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 -------------------------------------------------*/