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Diffstat (limited to 'Source/charon/utils/gmp_helper.c')
| -rw-r--r-- | Source/charon/utils/gmp_helper.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/Source/charon/utils/gmp_helper.c b/Source/charon/utils/gmp_helper.c new file mode 100644 index 000000000..6d6ddc52b --- /dev/null +++ b/Source/charon/utils/gmp_helper.c @@ -0,0 +1,170 @@ +/** + * @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; + + 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); +} |