ClearKeyStorage.cpp

/*
 * Copyright 2015, Mozilla Foundation and contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "ClearKeyStorage.h"

#include <assert.h>
// This include is required in order for content_decryption_module to work
// on Unix systems.
#include <stddef.h>

#include <vector>

#include "content_decryption_module.h"

#include "ArrayUtils.h"
#include "ClearKeyUtils.h"

using namespace cdm;

using std::function;
using std::string;
using std::vector;

class WriteRecordClient : public FileIOClient {
 public:
  /*
   * This function will take the memory ownership of the parameters and
   * delete them when done.
   */
  static void Write(Host_10* aHost, string& aRecordName,
                    const vector<uint8_t>& aData, function<void()>&& aOnSuccess,
                    function<void()>&& aOnFailure) {
    WriteRecordClient* client = new WriteRecordClient(
        aData, std::move(aOnSuccess), std::move(aOnFailure));
    client->Do(aRecordName, aHost);
  }

  void OnOpenComplete(Status aStatus) override {
    // If we hit an error, fail.
    if (aStatus != Status::kSuccess) {
      Done(aStatus);
    } else if (mFileIO) {  // Otherwise, write our data to the file.
      mFileIO->Write(&mData[0], mData.size());
    }
  }

  void OnReadComplete(Status aStatus, const uint8_t* aData,
                      uint32_t aDataSize) override {
    // This function should never be called, we only ever write data with this
    // client.
    assert(false);
  }

  void OnWriteComplete(Status aStatus) override { Done(aStatus); }

 private:
  explicit WriteRecordClient(const vector<uint8_t>& aData,
                             function<void()>&& aOnSuccess,
                             function<void()>&& aOnFailure)
      : mFileIO(nullptr),
        mOnSuccess(std::move(aOnSuccess)),
        mOnFailure(std::move(aOnFailure)),
        mData(aData) {}

  void Do(const string& aName, Host_10* aHost) {
    // Initialize the FileIO.
    mFileIO = aHost->CreateFileIO(this);
    mFileIO->Open(aName.c_str(), aName.size());
  }

  void Done(cdm::FileIOClient::Status aStatus) {
    // Note: Call Close() before running continuation, in case the
    // continuation tries to open the same record; if we call Close()
    // after running the continuation, the Close() call will arrive
    // just after the Open() call succeeds, immediately closing the
    // record we just opened.
    if (mFileIO) {
      mFileIO->Close();
    }

    if (IO_SUCCEEDED(aStatus)) {
      mOnSuccess();
    } else {
      mOnFailure();
    }

    delete this;
  }

  FileIO* mFileIO = nullptr;

  function<void()> mOnSuccess;
  function<void()> mOnFailure;

  const vector<uint8_t> mData;
};

void WriteData(Host_10* aHost, string& aRecordName,
               const vector<uint8_t>& aData, function<void()>&& aOnSuccess,
               function<void()>&& aOnFailure) {
  WriteRecordClient::Write(aHost, aRecordName, aData, std::move(aOnSuccess),
                           std::move(aOnFailure));
}

class ReadRecordClient : public FileIOClient {
 public:
  /*
   * This function will take the memory ownership of the parameters and
   * delete them when done.
   */
  static void Read(Host_10* aHost, string& aRecordName,
                   function<void(const uint8_t*, uint32_t)>&& aOnSuccess,
                   function<void()>&& aOnFailure) {
    (new ReadRecordClient(std::move(aOnSuccess), std::move(aOnFailure)))
        ->Do(aRecordName, aHost);
  }

  void OnOpenComplete(Status aStatus) override {
    auto err = aStatus;
    if (aStatus != Status::kSuccess) {
      Done(err, nullptr, 0);
    } else {
      mFileIO->Read();
    }
  }

  void OnReadComplete(Status aStatus, const uint8_t* aData,
                      uint32_t aDataSize) override {
    Done(aStatus, aData, aDataSize);
  }

  void OnWriteComplete(Status aStatus) override {
    // We should never reach here, this client only ever reads data.
    assert(false);
  }

 private:
  explicit ReadRecordClient(
      function<void(const uint8_t*, uint32_t)>&& aOnSuccess,
      function<void()>&& aOnFailure)
      : mFileIO(nullptr),
        mOnSuccess(std::move(aOnSuccess)),
        mOnFailure(std::move(aOnFailure)) {}

  void Do(const string& aName, Host_10* aHost) {
    mFileIO = aHost->CreateFileIO(this);
    mFileIO->Open(aName.c_str(), aName.size());
  }

  void Done(cdm::FileIOClient::Status aStatus, const uint8_t* aData,
            uint32_t aDataSize) {
    // Note: Call Close() before running continuation, in case the
    // continuation tries to open the same record; if we call Close()
    // after running the continuation, the Close() call will arrive
    // just after the Open() call succeeds, immediately closing the
    // record we just opened.
    if (mFileIO) {
      mFileIO->Close();
    }

    if (IO_SUCCEEDED(aStatus)) {
      mOnSuccess(aData, aDataSize);
    } else {
      mOnFailure();
    }

    delete this;
  }

  FileIO* mFileIO = nullptr;

  function<void(const uint8_t*, uint32_t)> mOnSuccess;
  function<void()> mOnFailure;
};

void ReadData(Host_10* aHost, string& aRecordName,
              function<void(const uint8_t*, uint32_t)>&& aOnSuccess,
              function<void()>&& aOnFailure) {
  ReadRecordClient::Read(aHost, aRecordName, std::move(aOnSuccess),
                         std::move(aOnFailure));
}