81 lines
1.9 KiB
C
81 lines
1.9 KiB
C
/* LibTomCrypt, modular cryptographic library -- Tom St Denis
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*
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* LibTomCrypt is a library that provides various cryptographic
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* algorithms in a highly modular and flexible manner.
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*
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* The library is free for all purposes without any express
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* gurantee it works.
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*
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* Tom St Denis, tomstdenis@iahu.ca, http://libtomcrypt.org
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*/
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#include "mycrypt.h"
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#ifdef MPI
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struct rng_data {
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prng_state *prng;
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int wprng;
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};
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#define UPPER_LIMIT PRIME_SIZE
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/* figures out if a number is prime (MR test) */
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int is_prime(mp_int *N, int *result)
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{
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int err;
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_ARGCHK(N != NULL);
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_ARGCHK(result != NULL);
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if ((err = mp_prime_is_prime(N, mp_prime_rabin_miller_trials(mp_count_bits(N)), result)) != MP_OKAY) {
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return mpi_to_ltc_error(err);
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}
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return CRYPT_OK;
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}
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static int rand_prime_helper(unsigned char *dst, int len, void *dat)
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{
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return (int)prng_descriptor[((struct rng_data *)dat)->wprng].read(dst, len, ((struct rng_data *)dat)->prng);
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}
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int rand_prime(mp_int *N, long len, prng_state *prng, int wprng)
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{
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struct rng_data rng;
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int type, err;
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_ARGCHK(N != NULL);
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/* allow sizes between 2 and 256 bytes for a prime size */
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if (len < 2 || len > 256) {
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return CRYPT_INVALID_PRIME_SIZE;
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}
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/* valid PRNG? Better be! */
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if ((err = prng_is_valid(wprng)) != CRYPT_OK) {
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return err;
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}
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/* setup our callback data, then world domination! */
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rng.prng = prng;
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rng.wprng = wprng;
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/* get type */
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if (len < 0) {
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type = 1;
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len = -len;
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} else {
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type = 0;
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}
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/* New prime generation makes the code even more cryptoish-insane. Do you know what this means!!!
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-- Gir: Yeah, oh wait, er, no.
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*/
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if ((err = mp_prime_random(N, mp_prime_rabin_miller_trials(len*8), len, type, rand_prime_helper, &rng)) != MP_OKAY) {
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return mpi_to_ltc_error(err);
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}
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return CRYPT_OK;
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}
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#endif
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