chrome/browser/component_updater/widevine_cdm_component_installer.cc

// Copyright (c) 2013 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/component_updater/widevine_cdm_component_installer.h"

#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include <memory>
#include <string>
#include <utility>
#include <vector>

#include "base/base_paths.h"
#include "base/bind.h"
#include "base/files/file_path.h"
#include "base/files/file_util.h"
#include "base/logging.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/native_library.h"
#include "base/strings/string16.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_split.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "base/task_scheduler/post_task.h"
#include "base/values.h"
#include "build/build_config.h"
#include "components/component_updater/component_installer.h"
#include "components/component_updater/component_updater_service.h"
#include "components/version_info/version_info.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/cdm_registry.h"
#include "content/public/common/cdm_info.h"
#include "crypto/sha2.h"
#include "media/base/video_codecs.h"
#include "media/cdm/supported_cdm_versions.h"
#include "third_party/widevine/cdm/widevine_cdm_common.h"

#include "widevine_cdm_version.h"  // In SHARED_INTERMEDIATE_DIR. NOLINT

using content::BrowserThread;
using content::CdmRegistry;

namespace component_updater {

#if defined(WIDEVINE_CDM_AVAILABLE) && defined(WIDEVINE_CDM_IS_COMPONENT)

namespace {

// CRX hash. The extension id is: oimompecagnajdejgnnjijobebaeigek.
const uint8_t kWidevineSha2Hash[] = {
    0xe8, 0xce, 0xcf, 0x42, 0x06, 0xd0, 0x93, 0x49, 0x6d, 0xd9, 0x89,
    0xe1, 0x41, 0x04, 0x86, 0x4a, 0x8f, 0xbd, 0x86, 0x12, 0xb9, 0x58,
    0x9b, 0xfb, 0x4f, 0xbb, 0x1b, 0xa9, 0xd3, 0x85, 0x37, 0xef};
static_assert(arraysize(kWidevineSha2Hash) == crypto::kSHA256Length,
              "Wrong hash length");

// Name of the Widevine CDM OS in the component manifest.
const char kWidevineCdmPlatform[] =
#if defined(OS_MACOSX)
    "mac";
#elif defined(OS_WIN)
    "win";
#else  // OS_LINUX, etc. TODO(viettrungluu): Separate out Chrome OS and Android?
    "linux";
#endif

// Name of the Widevine CDM architecture in the component manifest.
const char kWidevineCdmArch[] =
#if defined(ARCH_CPU_X86)
    "x86";
#elif defined(ARCH_CPU_X86_64)
    "x64";
#else  // TODO(viettrungluu): Support an ARM check?
    "???";
#endif

// The CDM manifest includes several custom values, all beginning with "x-cdm-".
// All values are strings.
// All values that are lists are delimited by commas. No trailing commas.
// For example, "1,2,4".
const char kCdmValueDelimiter[] = ",";

// The following entries are required.
//  Interface versions are lists of integers (e.g. "1" or "1,2,4").
//  These are checked in this file before registering the CDM.
//  All match the interface versions from content_decryption_module.h that the
//  CDM supports.
//    Matches CDM_MODULE_VERSION.
const char kCdmModuleVersionsName[] = "x-cdm-module-versions";
//    Matches supported ContentDecryptionModule_* version(s).
const char kCdmInterfaceVersionsName[] = "x-cdm-interface-versions";
//    Matches supported Host_* version(s).
const char kCdmHostVersionsName[] = "x-cdm-host-versions";
//  The codecs list is a list of simple codec names (e.g. "vp8,vorbis").
const char kCdmCodecsListName[] = "x-cdm-codecs";
//  Whether persistent license is supported by the CDM: "true" or "false".
const char kCdmPersistentLicenseSupportName[] =
    "x-cdm-persistent-license-support";

// The following strings are used to specify supported codecs in the
// parameter |kCdmCodecsListName|.
const char kCdmSupportedCodecVp8[] = "vp8";
const char kCdmSupportedCodecVp9[] = "vp9.0";
#if BUILDFLAG(USE_PROPRIETARY_CODECS)
const char kCdmSupportedCodecAvc1[] = "avc1";
#endif

// Widevine CDM is packaged as a multi-CRX. Widevine CDM binaries are located in
// _platform_specific/<platform_arch> folder in the package. This function
// returns the platform-specific subdirectory that is part of that multi-CRX.
base::FilePath GetPlatformDirectory(const base::FilePath& base_path) {
  std::string platform_arch = kWidevineCdmPlatform;
  platform_arch += '_';
  platform_arch += kWidevineCdmArch;
  return base_path.AppendASCII("_platform_specific").AppendASCII(platform_arch);
}

typedef bool (*VersionCheckFunc)(int version);

bool CheckForCompatibleVersion(const base::DictionaryValue& manifest,
                               const std::string version_name,
                               VersionCheckFunc version_check_func) {
  std::string versions_string;
  if (!manifest.GetString(version_name, &versions_string)) {
    DVLOG(1) << "Widevine CDM component manifest missing " << version_name;
    return false;
  }
  DVLOG_IF(1, versions_string.empty())
      << "Widevine CDM component manifest has empty " << version_name;

  for (const base::StringPiece& ver_str :
       base::SplitStringPiece(versions_string, kCdmValueDelimiter,
                              base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL)) {
    int version = 0;
    if (base::StringToInt(ver_str, &version))
      if (version_check_func(version))
        return true;
  }

  DVLOG(1) << "Widevine CDM component manifest has no supported "
           << version_name << " in '" << versions_string << "'";
  return false;
}

// Returns whether the CDM's API versions, as specified in the manifest, are
// compatible with this Chrome binary.
// Checks the module API, CDM interface API, and Host API.
// This should never fail except in rare cases where the component has not been
// updated recently or the user downgrades Chrome.
bool IsCompatibleWithChrome(const base::DictionaryValue& manifest) {
  return CheckForCompatibleVersion(manifest,
                                   kCdmModuleVersionsName,
                                   media::IsSupportedCdmModuleVersion) &&
         CheckForCompatibleVersion(manifest,
                                   kCdmInterfaceVersionsName,
                                   media::IsSupportedCdmInterfaceVersion) &&
         CheckForCompatibleVersion(manifest,
                                   kCdmHostVersionsName,
                                   media::IsSupportedCdmHostVersion);
}

std::string GetCodecs(const base::DictionaryValue& manifest) {
  std::string codecs;
  if (manifest.GetStringASCII(kCdmCodecsListName, &codecs)) {
    DVLOG_IF(1, codecs.empty())
        << "Widevine CDM component manifest has empty codecs list";
  } else {
    DVLOG(1) << "Widevine CDM component manifest is missing codecs";
  }
  return codecs;
}

std::vector<media::VideoCodec> ConvertCodecsString(const std::string& codecs) {
  std::vector<media::VideoCodec> supported_video_codecs;
  const std::vector<base::StringPiece> supported_codecs =
      base::SplitStringPiece(codecs, kCdmValueDelimiter, base::TRIM_WHITESPACE,
                             base::SPLIT_WANT_NONEMPTY);

  for (const auto& codec : supported_codecs) {
    if (codec == kCdmSupportedCodecVp8)
      supported_video_codecs.push_back(media::VideoCodec::kCodecVP8);
    else if (codec == kCdmSupportedCodecVp9)
      supported_video_codecs.push_back(media::VideoCodec::kCodecVP9);
#if BUILDFLAG(USE_PROPRIETARY_CODECS)
    else if (codec == kCdmSupportedCodecAvc1)
      supported_video_codecs.push_back(media::VideoCodec::kCodecH264);
#endif  // BUILDFLAG(USE_PROPRIETARY_CODECS)
  }

  return supported_video_codecs;
}

bool GetPersistentLicenseSupport(const base::DictionaryValue& manifest) {
  std::string supported;
  const base::Value* value = manifest.FindKey(kCdmPersistentLicenseSupportName);
  return value && value->is_bool() && value->GetBool();
}

void RegisterWidevineCdmWithChrome(
    const base::Version& cdm_version,
    const base::FilePath& cdm_install_dir,
    std::unique_ptr<base::DictionaryValue> manifest) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
  const std::string codecs = GetCodecs(*manifest);
  bool supports_persistent_license = GetPersistentLicenseSupport(*manifest);

  VLOG(1) << "Register Widevine CDM with Chrome";

  const base::FilePath cdm_path =
      GetPlatformDirectory(cdm_install_dir)
          .AppendASCII(base::GetNativeLibraryName(kWidevineCdmLibraryName));
  std::vector<media::VideoCodec> supported_video_codecs =
      ConvertCodecsString(codecs);

  CdmRegistry::GetInstance()->RegisterCdm(content::CdmInfo(
      kWidevineCdmDisplayName, kWidevineCdmGuid, cdm_version, cdm_path,
      kWidevineCdmFileSystemId, supported_video_codecs,
      supports_persistent_license, kWidevineKeySystem, false));
}

}  // namespace

class WidevineCdmComponentInstallerPolicy : public ComponentInstallerPolicy {
 public:
  WidevineCdmComponentInstallerPolicy();
  ~WidevineCdmComponentInstallerPolicy() override {}

 private:
  // The following methods override ComponentInstallerPolicy.
  bool SupportsGroupPolicyEnabledComponentUpdates() const override;
  bool RequiresNetworkEncryption() const override;
  update_client::CrxInstaller::Result OnCustomInstall(
      const base::DictionaryValue& manifest,
      const base::FilePath& install_dir) override;
  void OnCustomUninstall() override;
  bool VerifyInstallation(
      const base::DictionaryValue& manifest,
      const base::FilePath& install_dir) const override;
  void ComponentReady(const base::Version& version,
                      const base::FilePath& path,
                      std::unique_ptr<base::DictionaryValue> manifest) override;
  base::FilePath GetRelativeInstallDir() const override;
  void GetHash(std::vector<uint8_t>* hash) const override;
  std::string GetName() const override;
  update_client::InstallerAttributes GetInstallerAttributes() const override;
  std::vector<std::string> GetMimeTypes() const override;

  // Updates CDM path if necessary.
  void UpdateCdmPath(const base::Version& cdm_version,
                     const base::FilePath& cdm_install_dir,
                     std::unique_ptr<base::DictionaryValue> manifest);

  DISALLOW_COPY_AND_ASSIGN(WidevineCdmComponentInstallerPolicy);
};

WidevineCdmComponentInstallerPolicy::WidevineCdmComponentInstallerPolicy() {}

bool WidevineCdmComponentInstallerPolicy::
    SupportsGroupPolicyEnabledComponentUpdates() const {
  return true;
}

bool WidevineCdmComponentInstallerPolicy::RequiresNetworkEncryption() const {
  return false;
}

update_client::CrxInstaller::Result
WidevineCdmComponentInstallerPolicy::OnCustomInstall(
    const base::DictionaryValue& manifest,
    const base::FilePath& install_dir) {
  return update_client::CrxInstaller::Result(0);
}

void WidevineCdmComponentInstallerPolicy::OnCustomUninstall() {}

// Once the CDM is ready, update the CDM path.
void WidevineCdmComponentInstallerPolicy::ComponentReady(
    const base::Version& version,
    const base::FilePath& path,
    std::unique_ptr<base::DictionaryValue> manifest) {
  if (!IsCompatibleWithChrome(*manifest)) {
    VLOG(1) << "Installed Widevine CDM component is incompatible.";
    return;
  }

  base::PostTaskWithTraits(
      FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
      base::BindOnce(&WidevineCdmComponentInstallerPolicy::UpdateCdmPath,
                     base::Unretained(this), version, path,
                     base::Passed(&manifest)));
}

bool WidevineCdmComponentInstallerPolicy::VerifyInstallation(
    const base::DictionaryValue& manifest,
    const base::FilePath& install_dir) const {
  return IsCompatibleWithChrome(manifest) &&
         base::PathExists(GetPlatformDirectory(install_dir)
                              .AppendASCII(base::GetNativeLibraryName(
                                  kWidevineCdmLibraryName)));
}

// The base directory on Windows looks like:
// <profile>\AppData\Local\Google\Chrome\User Data\WidevineCdm\.
base::FilePath WidevineCdmComponentInstallerPolicy::GetRelativeInstallDir()
    const {
  return base::FilePath::FromUTF8Unsafe(kWidevineCdmBaseDirectory);
}

void WidevineCdmComponentInstallerPolicy::GetHash(
    std::vector<uint8_t>* hash) const {
  hash->assign(kWidevineSha2Hash,
               kWidevineSha2Hash + arraysize(kWidevineSha2Hash));
}

std::string WidevineCdmComponentInstallerPolicy::GetName() const {
  return kWidevineCdmDisplayName;
}

update_client::InstallerAttributes
WidevineCdmComponentInstallerPolicy::GetInstallerAttributes() const {
  return update_client::InstallerAttributes();
}

std::vector<std::string> WidevineCdmComponentInstallerPolicy::GetMimeTypes()
    const {
  return std::vector<std::string>();
}

void WidevineCdmComponentInstallerPolicy::UpdateCdmPath(
    const base::Version& cdm_version,
    const base::FilePath& cdm_install_dir,
    std::unique_ptr<base::DictionaryValue> manifest) {
  // On some platforms (e.g. Mac) we use symlinks for paths. Convert paths to
  // absolute paths to avoid unexpected failure. base::MakeAbsoluteFilePath()
  // requires IO so it can only be done in this function.
  const base::FilePath absolute_cdm_install_dir =
      base::MakeAbsoluteFilePath(cdm_install_dir);
  if (absolute_cdm_install_dir.empty()) {
    PLOG(WARNING) << "Failed to get absolute CDM install path.";
    return;
  }

  content::BrowserThread::GetTaskRunnerForThread(content::BrowserThread::UI)
      ->PostTask(
          FROM_HERE,
          base::BindOnce(&RegisterWidevineCdmWithChrome, cdm_version,
                         absolute_cdm_install_dir, base::Passed(&manifest)));
}

#endif  // defined(WIDEVINE_CDM_AVAILABLE) && defined(WIDEVINE_CDM_IS_COMPONENT)

void RegisterWidevineCdmComponent(ComponentUpdateService* cus) {
#if defined(WIDEVINE_CDM_AVAILABLE) && defined(WIDEVINE_CDM_IS_COMPONENT)
  auto installer = base::MakeRefCounted<ComponentInstaller>(
      std::make_unique<WidevineCdmComponentInstallerPolicy>());
  installer->Register(cus, base::OnceClosure());
#endif  // defined(WIDEVINE_CDM_AVAILABLE) && defined(WIDEVINE_CDM_IS_COMPONENT)
}

}  // namespace component_updater