crypto/external/bsd/heimdal/dist/lib/hcrypto/libtommath/bn_mp_copy.c

   1 /*      $NetBSD: bn_mp_copy.c,v 1.1.1.2 2014/04/24 12:45:31 pettai Exp $        */
   2
   3 #include <tommath.h>
   4 #ifdef BN_MP_COPY_C
   5 /* LibTomMath, multiple-precision integer library -- Tom St Denis
   6  *
   7  * LibTomMath is a library that provides multiple-precision
   8  * integer arithmetic as well as number theoretic functionality.
   9  *
  10  * The library was designed directly after the MPI library by
  11  * Michael Fromberger but has been written from scratch with
  12  * additional optimizations in place.
  13  *
  14  * The library is free for all purposes without any express
  15  * guarantee it works.
  16  *
  17  * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
  18  */
  19
  20 /* copy, b = a */
  21 int
  22 mp_copy (mp_int * a, mp_int * b)
  23 {
  24   int     res, n;
  25
  26   /* if dst == src do nothing */
  27   if (a == b) {
  28     return MP_OKAY;
  29   }
  30
  31   /* grow dest */
  32   if (b->alloc < a->used) {
  33      if ((res = mp_grow (b, a->used)) != MP_OKAY) {
  34         return res;
  35      }
  36   }
  37
  38   /* zero b and copy the parameters over */
  39   {
  40     register mp_digit *tmpa, *tmpb;
  41
  42     /* pointer aliases */
  43
  44     /* source */
  45     tmpa = a->dp;
  46
  47     /* destination */
  48     tmpb = b->dp;
  49
  50     /* copy all the digits */
  51     for (n = 0; n < a->used; n++) {
  52       *tmpb++ = *tmpa++;
  53     }
  54
  55     /* clear high digits */
  56     for (; n < b->used; n++) {
  57       *tmpb++ = 0;
  58     }
  59   }
  60
  61   /* copy used count and sign */
  62   b->used = a->used;
  63   b->sign = a->sign;
  64   return MP_OKAY;
  65 }
  66 #endif
  67
  68 /* Source: /cvs/libtom/libtommath/bn_mp_copy.c,v  */
  69 /* Revision: 1.4  */
  70 /* Date: 2006/12/28 01:25:13  */