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comparison libtommath/bn_mp_invmod.c @ 391:00fcf5045160

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propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head c1db4398d56c56c6d06ae1e20c1e0d04dbb598ed) to branch 'au.asn.ucc.matt.dropbear' (head d26d5eb2837f46b56a33fb0e7573aa0201abd4d5)
author Matt Johnston <matt@ucc.asn.au>
date Thu, 11 Jan 2007 04:29:08 +0000
parents 5ff8218bcee9
children 60fc6476e044
comparison
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390:d8e44bef7917 391:00fcf5045160
1 #include <tommath.h>
2 #ifdef BN_MP_INVMOD_C
3 /* LibTomMath, multiple-precision integer library -- Tom St Denis
4 *
5 * LibTomMath is a library that provides multiple-precision
6 * integer arithmetic as well as number theoretic functionality.
7 *
8 * The library was designed directly after the MPI library by
9 * Michael Fromberger but has been written from scratch with
10 * additional optimizations in place.
11 *
12 * The library is free for all purposes without any express
13 * guarantee it works.
14 *
15 * Tom St Denis, [email protected], http://math.libtomcrypt.com
16 */
17
18 /* hac 14.61, pp608 */
19 int mp_invmod (mp_int * a, mp_int * b, mp_int * c)
20 {
21 /* b cannot be negative */
22 if (b->sign == MP_NEG || mp_iszero(b) == 1) {
23 return MP_VAL;
24 }
25
26 #ifdef BN_FAST_MP_INVMOD_C
27 /* if the modulus is odd we can use a faster routine instead */
28 if (mp_isodd (b) == 1) {
29 return fast_mp_invmod (a, b, c);
30 }
31 #endif
32
33 #ifdef BN_MP_INVMOD_SLOW_C
34 return mp_invmod_slow(a, b, c);
35 #endif
36
37 return MP_VAL;
38 }
39 #endif
40
41 /* $Source: /cvs/libtom/libtommath/bn_mp_invmod.c,v $ */
42 /* $Revision: 1.3 $ */
43 /* $Date: 2006/03/31 14:18:44 $ */