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comparison libtommath/bn_mp_clamp.c @ 284:eed26cff980b

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propagate from branch 'au.asn.ucc.matt.ltm.dropbear' (head 6c790cad5a7fa866ad062cb3a0c279f7ba788583) to branch 'au.asn.ucc.matt.dropbear' (head fff0894a0399405a9410ea1c6d118f342cf2aa64)
author Matt Johnston <matt@ucc.asn.au>
date Wed, 08 Mar 2006 13:23:49 +0000
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children 5ff8218bcee9
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283:bd240aa12ba7 284:eed26cff980b
1 #include <tommath.h>
2 #ifdef BN_MP_CLAMP_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.org
16 */
17
18 /* trim unused digits
19 *
20 * This is used to ensure that leading zero digits are
21 * trimed and the leading "used" digit will be non-zero
22 * Typically very fast. Also fixes the sign if there
23 * are no more leading digits
24 */
25 void
26 mp_clamp (mp_int * a)
27 {
28 /* decrease used while the most significant digit is
29 * zero.
30 */
31 while (a->used > 0 && a->dp[a->used - 1] == 0) {
32 --(a->used);
33 }
34
35 /* reset the sign flag if used == 0 */
36 if (a->used == 0) {
37 a->sign = MP_ZPOS;
38 }
39 }
40 #endif