool is_cloud_managed =
        registration_mode_ == policy::DEVICE_MODE_ENTERPRISE ||
        registration_mode_ == policy::DEVICE_MODE_DEMO;
    state = (device_locked_ ? 1 : 0) | (is_cloud_managed ? 2 : 0) |
            (!reply.is_owner_password_present() ? 4 : 0);
  } else {
    LOG(WARNING) << "Failed to get TPM status after retries; status: "
                 << reply.status();
    state = 8;
  }
  UMA_HISTOGRAM_ENUMERATION("Enterprise.AttributesTPMConsistency", state, 9);

  // Run any action (LockDevice call) that might have queued behind the
  // consistency check.
  consistency_check_running_ = false;
  if (post_check_action_) {
    std::move(post_check_action_).Run();
    post_check_action_.Reset();
  }
}

void InstallAttributes::OnClearStoredOwnerPassword(
    const ::tpm_manager::ClearStoredOwnerPasswordReply& reply) {
  LOG_IF(WARNING, reply.status() != ::tpm_manager::STATUS_SUCCESS)
      << "Failed to call ClearStoredOwnerPassword; status: " << reply.status();
}

// Warning: The values for these keys (but not the keys themselves) are stored
// in the protobuf with a trailing zero.  Also note that some of these constants
// have been copied to login_manager/device_policy_service.cc.  Please make sure
// that all changes to the constants are reflected there as well.
const char InstallAttributes::kConsumerDeviceMode[] = "consumer";
const char InstallAttributes::kEnterpriseDeviceMode[] = "enterprise";
const char InstallAttributes::kLegacyRetailDeviceMode[] = "kiosk";
const char InstallAttributes::kLegacyConsumerKioskDeviceMode[] =
    "consumer_kiosk";
const char InstallAttributes::kDemoDeviceMode[] = "demo_mode";

const char InstallAttributes::kAttrEnterpriseDeviceId[] =
    "enterprise.device_id";
const char InstallAttributes::kAttrEnterpriseDomain[] = "enterprise.domain";
const char InstallAttributes::kAttrEnterpriseRealm[] = "enterprise.realm";
const char InstallAttributes::kAttrEnterpriseMode[] = "enterprise.mode";
const char InstallAttributes::kAttrEnterpriseOwned[] = "enterprise.owned";

void InstallAttributes::OnCryptohomeServiceInitiallyAvailable(
    bool service_is_ready) {
  if (!service_is_ready)
    LOG(ERROR) << "Failed waiting for cryptohome D-Bus service availability.";

  // Start the consistency check even if we failed to wait for availability;
  // hopefully the service will become available eventually.
  TriggerConsistencyCheck(kDbusRetryCount);
}

std::string InstallAttributes::GetDeviceModeString(policy::DeviceMode mode) {
  switch (mode) {
    case policy::DEVICE_MODE_CONSUMER:
      return InstallAttributes::kConsumerDeviceMode;
    case policy::DEVICE_MODE_ENTERPRISE:
      return InstallAttributes::kEnterpriseDeviceMode;
    case policy::DEPRECATED_DEVICE_MODE_LEGACY_RETAIL_MODE:
      return InstallAttributes::kLegacyRetailDeviceMode;
    case policy::DEPRECATED_DEVICE_MODE_CONSUMER_KIOSK_AUTOLAUNCH:
      return InstallAttributes::kLegacyConsumerKioskDeviceMode;
    case policy::DEVICE_MODE_DEMO:
      return InstallAttributes::kDemoDeviceMode;
    case policy::DEVICE_MODE_PENDING:
    case policy::DEVICE_MODE_NOT_SET:
      break;
  }
  NOTREACHED() << "Invalid device mode: " << mode;
}

policy::DeviceMode InstallAttributes::GetDeviceModeFromString(
    const std::string& mode) {
  if (mode == InstallAttributes::kConsumerDeviceMode)
    return policy::DEVICE_MODE_CONSUMER;
  if (mode == InstallAttributes::kEnterpriseDeviceMode)
    return policy::DEVICE_MODE_ENTERPRISE;
  if (mode == InstallAttributes::kLegacyRetailDeviceMode)
    return policy::DEPRECATED_DEVICE_MODE_LEGACY_RETAIL_MODE;
  if (mode == InstallAttributes::kLegacyConsumerKioskDeviceMode) {
    return policy::DEPRECATED_DEVICE_MODE_CONSUMER_KIOSK_AUTOLAUNCH;
  }
  if (mode == InstallAttributes::kDemoDeviceMode)
    return policy::DEVICE_MODE_DEMO;
  return policy::DEVICE_MODE_NOT_SET;
}

void InstallAttributes::DecodeInstallAttributes(
    const std::map<std::string, std::string>& attr_map) {
  // Start from a clean slate.
  registration_mode_ = policy::DEVICE_MODE_NOT_SET;
  registration_domain_.clear();
  registration_realm_.clear();
  registration_device_id_.clear();

  const std::string enterprise_owned =
      ReadMapKey(attr_map, kAttrEnterpriseOwned);
  const std::string mode = ReadMapKey(attr_map, kAttrEnterpriseMode);
  const std::string domain = ReadMapKey(attr_map, kAttrEnterpriseDomain);
  const std::string realm = ReadMapKey(attr_map, kAttrEnterpriseRealm);
  const std::string device_id = ReadMapKey(attr_map, kAttrEnterpriseDeviceId);

  if (enterprise_owned == "true") {
    registration_device_id_ = device_id;

    // Set registration_mode_.
    registration_mode_ = GetDeviceModeFromString(mode);
    if (registration_mode_ != policy::DEVICE_MODE_ENTERPRISE &&
        registration_mode_ != policy::DEVICE_MODE_DEMO) {
      if (!mode.empty()) {
        LOG(WARNING) << "Bad " << kAttrEnterpriseMode << ": " << mode;
      }
      registration_mode_ = policy::DEVICE_MODE_ENTERPRISE;
    }

    if (registration_mode_ == policy::DEVICE_MODE_ENTERPRISE ||
        registration_mode_ == policy::DEVICE_MODE_DEMO) {
      // Either set registration_domain_ ...
      WarnIfNonempty(attr_map, kAttrEnterpriseRealm);
      if (!domain.empty()) {
        // The canonicalization is for compatibility with earlier versions.
        registration_domain_ = gaia::CanonicalizeDomain(domain);
      } else {
        LOG(WARNING) << "Couldn't read domain.";
      }
    } else {
      // ... or set registration_realm_.
      WarnIfNonempty(attr_map, kAttrEnterpriseDomain);
      if (!realm.empty()) {
        registration_realm_ = realm;
      } else {
        LOG(WARNING) << "Couldn't read realm.";
      }
    }

    return;
  }

  WarnIfNonempty(attr_map, kAttrEnterpriseOwned);
  WarnIfNonempty(attr_map, kAttrEnterpriseDomain);
  WarnIfNonempty(attr_map, kAttrEnterpriseRealm);
  WarnIfNonempty(attr_map, kAttrEnterpriseDeviceId);

  registration_mode_ = policy::DEVICE_MODE_CONSUMER;
}

}  // namespace ash