Mercurial > dropbear
diff libtomcrypt/src/misc/mpi/rand_prime.c @ 285:1b9e69c058d2
propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
to branch 'au.asn.ucc.matt.dropbear' (head fdf4a7a3b97ae5046139915de7e40399cceb2c01)
author | Matt Johnston <matt@ucc.asn.au> |
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date | Wed, 08 Mar 2006 13:23:58 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/libtomcrypt/src/misc/mpi/rand_prime.c Wed Mar 08 13:23:58 2006 +0000 @@ -0,0 +1,70 @@ +/* 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, [email protected], 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 + + +/* $Source: /cvs/libtom/libtomcrypt/src/misc/mpi/rand_prime.c,v $ */ +/* $Revision: 1.3 $ */ +/* $Date: 2005/05/05 14:35:59 $ */