annotate bn_mp_init_size.c @ 282:91fbc376f010 libtommath-orig libtommath-0.35

Import of libtommath 0.35 From ltm-0.35.tar.bz2 SHA1 of 3f193dbae9351e92d02530994fa18236f7fde01c
author Matt Johnston <matt@ucc.asn.au>
date Wed, 08 Mar 2006 13:16:18 +0000
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children 97db060d0ef5
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1 #include <tommath.h>
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2 #ifdef BN_MP_INIT_SIZE_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 /* init an mp_init for a given size */
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19 int mp_init_size (mp_int * a, int size)
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20 {
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21 int x;
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22
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23 /* pad size so there are always extra digits */
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24 size += (MP_PREC * 2) - (size % MP_PREC);
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25
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26 /* alloc mem */
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27 a->dp = OPT_CAST(mp_digit) XMALLOC (sizeof (mp_digit) * size);
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28 if (a->dp == NULL) {
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29 return MP_MEM;
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30 }
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31
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32 /* set the members */
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33 a->used = 0;
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34 a->alloc = size;
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35 a->sign = MP_ZPOS;
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36
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37 /* zero the digits */
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38 for (x = 0; x < size; x++) {
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39 a->dp[x] = 0;
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40 }
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41
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42 return MP_OKAY;
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43 }
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44 #endif