Support HLS MPEG2 TS with SAMPLE-AES encryption.

media/formats/mp2t/mp2t_stream_parser_unittest.cc

Index: media/formats/mp2t/mp2t_stream_parser_unittest.cc
diff --git a/media/formats/mp2t/mp2t_stream_parser_unittest.cc b/media/formats/mp2t/mp2t_stream_parser_unittest.cc
index 6663a054814262dca5aa63809798656d3f6328db..5188683479ea2af03af5132e4a101bfeba05f66a 100644
--- a/media/formats/mp2t/mp2t_stream_parser_unittest.cc
+++ b/media/formats/mp2t/mp2t_stream_parser_unittest.cc
@@ -5,11 +5,20 @@
 #include <algorithm>
 #include <string>
 
+#ifdef ENABLE_HLS_SAMPLE_AES
+#include <openssl/aes.h>

[ddorwin, 2015/12/10 20:10:59]

The Clear Key implementation supports AES via crypto/ without going directly to
openssl. What is special here?

You'll probably need a crypto/ owner to review this (if you can't use crypto/
instead).

[dougsteed, 2015/12/14 22:51:46]

See comment on my change to BUILD.gn.

+#include <openssl/evp.h>
+#endif
+
 #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"
+#ifdef ENABLE_HLS_SAMPLE_AES
+#include "crypto/openssl_util.h"
+#endif
 #include "media/base/audio_decoder_config.h"
 #include "media/base/decoder_buffer.h"
 #include "media/base/stream_parser_buffer.h"
@@ -43,6 +52,93 @@ bool IsAlmostEqual(DecodeTimestamp t0, DecodeTimestamp t1) {
   return (diff >= -kMaxDeviation && diff <= kMaxDeviation);
 }
 
+#ifdef 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* input,
+                             int input_size,
+                             bool has_pattern) {
+  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*>(key.data()),
+                              reinterpret_cast<const uint8*>(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* in_ptr = const_cast<uint8*>(input);
+  uint8* out_ptr = reinterpret_cast<uint8*>(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() == kCipherModeAesCbc);
+  bool has_pattern = scheme.pattern().in_effect();
+  EXPECT_TRUE(!has_pattern ||
+              scheme.pattern().Matches(EncryptionScheme::PatternSpec(1, 9)));
+  std::string key = buffer.decrypt_config()->key_id();
+  std::string iv = buffer.decrypt_config()->iv();
+  EXPECT_EQ(key.size(), 16UL);
+  EXPECT_EQ(iv.size(), 16UL);
+  std::string result;
+  uint8* in_ptr = const_cast<uint8*>(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 {
@@ -56,7 +152,11 @@ class Mp2tStreamParserTest : public testing::Test {
         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_(),
+        audio_buffer_capture_index_(-1),
+        video_buffer_capture_index_(-1) {
     bool has_sbr = false;
     parser_.reset(new Mp2tStreamParser(has_sbr));
   }
@@ -73,6 +173,13 @@ class Mp2tStreamParserTest : public testing::Test {
   DecodeTimestamp video_min_dts_;
   DecodeTimestamp video_max_dts_;
 
+  AudioDecoderConfig current_audio_config_;
+  VideoDecoderConfig current_video_config_;
+  int audio_buffer_capture_index_;
+  int video_buffer_capture_index_;
+  scoped_refptr<StreamParserBuffer> audio_buffer_capture_;
+  scoped_refptr<StreamParserBuffer> video_buffer_capture_;
+
   void ResetStats() {
     segment_count_ = 0;
     config_count_ = 0;
@@ -113,10 +220,31 @@ class Mp2tStreamParserTest : public testing::Test {
              << ", 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 CaptureVideoBuffer(const StreamParser::BufferQueue& video_buffers) {
+    for (const auto& buffer : video_buffers) {
+      if (video_buffer_capture_index_ < 0)
+        return;
+      else if (video_buffer_capture_index_ == 0)
+        video_buffer_capture_ = buffer;
+      video_buffer_capture_index_--;
+    }
+  }
+
+  void CaptureAudioBuffer(const StreamParser::BufferQueue& audio_buffers) {
+    for (const auto& buffer : audio_buffers) {
+      if (audio_buffer_capture_index_ < 0)
+        return;
+      else if (audio_buffer_capture_index_ == 0)
+        audio_buffer_capture_ = buffer;
+      audio_buffer_capture_index_--;
+    }
+  }
 
   void DumpBuffers(const std::string& label,
                    const StreamParser::BufferQueue& buffers) {
@@ -135,6 +263,8 @@ class Mp2tStreamParserTest : public testing::Test {
     EXPECT_GT(config_count_, 0);
     DumpBuffers("audio_buffers", audio_buffers);
     DumpBuffers("video_buffers", video_buffers);
+    CaptureVideoBuffer(video_buffers);
+    CaptureAudioBuffer(audio_buffers);
 
     // TODO(wolenetz/acolwell): Add text track support to more MSE parsers. See
     // http://crbug.com/336926.
@@ -172,7 +302,6 @@ class Mp2tStreamParserTest : public testing::Test {
   }
 
   void OnKeyNeeded(EmeInitDataType type, const std::vector<uint8>& init_data) {
-    NOTREACHED() << "OnKeyNeeded not expected in the Mpeg2 TS parser";
   }
 
   void OnNewSegment() {
@@ -289,5 +418,46 @@ TEST_F(Mp2tStreamParserTest, AudioInPrivateStream1) {
   EXPECT_EQ(segment_count_, 1);
 }
 
+#ifdef ENABLE_HLS_SAMPLE_AES
+TEST_F(Mp2tStreamParserTest, HLSSampleAES) {
+  InitializeParser();
+  audio_buffer_capture_index_ = 0;
+  video_buffer_capture_index_ = 0;
+  ParseMpeg2TsFile("main.ts", 2048);
+  parser_->Flush();
+  EncryptionScheme video_encryption_scheme =
+      current_video_config_.encryption_scheme();
+  EXPECT_TRUE(video_encryption_scheme.is_encrypted());
+  std::string decrypted_video_buffer =
+      DecryptBuffer(*video_buffer_capture_.get(), video_encryption_scheme);
+  EncryptionScheme audio_encryption_scheme =
+      current_audio_config_.encryption_scheme();
+  EXPECT_TRUE(audio_encryption_scheme.is_encrypted());
+  std::string decrypted_audio_buffer =
+      DecryptBuffer(*audio_buffer_capture_.get(), audio_encryption_scheme);
+
+  parser_.reset(new Mp2tStreamParser(false));
+  ResetStats();
+  InitializeParser();
+  audio_buffer_capture_index_ = 0;
+  video_buffer_capture_index_ = 0;
+  ParseMpeg2TsFile("unencrypted.ts", 2048);
+  parser_->Flush();
+  video_encryption_scheme = current_video_config_.encryption_scheme();
+  EXPECT_FALSE(video_encryption_scheme.is_encrypted());
+  std::string unencrypted_video_buffer(
+      reinterpret_cast<const char*>(video_buffer_capture_->data()),
+      video_buffer_capture_->data_size());
+  audio_encryption_scheme = current_audio_config_.encryption_scheme();
+  EXPECT_FALSE(audio_encryption_scheme.is_encrypted());
+  std::string unencrypted_audio_buffer(
+      reinterpret_cast<const char*>(audio_buffer_capture_->data()),
+      audio_buffer_capture_->data_size());
+
+  EXPECT_EQ(decrypted_video_buffer, unencrypted_video_buffer);
+  EXPECT_EQ(decrypted_audio_buffer, unencrypted_audio_buffer);
+}
+#endif
+
 }  // namespace mp2t
 }  // namespace media