annotate bn_mp_clear.c @ 283:bd240aa12ba7 libtommath-dropbear

* Changes imported from Dropbear 0.47. * bn_mp_clear.c is changed so that some vars are volatile, so that the compiler won't optimise away
author Matt Johnston <matt@ucc.asn.au>
date Wed, 08 Mar 2006 13:22:52 +0000
parents 91fbc376f010
children 4663ced4968f
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1 #include <tommath.h>
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2 #ifdef BN_MP_CLEAR_C
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3 /* LibTomMath, multiple-precision integer library -- Tom St Denis
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4 *
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5 * LibTomMath is a library that provides multiple-precision
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6 * integer arithmetic as well as number theoretic functionality.
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7 *
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8 * The library was designed directly after the MPI library by
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9 * Michael Fromberger but has been written from scratch with
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10 * additional optimizations in place.
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11 *
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12 * The library is free for all purposes without any express
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13 * guarantee it works.
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14 *
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15 * Tom St Denis, [email protected], http://math.libtomcrypt.org
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16 */
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17
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18 /* clear one (frees) */
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19 void
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20 mp_clear (mp_int * a)
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21 {
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22 volatile mp_digit *p;
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23 int len;
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24
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25 /* only do anything if a hasn't been freed previously */
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26 if (a->dp != NULL) {
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27 /* first zero the digits */
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28 len = a->alloc;
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29 p = a->dp;
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30 while (len--) {
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31 *p++ = 0;
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32 }
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33
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34 /* free ram */
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35 XFREE(a->dp);
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36
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37 /* reset members to make debugging easier */
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38 a->dp = NULL;
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39 a->alloc = a->used = 0;
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40 a->sign = MP_ZPOS;
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41 }
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42 }
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43 #endif