chromecast/media/cma/ipc_streamer/decrypt_config_marshaller.cc

   1 // Copyright 2014 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 "chromecast/media/cma/ipc_streamer/decrypt_config_marshaller.h"
   6
   7 #include "base/logging.h"
   8 #include "chromecast/media/cma/base/cast_decrypt_config_impl.h"
   9 #include "chromecast/media/cma/ipc/media_message.h"
  10 #include "chromecast/public/media/cast_decrypt_config.h"
  11
  12 namespace chromecast {
  13 namespace media {
  14
  15 namespace {
  16 const size_t kMaxKeyIdSize = 256;
  17 const size_t kMaxIvSize = 256;
  18 const size_t kMaxSubsampleCount = 1024;
  19 }
  20
  21 // static
  22 void DecryptConfigMarshaller::Write(const CastDecryptConfig& config,
  23                                     MediaMessage* msg) {
  24   CHECK_GT(config.key_id().size(), 0u);
  25   CHECK_GT(config.iv().size(), 0u);
  26   CHECK_GT(config.subsamples().size(), 0u);
  27
  28   CHECK(msg->WritePod(config.key_id().size()));
  29   CHECK(msg->WriteBuffer(config.key_id().data(), config.key_id().size()));
  30   CHECK(msg->WritePod(config.iv().size()));
  31   CHECK(msg->WriteBuffer(config.iv().data(), config.iv().size()));
  32   CHECK(msg->WritePod(config.subsamples().size()));
  33   for (size_t k = 0; k < config.subsamples().size(); k++) {
  34     CHECK(msg->WritePod(config.subsamples()[k].clear_bytes));
  35     CHECK(msg->WritePod(config.subsamples()[k].cypher_bytes));
  36   }
  37 }
  38
  39 // static
  40 scoped_ptr<CastDecryptConfig> DecryptConfigMarshaller::Read(MediaMessage* msg) {
  41   size_t key_id_size = 0;
  42   CHECK(msg->ReadPod(&key_id_size));
  43   CHECK_GT(key_id_size, 0u);
  44   CHECK_LT(key_id_size, kMaxKeyIdSize);
  45   scoped_ptr<char[]> key_id(new char[key_id_size]);
  46   CHECK(msg->ReadBuffer(key_id.get(), key_id_size));
  47
  48   size_t iv_size = 0;
  49   CHECK(msg->ReadPod(&iv_size));
  50   CHECK_GT(iv_size, 0u);
  51   CHECK_LT(iv_size, kMaxIvSize);
  52   scoped_ptr<char[]> iv(new char[iv_size]);
  53   CHECK(msg->ReadBuffer(iv.get(), iv_size));
  54
  55   size_t subsample_count = 0;
  56   CHECK(msg->ReadPod(&subsample_count));
  57   CHECK_GT(subsample_count, 0u);
  58   CHECK_LT(subsample_count, kMaxSubsampleCount);
  59   std::vector<SubsampleEntry> subsamples(subsample_count);
  60   for (size_t k = 0; k < subsample_count; k++) {
  61     subsamples[k].clear_bytes = 0;
  62     subsamples[k].cypher_bytes = 0;
  63     CHECK(msg->ReadPod(&subsamples[k].clear_bytes));
  64     CHECK(msg->ReadPod(&subsamples[k].cypher_bytes));
  65   }
  66
  67   return scoped_ptr<CastDecryptConfig>(
  68       new CastDecryptConfigImpl(std::string(key_id.get(), key_id_size),
  69                                 std::string(iv.get(), iv_size), subsamples));
  70 }
  71
  72 }  // namespace media
  73 }  // namespace chromecast