Mercurial > dropbear

comparison libtomcrypt/src/misc/mpi/rand_prime.c @ 285:1b9e69c058d2

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
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>
date Wed, 08 Mar 2006 13:23:58 +0000
parents
children
comparison
equal deleted inserted replaced
281:997e6f7dc01e 285:1b9e69c058d2
1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
2 *
3 * LibTomCrypt is a library that provides various cryptographic
4 * algorithms in a highly modular and flexible manner.
5 *
6 * The library is free for all purposes without any express
7 * guarantee it works.
8 *
9 * Tom St Denis, [email protected], http://libtomcrypt.org
10 */
11 #include "tomcrypt.h"
12
13 /**
14 @file rand_prime.c
15 Generate a random prime, Tom St Denis
16 */
17 #ifdef MPI
18
19 struct rng_data {
20 prng_state *prng;
21 int wprng;
22 };
23
24 static int rand_prime_helper(unsigned char *dst, int len, void *dat)
25 {
26 return (int)prng_descriptor[((struct rng_data *)dat)->wprng].read(dst, len, ((struct rng_data *)dat)->prng);
27 }
28
29 int rand_prime(mp_int *N, long len, prng_state *prng, int wprng)
30 {
31 struct rng_data rng;
32 int type, err;
33
34 LTC_ARGCHK(N != NULL);
35
36 /* allow sizes between 2 and 256 bytes for a prime size */
37 if (len < 16 || len > 4096) {
38 return CRYPT_INVALID_PRIME_SIZE;
39 }
40
41 /* valid PRNG? Better be! */
42 if ((err = prng_is_valid(wprng)) != CRYPT_OK) {
43 return err;
44 }
45
46 /* setup our callback data, then world domination! */
47 rng.prng = prng;
48 rng.wprng = wprng;
49
50 /* get type */
51 if (len < 0) {
52 type = LTM_PRIME_BBS;
53 len = -len;
54 } else {
55 type = 0;
56 }
57 type |= LTM_PRIME_2MSB_ON;
58
59 /* New prime generation makes the code even more cryptoish-insane. Do you know what this means!!!
60 -- Gir: Yeah, oh wait, er, no.
61 */
62 return mpi_to_ltc_error(mp_prime_random_ex(N, mp_prime_rabin_miller_trials(len), len, type, rand_prime_helper, &rng));
63 }
64
65 #endif
66
67
68 /* $Source: /cvs/libtom/libtomcrypt/src/misc/mpi/rand_prime.c,v $ */
69 /* $Revision: 1.3 $ */
70 /* $Date: 2005/05/05 14:35:59 $ */