3 * Multiple simultaneous exponentiations
5 * (c) 1999 Straylight/Edgeware
8 /*----- Licensing notice --------------------------------------------------*
10 * This file is part of Catacomb.
12 * Catacomb is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU Library General Public License as
14 * published by the Free Software Foundation; either version 2 of the
15 * License, or (at your option) any later version.
17 * Catacomb is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU Library General Public License for more details.
22 * You should have received a copy of the GNU Library General Public
23 * License along with Catacomb; if not, write to the Free
24 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
28 /*----- Header files ------------------------------------------------------*/
31 #include "mpbarrett.h"
34 #include "mpbarrett-exp.h"
36 /*----- Main code ---------------------------------------------------------*/
38 /* --- @mpbarrett_mexp@ --- *
40 * Arguments: @const mpbarrett *mb@ = pointer to Barrett reduction context
41 * @mp *d@ = fake destination
42 * @const mp_expfactor *f@ = pointer to array of factors
43 * @size_t n@ = number of factors supplied
45 * Returns: If the bases are %$g_0, g_1, \ldots, g_{n-1}$% and the
46 * exponents are %$e_0, e_1, \ldots, e_{n-1}$% then the result
49 * %$g_0^{e_0} g_1^{e_1} \ldots g_{n-1}^{e_{n-1}} \bmod m$%
52 mp *mpbarrett_mexp(const mpbarrett *mb, mp *d,
53 const mp_expfactor *f, size_t n)
55 mp_expfactor *ff = xmalloc(n * sizeof(mp_expfactor));
62 for (i = 0; i < n; i++) {
63 if (f[i].exp->f & MP_BURN)
65 if (MP_NEGP(f[i].exp))
66 ff[i].base = mp_modinv(MP_NEW, f[i].base, mb->m);
68 ff[i].base = MP_COPY(f[i].base);
75 for (i = 0; i < n; i++)
81 /*----- Test rig ----------------------------------------------------------*/
85 #include <mLib/testrig.h>
87 static int verify(size_t n, dstr *v)
89 mp *m = *(mp **)v[0].buf;
90 mp_expfactor *f = xmalloc(n * sizeof(*f));
97 for (i = 0; i < n; i++) {
98 f[i].base = *(mp **)v[j++].buf;
99 f[i].exp = *(mp **)v[j++].buf;
102 rr = *(mp **)v[j].buf;
103 mpbarrett_create(&mb, m);
104 r = mpbarrett_mexp(&mb, MP_NEW, f, n);
106 fputs("\n*** mexp failed\n", stderr);
107 fputs("m = ", stderr); mp_writefile(m, stderr, 10);
108 for (i = 0; i < n; i++) {
109 fprintf(stderr, "\ng_%lu = ", (unsigned long)i);
110 mp_writefile(f[i].base, stderr, 10);
111 fprintf(stderr, "\ne_%lu = ", (unsigned long)i);
112 mp_writefile(f[i].exp, stderr, 10);
114 fputs("\nr = ", stderr); mp_writefile(r, stderr, 10);
115 fputs("\nR = ", stderr); mp_writefile(rr, stderr, 10);
120 for (i = 0; i < n; i++) {
127 mpbarrett_destroy(&mb);
128 assert(mparena_count(MPARENA_GLOBAL) == 0);
132 static int t1(dstr *v) { return verify(1, v); }
133 static int t2(dstr *v) { return verify(2, v); }
134 static int t3(dstr *v) { return verify(3, v); }
135 static int t4(dstr *v) { return verify(4, v); }
136 static int t5(dstr *v) { return verify(5, v); }
138 static test_chunk tests[] = {
139 { "mexp-1", t1, { &type_mp,
142 { "mexp-2", t2, { &type_mp,
146 { "mexp-3", t3, { &type_mp,
151 { "mexp-4", t4, { &type_mp,
157 { "mexp-5", t5, { &type_mp,
167 int main(int argc, char *argv[])
170 test_run(argc, argv, tests, SRCDIR "/t/mpbarrett");
176 /*----- That's all, folks -------------------------------------------------*/