127 lines
4 KiB
C++
127 lines
4 KiB
C++
/* Copyright 2015 OpenMarket Ltd
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#ifndef AXOLOTL_CIPHER_HH_
|
|
#define AXOLOTL_CIPHER_HH_
|
|
|
|
#include <cstdint>
|
|
|
|
namespace axolotl {
|
|
|
|
class Cipher {
|
|
public:
|
|
virtual ~Cipher();
|
|
|
|
/**
|
|
* Returns the length of the message authentication code that will be
|
|
* appended to the output.
|
|
*/
|
|
virtual std::size_t mac_length() const = 0;
|
|
|
|
/**
|
|
* Returns the length of cipher-text for a given length of plain-text.
|
|
*/
|
|
virtual std::size_t encrypt_ciphertext_length(
|
|
std::size_t plaintext_length
|
|
) const = 0;
|
|
|
|
/*
|
|
* Encrypts the plain-text into the output buffer and authenticates the
|
|
* contents of the output buffer covering both cipher-text and any other
|
|
* associated data in the output buffer.
|
|
*
|
|
* |---------------------------------------output_length-->|
|
|
* output |--ciphertext_length-->| |---mac_length-->|
|
|
* ciphertext
|
|
*
|
|
* Returns std::size_t(-1) if the length of the cipher-text or the output
|
|
* buffer is too small. Otherwise returns the length of the output buffer.
|
|
*/
|
|
virtual std::size_t encrypt(
|
|
std::uint8_t const * key, std::size_t key_length,
|
|
std::uint8_t const * plaintext, std::size_t plaintext_length,
|
|
std::uint8_t * ciphertext, std::size_t ciphertext_length,
|
|
std::uint8_t * output, std::size_t output_length
|
|
) const = 0;
|
|
|
|
/**
|
|
* Returns the maximum length of plain-text that a given length of
|
|
* cipher-text can contain.
|
|
*/
|
|
virtual std::size_t decrypt_max_plaintext_length(
|
|
std::size_t ciphertext_length
|
|
) const = 0;
|
|
|
|
/**
|
|
* Authenticates the input and decrypts the cipher-text into the plain-text
|
|
* buffer.
|
|
*
|
|
* |----------------------------------------input_length-->|
|
|
* input |--ciphertext_length-->| |---mac_length-->|
|
|
* ciphertext
|
|
*
|
|
* Returns std::size_t(-1) if the length of the plain-text buffer is too
|
|
* small or if the authentication check fails. Otherwise returns the length
|
|
* of the plain text.
|
|
*/
|
|
virtual std::size_t decrypt(
|
|
std::uint8_t const * key, std::size_t key_length,
|
|
std::uint8_t const * input, std::size_t input_length,
|
|
std::uint8_t const * ciphertext, std::size_t ciphertext_length,
|
|
std::uint8_t * plaintext, std::size_t max_plaintext_length
|
|
) const = 0;
|
|
};
|
|
|
|
|
|
class CipherAesSha256 : public Cipher {
|
|
public:
|
|
CipherAesSha256(
|
|
std::uint8_t const * kdf_info, std::size_t kdf_info_length
|
|
);
|
|
|
|
virtual std::size_t mac_length() const;
|
|
|
|
virtual std::size_t encrypt_ciphertext_length(
|
|
std::size_t plaintext_length
|
|
) const;
|
|
|
|
virtual std::size_t encrypt(
|
|
std::uint8_t const * key, std::size_t key_length,
|
|
std::uint8_t const * plaintext, std::size_t plaintext_length,
|
|
std::uint8_t * ciphertext, std::size_t ciphertext_length,
|
|
std::uint8_t * output, std::size_t output_length
|
|
) const;
|
|
|
|
virtual std::size_t decrypt_max_plaintext_length(
|
|
std::size_t ciphertext_length
|
|
) const;
|
|
|
|
virtual std::size_t decrypt(
|
|
std::uint8_t const * key, std::size_t key_length,
|
|
std::uint8_t const * input, std::size_t input_length,
|
|
std::uint8_t const * ciphertext, std::size_t ciphertext_length,
|
|
std::uint8_t * plaintext, std::size_t max_plaintext_length
|
|
) const;
|
|
|
|
private:
|
|
std::uint8_t const * kdf_info;
|
|
std::size_t kdf_info_length;
|
|
};
|
|
|
|
|
|
} // namespace
|
|
|
|
|
|
#endif /* AXOLOTL_CIPHER_HH_ */
|