| /* LibTomCrypt, modular cryptographic library -- Tom St Denis |
| * |
| * LibTomCrypt is a library that provides various cryptographic |
| * algorithms in a highly modular and flexible manner. |
| * |
| * The library is free for all purposes without any express |
| * guarantee it works. |
| * |
| * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.org |
| */ |
| #include "tomcrypt.h" |
| |
| /** |
| @file rand_prime.c |
| Generate a random prime, Tom St Denis |
| */ |
| #ifdef MPI |
| |
| struct rng_data { |
| prng_state *prng; |
| int wprng; |
| }; |
| |
| static int rand_prime_helper(unsigned char *dst, int len, void *dat) |
| { |
| return (int)prng_descriptor[((struct rng_data *)dat)->wprng].read(dst, len, ((struct rng_data *)dat)->prng); |
| } |
| |
| int rand_prime(mp_int *N, long len, prng_state *prng, int wprng) |
| { |
| struct rng_data rng; |
| int type, err; |
| |
| LTC_ARGCHK(N != NULL); |
| |
| /* allow sizes between 2 and 256 bytes for a prime size */ |
| if (len < 16 || len > 4096) { |
| return CRYPT_INVALID_PRIME_SIZE; |
| } |
| |
| /* valid PRNG? Better be! */ |
| if ((err = prng_is_valid(wprng)) != CRYPT_OK) { |
| return err; |
| } |
| |
| /* setup our callback data, then world domination! */ |
| rng.prng = prng; |
| rng.wprng = wprng; |
| |
| /* get type */ |
| if (len < 0) { |
| type = LTM_PRIME_BBS; |
| len = -len; |
| } else { |
| type = 0; |
| } |
| type |= LTM_PRIME_2MSB_ON; |
| |
| /* New prime generation makes the code even more cryptoish-insane. Do you know what this means!!! |
| -- Gir: Yeah, oh wait, er, no. |
| */ |
| return mpi_to_ltc_error(mp_prime_random_ex(N, mp_prime_rabin_miller_trials(len), len, type, rand_prime_helper, &rng)); |
| } |
| |
| #endif |
| |