+++ /dev/null
-/* -*-c-*-
- *
- * $Id: dsa-sign.c,v 1.3 2004/04/08 01:36:15 mdw Exp $
- *
- * DSA signing operation
- *
- * (c) 1999 Straylight/Edgeware
- */
-
-/*----- Licensing notice --------------------------------------------------*
- *
- * This file is part of Catacomb.
- *
- * Catacomb is free software; you can redistribute it and/or modify
- * it under the terms of the GNU Library General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or (at your option) any later version.
- *
- * Catacomb 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 Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library General Public
- * License along with Catacomb; if not, write to the Free
- * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
- * MA 02111-1307, USA.
- */
-
-/*----- Header files ------------------------------------------------------*/
-
-#include "dsa.h"
-#include "mp.h"
-#include "mpbarrett.h"
-#include "mpmont.h"
-
-/*----- Main code ---------------------------------------------------------*/
-
-/* --- @dsa_mksig@ --- *
- *
- * Arguments: @const dsa_param *dp@ = pointer to DSA parameters
- * @mp *a@ = secret signing key
- * @mp *m@ = message to be signed
- * @mp *k@ = random data
- * @mp **rr, **ss@ = where to put output parameters
- *
- * Returns: ---
- *
- * Use: Computes a DSA signature of a message.
- */
-
-void dsa_mksig(const dsa_param *dp, mp *a, mp *m, mp *k, mp **rr, mp **ss)
-{
- mpmont pm;
- mpbarrett qb;
- mp *k1, *r;
- mp *ar;
-
- /* --- Compute %$r = (g^k \bmod p) \bmod q$% --- */
-
- mpmont_create(&pm, dp->p);
- r = mpmont_exp(&pm, MP_NEW, dp->g, k);
- mpmont_destroy(&pm);
- mp_div(0, &r, r, dp->q);
-
- /* --- Compute %$k^{-1} \bmod q$% --- */
-
- k1 = mp_modinv(MP_NEW, k, dp->q);
-
- /* --- Now for %$k^{-1}(m + ar)$% --- */
-
- mpbarrett_create(&qb, dp->q);
- ar = mp_mul(MP_NEW, a, r);
- ar = mp_add(ar, ar, m);
- ar = mpbarrett_reduce(&qb, ar, ar);
- ar = mp_mul(ar, ar, k1);
- ar = mpbarrett_reduce(&qb, ar, ar);
- mpbarrett_destroy(&qb);
- MP_DROP(k1);
- if (*rr) MP_DROP(*rr);
- if (*ss) MP_DROP(*ss);
- *rr = r;
- *ss = ar;
-}
-
-/* --- @dsa_sign@ --- *
- *
- * Arguments: @dsa_param *dp@ = pointer to DSA parameters
- * @mp *a@ = pointer to secret signing key
- * @const void *m@ = pointer to message
- * @size_t msz@ = size of the message
- * @const void *k@ = secret random data for securing signature
- * @size_t ksz@ = size of secret data
- * @void *r@ = pointer to output space for @r@
- * @size_t rsz@ = size of output space for @r@
- * @void *s@ = pointer to output space for @s@
- * @size_t ssz@ = size of output space for @s@
- *
- * Returns: ---
- *
- * Use: Signs a message, storing the results in a big-endian binary
- * form.
- */
-
-void dsa_sign(dsa_param *dp, mp *a,
- const void *m, size_t msz, const void *k, size_t ksz,
- void *r, size_t rsz, void *s, size_t ssz)
-{
- mp *mm = dsa_h2n(MP_NEW, dp->q, m, msz);
- mp *km = mp_loadb(MP_NEW, k, ksz);
- mp *rm = MP_NEW, *sm = MP_NEW;
- dsa_mksig(dp, a, mm, km, &rm, &sm);
- mp_storeb(rm, r, rsz);
- mp_storeb(sm, s, ssz);
- mp_drop(mm); mp_drop(km);
- mp_drop(rm); mp_drop(sm);
-}
-
-/*----- Test rig ----------------------------------------------------------*/
-
-#ifdef TEST_RIG
-
-#include <mLib/testrig.h>
-
-#include "sha.h"
-
-static int verify(dstr *v)
-{
- dsa_param dp;
- mp *x;
- sha_ctx c;
- octet hash[SHA_HASHSZ];
- dsa_sig s;
- int ok = 1;
-
- dp.q = *(mp **)v[0].buf;
- dp.p = *(mp **)v[1].buf;
- dp.g = *(mp **)v[2].buf;
- x = *(mp **)v[3].buf;
-
- sha_init(&c);
- sha_hash(&c, v[4].buf, v[4].len);
- sha_done(&c, hash);
-
- dsa_sign(&dp, x, hash, sizeof(hash), v[5].buf, v[5].len,
- s.r, sizeof(s.r), s.s, sizeof(s.s));
-
- if (v[6].len != sizeof(s.r) || v[7].len != sizeof(s.s) ||
- memcmp(s.r, v[6].buf, sizeof(s.r)) != 0 ||
- memcmp(s.s, v[7].buf, sizeof(s.s)) != 0) {
- fputs("\n*** signature failed", stderr);
- fputs("\nq = ", stderr); mp_writefile(dp.q, stderr, 16);
- fputs("\np = ", stderr); mp_writefile(dp.p, stderr, 16);
- fputs("\ng = ", stderr); mp_writefile(dp.g, stderr, 16);
- fputs("\nx = ", stderr); mp_writefile(x, stderr, 16);
- fprintf(stderr, "\nmessage = `%s'", v[4].buf);
- fputs("\nk = ", stderr); type_hex.dump(&v[5], stderr);
- fputs("\nR = ", stderr); type_hex.dump(&v[6], stderr);
- fputs("\nS = ", stderr); type_hex.dump(&v[7], stderr);
-
- {
- mp *m = MP_NEW;
- m = mp_loadb(m, hash, sizeof(hash));
- fputs("\nm = ", stderr); mp_writefile(m, stderr, 16);
- m = mp_loadb(m, s.r, sizeof(s.r));
- fputs("\nr = ", stderr); mp_writefile(m, stderr, 16);
- m = mp_loadb(m, s.s, sizeof(s.s));
- fputs("\ns = ", stderr); mp_writefile(m, stderr, 16);
- mp_drop(m);
- }
-
- fputc('\n', stderr);
- ok = 0;
- }
-
- mp_drop(dp.p);
- mp_drop(dp.q);
- mp_drop(dp.g);
- mp_drop(x);
- assert(mparena_count(MPARENA_GLOBAL) == 0);
- return (ok);
-}
-
-static test_chunk tests[] = {
- { "sign", verify,
- { &type_mp, &type_mp, &type_mp, &type_mp,
- &type_string, &type_hex, &type_hex, &type_hex, 0 } },
- { 0, 0, { 0 } }
-};
-
-int main(int argc, char *argv[])
-{
- sub_init();
- test_run(argc, argv, tests, SRCDIR "/tests/dsa");
- return (0);
-}
-
-#endif
-
-/*----- That's all, folks -------------------------------------------------*/
projects / u / mdw / catacomb / blobdiff