172 lines
3.9 KiB
C
172 lines
3.9 KiB
C
/**
|
|
* @file gmp_helper.c
|
|
*
|
|
* @brief Class with helper functions for gmp operations
|
|
*
|
|
*/
|
|
|
|
/*
|
|
* Copyright (C) 2005 Jan Hutter, Martin Willi
|
|
* Hochschule fuer Technik Rapperswil
|
|
*
|
|
* 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. See <http://www.fsf.org/copyleft/gpl.txt>.
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#include "gmp_helper.h"
|
|
|
|
#include "allocator.h"
|
|
#include "randomizer.h"
|
|
|
|
/**
|
|
* Private data of an gmp_helper_t object.
|
|
*
|
|
*/
|
|
typedef struct private_gmp_helper_s private_gmp_helper_t;
|
|
|
|
struct private_gmp_helper_s {
|
|
/**
|
|
* public gmp_helper_t interface
|
|
*/
|
|
gmp_helper_t public;
|
|
|
|
};
|
|
|
|
|
|
/**
|
|
* Implements private_gmp_helper_t's chunk_to_mpz function.
|
|
* See #private_gmp_helper_t.chunk_to_mpz for description.
|
|
*/
|
|
static void chunk_to_mpz(private_gmp_helper_t *this, mpz_t *mpz_value, chunk_t data)
|
|
{
|
|
size_t i;
|
|
|
|
mpz_init_set_ui(*(mpz_value), 0);
|
|
|
|
for (i = 0; i < data.len; i++)
|
|
{
|
|
mpz_mul_ui(*(mpz_value),*(mpz_value), 1 << 8);
|
|
mpz_add_ui(*(mpz_value),*(mpz_value), data.ptr[i]);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Implements private_gmp_helper_t's mpz_to_chunk function.
|
|
* See #private_gmp_helper_t.mpz_to_chunk for description.
|
|
*/
|
|
static status_t mpz_to_chunk (private_gmp_helper_t *this,mpz_t *mpz_value, chunk_t *data,size_t bytes)
|
|
{
|
|
mpz_t temp1, temp2;
|
|
status_t status = SUCCESS;
|
|
int i;
|
|
|
|
data->len = bytes;
|
|
data->ptr = allocator_alloc(data->len);
|
|
|
|
if (data->ptr == NULL)
|
|
{
|
|
return OUT_OF_RES;
|
|
}
|
|
|
|
/* free memory */
|
|
memset(data->ptr,0,data->len);
|
|
|
|
mpz_init(temp1);
|
|
mpz_init(temp2);
|
|
|
|
mpz_set(temp1, *mpz_value);
|
|
|
|
for (i = data->len-1; i >= 0; i--)
|
|
{
|
|
data->ptr[i] = mpz_mdivmod_ui(temp2, NULL, temp1, 1 << 8);
|
|
mpz_set(temp1, temp2);
|
|
|
|
}
|
|
|
|
if (mpz_sgn(temp1) != 0)
|
|
{
|
|
status = FAILED;
|
|
}
|
|
mpz_clear(temp1);
|
|
mpz_clear(temp2);
|
|
return status;
|
|
}
|
|
|
|
/**
|
|
* Implements gmp_helper_t's init_prime function.
|
|
* See #gmp_helper_t.init_prime for description.
|
|
*/
|
|
static status_t init_prime (private_gmp_helper_t *this, mpz_t *prime, int bytes)
|
|
{
|
|
randomizer_t *randomizer;
|
|
chunk_t random_bytes;
|
|
status_t status;
|
|
randomizer = randomizer_create();
|
|
|
|
if (randomizer == NULL)
|
|
{
|
|
return OUT_OF_RES;
|
|
}
|
|
|
|
status = randomizer->allocate_random_bytes(randomizer,bytes, &random_bytes);
|
|
/* not needed anymore */
|
|
randomizer->destroy(randomizer);
|
|
if (status != SUCCESS)
|
|
{
|
|
return status;
|
|
}
|
|
|
|
/* convert chunk to mpz value */
|
|
this->public.chunk_to_mpz(&(this->public),prime, random_bytes);
|
|
|
|
/* chunk is not used anymore */
|
|
allocator_free(random_bytes.ptr);
|
|
random_bytes.ptr = NULL;
|
|
|
|
/* composites are possible but should never occur */
|
|
mpz_nextprime (*(prime),*(prime));
|
|
|
|
return SUCCESS;
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
* Implements gmp_helper_t's destroy function.
|
|
* See #gmp_helper_t.destroy for description.
|
|
*/
|
|
static status_t destroy(private_gmp_helper_t *this)
|
|
{
|
|
allocator_free(this);
|
|
return SUCCESS;
|
|
}
|
|
|
|
/*
|
|
* Described in header
|
|
*/
|
|
gmp_helper_t *gmp_helper_create()
|
|
{
|
|
private_gmp_helper_t *this = allocator_alloc_thing(private_gmp_helper_t);
|
|
if ((this == NULL))
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
/* public functions */
|
|
this->public.destroy = (status_t (*)(gmp_helper_t *)) destroy;
|
|
this->public.init_prime = (status_t (*) (gmp_helper_t *, mpz_t *, int)) init_prime;
|
|
|
|
/* private functions */
|
|
this->public.chunk_to_mpz = (void (*) (gmp_helper_t *,mpz_t *, chunk_t )) chunk_to_mpz;
|
|
this->public.mpz_to_chunk = (status_t (*) (gmp_helper_t *,mpz_t *, chunk_t *,size_t )) mpz_to_chunk;
|
|
|
|
return &(this->public);
|
|
}
|