5 * General-purpose modular exponentiation
7 * (c) 2006 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Catacomb.
14 * Catacomb is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU Library General Public License as
16 * published by the Free Software Foundation; either version 2 of the
17 * License, or (at your option) any later version.
19 * Catacomb is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU Library General Public License for more details.
24 * You should have received a copy of the GNU Library General Public
25 * License along with Catacomb; if not, write to the Free
26 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
30 /*----- Header files ------------------------------------------------------*/
33 #include "mpbarrett.h"
36 /*----- Main code ---------------------------------------------------------*/
38 /* --- @mp_modexp@ --- *
40 * Arguments: @mp *d@ = fake destination
41 * @mp *x@ = base of exponentiation
43 * @mp *n@ = modulus (must be positive)
45 * Returns: The value %$x^e \bmod n$%.
48 mp
*mp_modexp(mp
*d
, mp
*x
, mp
*e
, mp
*n
)
52 mpmont_create(&mm
, n
);
53 d
= mpmont_exp(&mm
, d
, x
, e
);
57 mpbarrett_create(&mb
, n
);
58 d
= mpbarrett_exp(&mb
, d
, x
, e
);
59 mpbarrett_destroy(&mb
);
64 /*----- Test rig ----------------------------------------------------------*/
68 static int tmodexp(dstr
*v
)
70 mp
*a
= *(mp
**)v
[0].buf
;
71 mp
*b
= *(mp
**)v
[1].buf
;
72 mp
*m
= *(mp
**)v
[2].buf
;
73 mp
*r
= *(mp
**)v
[3].buf
;
77 mr
= mp_modexp(MP_NEW
, a
, b
, m
);
80 fputs("\n*** modexp failed", stderr
);
81 fputs("\n a = ", stderr
); mp_writefile(a
, stderr
, 10);
82 fputs("\n e = ", stderr
); mp_writefile(b
, stderr
, 10);
83 fputs("\n m = ", stderr
); mp_writefile(m
, stderr
, 10);
84 fputs("\n r = ", stderr
); mp_writefile(r
, stderr
, 10);
85 fputs("\nmr = ", stderr
); mp_writefile(mr
, stderr
, 10);
95 assert(mparena_count(MPARENA_GLOBAL
) == 0);
99 static test_chunk tests
[] = {
100 { "modexp", tmodexp
, { &type_mp
, &type_mp
, &type_mp
, &type_mp
, 0 } },
104 int main(int argc
, char *argv
[])
107 test_run(argc
, argv
, tests
, SRCDIR
"/tests/mp");
113 /*----- That's all, folks -------------------------------------------------*/