annotate bn_mp_abs.c @ 387:4663ced4968f libtommath-dropbear

propagate from branch 'au.asn.ucc.matt.ltm.orig' (head 1c2b7d389d0682caf980235dad97493e3206389c) to branch 'au.asn.ucc.matt.ltm.dropbear' (head 40ab3795de3a6157f34e52ed3f0be3eebe9a2eaa)
author Matt Johnston <matt@ucc.asn.au>
date Thu, 11 Jan 2007 03:13:04 +0000
parents 97db060d0ef5
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
282
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
1 #include <tommath.h>
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
2 #ifdef BN_MP_ABS_C
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
3 /* LibTomMath, multiple-precision integer library -- Tom St Denis
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
4 *
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
5 * LibTomMath is a library that provides multiple-precision
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
6 * integer arithmetic as well as number theoretic functionality.
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
7 *
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
8 * The library was designed directly after the MPI library by
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
9 * Michael Fromberger but has been written from scratch with
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
10 * additional optimizations in place.
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
11 *
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
12 * The library is free for all purposes without any express
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
13 * guarantee it works.
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
14 *
386
97db060d0ef5 Update to LibTomMath 0.40
Matt Johnston <matt@ucc.asn.au>
parents: 282
diff changeset
15 * Tom St Denis, [email protected], http://math.libtomcrypt.com
282
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
16 */
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
17
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
18 /* b = |a|
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
19 *
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
20 * Simple function copies the input and fixes the sign to positive
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
21 */
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
22 int
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
23 mp_abs (mp_int * a, mp_int * b)
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
24 {
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
25 int res;
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
26
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
27 /* copy a to b */
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
28 if (a != b) {
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
29 if ((res = mp_copy (a, b)) != MP_OKAY) {
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
30 return res;
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
31 }
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
32 }
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
33
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
34 /* force the sign of b to positive */
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
35 b->sign = MP_ZPOS;
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
36
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
37 return MP_OKAY;
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
38 }
91fbc376f010 Import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
39 #endif
386
97db060d0ef5 Update to LibTomMath 0.40
Matt Johnston <matt@ucc.asn.au>
parents: 282
diff changeset
40
97db060d0ef5 Update to LibTomMath 0.40
Matt Johnston <matt@ucc.asn.au>
parents: 282
diff changeset
41 /* $Source: /cvs/libtom/libtommath/bn_mp_abs.c,v $ */
97db060d0ef5 Update to LibTomMath 0.40
Matt Johnston <matt@ucc.asn.au>
parents: 282
diff changeset
42 /* $Revision: 1.3 $ */
97db060d0ef5 Update to LibTomMath 0.40
Matt Johnston <matt@ucc.asn.au>
parents: 282
diff changeset
43 /* $Date: 2006/03/31 14:18:44 $ */