Check CDM API version compatibility before registering component.

Compatibility is not checked before installing a component. This should be prevented on the server side.

BUG=311374
TEST=video.canPlayType('video/webm; codecs="vp8"', 'com.widevine.alpha'); is affirmative when manifest contains supported "x-cdm-*-versions" values and "" when any value is unsupported.

Review URL: https://codereview.chromium.org/47513020

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@232424 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/component_updater/DEPS

@@ -1,4 +1,5 @@
 include_rules = [
+  "+media/cdm/ppapi/supported_cdm_versions.h",
   "+ppapi/shared_impl/ppapi_permissions.h",
   "+ppapi/thunk",
   "+third_party/widevine"

chrome/browser/component_updater/widevine_cdm_component_installer.cc

@@ -16,6 +16,8 @@
 #include "base/logging.h"
 #include "base/path_service.h"
 #include "base/strings/string16.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_split.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "build/build_config.h"
@@ -28,6 +30,7 @@
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/plugin_service.h"
 #include "content/public/common/pepper_plugin_info.h"
+#include "media/cdm/ppapi/supported_cdm_versions.h"
 #include "third_party/widevine/cdm/widevine_cdm_common.h"
 
 #include "widevine_cdm_version.h"  // In SHARED_INTERMEDIATE_DIR.
@@ -68,6 +71,23 @@ const char kWidevineCdmArch[] =
     "???";
 #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 = ',';
+COMPILE_ASSERT(kCdmValueDelimiter == kCdmSupportedCodecsValueDelimiter,
+               cdm_delimiters_do_not_match);
+// 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.
+const char kCdmModuleVersionsName[] = "x-cdm-module-versions";
+const char kCdmInstanceVersionsName[] = "x-cdm-instance-versions";
+const char kCdmHostVersionsName[] = "x-cdm-host-versions";
+//  The codecs list is a list of simple codec names (e.g. "vp8,vorbis").
+//  The list is passed to other parts of Chrome.
+const char kCdmCodecsListName[] = "x-cdm-codecs";
+
 // 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.
@@ -109,11 +129,67 @@ bool MakeWidevineCdmPluginInfo(
   return true;
 }
 
+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)) {
+    DLOG(WARNING)
+        << "Widevine CDM component manifest is missing " << version_name;
+    // TODO(ddorwin): Remove this once all users have been updated.
+    // The original manifests did not include this string, so add its version.
+    if (version_name == kCdmModuleVersionsName)
+      versions_string = "4";
+    else if (version_name == kCdmInstanceVersionsName)
+      versions_string = "1";
+    else if (version_name == kCdmHostVersionsName)
+      versions_string = "1";
+  }
+  DLOG_IF(WARNING, versions_string.empty())
+      << "Widevine CDM component manifest has empty " << version_name;
+
+  std::vector<std::string> versions;
+  base::SplitString(versions_string,
+                    kCdmValueDelimiter,
+                    &versions);
+
+  for (size_t i = 0; i < versions.size(); ++i) {
+    int version = 0;
+    if (base::StringToInt(versions[i], &version))
+      if (version_check_func(version))
+        return true;
+  }
+
+  DLOG(WARNING) << "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 instance 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,
+                                kCdmInstanceVersionsName,
+                                media::IsSupportedCdmInterfaceVersion) &&
+      CheckForCompatibleVersion(manifest,
+                                kCdmHostVersionsName,
+                                media::IsSupportedCdmHostVersion);
+}
+
 void GetAdditionalParams(const base::DictionaryValue& manifest,
                          std::vector<base::string16>* additional_param_names,
                          std::vector<base::string16>* additional_param_values) {
   base::string16 codecs;
-  if (manifest.GetString("x-cdm-codecs", &codecs)) {
+  if (manifest.GetString(kCdmCodecsListName, &codecs)) {
     DLOG_IF(WARNING, codecs.empty())
         << "Widevine CDM component manifest has empty codecs list";
     additional_param_names->push_back(
@@ -199,7 +275,11 @@ void WidevineCdmComponentInstallerTraits::ComponentReady(
     const base::Version& version,
     const base::FilePath& path,
     scoped_ptr<base::DictionaryValue> manifest) {
-  // TODO(ddorwin): Check API version compatibility. Return if fails.
+  if (!IsCompatibleWithChrome(*manifest)) {
+    DLOG(WARNING) << "Installed Widevine CDM component is incompatible.";
+    return;
+  }
+
   base::FilePath adapter_install_path = GetPlatformDirectory(path)
       .AppendASCII(kWidevineCdmAdapterFileName);
   RegisterWidevineCdmWithChrome(version,

media/cdm/ppapi/cdm_adapter.cc

@@ -5,6 +5,7 @@
 #include "media/cdm/ppapi/cdm_adapter.h"
 
 #include "media/cdm/ppapi/cdm_helpers.h"
+#include "media/cdm/ppapi/supported_cdm_versions.h"
 
 #if defined(CHECK_DOCUMENT_URL)
 #include "ppapi/cpp/dev/url_util_dev.h"
@@ -912,12 +913,34 @@ void* GetCdmHost(int host_interface_version, void* user_data) {
   if (!host_interface_version || !user_data)
     return NULL;
 
+  COMPILE_ASSERT(cdm::ContentDecryptionModule::Host::kVersion ==
+                 cdm::ContentDecryptionModule_2::Host::kVersion,
+                 update_code_below);
+
+  // Ensure IsSupportedCdmHostVersion matches implementation of this function.
+  // Always update this DCHECK when updating this function.
+  // If this check fails, update this function and DCHECK or update
+  // IsSupportedCdmHostVersion.
+  PP_DCHECK(
+      // Future version is not supported.
+      !IsSupportedCdmHostVersion(
+          cdm::ContentDecryptionModule::Host::kVersion + 1) &&
+      // Current version is supported.
+      IsSupportedCdmHostVersion(cdm::ContentDecryptionModule::Host::kVersion) &&
+      // Include all previous supported versions here.
+      IsSupportedCdmHostVersion(cdm::Host_1::kVersion) &&
+      // One older than the oldest supported version is not supported.
+      !IsSupportedCdmHostVersion(cdm::Host_1::kVersion - 1));
+  PP_DCHECK(IsSupportedCdmHostVersion(host_interface_version));
+
   CdmAdapter* cdm_adapter = static_cast<CdmAdapter*>(user_data);
   switch (host_interface_version) {
-    case cdm::ContentDecryptionModule_1::Host::kVersion:
-      return static_cast<cdm::ContentDecryptionModule_1::Host*>(cdm_adapter);
-    case cdm::ContentDecryptionModule_2::Host::kVersion:
-      return static_cast<cdm::ContentDecryptionModule_2::Host*>(cdm_adapter);
+    // The latest CDM host version.
+    case cdm::ContentDecryptionModule::Host::kVersion:
+      return static_cast<cdm::ContentDecryptionModule::Host*>(cdm_adapter);
+    // Older supported version(s) of the CDM host.
+    case cdm::Host_1::kVersion:
+      return static_cast<cdm::Host_1*>(cdm_adapter);
     default:
       PP_NOTREACHED();
       return NULL;

media/cdm/ppapi/cdm_wrapper.h

@@ -8,6 +8,7 @@
 #include "base/basictypes.h"
 #include "media/cdm/ppapi/api/content_decryption_module.h"
 #include "media/cdm/ppapi/cdm_helpers.h"
+#include "media/cdm/ppapi/supported_cdm_versions.h"
 #include "ppapi/cpp/logging.h"
 
 namespace media {
@@ -215,22 +216,40 @@ CdmWrapper* CdmWrapper::Create(const char* key_system,
                                uint32_t key_system_size,
                                GetCdmHostFunc get_cdm_host_func,
                                void* user_data) {
+  COMPILE_ASSERT(cdm::ContentDecryptionModule::kVersion ==
+                 cdm::ContentDecryptionModule_2::kVersion,
+                 update_code_below);
+
+  // Ensure IsSupportedCdmInterfaceVersion matches this implementation.
+  // Always update this DCHECK when updating this function.
+  // If this check fails, update this function and DCHECK or update
+  // IsSupportedCdmInterfaceVersion.
+  PP_DCHECK(
+      !IsSupportedCdmInterfaceVersion(
+          cdm::ContentDecryptionModule::kVersion + 1) &&
+      IsSupportedCdmInterfaceVersion(cdm::ContentDecryptionModule::kVersion) &&
+      IsSupportedCdmInterfaceVersion(
+          cdm::ContentDecryptionModule_1::kVersion) &&
+      !IsSupportedCdmInterfaceVersion(
+          cdm::ContentDecryptionModule_1::kVersion - 1));
+
   // Try to create the CDM using the latest CDM interface version.
-  CdmWrapper* cdm_adapter =
+  CdmWrapper* cdm_wrapper =
       CdmWrapperImpl<cdm::ContentDecryptionModule>::Create(
           key_system, key_system_size, get_cdm_host_func, user_data);
-  if (cdm_adapter)
-    return cdm_adapter;
+  if (cdm_wrapper)
+    return cdm_wrapper;
 
-  // Try to see if the CDM supports older version(s) of CDM interface(s).
-  cdm_adapter = CdmWrapperImpl<cdm::ContentDecryptionModule_1>::Create(
+  // Try to see if the CDM supports older version(s) of the CDM interface.
+  cdm_wrapper = CdmWrapperImpl<cdm::ContentDecryptionModule_1>::Create(
       key_system, key_system_size, get_cdm_host_func, user_data);
-  return cdm_adapter;
+  return cdm_wrapper;
 }
 
 // When updating the CdmAdapter, ensure you've updated the CdmWrapper to contain
 // stub implementations for new or modified methods that the older CDM interface
 // does not have.
+// Also update supported_cdm_versions.h.
 COMPILE_ASSERT(cdm::ContentDecryptionModule::kVersion ==
                    cdm::ContentDecryptionModule_2::kVersion,
                ensure_cdm_wrapper_templates_have_old_version_support);

media/cdm/ppapi/supported_cdm_versions.h

@@ -0,0 +1,56 @@
+// Copyright 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.
+
+#ifndef MEDIA_CDM_PPAPI_SUPPORTED_CDM_VERSIONS_H_
+#define MEDIA_CDM_PPAPI_SUPPORTED_CDM_VERSIONS_H_
+
+#include "media/cdm/ppapi/api/content_decryption_module.h"
+
+namespace media {
+
+// TODO(ddorwin): Move to content_decryption_module.h.
+#define CDM_MODULE_VERSION 4
+
+bool IsSupportedCdmModuleVersion(int version) {
+  switch(version) {
+    // Latest.
+    case CDM_MODULE_VERSION:
+      return true;
+    default:
+      return false;
+  }
+}
+
+bool IsSupportedCdmInterfaceVersion(int version) {
+  COMPILE_ASSERT(cdm::ContentDecryptionModule::kVersion ==
+                 cdm::ContentDecryptionModule_2::kVersion,
+                 update_code_below);
+  switch(version) {
+    // Latest.
+    case cdm::ContentDecryptionModule::kVersion:
+    // Older supported versions.
+    case cdm::ContentDecryptionModule_1::kVersion:
+      return true;
+    default:
+      return false;
+  }
+}
+
+bool IsSupportedCdmHostVersion(int version) {
+  COMPILE_ASSERT(cdm::ContentDecryptionModule::Host::kVersion ==
+                 cdm::ContentDecryptionModule_2::Host::kVersion,
+                 update_code_below);
+  switch(version) {
+    // Supported versions in increasing order (there is no default).
+    case cdm::Host_1::kVersion:
+    case cdm::Host_2::kVersion:
+      return true;
+    default:
+      return false;
+  }
+}
+
+}  // namespace media
+
+#endif  // MEDIA_CDM_PPAPI_SUPPORTED_CDM_VERSIONS_H_

media/media_cdm.gypi

@@ -105,6 +105,7 @@
         'cdm/ppapi/cdm_helpers.h',
         'cdm/ppapi/cdm_wrapper.h',
         'cdm/ppapi/linked_ptr.h',
+        'cdm/ppapi/supported_cdm_versions.h',
       ],
       'conditions': [
         ['os_posix == 1 and OS != "mac" and enable_pepper_cdms==1', {

third_party/widevine/cdm/widevine_cdm.gyp

@@ -67,6 +67,7 @@
             '<(DEPTH)/media/cdm/ppapi/cdm_helpers.h',
             '<(DEPTH)/media/cdm/ppapi/cdm_wrapper.h',
             '<(DEPTH)/media/cdm/ppapi/linked_ptr.h',
+            '<(DEPTH)/media/cdm/ppapi/supported_cdm_versions.h',
           ],
           'conditions': [
             [ 'os_posix == 1 and OS != "mac"', {