[Fuchsia] Always enable CBCS encryption scheme

enable_cbcs_encryption_scheme flag was set on all platforms except
Fuchsia. There is no reason this feature needs to be disabled on
Fuchsia. Remove this flag.

Bug: 1021308
Change-Id: If79065f337119f9098254f21caa12bec79609b4d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1898640Reviewed-by: John Rummell <jrummell@chromium.org>
Reviewed-by: David Dorwin <ddorwin@chromium.org>
Commit-Queue: Sergey Ulanov <sergeyu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#712815}

chrome/browser/media/encrypted_media_browsertest.cc

@@ -722,11 +722,7 @@ IN_PROC_BROWSER_TEST_P(EncryptedMediaTest, Playback_Encryption_CBCS) {
     return;
   }
 
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
   TestSimplePlayback("bear-640x360-v_frag-cbcs.mp4");
-#else
-  DVLOG(0) << "Skipping test; 'cbcs' decryption not supported.";
-#endif
 }
 
 IN_PROC_BROWSER_TEST_P(EncryptedMediaTest,
@@ -861,9 +857,7 @@ IN_PROC_BROWSER_TEST_P(ECKEncryptedMediaTest, DecryptOnly_VideoOnly_MP4_CBCS) {
   // 'cbcs' decryption is only supported on CDM 10 or later as long as
   // the appropriate buildflag is enabled.
   std::string expected_result =
-      GetCdmInterfaceVersion() >= 10 && BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
-          ? media::kEnded
-          : media::kError;
+      GetCdmInterfaceVersion() >= 10 ? media::kEnded : media::kError;
   RunEncryptedMediaTest(kDefaultEmePlayer, "bear-640x360-v_frag-cbcs.mp4",
                         kExternalClearKeyDecryptOnlyKeySystem, SrcType::MSE,
                         kNoSessionToLoad, false, PlayCount::ONCE,
@@ -894,9 +888,7 @@ IN_PROC_BROWSER_TEST_P(ECKEncryptedMediaTest, Playback_Encryption_CBCS) {
   // 'cbcs' decryption is only supported on CDM 10 or later as long as
   // the appropriate buildflag is enabled.
   std::string expected_result =
-      GetCdmInterfaceVersion() >= 10 && BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
-          ? media::kEnded
-          : media::kError;
+      GetCdmInterfaceVersion() >= 10 ? media::kEnded : media::kError;
   RunEncryptedMediaMultipleFileTest(
       kExternalClearKeyKeySystem, "bear-640x360-v_frag-cbcs.mp4",
       "bear-640x360-a_frag-cbcs.mp4", expected_result);

content/browser/media/encrypted_media_browsertest.cc

@@ -383,26 +383,20 @@ IN_PROC_BROWSER_TEST_P(EncryptedMediaTest, Playback_Encryption_CENS) {
 }
 
 IN_PROC_BROWSER_TEST_P(EncryptedMediaTest, Playback_Encryption_CBCS) {
-  std::string expected_result =
-      BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME) ? media::kEnded : media::kError;
   RunMultipleFileTest("bear-640x360-v_frag-cbcs.mp4",
-                      "bear-640x360-a_frag-cbcs.mp4", expected_result);
+                      "bear-640x360-a_frag-cbcs.mp4", media::kEnded);
 }
 
 IN_PROC_BROWSER_TEST_P(EncryptedMediaTest,
                        Playback_Encryption_CBCS_Video_CENC_Audio) {
-  std::string expected_result =
-      BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME) ? media::kEnded : media::kError;
   RunMultipleFileTest("bear-640x360-v_frag-cbcs.mp4",
-                      "bear-640x360-a_frag-cenc.mp4", expected_result);
+                      "bear-640x360-a_frag-cenc.mp4", media::kEnded);
 }
 
 IN_PROC_BROWSER_TEST_P(EncryptedMediaTest,
                        Playback_Encryption_CENC_Video_CBCS_Audio) {
-  std::string expected_result =
-      BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME) ? media::kEnded : media::kError;
   RunMultipleFileTest("bear-640x360-v_frag-cenc.mp4",
-                      "bear-640x360-a_frag-cbcs.mp4", expected_result);
+                      "bear-640x360-a_frag-cbcs.mp4", media::kEnded);
 }
 #endif  // BUILDFLAG(USE_PROPRIETARY_CODECS)
 

media/BUILD.gn

@@ -21,7 +21,6 @@ buildflag_header("media_buildflags") {
     "ALTERNATE_CDM_STORAGE_ID_KEY=\"$alternate_cdm_storage_id_key\"",
     "CDM_PLATFORM_SPECIFIC_PATH=\"$cdm_platform_specific_path\"",
     "ENABLE_PLATFORM_AC3_EAC3_AUDIO=$enable_platform_ac3_eac3_audio",
-    "ENABLE_CBCS_ENCRYPTION_SCHEME=$enable_cbcs_encryption_scheme",
     "ENABLE_CDM_HOST_VERIFICATION=$enable_cdm_host_verification",
     "ENABLE_CDM_PROXY=$enable_cdm_proxy",
     "ENABLE_CDM_STORAGE_ID=$enable_cdm_storage_id",

media/formats/mp4/box_definitions.cc

@@ -297,15 +297,10 @@ bool SchemeType::Parse(BoxReader* reader) {
 
 TrackEncryption::TrackEncryption()
     : is_encrypted(false),
-      default_iv_size(0)
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
-      ,
+      default_iv_size(0),
       default_crypt_byte_block(0),
       default_skip_byte_block(0),
-      default_constant_iv_size(0)
-#endif
-{
-}
+      default_constant_iv_size(0) {}
 TrackEncryption::TrackEncryption(const TrackEncryption& other) = default;
 TrackEncryption::~TrackEncryption() = default;
 FourCC TrackEncryption::BoxType() const { return FOURCC_TENC; }
@@ -320,7 +315,6 @@ bool TrackEncryption::Parse(BoxReader* reader) {
          reader->ReadVec(&default_kid, kKeyIdSize));
   is_encrypted = (flag != 0);
   if (is_encrypted) {
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
     if (reader->version() > 0) {
       default_crypt_byte_block = (possible_pattern_info >> 4) & 0x0f;
       default_skip_byte_block = possible_pattern_info & 0x0f;
@@ -334,9 +328,6 @@ bool TrackEncryption::Parse(BoxReader* reader) {
     } else {
       RCHECK(default_iv_size == 8 || default_iv_size == 16);
     }
-#else
-    RCHECK(default_iv_size == 8 || default_iv_size == 16);
-#endif
   } else {
     RCHECK(default_iv_size == 0);
   }
@@ -373,22 +364,12 @@ bool ProtectionSchemeInfo::Parse(BoxReader* reader) {
 
 bool ProtectionSchemeInfo::HasSupportedScheme() const {
   FourCC four_cc = type.type;
-  if (four_cc == FOURCC_CENC)
-    return true;
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
-  if (four_cc == FOURCC_CBCS)
-    return true;
-#endif
-  return false;
+  return (four_cc == FOURCC_CENC || four_cc == FOURCC_CBCS);
 }
 
 bool ProtectionSchemeInfo::IsCbcsEncryptionScheme() const {
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
   FourCC four_cc = type.type;
   return (four_cc == FOURCC_CBCS);
-#else
-  return false;
-#endif
 }
 
 MovieHeader::MovieHeader()
@@ -1614,15 +1595,10 @@ bool SampleToGroup::Parse(BoxReader* reader) {
 
 CencSampleEncryptionInfoEntry::CencSampleEncryptionInfoEntry()
     : is_encrypted(false),
-      iv_size(0)
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
-      ,
+      iv_size(0),
       crypt_byte_block(0),
       skip_byte_block(0),
-      constant_iv_size(0)
-#endif
-{
-}
+      constant_iv_size(0) {}
 CencSampleEncryptionInfoEntry::CencSampleEncryptionInfoEntry(
     const CencSampleEncryptionInfoEntry& other) = default;
 CencSampleEncryptionInfoEntry::~CencSampleEncryptionInfoEntry() = default;
@@ -1636,7 +1612,6 @@ bool CencSampleEncryptionInfoEntry::Parse(BoxReader* reader) {
 
   is_encrypted = (flag != 0);
   if (is_encrypted) {
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
     crypt_byte_block = (possible_pattern_info >> 4) & 0x0f;
     skip_byte_block = possible_pattern_info & 0x0f;
     if (iv_size == 0) {
@@ -1648,9 +1623,6 @@ bool CencSampleEncryptionInfoEntry::Parse(BoxReader* reader) {
     } else {
       RCHECK(iv_size == 8 || iv_size == 16);
     }
-#else
-    RCHECK(iv_size == 8 || iv_size == 16);
-#endif
   } else {
     RCHECK(iv_size == 0);
   }

media/formats/mp4/box_definitions.h

@@ -133,12 +133,10 @@ struct MEDIA_EXPORT TrackEncryption : Box {
   bool is_encrypted;
   uint8_t default_iv_size;
   std::vector<uint8_t> default_kid;
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
   uint8_t default_crypt_byte_block;
   uint8_t default_skip_byte_block;
   uint8_t default_constant_iv_size;
   uint8_t default_constant_iv[kInitializationVectorSize];
-#endif
 };
 
 struct MEDIA_EXPORT SchemeInfo : Box {
@@ -357,12 +355,10 @@ struct MEDIA_EXPORT CencSampleEncryptionInfoEntry {
   bool is_encrypted;
   uint8_t iv_size;
   std::vector<uint8_t> key_id;
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
   uint8_t crypt_byte_block;
   uint8_t skip_byte_block;
   uint8_t constant_iv_size;
   uint8_t constant_iv[kInitializationVectorSize];
-#endif
 };
 
 struct MEDIA_EXPORT SampleGroupDescription : Box {  // 'sgpd'.

media/formats/mp4/mp4_stream_parser.cc

@@ -51,29 +51,23 @@ EncryptionScheme GetEncryptionScheme(const ProtectionSchemeInfo& sinf) {
   FourCC fourcc = sinf.type.type;
   EncryptionScheme::CipherMode mode = EncryptionScheme::CIPHER_MODE_UNENCRYPTED;
   EncryptionPattern pattern;
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
   bool uses_pattern_encryption = false;
-#endif
   switch (fourcc) {
     case FOURCC_CENC:
       mode = EncryptionScheme::CIPHER_MODE_AES_CTR;
       break;
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
     case FOURCC_CBCS:
       mode = EncryptionScheme::CIPHER_MODE_AES_CBC;
       uses_pattern_encryption = true;
       break;
-#endif
     default:
       NOTREACHED();
       break;
   }
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
   if (uses_pattern_encryption) {
     pattern = {sinf.info.track_encryption.default_crypt_byte_block,
                sinf.info.track_encryption.default_skip_byte_block};
   }
-#endif
   return EncryptionScheme(mode, pattern);
 }
 }  // namespace

media/formats/mp4/track_run_iterator.cc

@@ -57,9 +57,7 @@ struct TrackRunInfo {
   int aux_info_total_size;
 
   EncryptionMode encryption_mode;
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
   EncryptionPattern encryption_pattern;
-#endif  // BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
 
   std::vector<CencSampleEncryptionInfoEntry> fragment_sample_encryption_info;
 
@@ -376,17 +374,12 @@ bool TrackRunIterator::Init(const MovieFragment& moof) {
       if (!sinf->HasSupportedScheme()) {
         tri.encryption_mode = EncryptionMode::kUnencrypted;
       } else {
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
         tri.encryption_mode = sinf->IsCbcsEncryptionScheme()
                                   ? EncryptionMode::kCbcs
                                   : EncryptionMode::kCenc;
         tri.encryption_pattern =
             EncryptionPattern(track_encryption->default_crypt_byte_block,
                               track_encryption->default_skip_byte_block);
-#else
-        DCHECK(!sinf->IsCbcsEncryptionScheme());
-        tri.encryption_mode = EncryptionMode::kCenc;
-#endif
       }
 
       // Initialize aux_info variables only if no sample encryption entries.
@@ -500,7 +493,6 @@ bool TrackRunIterator::Init(const MovieFragment& moof) {
           SampleEncryptionEntry& entry = tri.sample_encryption_entries[k];
           RCHECK(entry.Parse(sample_encryption_reader.get(), iv_size,
                              traf.sample_encryption.use_subsample_encryption));
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
           // If we don't have a per-sample IV, get the constant IV.
           bool is_encrypted = index == 0 ? track_encryption->is_encrypted
                                          : info_entry->is_encrypted;
@@ -534,7 +526,6 @@ bool TrackRunIterator::Init(const MovieFragment& moof) {
                            : info_entry->constant_iv;
             memcpy(entry.initialization_vector, constant_iv, constant_iv_size);
           }
-#endif  // BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
         }
       }
       runs_.push_back(tri);
@@ -620,12 +611,10 @@ bool TrackRunIterator::CacheAuxInfo(const uint8_t* buf, int buf_size) {
       RCHECK_MEDIA_LOGGED(
           entry.Parse(&reader, iv_size, has_subsamples), media_log_,
           "SampleEncryptionEntry parse failed when caching aux info");
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
       // if we don't have a per-sample IV, get the constant IV.
       if (!iv_size) {
         RCHECK(ApplyConstantIv(i, &entry));
       }
-#endif
     }
     pos += info_size;
   }
@@ -751,7 +740,6 @@ std::unique_ptr<DecryptConfig> TrackRunIterator::GetDecryptConfig() {
 
   if (run_itr_->sample_encryption_entries.empty()) {
     DCHECK_EQ(0, aux_info_size());
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
     // The 'cbcs' scheme allows empty aux info when a constant IV is in use
     // with full sample encryption. That case will fall through to here.
     SampleEncryptionEntry sample_encryption_entry;
@@ -771,7 +759,6 @@ std::unique_ptr<DecryptConfig> TrackRunIterator::GetDecryptConfig() {
               run_itr_->encryption_pattern);
       }
     }
-#endif
     MEDIA_LOG(ERROR, media_log_) << "Sample encryption info is not available.";
     return nullptr;
   }
@@ -791,7 +778,6 @@ std::unique_ptr<DecryptConfig> TrackRunIterator::GetDecryptConfig() {
     return nullptr;
   }
 
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
   if (protection_scheme_info().IsCbcsEncryptionScheme()) {
     uint32_t index = GetGroupDescriptionIndex(sample_idx);
     uint32_t encrypt_blocks =
@@ -806,7 +792,6 @@ std::unique_ptr<DecryptConfig> TrackRunIterator::GetDecryptConfig() {
         key_id, iv, sample_encryption_entry.subsamples,
         EncryptionPattern(encrypt_blocks, skip_blocks));
   }
-#endif
 
   return DecryptConfig::CreateCencConfig(key_id, iv,
                                          sample_encryption_entry.subsamples);
@@ -839,7 +824,6 @@ uint8_t TrackRunIterator::GetIvSize(size_t sample_index) const {
                       : GetSampleEncryptionInfoEntry(*run_itr_, index)->iv_size;
 }
 
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
 bool TrackRunIterator::ApplyConstantIv(size_t sample_index,
                                        SampleEncryptionEntry* entry) const {
   DCHECK(IsSampleEncrypted(sample_index));
@@ -856,7 +840,6 @@ bool TrackRunIterator::ApplyConstantIv(size_t sample_index,
   memcpy(entry->initialization_vector, constant_iv, kInitializationVectorSize);
   return true;
 }
-#endif
 
 }  // namespace mp4
 }  // namespace media

media/formats/mp4/track_run_iterator.h

@@ -104,9 +104,7 @@ class MEDIA_EXPORT TrackRunIterator {
   bool IsSampleEncrypted(size_t sample_index) const;
   uint8_t GetIvSize(size_t sample_index) const;
   const std::vector<uint8_t>& GetKeyId(size_t sample_index) const;
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
   bool ApplyConstantIv(size_t sample_index, SampleEncryptionEntry* entry) const;
-#endif
 
   const Movie* moov_;
   MediaLog* media_log_;

media/formats/mp4/track_run_iterator_unittest.cc

@@ -97,7 +97,6 @@ const uint8_t kFragmentCencSampleGroupKeyId[] = {
     0x74, 0x43, 0x65, 0x6e, 0x63, 0x53, 0x61, 0x6d,
 };
 
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
 // Sample encryption data for two samples, using constant IV (defined by 'tenc'
 // or sample group entry).
 const uint8_t kSampleEncryptionDataWithSubsamplesAndConstantIv[] = {
@@ -137,7 +136,6 @@ const char kIv5[] = {
     0x41, 0x54, 0x65, 0x73, 0x74, 0x49, 0x76, 0x35,
     0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
 };
-#endif
 
 }  // namespace
 
@@ -425,7 +423,6 @@ class TrackRunIteratorTest : public testing::Test {
     }
   }
 
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
   // Update the first sample description of a Track to indicate CBCS encryption
   // with a constant IV and pattern.
   void AddEncryptionCbcs(Track* track) {
@@ -487,7 +484,6 @@ class TrackRunIteratorTest : public testing::Test {
     frag->auxiliary_size.sample_info_sizes.push_back(16);
     frag->auxiliary_size.sample_info_sizes.push_back(16);
   }
-#endif
 
   bool InitMoofWithArbitraryAuxInfo(MovieFragment* moof) {
     // Add aux info header (equal sized aux info for every sample).
@@ -1017,7 +1013,6 @@ TEST_F(TrackRunIteratorTest, KeyFrameFlagCombinations) {
   EXPECT_EQ("2 K P P P K P", KeyframeAndRAPInfo(iter_.get()));
 }
 
-#if BUILDFLAG(ENABLE_CBCS_ENCRYPTION_SCHEME)
 TEST_F(TrackRunIteratorTest, DecryptConfigTestWithConstantIvNoAuxInfo) {
   AddEncryptionCbcs(&moov_.tracks[1]);
   iter_.reset(new TrackRunIterator(&moov_, &media_log_));
@@ -1107,7 +1102,5 @@ TEST_F(TrackRunIteratorTest, DecryptConfigTestWithSampleGroupsAndConstantIv) {
   EXPECT_EQ(track_encryption_iv, iter_->GetDecryptConfig()->iv());
 }
 
-#endif
-
 }  // namespace mp4
 }  // namespace media

media/media_options.gni

@@ -70,11 +70,6 @@ declare_args() {
   enable_mse_mpeg2ts_stream_parser =
       proprietary_codecs && (is_chromecast || is_fuchsia || use_fuzzing_engine)
 
-  # Enable parsing for the 'cbcs' encryption scheme added by MPEG Common
-  # Encryption 3rd Edition (ISO/IEC 23001-7), published 02/15/2016.
-  enable_cbcs_encryption_scheme =
-      is_chromecast || is_mac || is_win || is_linux || is_android
-
   # Enable HEVC/H265 demuxing. Actual decoding must be provided by the
   # platform. Enabled by default for Chromecast.
   enable_platform_hevc = proprietary_codecs && is_chromecast