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comparison libtommath/bn_mp_read_signed_bin.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_READ_SIGNED_BIN_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 /* read signed bin, big endian, first byte is 0==positive or 1==negative */
19 int
20 mp_read_signed_bin (mp_int * a, unsigned char *b, int c)
21 {
22 int res;
23
24 /* read magnitude */
25 if ((res = mp_read_unsigned_bin (a, b + 1, c - 1)) != MP_OKAY) {
26 return res;
27 }
28
29 /* first byte is 0 for positive, non-zero for negative */
30 if (b[0] == 0) {
31 a->sign = MP_ZPOS;
32 } else {
33 a->sign = MP_NEG;
34 }
35
36 return MP_OKAY;
37 }
38 #endif