https://github.com/AGWA/git-crypt
crypto.hpp
/*
* Copyright 2012, 2014 Andrew Ayer
*
* This file is part of git-crypt.
*
* git-crypt is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* git-crypt is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with git-crypt. If not, see <http://www.gnu.org/licenses/>.
*
* Additional permission under GNU GPL version 3 section 7:
*
* If you modify the Program, or any covered work, by linking or
* combining it with the OpenSSL project's OpenSSL library (or a
* modified version of that library), containing parts covered by the
* terms of the OpenSSL or SSLeay licenses, the licensors of the Program
* grant you additional permission to convey the resulting work.
* Corresponding Source for a non-source form of such a combination
* shall include the source code for the parts of OpenSSL used as well
* as that of the covered work.
*/
#ifndef GIT_CRYPT_CRYPTO_HPP
#define GIT_CRYPT_CRYPTO_HPP
#include "key.hpp"
#include <stdint.h>
#include <stddef.h>
#include <iosfwd>
#include <string>
#include <memory>
void init_crypto ();
struct Crypto_error {
std::string where;
std::string message;
Crypto_error (const std::string& w, const std::string& m) : where(w), message(m) { }
};
class Aes_ecb_encryptor {
public:
enum {
KEY_LEN = AES_KEY_LEN,
BLOCK_LEN = 16
};
private:
struct Aes_impl;
std::unique_ptr<Aes_impl> impl;
public:
Aes_ecb_encryptor (const unsigned char* key);
~Aes_ecb_encryptor ();
void encrypt (const unsigned char* plain, unsigned char* cipher);
};
class Aes_ctr_encryptor {
public:
enum {
NONCE_LEN = 12,
KEY_LEN = AES_KEY_LEN,
BLOCK_LEN = 16,
MAX_CRYPT_BYTES = (1ULL<<32)*16 // Don't encrypt more than this or the CTR value will repeat itself
};
private:
Aes_ecb_encryptor ecb;
unsigned char ctr_value[BLOCK_LEN]; // Current CTR value (used as input to AES to derive pad)
unsigned char pad[BLOCK_LEN]; // Current encryption pad (output of AES)
uint32_t byte_counter; // How many bytes processed so far?
public:
Aes_ctr_encryptor (const unsigned char* key, const unsigned char* nonce);
~Aes_ctr_encryptor ();
void process (const unsigned char* in, unsigned char* out, size_t len);
// Encrypt/decrypt an entire input stream, writing to the given output stream
static void process_stream (std::istream& in, std::ostream& out, const unsigned char* key, const unsigned char* nonce);
};
typedef Aes_ctr_encryptor Aes_ctr_decryptor;
class Hmac_sha1_state {
public:
enum {
LEN = 20,
KEY_LEN = HMAC_KEY_LEN
};
private:
struct Hmac_impl;
std::unique_ptr<Hmac_impl> impl;
public:
Hmac_sha1_state (const unsigned char* key, size_t key_len);
~Hmac_sha1_state ();
void add (const unsigned char* buffer, size_t buffer_len);
void get (unsigned char*);
};
void random_bytes (unsigned char*, size_t);
#endif