aes_pattern_cryptor.h

// Copyright 2016 Google LLC. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
 
#include <cstddef>
#include <cstdint>
#include <memory>
#include <vector>
 
#include <packager/macros/classes.h>
#include <packager/media/base/aes_cryptor.h>
 
namespace shaka {
namespace media {
 
class AesPatternCryptor : public AesCryptor {
 public:
  enum PatternEncryptionMode {
    kEncryptIfCryptByteBlockRemaining,
    kSkipIfCryptByteBlockRemaining,
  };
 
  AesPatternCryptor(uint8_t crypt_byte_block,
                    uint8_t skip_byte_block,
                    PatternEncryptionMode encryption_mode,
                    ConstantIvFlag constant_iv_flag,
                    std::unique_ptr<AesCryptor> cryptor);
  ~AesPatternCryptor() override;
 
  bool InitializeWithIv(const std::vector<uint8_t>& key,
                        const std::vector<uint8_t>& iv) override;
 
 private:
  bool CryptInternal(const uint8_t* text,
                     size_t text_size,
                     uint8_t* crypt_text,
                     size_t* crypt_text_size) override;
  void SetIvInternal() override;
 
  uint8_t crypt_byte_block_;
  const uint8_t skip_byte_block_;
  const PatternEncryptionMode encryption_mode_;
  std::unique_ptr<AesCryptor> cryptor_;
 
  DISALLOW_COPY_AND_ASSIGN(AesPatternCryptor);
};
 
}  // namespace media
}  // namespace shaka