// 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 "chromeos/dbus/auth_policy/fake_auth_policy_client.h"

#include <memory>
#include <vector>

#include "base/bind.h"
#include "base/location.h"
#include "base/md5.h"
#include "base/strings/string_split.h"
#include "base/task/post_task.h"
#include "base/threading/platform_thread.h"
#include "base/threading/thread_task_runner_handle.h"
#include "chromeos/dbus/cryptohome/cryptohome_client.h"
#include "chromeos/dbus/cryptohome/rpc.pb.h"
#include "chromeos/dbus/cryptohome/tpm_util.h"
#include "chromeos/dbus/dbus_thread_manager.h"
#include "chromeos/dbus/session_manager/session_manager_client.h"
#include "components/account_id/account_id.h"
#include "components/policy/proto/cloud_policy.pb.h"
#include "dbus/message.h"
#include "third_party/cros_system_api/dbus/service_constants.h"

namespace em = enterprise_management;

namespace chromeos {

namespace {

constexpr size_t kMaxMachineNameLength = 15;
constexpr char kInvalidMachineNameCharacters[] = "\\/:*?\"<>|";
constexpr char kDefaultKerberosCreds[] = "credentials";
constexpr char kDefaultKerberosConf[] = "configuration";

FakeAuthPolicyClient* g_instance = nullptr;

void OnStorePolicy(AuthPolicyClient::RefreshPolicyCallback callback,
                   bool success) {
  const authpolicy::ErrorType error =
      success ? authpolicy::ERROR_NONE : authpolicy::ERROR_STORE_POLICY_FAILED;
  std::move(callback).Run(error);
}

// Posts |closure| on the ThreadTaskRunner with |delay|.
void PostDelayedClosure(base::OnceClosure closure,
                        const base::TimeDelta& delay) {
  base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
      FROM_HERE, std::move(closure), delay);
}

// Runs |signal_callback| with Signal*. Needed to own Signal object.
void RunSignalCallback(const std::string& interface_name,
                       const std::string& method_name,
                       dbus::ObjectProxy::SignalCallback signal_callback) {
  signal_callback.Run(
      std::make_unique<dbus::Signal>(interface_name, method_name).get());
}

}  // namespace

FakeAuthPolicyClient::FakeAuthPolicyClient() {
  DCHECK(!g_instance);
  g_instance = this;
}

FakeAuthPolicyClient::~FakeAuthPolicyClient() {
  DCHECK_EQ(this, g_instance);
  g_instance = nullptr;
}

// static
FakeAuthPolicyClient* FakeAuthPolicyClient::Get() {
  return g_instance;
}

void FakeAuthPolicyClient::JoinAdDomain(
    const authpolicy::JoinDomainRequest& request,
    int password_fd,
    JoinCallback callback) {
  DCHECK(!tpm_util::IsActiveDirectoryLocked());
  authpolicy::ErrorType error = authpolicy::ERROR_NONE;
  std::string machine_domain;
  if (!started_) {
    LOG(ERROR) << "authpolicyd not started";
    error = authpolicy::ERROR_DBUS_FAILURE;
  } else if (request.machine_name().size() > kMaxMachineNameLength) {
    error = authpolicy::ERROR_MACHINE_NAME_TOO_LONG;
  } else if (request.machine_name().empty() ||
             request.machine_name().find_first_of(
                 kInvalidMachineNameCharacters) != std::string::npos) {
    error = authpolicy::ERROR_INVALID_MACHINE_NAME;
  } else if (request.kerberos_encryption_types() ==
             authpolicy::KerberosEncryptionTypes::ENC_TYPES_LEGACY) {
    // Pretend that server does not support legacy types.
    error = authpolicy::ERROR_KDC_DOES_NOT_SUPPORT_ENCRYPTION_TYPE;
  } else {
    std::vector<std::string> parts =
        base::SplitString(request.user_principal_name(), "@",
                          base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
    if (parts.size() != 2 || parts[0].empty() || parts[1].empty()) {
      error = authpolicy::ERROR_PARSE_UPN_FAILED;
    } else {
      machine_domain = parts[1];
    }
  }

  if (error == authpolicy::ERROR_NONE)
    machine_name_ = request.machine_name();
  if (error != authpolicy::ERROR_NONE)
    machine_domain.clear();
  else if (request.has_machine_domain() && !request.machine_domain().empty())
    machine_domain = request.machine_domain();
  PostDelayedClosure(base::BindOnce(std::move(callback), error, machine_domain),
                     dbus_operation_delay_);
}

void FakeAuthPolicyClient::AuthenticateUser(
    const authpolicy::AuthenticateUserRequest& request,
    int password_fd,
    AuthCallback callback) {
  DCHECK(tpm_util::IsActiveDirectoryLocked());
  authpolicy::ErrorType error = authpolicy::ERROR_NONE;
  authpolicy::ActiveDirectoryAccountInfo account_info;
  if (auth_error_ != authpolicy::ERROR_NONE) {
    error = auth_error_;
  } else if (!started_) {
    LOG(ERROR) << "authpolicyd not started";
    error = authpolicy::ERROR_DBUS_FAILURE;
  } else {
    std::vector<std::string> parts =
        base::SplitString(request.user_principal_name(), "@",
                          base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
    if (parts.size() != 2 || parts[0].empty() || parts[1].empty())
      error = authpolicy::ERROR_PARSE_UPN_FAILED;
  }

  if (error == authpolicy::ERROR_NONE) {
    if (request.account_id().empty()) {
      account_info.set_account_id(
          base::MD5String(request.user_principal_name()));
    } else {
      account_info.set_account_id(request.account_id());
    }
    SetUserKerberosFiles(kDefaultKerberosCreds, kDefaultKerberosConf);
  }
  PostDelayedClosure(base::BindOnce(std::move(callback), error, account_info),
                     dbus_operation_delay_);
}

void FakeAuthPolicyClient::GetUserStatus(
    const authpolicy::GetUserStatusRequest& request,
    GetUserStatusCallback callback) {
  authpolicy::ActiveDirectoryUserStatus user_status;
  user_status.set_password_status(password_status_);
  user_status.set_tgt_status(tgt_status_);

  authpolicy::ActiveDirectoryAccountInfo* const account_info =
      user_status.mutable_account_info();
  account_info->set_account_id(request.account_id());
  if (!display_name_.empty())
    account_info->set_display_name(display_name_);
  if (!given_name_.empty())
    account_info->set_given_name(given_name_);

  PostDelayedClosure(
      base::BindOnce(std::move(callback), authpolicy::ERROR_NONE, user_status),
      dbus_operation_delay_);
  if (!on_get_status_closure_.is_null())
    PostDelayedClosure(std::move(on_get_status_closure_),
                       dbus_operation_delay_);
}

void FakeAuthPolicyClient::GetUserKerberosFiles(
    const std::string& object_guid,
    GetUserKerberosFilesCallback callback) {
  authpolicy::KerberosFiles files;
  files.set_krb5cc(user_kerberos_creds());
  files.set_krb5conf(user_kerberos_conf());
  PostDelayedClosure(
      base::BindOnce(std::move(callback), authpolicy::ERROR_NONE, files),
      dbus_operation_delay_);
}

void FakeAuthPolicyClient::RefreshDevicePolicy(RefreshPolicyCallback callback) {
  if (!started_) {
    LOG(ERROR) << "authpolicyd not started";
    std::move(callback).Run(authpolicy::ERROR_DBUS_FAILURE);
    return;
  }

  if (!tpm_util::IsActiveDirectoryLocked()) {
    // Pretend that policy was fetched and cached inside authpolicyd.
    std::move(callback).Run(
        authpolicy::ERROR_DEVICE_POLICY_CACHED_BUT_NOT_SENT);
    return;
  }

  SessionManagerClient* session_manager_client =
      DBusThreadManager::Get()->GetSessionManagerClient();

  // On first refresh, we need to restore |machine_name| and |dm_token| from
  // the stored policy.
  if (machine_name_.empty() || dm_token_.empty()) {
    session_manager_client->RetrieveDevicePolicy(
        base::BindOnce(&FakeAuthPolicyClient::OnDevicePolicyRetrieved,
                       weak_factory_.GetWeakPtr(), std::move(callback)));
    return;
  }

  StoreDevicePolicy(std::move(callback));
}

void FakeAuthPolicyClient::RefreshUserPolicy(const AccountId& account_id,
                                             RefreshPolicyCallback callback) {
  DCHECK(tpm_util::IsActiveDirectoryLocked());
  if (!started_) {
    LOG(ERROR) << "authpolicyd not started";
    std::move(callback).Run(authpolicy::ERROR_DBUS_FAILURE);
    return;
  }

  SessionManagerClient* session_manager_client =
      DBusThreadManager::Get()->GetSessionManagerClient();

  em::CloudPolicySettings policy;
  std::string payload;
  CHECK(policy.SerializeToString(&payload));

  em::PolicyData policy_data;
  policy_data.set_policy_type("google/chromeos/user");
  policy_data.set_username(account_id.GetUserEmail());
  policy_data.set_device_id(account_id.GetObjGuid());
  policy_data.set_timestamp(base::Time::Now().ToJavaTime());
  policy_data.set_policy_value(payload);
  for (const auto& id : user_affiliation_ids_)
    policy_data.add_user_affiliation_ids(id);

  em::PolicyFetchResponse response;
  response.set_policy_data(policy_data.SerializeAsString());

  cryptohome::AccountIdentifier account_identifier;
  account_identifier.set_account_id(account_id.GetAccountIdKey());
  session_manager_client->StorePolicyForUser(
      account_identifier, response.SerializeAsString(),
      base::BindOnce(&OnStorePolicy, std::move(callback)));
}

void FakeAuthPolicyClient::ConnectToSignal(
    const std::string& signal_name,
    dbus::ObjectProxy::SignalCallback signal_callback,
    dbus::ObjectProxy::OnConnectedCallback on_connected_callback) {
  DCHECK_EQ(authpolicy::kUserKerberosFilesChangedSignal, signal_name);
  DCHECK(!user_kerberos_files_changed_callback_);
  user_kerberos_files_changed_callback_ = signal_callback;
  std::move(on_connected_callback)
      .Run(authpolicy::kAuthPolicyInterface, signal_name, true /* success */);
}

void FakeAuthPolicyClient::WaitForServiceToBeAvailable(
    dbus::ObjectProxy::WaitForServiceToBeAvailableCallback callback) {
  if (started_) {
    base::ThreadTaskRunnerHandle::Get()->PostTask(
        FROM_HERE,
        base::BindOnce(std::move(callback), true /* service_is_available */));
    return;
  }
  wait_for_service_to_be_available_callbacks_.push_back(std::move(callback));
}

void FakeAuthPolicyClient::SetUserKerberosFiles(const std::string& creds,
                                                const std::string& conf) {
  const bool run_signal =
      user_kerberos_files_changed_callback_ &&
      (creds != user_kerberos_creds_ || conf != user_kerberos_conf_);
  user_kerberos_creds_ = creds;
  user_kerberos_conf_ = conf;
  if (run_signal) {
    PostDelayedClosure(
        base::BindOnce(RunSignalCallback, authpolicy::kAuthPolicyInterface,
                       authpolicy::kUserKerberosFilesChangedSignal,
                       user_kerberos_files_changed_callback_),
        dbus_operation_delay_);
  }
}

void FakeAuthPolicyClient::SetStarted(bool started) {
  started_ = started;
  if (started_) {
    std::vector<WaitForServiceToBeAvailableCallback> callbacks;
    callbacks.swap(wait_for_service_to_be_available_callbacks_);
    for (size_t i = 0; i < callbacks.size(); ++i)
      std::move(callbacks[i]).Run(true /* service_is_available*/);
  }
}

void FakeAuthPolicyClient::OnDevicePolicyRetrieved(
    RefreshPolicyCallback callback,
    SessionManagerClient::RetrievePolicyResponseType response_type,
    const std::string& protobuf) {
  if (response_type !=
      SessionManagerClient::RetrievePolicyResponseType::SUCCESS) {
    std::move(callback).Run(authpolicy::ERROR_DBUS_FAILURE);
    return;
  }

  em::PolicyFetchResponse response;
  response.ParseFromString(protobuf);

  em::PolicyData policy_data;
  policy_data.ParseFromString(response.policy_data());

  if (policy_data.has_device_id())
    machine_name_ = policy_data.device_id();
  if (policy_data.has_request_token())
    dm_token_ = policy_data.request_token();

  StoreDevicePolicy(std::move(callback));
}

void FakeAuthPolicyClient::StoreDevicePolicy(RefreshPolicyCallback callback) {
  std::string payload;
  CHECK(device_policy_.SerializeToString(&payload));

  em::PolicyData policy_data;
  policy_data.set_policy_type("google/chromeos/device");
  policy_data.set_device_id(machine_name_);
  policy_data.set_request_token(dm_token_);
  policy_data.set_policy_value(payload);
  policy_data.set_timestamp(base::Time::Now().ToJavaTime());
  for (const auto& id : device_affiliation_ids_)
    policy_data.add_device_affiliation_ids(id);

  em::PolicyFetchResponse response;
  response.set_policy_data(policy_data.SerializeAsString());

  SessionManagerClient* session_manager_client =
      DBusThreadManager::Get()->GetSessionManagerClient();
  session_manager_client->StoreDevicePolicy(
      response.SerializeAsString(),
      base::BindOnce(&OnStorePolicy, std::move(callback)));
}

}  // namespace chromeos