media/base/key_systems.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "media/base/key_systems.h"
   6
   7 #include <string>
   8
   9 #include "base/containers/hash_tables.h"
  10 #include "base/lazy_instance.h"
  11 #include "base/logging.h"
  12 #include "base/strings/string_util.h"
  13 #include "base/threading/thread_checker.h"
  14 #include "base/time/time.h"
  15 #include "media/base/eme_constants.h"
  16 #include "media/base/key_system_info.h"
  17 #include "media/base/key_systems_support_uma.h"
  18 #include "media/base/media_client.h"
  19 #include "media/cdm/key_system_names.h"
  20 #include "third_party/widevine/cdm/widevine_cdm_common.h"
  21
  22 namespace media {
  23
  24 const char kClearKeyKeySystem[] = "org.w3.clearkey";
  25 const char kPrefixedClearKeyKeySystem[] = "webkit-org.w3.clearkey";
  26 const char kUnsupportedClearKeyKeySystem[] = "unsupported-org.w3.clearkey";
  27
  28 // These names are used by UMA. Do not change them!
  29 const char kClearKeyKeySystemNameForUMA[] = "ClearKey";
  30 const char kUnknownKeySystemNameForUMA[] = "Unknown";
  31
  32 struct NamedCodec {
  33   const char* name;
  34   EmeCodec type;
  35 };
  36
  37 // Mapping between containers and their codecs.
  38 // Only audio codec can belong to a "audio/*" container. Both audio and video
  39 // codecs can belong to a "video/*" container.
  40 // TODO(sandersd): This definition only makes sense for prefixed EME. Change it
  41 // when prefixed EME is removed. http://crbug.com/249976
  42 static NamedCodec kContainerToCodecMasks[] = {
  43     {"audio/webm", EME_CODEC_WEBM_AUDIO_ALL},
  44     {"video/webm", EME_CODEC_WEBM_ALL},
  45 #if defined(USE_PROPRIETARY_CODECS)
  46     {"audio/mp4", EME_CODEC_MP4_AUDIO_ALL},
  47     {"video/mp4", EME_CODEC_MP4_ALL}
  48 #endif  // defined(USE_PROPRIETARY_CODECS)
  49 };
  50
  51 // Mapping between codec names and enum values.
  52 static NamedCodec kCodecStrings[] = {
  53     {"opus", EME_CODEC_WEBM_OPUS},
  54     {"vorbis", EME_CODEC_WEBM_VORBIS},
  55     {"vp8", EME_CODEC_WEBM_VP8},
  56     {"vp8.0", EME_CODEC_WEBM_VP8},
  57     {"vp9", EME_CODEC_WEBM_VP9},
  58     {"vp9.0", EME_CODEC_WEBM_VP9},
  59 #if defined(USE_PROPRIETARY_CODECS)
  60     {"mp4a", EME_CODEC_MP4_AAC},
  61     {"avc1", EME_CODEC_MP4_AVC1},
  62     {"avc3", EME_CODEC_MP4_AVC1}
  63 #endif  // defined(USE_PROPRIETARY_CODECS)
  64 };
  65
  66 static EmeConfigRule ConvertSessionTypeSupport(
  67     EmeSessionTypeSupport support) {
  68   switch (support) {
  69     case EME_SESSION_TYPE_INVALID:
  70       NOTREACHED();
  71       return EmeConfigRule::NOT_SUPPORTED;
  72     case EME_SESSION_TYPE_NOT_SUPPORTED:
  73       return EmeConfigRule::NOT_SUPPORTED;
  74     case EME_SESSION_TYPE_SUPPORTED_WITH_IDENTIFIER:
  75       return EmeConfigRule::IDENTIFIER_AND_PERSISTENCE_REQUIRED;
  76     case EME_SESSION_TYPE_SUPPORTED:
  77       return EmeConfigRule::PERSISTENCE_REQUIRED;
  78   }
  79   NOTREACHED();
  80   return EmeConfigRule::NOT_SUPPORTED;
  81 }
  82
  83 static EmeRobustness ConvertRobustness(const std::string& robustness) {
  84   if (robustness.empty())
  85     return EmeRobustness::EMPTY;
  86   if (robustness == "SW_SECURE_CRYPTO")
  87     return EmeRobustness::SW_SECURE_CRYPTO;
  88   if (robustness == "SW_SECURE_DECODE")
  89     return EmeRobustness::SW_SECURE_DECODE;
  90   if (robustness == "HW_SECURE_CRYPTO")
  91     return EmeRobustness::HW_SECURE_CRYPTO;
  92   if (robustness == "HW_SECURE_DECODE")
  93     return EmeRobustness::HW_SECURE_DECODE;
  94   if (robustness == "HW_SECURE_ALL")
  95     return EmeRobustness::HW_SECURE_ALL;
  96   return EmeRobustness::INVALID;
  97 }
  98
  99 static void AddClearKey(std::vector<KeySystemInfo>* concrete_key_systems) {
 100   KeySystemInfo info;
 101   info.key_system = kClearKeyKeySystem;
 102
 103   // On Android, Vorbis, VP8, AAC and AVC1 are supported in MediaCodec:
 104   // http://developer.android.com/guide/appendix/media-formats.html
 105   // VP9 support is device dependent.
 106
 107   info.supported_init_data_types =
 108       kInitDataTypeMaskWebM | kInitDataTypeMaskKeyIds;
 109   info.supported_codecs = EME_CODEC_WEBM_ALL;
 110
 111 #if defined(OS_ANDROID)
 112   // Temporarily disable VP9 support for Android.
 113   // TODO(xhwang): Use mime_util.h to query VP9 support on Android.
 114   info.supported_codecs &= ~EME_CODEC_WEBM_VP9;
 115
 116   // Opus is not supported on Android yet. http://crbug.com/318436.
 117   // TODO(sandersd): Check for platform support to set this bit.
 118   info.supported_codecs &= ~EME_CODEC_WEBM_OPUS;
 119 #endif  // defined(OS_ANDROID)
 120
 121 #if defined(USE_PROPRIETARY_CODECS)
 122   info.supported_init_data_types |= kInitDataTypeMaskCenc;
 123   info.supported_codecs |= EME_CODEC_MP4_ALL;
 124 #endif  // defined(USE_PROPRIETARY_CODECS)
 125
 126   info.max_audio_robustness = EmeRobustness::EMPTY;
 127   info.max_video_robustness = EmeRobustness::EMPTY;
 128   info.persistent_license_support = EME_SESSION_TYPE_NOT_SUPPORTED;
 129   info.persistent_release_message_support = EME_SESSION_TYPE_NOT_SUPPORTED;
 130   info.persistent_state_support = EME_FEATURE_NOT_SUPPORTED;
 131   info.distinctive_identifier_support = EME_FEATURE_NOT_SUPPORTED;
 132
 133   info.use_aes_decryptor = true;
 134
 135   concrete_key_systems->push_back(info);
 136 }
 137
 138 // Returns whether the |key_system| is known to Chromium and is thus likely to
 139 // be implemented in an interoperable way.
 140 // True is always returned for a |key_system| that begins with "x-".
 141 //
 142 // As with other web platform features, advertising support for a key system
 143 // implies that it adheres to a defined and interoperable specification.
 144 //
 145 // To ensure interoperability, implementations of a specific |key_system| string
 146 // must conform to a specification for that identifier that defines
 147 // key system-specific behaviors not fully defined by the EME specification.
 148 // That specification should be provided by the owner of the domain that is the
 149 // reverse of the |key_system| string.
 150 // This involves more than calling a library, SDK, or platform API.
 151 // KeySystemsImpl must be populated appropriately, and there will likely be glue
 152 // code to adapt to the API of the library, SDK, or platform API.
 153 //
 154 // Chromium mainline contains this data and glue code for specific key systems,
 155 // which should help ensure interoperability with other implementations using
 156 // these key systems.
 157 //
 158 // If you need to add support for other key systems, ensure that you have
 159 // obtained the specification for how to integrate it with EME, implemented the
 160 // appropriate glue/adapter code, and added all the appropriate data to
 161 // KeySystemsImpl. Only then should you change this function.
 162 static bool IsPotentiallySupportedKeySystem(const std::string& key_system) {
 163   // Known and supported key systems.
 164   if (key_system == kWidevineKeySystem)
 165     return true;
 166   if (key_system == kClearKey)
 167     return true;
 168
 169   // External Clear Key is known and supports suffixes for testing.
 170   if (IsExternalClearKey(key_system))
 171     return true;
 172
 173   // Chromecast defines behaviors for Cast clients within its reverse domain.
 174   const char kChromecastRoot[] = "com.chromecast";
 175   if (IsParentKeySystemOf(kChromecastRoot, key_system))
 176     return true;
 177
 178   // Implementations that do not have a specification or appropriate glue code
 179   // can use the "x-" prefix to avoid conflicting with and advertising support
 180   // for real key system names. Use is discouraged.
 181   const char kExcludedPrefix[] = "x-";
 182   if (key_system.find(kExcludedPrefix, 0, arraysize(kExcludedPrefix) - 1) == 0)
 183     return true;
 184
 185   return false;
 186 }
 187
 188 class KeySystemsImpl : public KeySystems {
 189  public:
 190   static KeySystemsImpl& GetInstance();
 191
 192   void UpdateIfNeeded();
 193
 194   bool IsConcreteSupportedKeySystem(const std::string& key_system) const;
 195
 196   bool PrefixedIsSupportedKeySystemWithMediaMimeType(
 197       const std::string& mime_type,
 198       const std::vector<std::string>& codecs,
 199       const std::string& key_system);
 200
 201   std::string GetKeySystemNameForUMA(const std::string& key_system) const;
 202
 203   bool UseAesDecryptor(const std::string& concrete_key_system) const;
 204
 205 #if defined(ENABLE_PEPPER_CDMS)
 206   std::string GetPepperType(const std::string& concrete_key_system) const;
 207 #endif
 208
 209   void AddContainerMask(const std::string& container, uint32 mask);
 210   void AddCodecMask(
 211       EmeMediaType media_type,
 212       const std::string& codec,
 213       uint32 mask);
 214
 215   // Implementation of KeySystems interface.
 216   bool IsSupportedKeySystem(const std::string& key_system) const override;
 217
 218   bool IsSupportedInitDataType(const std::string& key_system,
 219                                EmeInitDataType init_data_type) const override;
 220
 221   bool IsSupportedCodecCombination(
 222       const std::string& key_system,
 223       EmeMediaType media_type,
 224       const std::string& container_mime_type,
 225       const std::vector<std::string>& codecs) const override;
 226
 227   EmeConfigRule GetRobustnessConfigRule(
 228       const std::string& key_system,
 229       EmeMediaType media_type,
 230       const std::string& requested_robustness) const override;
 231
 232   EmeConfigRule GetPersistentLicenseSessionConfigRule(
 233       const std::string& key_system) const override;
 234
 235   EmeConfigRule GetPersistentReleaseMessageSessionConfigRule(
 236       const std::string& key_system) const override;
 237
 238   EmeConfigRule GetPersistentStateConfigRule(
 239       const std::string& key_system,
 240       EmeFeatureRequirement requirement) const override;
 241
 242   EmeConfigRule GetDistinctiveIdentifierConfigRule(
 243       const std::string& key_system,
 244       EmeFeatureRequirement requirement) const override;
 245
 246  private:
 247   void InitializeUMAInfo();
 248
 249   void UpdateSupportedKeySystems();
 250
 251   void AddConcreteSupportedKeySystems(
 252       const std::vector<KeySystemInfo>& concrete_key_systems);
 253
 254   friend struct base::DefaultLazyInstanceTraits<KeySystemsImpl>;
 255
 256   typedef base::hash_map<std::string, KeySystemInfo> KeySystemInfoMap;
 257   typedef base::hash_map<std::string, std::string> ParentKeySystemMap;
 258   typedef base::hash_map<std::string, SupportedCodecs> ContainerCodecsMap;
 259   typedef base::hash_map<std::string, EmeCodec> CodecsMap;
 260   typedef base::hash_map<std::string, EmeInitDataType> InitDataTypesMap;
 261   typedef base::hash_map<std::string, std::string> KeySystemNameForUMAMap;
 262
 263   KeySystemsImpl();
 264   ~KeySystemsImpl() {}
 265
 266   // TODO(sandersd): Separate container enum from codec mask value.
 267   // http://crbug.com/417440
 268   SupportedCodecs GetCodecMaskForContainer(
 269       const std::string& container) const;
 270   EmeCodec GetCodecForString(const std::string& codec) const;
 271
 272   const std::string& PrefixedGetConcreteKeySystemNameFor(
 273       const std::string& key_system) const;
 274
 275   // Returns whether a |container| type is supported by checking
 276   // |key_system_supported_codecs|.
 277   // TODO(xhwang): Update this to actually check initDataType support.
 278   bool IsSupportedContainer(const std::string& container,
 279                             SupportedCodecs key_system_supported_codecs) const;
 280
 281   // Returns true if all |codecs| are supported in |container| by checking
 282   // |key_system_supported_codecs|.
 283   bool IsSupportedContainerAndCodecs(
 284       const std::string& container,
 285       const std::vector<std::string>& codecs,
 286       SupportedCodecs key_system_supported_codecs) const;
 287
 288   // Map from key system string to capabilities.
 289   KeySystemInfoMap concrete_key_system_map_;
 290
 291   // Map from parent key system to the concrete key system that should be used
 292   // to represent its capabilities.
 293   ParentKeySystemMap parent_key_system_map_;
 294
 295   KeySystemsSupportUMA key_systems_support_uma_;
 296
 297   ContainerCodecsMap container_to_codec_mask_map_;
 298   CodecsMap codec_string_map_;
 299   KeySystemNameForUMAMap key_system_name_for_uma_map_;
 300
 301   SupportedCodecs audio_codec_mask_;
 302   SupportedCodecs video_codec_mask_;
 303
 304   // Makes sure all methods are called from the same thread.
 305   base::ThreadChecker thread_checker_;
 306
 307   DISALLOW_COPY_AND_ASSIGN(KeySystemsImpl);
 308 };
 309
 310 static base::LazyInstance<KeySystemsImpl> g_key_systems =
 311     LAZY_INSTANCE_INITIALIZER;
 312
 313 KeySystemsImpl& KeySystemsImpl::GetInstance() {
 314   KeySystemsImpl& key_systems = g_key_systems.Get();
 315   key_systems.UpdateIfNeeded();
 316   return key_systems;
 317 }
 318
 319 // Because we use a LazyInstance, the key systems info must be populated when
 320 // the instance is lazily initiated.
 321 KeySystemsImpl::KeySystemsImpl() :
 322     audio_codec_mask_(EME_CODEC_AUDIO_ALL),
 323     video_codec_mask_(EME_CODEC_VIDEO_ALL) {
 324   for (size_t i = 0; i < arraysize(kContainerToCodecMasks); ++i) {
 325     const std::string& name = kContainerToCodecMasks[i].name;
 326     DCHECK(!container_to_codec_mask_map_.count(name));
 327     container_to_codec_mask_map_[name] = kContainerToCodecMasks[i].type;
 328   }
 329   for (size_t i = 0; i < arraysize(kCodecStrings); ++i) {
 330     const std::string& name = kCodecStrings[i].name;
 331     DCHECK(!codec_string_map_.count(name));
 332     codec_string_map_[name] = kCodecStrings[i].type;
 333   }
 334
 335   InitializeUMAInfo();
 336
 337   // Always update supported key systems during construction.
 338   UpdateSupportedKeySystems();
 339 }
 340
 341 SupportedCodecs KeySystemsImpl::GetCodecMaskForContainer(
 342     const std::string& container) const {
 343   ContainerCodecsMap::const_iterator iter =
 344       container_to_codec_mask_map_.find(container);
 345   if (iter != container_to_codec_mask_map_.end())
 346     return iter->second;
 347   return EME_CODEC_NONE;
 348 }
 349
 350 EmeCodec KeySystemsImpl::GetCodecForString(const std::string& codec) const {
 351   CodecsMap::const_iterator iter = codec_string_map_.find(codec);
 352   if (iter != codec_string_map_.end())
 353     return iter->second;
 354   return EME_CODEC_NONE;
 355 }
 356
 357 const std::string& KeySystemsImpl::PrefixedGetConcreteKeySystemNameFor(
 358     const std::string& key_system) const {
 359   ParentKeySystemMap::const_iterator iter =
 360       parent_key_system_map_.find(key_system);
 361   if (iter != parent_key_system_map_.end())
 362     return iter->second;
 363   return key_system;
 364 }
 365
 366 void KeySystemsImpl::InitializeUMAInfo() {
 367   DCHECK(thread_checker_.CalledOnValidThread());
 368   DCHECK(key_system_name_for_uma_map_.empty());
 369
 370   std::vector<KeySystemInfoForUMA> key_systems_info_for_uma;
 371   if (GetMediaClient())
 372     GetMediaClient()->AddKeySystemsInfoForUMA(&key_systems_info_for_uma);
 373
 374   for (const KeySystemInfoForUMA& info : key_systems_info_for_uma) {
 375     key_system_name_for_uma_map_[info.key_system] =
 376         info.key_system_name_for_uma;
 377     if (info.reports_key_system_support_to_uma)
 378       key_systems_support_uma_.AddKeySystemToReport(info.key_system);
 379   }
 380
 381   // Clear Key is always supported.
 382   key_system_name_for_uma_map_[kClearKeyKeySystem] =
 383       kClearKeyKeySystemNameForUMA;
 384 }
 385
 386 void KeySystemsImpl::UpdateIfNeeded() {
 387   if (GetMediaClient() && GetMediaClient()->IsKeySystemsUpdateNeeded())
 388     UpdateSupportedKeySystems();
 389 }
 390
 391 void KeySystemsImpl::UpdateSupportedKeySystems() {
 392   DCHECK(thread_checker_.CalledOnValidThread());
 393   concrete_key_system_map_.clear();
 394   parent_key_system_map_.clear();
 395
 396   // Build KeySystemInfo.
 397   std::vector<KeySystemInfo> key_systems_info;
 398
 399   // Add key systems supported by the MediaClient implementation.
 400   if (GetMediaClient())
 401     GetMediaClient()->AddSupportedKeySystems(&key_systems_info);
 402
 403   // Clear Key is always supported.
 404   AddClearKey(&key_systems_info);
 405
 406   AddConcreteSupportedKeySystems(key_systems_info);
 407 }
 408
 409 void KeySystemsImpl::AddConcreteSupportedKeySystems(
 410     const std::vector<KeySystemInfo>& concrete_key_systems) {
 411   DCHECK(thread_checker_.CalledOnValidThread());
 412   DCHECK(concrete_key_system_map_.empty());
 413   DCHECK(parent_key_system_map_.empty());
 414
 415   for (const KeySystemInfo& info : concrete_key_systems) {
 416     DCHECK(!info.key_system.empty());
 417     DCHECK(info.max_audio_robustness != EmeRobustness::INVALID);
 418     DCHECK(info.max_video_robustness != EmeRobustness::INVALID);
 419     DCHECK(info.persistent_license_support != EME_SESSION_TYPE_INVALID);
 420     DCHECK(info.persistent_release_message_support != EME_SESSION_TYPE_INVALID);
 421     DCHECK(info.persistent_state_support != EME_FEATURE_INVALID);
 422     DCHECK(info.distinctive_identifier_support != EME_FEATURE_INVALID);
 423
 424     // Supporting persistent state is a prerequsite for supporting persistent
 425     // sessions.
 426     if (info.persistent_state_support == EME_FEATURE_NOT_SUPPORTED) {
 427       DCHECK(info.persistent_license_support == EME_SESSION_TYPE_NOT_SUPPORTED);
 428       DCHECK(info.persistent_release_message_support ==
 429              EME_SESSION_TYPE_NOT_SUPPORTED);
 430     }
 431
 432     // persistent-release-message sessions are not currently supported.
 433     // http://crbug.com/448888
 434     DCHECK(info.persistent_release_message_support ==
 435            EME_SESSION_TYPE_NOT_SUPPORTED);
 436
 437     // If distinctive identifiers are not supported, then no other features can
 438     // require them.
 439     if (info.distinctive_identifier_support == EME_FEATURE_NOT_SUPPORTED) {
 440       DCHECK(info.persistent_license_support !=
 441              EME_SESSION_TYPE_SUPPORTED_WITH_IDENTIFIER);
 442       DCHECK(info.persistent_release_message_support !=
 443              EME_SESSION_TYPE_SUPPORTED_WITH_IDENTIFIER);
 444     }
 445
 446     // Distinctive identifiers and persistent state can only be reliably blocked
 447     // (and therefore be safely configurable) for Pepper-hosted key systems. For
 448     // other platforms, only non-configurable values are valid.
 449     bool can_block = false;
 450 #if defined(ENABLE_PEPPER_CDMS)
 451     DCHECK_EQ(info.use_aes_decryptor, info.pepper_type.empty());
 452     can_block = !info.pepper_type.empty();
 453 #endif
 454     if (!can_block) {
 455       DCHECK(info.distinctive_identifier_support == EME_FEATURE_NOT_SUPPORTED ||
 456              info.distinctive_identifier_support == EME_FEATURE_ALWAYS_ENABLED);
 457       DCHECK(info.persistent_state_support == EME_FEATURE_NOT_SUPPORTED ||
 458              info.persistent_state_support == EME_FEATURE_ALWAYS_ENABLED);
 459     }
 460
 461     DCHECK(!IsSupportedKeySystem(info.key_system))
 462         << "Key system '" << info.key_system << "' already registered";
 463     DCHECK(!parent_key_system_map_.count(info.key_system))
 464         <<  "'" << info.key_system << "' is already registered as a parent";
 465     concrete_key_system_map_[info.key_system] = info;
 466     if (!info.parent_key_system.empty()) {
 467       DCHECK(!IsConcreteSupportedKeySystem(info.parent_key_system))
 468           << "Parent '" << info.parent_key_system << "' "
 469           << "already registered concrete";
 470       DCHECK(!parent_key_system_map_.count(info.parent_key_system))
 471           << "Parent '" << info.parent_key_system << "' already registered";
 472       parent_key_system_map_[info.parent_key_system] = info.key_system;
 473     }
 474   }
 475 }
 476
 477 bool KeySystemsImpl::IsConcreteSupportedKeySystem(
 478     const std::string& key_system) const {
 479   DCHECK(thread_checker_.CalledOnValidThread());
 480   return concrete_key_system_map_.count(key_system) != 0;
 481 }
 482
 483 bool KeySystemsImpl::IsSupportedContainer(
 484     const std::string& container,
 485     SupportedCodecs key_system_supported_codecs) const {
 486   DCHECK(thread_checker_.CalledOnValidThread());
 487   DCHECK(!container.empty());
 488
 489   // When checking container support for EME, "audio/foo" should be treated the
 490   // same as "video/foo". Convert the |container| to achieve this.
 491   // TODO(xhwang): Replace this with real checks against supported initDataTypes
 492   // combined with supported demuxers.
 493   std::string canonical_container = container;
 494   if (container.find("audio/") == 0)
 495     canonical_container.replace(0, 6, "video/");
 496
 497   // A container is supported iif at least one codec in that container is
 498   // supported.
 499   SupportedCodecs supported_codecs =
 500       GetCodecMaskForContainer(canonical_container);
 501   return (supported_codecs & key_system_supported_codecs) != 0;
 502 }
 503
 504 bool KeySystemsImpl::IsSupportedContainerAndCodecs(
 505     const std::string& container,
 506     const std::vector<std::string>& codecs,
 507     SupportedCodecs key_system_supported_codecs) const {
 508   DCHECK(thread_checker_.CalledOnValidThread());
 509   DCHECK(!container.empty());
 510   DCHECK(!codecs.empty());
 511   DCHECK(IsSupportedContainer(container, key_system_supported_codecs));
 512
 513   SupportedCodecs container_supported_codecs =
 514       GetCodecMaskForContainer(container);
 515
 516   for (size_t i = 0; i < codecs.size(); ++i) {
 517     if (codecs[i].empty())
 518       continue;
 519
 520     EmeCodec codec = GetCodecForString(codecs[i]);
 521
 522     // Unsupported codec.
 523     if (!(codec & key_system_supported_codecs))
 524       return false;
 525
 526     // Unsupported codec/container combination, e.g. "video/webm" and "avc1".
 527     if (!(codec & container_supported_codecs))
 528       return false;
 529   }
 530
 531   return true;
 532 }
 533
 534 bool KeySystemsImpl::IsSupportedInitDataType(
 535     const std::string& key_system,
 536     EmeInitDataType init_data_type) const {
 537   DCHECK(thread_checker_.CalledOnValidThread());
 538
 539   // Locate |key_system|. Only concrete key systems are supported in unprefixed.
 540   KeySystemInfoMap::const_iterator key_system_iter =
 541       concrete_key_system_map_.find(key_system);
 542   if (key_system_iter == concrete_key_system_map_.end()) {
 543     NOTREACHED();
 544     return false;
 545   }
 546
 547   // Check |init_data_type|.
 548   InitDataTypeMask available_init_data_types =
 549       key_system_iter->second.supported_init_data_types;
 550   switch (init_data_type) {
 551     case EmeInitDataType::UNKNOWN:
 552       return false;
 553     case EmeInitDataType::WEBM:
 554       return (available_init_data_types & kInitDataTypeMaskWebM) != 0;
 555     case EmeInitDataType::CENC:
 556       return (available_init_data_types & kInitDataTypeMaskCenc) != 0;
 557     case EmeInitDataType::KEYIDS:
 558       return (available_init_data_types & kInitDataTypeMaskKeyIds) != 0;
 559   }
 560   NOTREACHED();
 561   return false;
 562 }
 563
 564 bool KeySystemsImpl::PrefixedIsSupportedKeySystemWithMediaMimeType(
 565     const std::string& mime_type,
 566     const std::vector<std::string>& codecs,
 567     const std::string& key_system) {
 568   DCHECK(thread_checker_.CalledOnValidThread());
 569
 570   const std::string& concrete_key_system =
 571       PrefixedGetConcreteKeySystemNameFor(key_system);
 572
 573   bool has_type = !mime_type.empty();
 574
 575   key_systems_support_uma_.ReportKeySystemQuery(key_system, has_type);
 576
 577   // Check key system support.
 578   KeySystemInfoMap::const_iterator key_system_iter =
 579       concrete_key_system_map_.find(concrete_key_system);
 580   if (key_system_iter == concrete_key_system_map_.end())
 581     return false;
 582
 583   key_systems_support_uma_.ReportKeySystemSupport(key_system, false);
 584
 585   if (!has_type) {
 586     DCHECK(codecs.empty());
 587     return true;
 588   }
 589
 590   SupportedCodecs key_system_supported_codecs =
 591       key_system_iter->second.supported_codecs;
 592
 593   if (!IsSupportedContainer(mime_type, key_system_supported_codecs))
 594     return false;
 595
 596   if (!codecs.empty() &&
 597       !IsSupportedContainerAndCodecs(
 598           mime_type, codecs, key_system_supported_codecs)) {
 599     return false;
 600   }
 601
 602   key_systems_support_uma_.ReportKeySystemSupport(key_system, true);
 603
 604   return true;
 605 }
 606
 607 std::string KeySystemsImpl::GetKeySystemNameForUMA(
 608     const std::string& key_system) const {
 609   DCHECK(thread_checker_.CalledOnValidThread());
 610
 611   KeySystemNameForUMAMap::const_iterator iter =
 612       key_system_name_for_uma_map_.find(key_system);
 613   if (iter == key_system_name_for_uma_map_.end())
 614     return kUnknownKeySystemNameForUMA;
 615
 616   return iter->second;
 617 }
 618
 619 bool KeySystemsImpl::UseAesDecryptor(
 620     const std::string& concrete_key_system) const {
 621   DCHECK(thread_checker_.CalledOnValidThread());
 622
 623   KeySystemInfoMap::const_iterator key_system_iter =
 624       concrete_key_system_map_.find(concrete_key_system);
 625   if (key_system_iter == concrete_key_system_map_.end()) {
 626       DLOG(FATAL) << concrete_key_system << " is not a known concrete system";
 627       return false;
 628   }
 629
 630   return key_system_iter->second.use_aes_decryptor;
 631 }
 632
 633 #if defined(ENABLE_PEPPER_CDMS)
 634 std::string KeySystemsImpl::GetPepperType(
 635     const std::string& concrete_key_system) const {
 636   DCHECK(thread_checker_.CalledOnValidThread());
 637
 638   KeySystemInfoMap::const_iterator key_system_iter =
 639       concrete_key_system_map_.find(concrete_key_system);
 640   if (key_system_iter == concrete_key_system_map_.end()) {
 641       DLOG(FATAL) << concrete_key_system << " is not a known concrete system";
 642       return std::string();
 643   }
 644
 645   const std::string& type = key_system_iter->second.pepper_type;
 646   DLOG_IF(FATAL, type.empty()) << concrete_key_system << " is not Pepper-based";
 647   return type;
 648 }
 649 #endif
 650
 651 void KeySystemsImpl::AddContainerMask(
 652     const std::string& container,
 653     uint32 mask) {
 654   DCHECK(thread_checker_.CalledOnValidThread());
 655   DCHECK(!container_to_codec_mask_map_.count(container));
 656   container_to_codec_mask_map_[container] = static_cast<EmeCodec>(mask);
 657 }
 658
 659 void KeySystemsImpl::AddCodecMask(
 660     EmeMediaType media_type,
 661     const std::string& codec,
 662     uint32 mask) {
 663   DCHECK(thread_checker_.CalledOnValidThread());
 664   DCHECK(!codec_string_map_.count(codec));
 665   codec_string_map_[codec] = static_cast<EmeCodec>(mask);
 666   if (media_type == EmeMediaType::AUDIO) {
 667     audio_codec_mask_ |= mask;
 668   } else {
 669     video_codec_mask_ |= mask;
 670   }
 671 }
 672
 673 bool KeySystemsImpl::IsSupportedKeySystem(const std::string& key_system) const {
 674   DCHECK(thread_checker_.CalledOnValidThread());
 675   return concrete_key_system_map_.count(key_system) != 0;
 676 }
 677
 678 bool KeySystemsImpl::IsSupportedCodecCombination(
 679     const std::string& key_system,
 680     EmeMediaType media_type,
 681     const std::string& container_mime_type,
 682     const std::vector<std::string>& codecs) const {
 683   DCHECK(thread_checker_.CalledOnValidThread());
 684
 685   // Make sure the container matches |media_type|.
 686   SupportedCodecs media_type_codec_mask = EME_CODEC_NONE;
 687   switch (media_type) {
 688     case EmeMediaType::AUDIO:
 689       if (!StartsWithASCII(container_mime_type, "audio/", true))
 690         return false;
 691       media_type_codec_mask = audio_codec_mask_;
 692       break;
 693     case EmeMediaType::VIDEO:
 694       if (!StartsWithASCII(container_mime_type, "video/", true))
 695         return false;
 696       media_type_codec_mask = video_codec_mask_;
 697       break;
 698   }
 699
 700   // Look up the key system's supported codecs.
 701   KeySystemInfoMap::const_iterator key_system_iter =
 702       concrete_key_system_map_.find(key_system);
 703   if (key_system_iter == concrete_key_system_map_.end()) {
 704     NOTREACHED();
 705     return false;
 706   }
 707   SupportedCodecs key_system_codec_mask =
 708       key_system_iter->second.supported_codecs;
 709
 710   // Check that the container is supported by the key system. (This check is
 711   // necessary because |codecs| may be empty.)
 712   SupportedCodecs container_codec_mask =
 713       GetCodecMaskForContainer(container_mime_type) & media_type_codec_mask;
 714   if ((key_system_codec_mask & container_codec_mask) == 0)
 715     return false;
 716
 717   // Check that the codecs are supported by the key system and container.
 718   for (size_t i = 0; i < codecs.size(); i++) {
 719     SupportedCodecs codec = GetCodecForString(codecs[i]);
 720     if ((codec & key_system_codec_mask & container_codec_mask) == 0)
 721       return false;
 722   }
 723
 724   return true;
 725 }
 726
 727 EmeConfigRule KeySystemsImpl::GetRobustnessConfigRule(
 728     const std::string& key_system,
 729     EmeMediaType media_type,
 730     const std::string& requested_robustness) const {
 731   DCHECK(thread_checker_.CalledOnValidThread());
 732
 733   EmeRobustness robustness = ConvertRobustness(requested_robustness);
 734   if (robustness == EmeRobustness::INVALID)
 735     return EmeConfigRule::NOT_SUPPORTED;
 736   if (robustness == EmeRobustness::EMPTY)
 737     return EmeConfigRule::SUPPORTED;
 738
 739   KeySystemInfoMap::const_iterator key_system_iter =
 740       concrete_key_system_map_.find(key_system);
 741   if (key_system_iter == concrete_key_system_map_.end()) {
 742     NOTREACHED();
 743     return EmeConfigRule::NOT_SUPPORTED;
 744   }
 745
 746   EmeRobustness max_robustness = EmeRobustness::INVALID;
 747   switch (media_type) {
 748     case EmeMediaType::AUDIO:
 749       max_robustness = key_system_iter->second.max_audio_robustness;
 750       break;
 751     case EmeMediaType::VIDEO:
 752       max_robustness = key_system_iter->second.max_video_robustness;
 753       break;
 754   }
 755
 756   // We can compare robustness levels whenever they are not HW_SECURE_CRYPTO
 757   // and SW_SECURE_DECODE in some order. If they are exactly those two then the
 758   // robustness requirement is not supported.
 759   if ((max_robustness == EmeRobustness::HW_SECURE_CRYPTO &&
 760        robustness == EmeRobustness::SW_SECURE_DECODE) ||
 761       (max_robustness == EmeRobustness::SW_SECURE_DECODE &&
 762        robustness == EmeRobustness::HW_SECURE_CRYPTO) ||
 763       robustness > max_robustness) {
 764     return EmeConfigRule::NOT_SUPPORTED;
 765   }
 766
 767 #if defined(OS_CHROMEOS)
 768   if (key_system == kWidevineKeySystem) {
 769     // Hardware security requires remote attestation.
 770     if (robustness >= EmeRobustness::HW_SECURE_CRYPTO)
 771       return EmeConfigRule::IDENTIFIER_REQUIRED;
 772
 773     // For video, recommend remote attestation if HW_SECURE_ALL is available,
 774     // because it enables hardware accelerated decoding.
 775     // TODO(sandersd): Only do this when hardware accelerated decoding is
 776     // available for the requested codecs.
 777     if (media_type == EmeMediaType::VIDEO &&
 778         max_robustness == EmeRobustness::HW_SECURE_ALL) {
 779       return EmeConfigRule::IDENTIFIER_RECOMMENDED;
 780     }
 781   }
 782 #endif  // defined(OS_CHROMEOS)
 783
 784   return EmeConfigRule::SUPPORTED;
 785 }
 786
 787 EmeConfigRule KeySystemsImpl::GetPersistentLicenseSessionConfigRule(
 788     const std::string& key_system) const {
 789   DCHECK(thread_checker_.CalledOnValidThread());
 790
 791   KeySystemInfoMap::const_iterator key_system_iter =
 792       concrete_key_system_map_.find(key_system);
 793   if (key_system_iter == concrete_key_system_map_.end()) {
 794     NOTREACHED();
 795     return EmeConfigRule::NOT_SUPPORTED;
 796   }
 797   return ConvertSessionTypeSupport(
 798       key_system_iter->second.persistent_license_support);
 799 }
 800
 801 EmeConfigRule KeySystemsImpl::GetPersistentReleaseMessageSessionConfigRule(
 802     const std::string& key_system) const {
 803   DCHECK(thread_checker_.CalledOnValidThread());
 804
 805   KeySystemInfoMap::const_iterator key_system_iter =
 806       concrete_key_system_map_.find(key_system);
 807   if (key_system_iter == concrete_key_system_map_.end()) {
 808     NOTREACHED();
 809     return EmeConfigRule::NOT_SUPPORTED;
 810   }
 811   return ConvertSessionTypeSupport(
 812       key_system_iter->second.persistent_release_message_support);
 813 }
 814
 815 EmeConfigRule KeySystemsImpl::GetPersistentStateConfigRule(
 816     const std::string& key_system,
 817     EmeFeatureRequirement requirement) const {
 818   DCHECK(thread_checker_.CalledOnValidThread());
 819
 820   KeySystemInfoMap::const_iterator key_system_iter =
 821       concrete_key_system_map_.find(key_system);
 822   if (key_system_iter == concrete_key_system_map_.end()) {
 823     NOTREACHED();
 824     return EmeConfigRule::NOT_SUPPORTED;
 825   }
 826
 827   // For NOT_ALLOWED and REQUIRED, the result is as expected. For OPTIONAL, we
 828   // return the most restrictive rule that is not more restrictive than for
 829   // NOT_ALLOWED or REQUIRED. Those values will be checked individually when
 830   // the option is resolved.
 831   //
 832   // Note that even though a distinctive identifier can not be required for
 833   // persistent state, it may still be required for persistent sessions.
 834   //
 835   //                   NOT_ALLOWED    OPTIONAL       REQUIRED
 836   //    NOT_SUPPORTED  P_NOT_ALLOWED  P_NOT_ALLOWED  NOT_SUPPORTED
 837   //      REQUESTABLE  P_NOT_ALLOWED  SUPPORTED      P_REQUIRED
 838   //   ALWAYS_ENABLED  NOT_SUPPORTED  P_REQUIRED     P_REQUIRED
 839   EmeFeatureSupport support = key_system_iter->second.persistent_state_support;
 840   DCHECK(support == EME_FEATURE_NOT_SUPPORTED ||
 841          support == EME_FEATURE_REQUESTABLE ||
 842          support == EME_FEATURE_ALWAYS_ENABLED);
 843   DCHECK(requirement == EME_FEATURE_NOT_ALLOWED ||
 844          requirement == EME_FEATURE_OPTIONAL ||
 845          requirement == EME_FEATURE_REQUIRED);
 846   if ((support == EME_FEATURE_NOT_SUPPORTED &&
 847        requirement == EME_FEATURE_REQUIRED) ||
 848       (support == EME_FEATURE_ALWAYS_ENABLED &&
 849        requirement == EME_FEATURE_NOT_ALLOWED)) {
 850     return EmeConfigRule::NOT_SUPPORTED;
 851   }
 852   if (support == EME_FEATURE_REQUESTABLE &&
 853       requirement == EME_FEATURE_OPTIONAL) {
 854     return EmeConfigRule::SUPPORTED;
 855   }
 856   if (support == EME_FEATURE_NOT_SUPPORTED ||
 857       requirement == EME_FEATURE_NOT_ALLOWED) {
 858     return EmeConfigRule::PERSISTENCE_NOT_ALLOWED;
 859   }
 860   return EmeConfigRule::PERSISTENCE_REQUIRED;
 861 }
 862
 863 EmeConfigRule KeySystemsImpl::GetDistinctiveIdentifierConfigRule(
 864     const std::string& key_system,
 865     EmeFeatureRequirement requirement) const {
 866   DCHECK(thread_checker_.CalledOnValidThread());
 867
 868   KeySystemInfoMap::const_iterator key_system_iter =
 869       concrete_key_system_map_.find(key_system);
 870   if (key_system_iter == concrete_key_system_map_.end()) {
 871     NOTREACHED();
 872     return EmeConfigRule::NOT_SUPPORTED;
 873   }
 874
 875   // For NOT_ALLOWED and REQUIRED, the result is as expected. For OPTIONAL, we
 876   // return the most restrictive rule that is not more restrictive than for
 877   // NOT_ALLOWED or REQUIRED. Those values will be checked individually when
 878   // the option is resolved.
 879   //
 880   //                   NOT_ALLOWED    OPTIONAL       REQUIRED
 881   //    NOT_SUPPORTED  I_NOT_ALLOWED  I_NOT_ALLOWED  NOT_SUPPORTED
 882   //      REQUESTABLE  I_NOT_ALLOWED  SUPPORTED      I_REQUIRED
 883   //   ALWAYS_ENABLED  NOT_SUPPORTED  I_REQUIRED     I_REQUIRED
 884   EmeFeatureSupport support =
 885       key_system_iter->second.distinctive_identifier_support;
 886   DCHECK(support == EME_FEATURE_NOT_SUPPORTED ||
 887          support == EME_FEATURE_REQUESTABLE ||
 888          support == EME_FEATURE_ALWAYS_ENABLED);
 889   DCHECK(requirement == EME_FEATURE_NOT_ALLOWED ||
 890          requirement == EME_FEATURE_OPTIONAL ||
 891          requirement == EME_FEATURE_REQUIRED);
 892   if ((support == EME_FEATURE_NOT_SUPPORTED &&
 893        requirement == EME_FEATURE_REQUIRED) ||
 894       (support == EME_FEATURE_ALWAYS_ENABLED &&
 895        requirement == EME_FEATURE_NOT_ALLOWED)) {
 896     return EmeConfigRule::NOT_SUPPORTED;
 897   }
 898   if (support == EME_FEATURE_REQUESTABLE &&
 899              requirement == EME_FEATURE_OPTIONAL) {
 900     return EmeConfigRule::SUPPORTED;
 901   }
 902   if (support == EME_FEATURE_NOT_SUPPORTED ||
 903              requirement == EME_FEATURE_NOT_ALLOWED) {
 904     return EmeConfigRule::IDENTIFIER_NOT_ALLOWED;
 905   }
 906   return EmeConfigRule::IDENTIFIER_REQUIRED;
 907 }
 908
 909 KeySystems& KeySystems::GetInstance() {
 910   return KeySystemsImpl::GetInstance();
 911 }
 912
 913 //------------------------------------------------------------------------------
 914
 915 std::string GetUnprefixedKeySystemName(const std::string& key_system) {
 916   if (key_system == kClearKeyKeySystem)
 917     return kUnsupportedClearKeyKeySystem;
 918
 919   if (key_system == kPrefixedClearKeyKeySystem)
 920     return kClearKeyKeySystem;
 921
 922   return key_system;
 923 }
 924
 925 std::string GetPrefixedKeySystemName(const std::string& key_system) {
 926   DCHECK_NE(key_system, kPrefixedClearKeyKeySystem);
 927
 928   if (key_system == kClearKeyKeySystem)
 929     return kPrefixedClearKeyKeySystem;
 930
 931   return key_system;
 932 }
 933
 934 bool PrefixedIsSupportedConcreteKeySystem(const std::string& key_system) {
 935   return KeySystemsImpl::GetInstance().IsConcreteSupportedKeySystem(key_system);
 936 }
 937
 938 bool IsSupportedKeySystem(const std::string& key_system) {
 939   if (!KeySystemsImpl::GetInstance().IsSupportedKeySystem(key_system))
 940     return false;
 941
 942   // TODO(ddorwin): Move this to where we add key systems when prefixed EME is
 943   // removed (crbug.com/249976).
 944   if (!IsPotentiallySupportedKeySystem(key_system)) {
 945     // If you encounter this path, see the comments for the above function.
 946     NOTREACHED() << "Unrecognized key system " << key_system
 947                  << ". See code comments.";
 948     return false;
 949   }
 950
 951   return true;
 952 }
 953
 954 bool IsSupportedKeySystemWithInitDataType(const std::string& key_system,
 955                                           EmeInitDataType init_data_type) {
 956   return KeySystemsImpl::GetInstance().IsSupportedInitDataType(key_system,
 957                                                                init_data_type);
 958 }
 959
 960 bool PrefixedIsSupportedKeySystemWithMediaMimeType(
 961     const std::string& mime_type,
 962     const std::vector<std::string>& codecs,
 963     const std::string& key_system) {
 964   return KeySystemsImpl::GetInstance()
 965       .PrefixedIsSupportedKeySystemWithMediaMimeType(mime_type, codecs,
 966                                                      key_system);
 967 }
 968
 969 std::string GetKeySystemNameForUMA(const std::string& key_system) {
 970   return KeySystemsImpl::GetInstance().GetKeySystemNameForUMA(key_system);
 971 }
 972
 973 bool CanUseAesDecryptor(const std::string& concrete_key_system) {
 974   return KeySystemsImpl::GetInstance().UseAesDecryptor(concrete_key_system);
 975 }
 976
 977 #if defined(ENABLE_PEPPER_CDMS)
 978 std::string GetPepperType(const std::string& concrete_key_system) {
 979   return KeySystemsImpl::GetInstance().GetPepperType(concrete_key_system);
 980 }
 981 #endif
 982
 983 // These two functions are for testing purpose only. The declaration in the
 984 // header file is guarded by "#if defined(UNIT_TEST)" so that they can be used
 985 // by tests but not non-test code. However, this .cc file is compiled as part of
 986 // "media" where "UNIT_TEST" is not defined. So we need to specify
 987 // "MEDIA_EXPORT" here again so that they are visible to tests.
 988
 989 MEDIA_EXPORT void AddContainerMask(const std::string& container, uint32 mask) {
 990   KeySystemsImpl::GetInstance().AddContainerMask(container, mask);
 991 }
 992
 993 MEDIA_EXPORT void AddCodecMask(
 994     EmeMediaType media_type,
 995     const std::string& codec,
 996     uint32 mask) {
 997   KeySystemsImpl::GetInstance().AddCodecMask(media_type, codec, mask);
 998 }
 999
1000 }  // namespace media