File: bn_mp_read_signed_bin.c

package info (click to toggle)
libtommath 0.42.0-1
  • links: PTS
  • area: main
  • in suites: wheezy
  • size: 4,764 kB
  • sloc: ansic: 14,350; perl: 361; makefile: 255; asm: 30; sh: 1
file content (41 lines) | stat: -rwxr-xr-x 1,083 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
#include <tommath.h>
#ifdef BN_MP_READ_SIGNED_BIN_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis
 *
 * LibTomMath is a library that provides multiple-precision
 * integer arithmetic as well as number theoretic functionality.
 *
 * The library was designed directly after the MPI library by
 * Michael Fromberger but has been written from scratch with
 * additional optimizations in place.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
 */

/* read signed bin, big endian, first byte is 0==positive or 1==negative */
int mp_read_signed_bin (mp_int * a, const unsigned char *b, int c)
{
  int     res;

  /* read magnitude */
  if ((res = mp_read_unsigned_bin (a, b + 1, c - 1)) != MP_OKAY) {
    return res;
  }

  /* first byte is 0 for positive, non-zero for negative */
  if (b[0] == 0) {
     a->sign = MP_ZPOS;
  } else {
     a->sign = MP_NEG;
  }

  return MP_OKAY;
}
#endif

/* $Source$ */
/* $Revision: 0.41 $ */
/* $Date: 2007-04-18 09:58:18 +0000 $ */