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annotate libtommath/bn_mp_read_signed_bin.c @ 1200:9a944a243f08 DROPBEAR_2015.71

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2015.71
author Matt Johnston <matt@ucc.asn.au>
date Thu, 03 Dec 2015 21:23:54 +0800
parents 5ff8218bcee9
children 60fc6476e044
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1 #include <tommath.h>
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2 #ifdef BN_MP_READ_SIGNED_BIN_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.com
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16 */
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18 /* read signed bin, big endian, first byte is 0==positive or 1==negative */
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19 int mp_read_signed_bin (mp_int * a, const unsigned char *b, int c)
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20 {
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21 int res;
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23 /* read magnitude */
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24 if ((res = mp_read_unsigned_bin (a, b + 1, c - 1)) != MP_OKAY) {
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25 return res;
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26 }
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28 /* first byte is 0 for positive, non-zero for negative */
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29 if (b[0] == 0) {
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30 a->sign = MP_ZPOS;
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31 } else {
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32 a->sign = MP_NEG;
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33 }
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35 return MP_OKAY;
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36 }
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37 #endif
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39 /* $Source: /cvs/libtom/libtommath/bn_mp_read_signed_bin.c,v $ */
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40 /* $Revision: 1.4 $ */
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41 /* $Date: 2006/03/31 14:18:44 $ */