shaka-packager/packager/media/base/aes_decryptor.h

154 lines
4.4 KiB
C++

// Copyright 2016 Google Inc. 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
//
// AES Decryptor implementation using openssl.
#ifndef MEDIA_BASE_AES_DECRYPTOR_H_
#define MEDIA_BASE_AES_DECRYPTOR_H_
#include <string>
#include <vector>
#include "packager/base/memory/scoped_ptr.h"
#include "packager/base/stl_util.h"
#include "packager/media/base/aes_encryptor.h"
struct aes_key_st;
typedef struct aes_key_st AES_KEY;
namespace edash_packager {
namespace media {
class AesDecryptor {
public:
AesDecryptor();
virtual ~AesDecryptor();
virtual bool InitializeWithIv(const std::vector<uint8_t>& key,
const std::vector<uint8_t>& iv) = 0;
/// @name Various forms of decrypt calls.
/// The plaintext and ciphertext pointers can be the same address.
/// @{
virtual bool Decrypt(const uint8_t* ciphertext,
size_t ciphertext_size,
uint8_t* plaintext) = 0;
virtual bool Decrypt(const std::vector<uint8_t>& ciphertext,
std::vector<uint8_t>* plaintext) = 0;
virtual bool Decrypt(const std::string& ciphertext,
std::string* plaintext) = 0;
/// @}
/// Set IV. @a block_offset_ is reset to 0 on success.
/// @return true if successful, false if the input is invalid.
virtual bool SetIv(const std::vector<uint8_t>& iv) = 0;
const std::vector<uint8_t>& iv() const { return iv_; }
protected:
// Initialization vector, with size 8 or 16.
std::vector<uint8_t> iv_;
// Openssl AES_KEY.
scoped_ptr<AES_KEY> aes_key_;
private:
DISALLOW_COPY_AND_ASSIGN(AesDecryptor);
};
// Class which implements AES-CTR counter-mode decryption.
class AesCtrDecryptor : public AesDecryptor {
public:
AesCtrDecryptor();
~AesCtrDecryptor() override;
/// @name AesDecryptor implementation overrides.
/// @{
bool InitializeWithIv(const std::vector<uint8_t>& key,
const std::vector<uint8_t>& iv) override;
bool Decrypt(const uint8_t* ciphertext,
size_t ciphertext_size,
uint8_t* plaintext) override;
bool Decrypt(const std::vector<uint8_t>& ciphertext,
std::vector<uint8_t>* plaintext) override;
bool Decrypt(const std::string& ciphertext, std::string* plaintext) override;
bool SetIv(const std::vector<uint8_t>& iv) override;
/// @}
uint32_t block_offset() const { return encryptor_->block_offset(); }
private:
scoped_ptr<AesCtrEncryptor> encryptor_;
DISALLOW_COPY_AND_ASSIGN(AesCtrDecryptor);
};
// Class which implements AES-CBC (Cipher block chaining) decryption with
// PKCS#5 padding.
class AesCbcPkcs5Decryptor : public AesDecryptor {
public:
AesCbcPkcs5Decryptor();
~AesCbcPkcs5Decryptor() override;
/// @name AesDecryptor implementation overrides.
/// @{
bool InitializeWithIv(const std::vector<uint8_t>& key,
const std::vector<uint8_t>& iv) override;
bool Decrypt(const uint8_t* ciphertext,
size_t ciphertext_size,
uint8_t* plaintext) override;
bool Decrypt(const std::vector<uint8_t>& ciphertext,
std::vector<uint8_t>* plaintext) override;
bool Decrypt(const std::string& ciphertext, std::string* plaintext) override;
bool SetIv(const std::vector<uint8_t>& iv) override;
/// @}
private:
DISALLOW_COPY_AND_ASSIGN(AesCbcPkcs5Decryptor);
};
// Class which implements AES-CBC (Cipher block chaining) decryption with
// Ciphertext stealing.
class AesCbcCtsDecryptor : public AesDecryptor {
public:
AesCbcCtsDecryptor();
~AesCbcCtsDecryptor() override;
/// @name AesDecryptor implementation overrides.
/// @{
bool InitializeWithIv(const std::vector<uint8_t>& key,
const std::vector<uint8_t>& iv) override;
bool Decrypt(const uint8_t* ciphertext,
size_t ciphertext_size,
uint8_t* plaintext) override;
bool Decrypt(const std::vector<uint8_t>& ciphertext,
std::vector<uint8_t>* plaintext) override;
bool Decrypt(const std::string& ciphertext, std::string* plaintext) override;
bool SetIv(const std::vector<uint8_t>& iv) override;
/// @}
private:
DISALLOW_COPY_AND_ASSIGN(AesCbcCtsDecryptor);
};
} // namespace media
} // namespace edash_packager
#endif // MEDIA_BASE_AES_DECRYPTOR_H_