Support HLS MPEG2 TS with SAMPLE-AES encryption.

media/formats/mp2t/mp2t_stream_parser_unittest.cc

 // Copyright 2014 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 <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
+#include "base/strings/string_number_conversions.h"
 #include "base/time/time.h"
 #include "media/base/audio_decoder_config.h"
 #include "media/base/decoder_buffer.h"
 #include "media/base/media_track.h"
 #include "media/base/media_tracks.h"
 #include "media/base/stream_parser_buffer.h"
 #include "media/base/test_data_util.h"
 #include "media/base/text_track_config.h"
 #include "media/base/video_decoder_config.h"
 #include "media/formats/mp2t/mp2t_stream_parser.h"
+#include "media/media_features.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+#if BUILDFLAG(ENABLE_HLS_SAMPLE_AES)
+#include <openssl/aes.h>
+#include <openssl/evp.h>
+#include "crypto/openssl_util.h"
+#endif
+
 namespace media {
 namespace mp2t {
 
 namespace {
 
 bool IsMonotonic(const StreamParser::BufferQueue& buffers) {
   if (buffers.empty())
     return true;
 
   StreamParser::BufferQueue::const_iterator it1 = buffers.begin();
   StreamParser::BufferQueue::const_iterator it2 = ++it1;
   for ( ; it2 != buffers.end(); ++it1, ++it2) {
     if ((*it2)->GetDecodeTimestamp() < (*it1)->GetDecodeTimestamp())
       return false;
   }
   return true;
 }
 
 bool IsAlmostEqual(DecodeTimestamp t0, DecodeTimestamp t1) {
   base::TimeDelta kMaxDeviation = base::TimeDelta::FromMilliseconds(5);
   base::TimeDelta diff = t1 - t0;
   return (diff >= -kMaxDeviation && diff <= kMaxDeviation);
 }
 
+#if BUILDFLAG(ENABLE_HLS_SAMPLE_AES)
+class ScopedCipherCTX {
+ public:
+  explicit ScopedCipherCTX() { EVP_CIPHER_CTX_init(&ctx_); }
+  ~ScopedCipherCTX() {
+    EVP_CIPHER_CTX_cleanup(&ctx_);
+    crypto::ClearOpenSSLERRStack(FROM_HERE);
+  }
+  EVP_CIPHER_CTX* get() { return &ctx_; }
+
+ private:
+  EVP_CIPHER_CTX ctx_;
+};
+
+std::string DecryptSampleAES(const std::string& key,
+                             const std::string& iv,
+                             const uint8_t* input,
+                             int input_size,
+                             bool has_pattern) {
+  DCHECK(input);
+  EXPECT_EQ(input_size % 16, 0);
+  crypto::EnsureOpenSSLInit();
+  std::string result;
+  const EVP_CIPHER* cipher = EVP_aes_128_cbc();
+  ScopedCipherCTX ctx;
+  EXPECT_EQ(EVP_CipherInit_ex(ctx.get(), cipher, NULL,
+                              reinterpret_cast<const uint8_t*>(key.data()),
+                              reinterpret_cast<const uint8_t*>(iv.data()), 0),
+            1);
+  EVP_CIPHER_CTX_set_padding(ctx.get(), 0);
+  const size_t output_size = input_size;
+  scoped_ptr<char[]> output(new char[output_size]);
+  uint8_t* in_ptr = const_cast<uint8_t*>(input);
+  uint8_t* out_ptr = reinterpret_cast<uint8_t*>(output.get());
+  size_t bytes_remaining = output_size;
+
+  while (bytes_remaining) {
+    int unused;
+    size_t amount_to_decrypt = has_pattern ? 16UL : bytes_remaining;
+    EXPECT_EQ(EVP_CipherUpdate(ctx.get(), out_ptr, &unused, in_ptr,
+                               amount_to_decrypt),
+              1);
+    bytes_remaining -= amount_to_decrypt;
+    if (bytes_remaining) {
+      out_ptr += amount_to_decrypt;
+      in_ptr += amount_to_decrypt;
+      size_t amount_to_skip = 144UL;
+      if (amount_to_skip > bytes_remaining)
+        amount_to_skip = bytes_remaining;
+      memcpy(out_ptr, in_ptr, amount_to_skip);
+      out_ptr += amount_to_skip;
+      in_ptr += amount_to_skip;
+      bytes_remaining -= amount_to_skip;
+    }
+  }
+
+  result.assign(output.get(), output_size);
+  return result;
+}
+
+// We only support AES-CBC at this time.
+// For the purpose of these tests, the key id is also used as the actual key.
+std::string DecryptBuffer(const StreamParserBuffer& buffer,
+                          const EncryptionScheme& scheme) {
+  EXPECT_TRUE(scheme.is_encrypted());
+  EXPECT_TRUE(scheme.mode() == EncryptionScheme::CIPHER_MODE_AES_CBC);
+  bool has_pattern = scheme.pattern().IsInEffect();
+  EXPECT_TRUE(!has_pattern ||
+              scheme.pattern().Matches(EncryptionScheme::Pattern(1, 9)));
+  std::string key = buffer.decrypt_config()->key_id();

[ddorwin, 2016/03/24 22:44:52]

Related to my other comment, I suggest actually doing a lookup. All of our other
files are encrypted with the same key. See
https://code.google.com/p/chromium/codesearch#chromium/src/media/test/pipelin....
That would also allow these files to be run through pipeline and browser tests
if you wished.

[dougsteed, 2016/03/31 19:09:50]

Done.

+  std::string iv = buffer.decrypt_config()->iv();
+  EXPECT_EQ(key.size(), 16UL);
+  EXPECT_EQ(iv.size(), 16UL);
+  std::string result;
+  uint8_t* in_ptr = const_cast<uint8_t*>(buffer.data());
+  const DecryptConfig* decrypt_config = buffer.decrypt_config();
+  for (const auto& subsample : decrypt_config->subsamples()) {
+    std::string clear(reinterpret_cast<char*>(in_ptr), subsample.clear_bytes);
+    result += clear;
+    in_ptr += subsample.clear_bytes;
+    result +=
+        DecryptSampleAES(key, iv, in_ptr, subsample.cypher_bytes, has_pattern);
+    in_ptr += subsample.cypher_bytes;
+  }
+  return result;
+}
+#endif
+
 }  // namespace
 
 class Mp2tStreamParserTest : public testing::Test {
  public:
   Mp2tStreamParserTest()
       : segment_count_(0),
         config_count_(0),
         audio_frame_count_(0),
         video_frame_count_(0),
         has_video_(true),
         audio_min_dts_(kNoDecodeTimestamp()),
         audio_max_dts_(kNoDecodeTimestamp()),
         video_min_dts_(kNoDecodeTimestamp()),
-        video_max_dts_(kNoDecodeTimestamp()) {
+        video_max_dts_(kNoDecodeTimestamp()),
+        current_audio_config_(),
+        current_video_config_(),
+        capture_buffers(false) {
     bool has_sbr = false;
     parser_.reset(new Mp2tStreamParser(has_sbr));
   }
 
  protected:
   scoped_ptr<Mp2tStreamParser> parser_;
   int segment_count_;
   int config_count_;
   int audio_frame_count_;
   int video_frame_count_;
   bool has_video_;
   DecodeTimestamp audio_min_dts_;
   DecodeTimestamp audio_max_dts_;
   DecodeTimestamp video_min_dts_;
   DecodeTimestamp video_max_dts_;
 
+  AudioDecoderConfig current_audio_config_;
+  VideoDecoderConfig current_video_config_;
+  std::vector<scoped_refptr<StreamParserBuffer>> audio_buffer_capture_;
+  std::vector<scoped_refptr<StreamParserBuffer>> video_buffer_capture_;
+  bool capture_buffers;
+
   void ResetStats() {
     segment_count_ = 0;
     config_count_ = 0;
     audio_frame_count_ = 0;
     video_frame_count_ = 0;
     audio_min_dts_ = kNoDecodeTimestamp();
     audio_max_dts_ = kNoDecodeTimestamp();
     video_min_dts_ = kNoDecodeTimestamp();
     video_max_dts_ = kNoDecodeTimestamp();
   }
@@ skipping 24 matching lines @@
 
   bool OnNewConfig(scoped_ptr<MediaTracks> tracks,
                    const StreamParser::TextTrackConfigMap& tc) {
     const AudioDecoderConfig& ac = tracks->getFirstAudioConfig();
     const VideoDecoderConfig& vc = tracks->getFirstVideoConfig();
     DVLOG(1) << "OnNewConfig: media tracks count=" << tracks->tracks().size()
              << ", audio=" << ac.IsValidConfig()
              << ", video=" << vc.IsValidConfig();
     config_count_++;
     EXPECT_TRUE(ac.IsValidConfig());
+    current_audio_config_ = ac;
     EXPECT_EQ(vc.IsValidConfig(), has_video_);
+    current_video_config_ = vc;
     return true;
   }
 
+  void CaptureVideoBuffers(const StreamParser::BufferQueue& video_buffers) {
+    for (const auto& buffer : video_buffers) {
+      video_buffer_capture_.push_back(buffer);
+    }
+  }
+
+  void CaptureAudioBuffers(const StreamParser::BufferQueue& audio_buffers) {
+    for (const auto& buffer : audio_buffers) {
+      audio_buffer_capture_.push_back(buffer);
+    }
+  }
 
   void DumpBuffers(const std::string& label,
                    const StreamParser::BufferQueue& buffers) {
     DVLOG(2) << "DumpBuffers: " << label << " size " << buffers.size();
     for (StreamParser::BufferQueue::const_iterator buf = buffers.begin();
          buf != buffers.end(); buf++) {
       DVLOG(3) << "  n=" << buf - buffers.begin()
                << ", size=" << (*buf)->data_size()
                << ", dur=" << (*buf)->duration().InMilliseconds();
     }
   }
 
   bool OnNewBuffers(const StreamParser::BufferQueue& audio_buffers,
                     const StreamParser::BufferQueue& video_buffers,
                     const StreamParser::TextBufferQueueMap& text_map) {
     EXPECT_GT(config_count_, 0);
     DumpBuffers("audio_buffers", audio_buffers);
     DumpBuffers("video_buffers", video_buffers);
+    if (capture_buffers) {
+      CaptureVideoBuffers(video_buffers);
+      CaptureAudioBuffers(audio_buffers);
+    }
 
     // TODO(wolenetz/acolwell): Add text track support to more MSE parsers. See
     // http://crbug.com/336926.
     if (!text_map.empty())
       return false;
 
     // Verify monotonicity.
     if (!IsMonotonic(video_buffers))
       return false;
     if (!IsMonotonic(audio_buffers))
@@ skipping 18 matching lines @@
       audio_max_dts_ = last_dts;
     }
 
     audio_frame_count_ += audio_buffers.size();
     video_frame_count_ += video_buffers.size();
     return true;
   }
 
   void OnKeyNeeded(EmeInitDataType type,
                    const std::vector<uint8_t>& init_data) {
-    NOTREACHED() << "OnKeyNeeded not expected in the Mpeg2 TS parser";
   }
 
   void OnNewSegment() {
     DVLOG(1) << "OnNewSegment";
     segment_count_++;
   }
 
   void OnEndOfSegment() {
     NOTREACHED() << "OnEndOfSegment not expected in the Mpeg2 TS parser";
   }
@@ skipping 96 matching lines @@
   has_video_ = false;
   ParseMpeg2TsFile("bear_adts_in_private_stream_1.ts", 512);
   parser_->Flush();
   EXPECT_EQ(audio_frame_count_, 40);
   EXPECT_EQ(video_frame_count_, 0);
   // This stream has no mid-stream configuration change.
   EXPECT_EQ(config_count_, 1);
   EXPECT_EQ(segment_count_, 1);
 }
 
+#if BUILDFLAG(ENABLE_HLS_SAMPLE_AES)
+TEST_F(Mp2tStreamParserTest, HLSSampleAES) {
+  std::vector<std::string> decrypted_video_buffers;
+  std::vector<std::string> decrypted_audio_buffers;
+  InitializeParser();
+  capture_buffers = true;
+  ParseMpeg2TsFile("bear-1280x720-hls-sample-aes.ts", 2048);
+  parser_->Flush();
+  EncryptionScheme video_encryption_scheme =
+      current_video_config_.encryption_scheme();
+  EXPECT_TRUE(video_encryption_scheme.is_encrypted());
+  for (const auto& buffer : video_buffer_capture_) {
+    std::string decrypted_video_buffer =
+        DecryptBuffer(*buffer.get(), video_encryption_scheme);
+    decrypted_video_buffers.push_back(decrypted_video_buffer);
+  }
+  EncryptionScheme audio_encryption_scheme =
+      current_audio_config_.encryption_scheme();
+  EXPECT_TRUE(audio_encryption_scheme.is_encrypted());
+  for (const auto& buffer : audio_buffer_capture_) {
+    std::string decrypted_audio_buffer =
+        DecryptBuffer(*buffer.get(), audio_encryption_scheme);
+    decrypted_audio_buffers.push_back(decrypted_audio_buffer);
+  }
+
+  parser_.reset(new Mp2tStreamParser(false));
+  ResetStats();
+  InitializeParser();
+  video_buffer_capture_.clear();
+  audio_buffer_capture_.clear();
+  ParseMpeg2TsFile("bear-1280x720-hls.ts", 2048);
+  parser_->Flush();
+  video_encryption_scheme = current_video_config_.encryption_scheme();
+  EXPECT_FALSE(video_encryption_scheme.is_encrypted());
+  // Skip the last buffer, which may be truncated.
+  for (size_t i = 0; i + 1 < video_buffer_capture_.size(); i++) {
+    const auto& buffer = video_buffer_capture_[i];
+    std::string unencrypted_video_buffer(
+        reinterpret_cast<const char*>(buffer->data()), buffer->data_size());
+    EXPECT_EQ(decrypted_video_buffers[i], unencrypted_video_buffer);
+  }
+  audio_encryption_scheme = current_audio_config_.encryption_scheme();
+  EXPECT_FALSE(audio_encryption_scheme.is_encrypted());
+  for (size_t i = 0; i + 1 < audio_buffer_capture_.size(); i++) {
+    const auto& buffer = audio_buffer_capture_[i];
+    std::string unencrypted_audio_buffer(
+        reinterpret_cast<const char*>(buffer->data()), buffer->data_size());
+    EXPECT_EQ(decrypted_audio_buffers[i], unencrypted_audio_buffer);
+  }
+}
+#endif
+
 }  // namespace mp2t
 }  // namespace media