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crypto_sym.hpp
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//*********************************************************************/
// dar - disk archive - a backup/restoration program
// Copyright (C) 2002-2025 Denis Corbin
//
// This program 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 2
// of the License, or (at your option) any later version.
//
// This program 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 this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
//
// to contact the author, see the AUTHOR file
/*********************************************************************/
#ifndef CRYPTO_SYM_HPP
#define CRYPTO_SYM_HPP
extern "C"
{
#if HAVE_GCRYPT_H
#ifndef GCRYPT_NO_DEPRECATED
#define GCRYPT_NO_DEPRECATED
#endif
#include <gcrypt.h>
#endif
}
#include "../my_config.h"
#include <string>
#include "crypto_module.hpp"
#include "secu_string.hpp"
#include "crypto.hpp"
#include "archive_aux.hpp"
#include "archive_version.hpp"
namespace libdar
{
inline bool crypto_min_ver_libgcrypt_no_bug()
{
#if CRYPTO_AVAILABLE
return gcry_check_version(MIN_VERSION_GCRYPT_HASH_BUG);
#else
return true;
#endif
}
class crypto_sym : public crypto_module
{
public:
crypto_sym(const secu_string & password,
const archive_version & reading_ver,
crypto_algo algo,
const std::string & salt,
const infinint & iteration_count,
hash_algo kdf_hash,
bool use_pkcs5
);
crypto_sym(const crypto_sym & ref) { copy_from(ref); };
crypto_sym(crypto_sym && ref) noexcept { try { move_from(std::move(ref)); } catch(...) {} };
crypto_sym & operator = (const crypto_sym & ref) { detruit(); copy_from(ref); return *this; };
crypto_sym & operator = (crypto_sym && ref) noexcept { try { detruit(); move_from(std::move(ref)); } catch(...) {} return *this; };
virtual ~crypto_sym() noexcept { try { detruit(); } catch(...) {} };
// inherited from class crypto_module
virtual U_32 encrypted_block_size_for(U_32 clear_block_size) override;
virtual U_32 clear_block_allocated_size_for(U_32 clear_block_size) override;
virtual U_32 encrypt_data(const infinint & block_num,
const char *clear_buf,
const U_32 clear_size,
const U_32 clear_allocated,
char *crypt_buf, U_32 crypt_size) override;
virtual U_32 decrypt_data(const infinint & block_num,
const char *crypt_buf,
const U_32 crypt_size,
char *clear_buf,
U_32 clear_size) override;
virtual std::unique_ptr<crypto_module> clone() const override;
const std::string & get_salt() const { return sel; };
static size_t max_key_len(crypto_algo algo);
static size_t max_key_len_libdar(crypto_algo algo);
static bool is_a_strong_password(crypto_algo algo, const secu_string & password);
private:
std::string sel;
#if CRYPTO_AVAILABLE
archive_version reading_ver;
crypto_algo algo;
secu_string hashed_password;
secu_string essiv_password;
gcry_cipher_hd_t main_clef;
gcry_cipher_hd_t essiv_clef;
size_t algo_block_size;
unsigned char *ivec;
void init_hashed_password(const secu_string & password,
bool use_pkcs5,
const std::string & salt,
infinint iteration_count,
hash_algo kdf_hash,
crypto_algo algo);
void init_essiv_password(const secu_string & key,
unsigned int IV_hashing);
void init_main_clef(const secu_string & password,
crypto_algo algo
);
void init_essiv_clef(const secu_string & essiv_password,
U_I IV_cipher,
U_I main_cipher_algo_block_size);
void init_algo_block_size(crypto_algo algo);
void init_ivec(crypto_algo algo, size_t algo_block_size);
void detruit();
void copy_from(const crypto_sym & ref);
void move_from(crypto_sym && ref);
static void get_IV_cipher_and_hashing(const archive_version & ver, U_I main_cipher, U_I & cipher, U_I & hashing);
static void make_ivec(const infinint & ref,
unsigned char *ivec,
U_I size,
const gcry_cipher_hd_t & IVkey);
static secu_string pkcs5_pass2key(const secu_string & password,
const std::string & salt,
U_I iteration_count,
U_I hash_gcrypt,
U_I output_length);
static secu_string argon2_pass2key(const secu_string & password,
const std::string & salt,
U_I iteration_count,
U_I output_length);
static U_I get_algo_id(crypto_algo algo);
static std::string generate_salt(U_I size);
#ifdef LIBDAR_NO_OPTIMIZATION
static bool self_tested;
static void self_test(void);
#endif
#else
void detruit() { throw Ecompilation(gettext("Strong encryption support (libgcrypt)")); };
void copy_from(const crypto_sym & ref) { throw Ecompilation(gettext("Strong encryption support (libgcrypt)")); };
void move_from(crypto_sym && ref) { throw Ecompilation(gettext("Strong encryption support (libgcrypt)")); };
#endif
};
} // end of namespace
#endif
archive_aux.hpp
set of datastructures used to interact with a catalogue object
archive_version.hpp
class archive_version that rules which archive format to follow
libdar::Ecompilation
exception used when a requested fearture has not beed activated at compilation time
Definition erreurs.hpp:366
libdar::archive_version
class archive_version manages the version of the archive format
Definition archive_version.hpp:47
libdar::crypto_sym
symetrical strong encryption, interface to grypt library
Definition crypto_sym.hpp:67
libdar::crypto_sym::sel
std::string sel
the salt
Definition crypto_sym.hpp:113
libdar::crypto_sym::crypto_sym
crypto_sym(const secu_string &password, const archive_version &reading_ver, crypto_algo algo, const std::string &salt, const infinint &iteration_count, hash_algo kdf_hash, bool use_pkcs5)
libdar::crypto_sym::max_key_len_libdar
static size_t max_key_len_libdar(crypto_algo algo)
returns the max key length in octets to use to compute a key from a user provided password
libdar::crypto_sym::is_a_strong_password
static bool is_a_strong_password(crypto_algo algo, const secu_string &password)
check whether the given password is reported as strong in regard to the given cipher
libdar::crypto_sym::get_salt
const std::string & get_salt() const
give access to the calculated or provided salt
Definition crypto_sym.hpp:100
libdar::crypto_sym::max_key_len
static size_t max_key_len(crypto_algo algo)
returns the max key length in octets for the given algorithm
libdar::infinint
the arbitrary large positive integer class
Definition real_infinint.hpp:62
libdar::secu_string
class secu_string
Definition secu_string.hpp:54
crypto.hpp
the crypto algoritm definition
crypto_module.hpp
per block cryptography implementation
libdar::hash_algo
hash_algo
hashing algorithm available
Definition archive_aux.hpp:63
libdar::crypto_algo
crypto_algo
the different cypher available for encryption (strong or weak)
Definition crypto.hpp:50
my_config.h
include macro defined by the configure script and some specific additional ones
libdar
libdar namespace encapsulate all libdar symbols
Definition archive.hpp:47
secu_string.hpp
this file contains the definition of secu_string class, a std::string like class but allocated in sec...