Blame view

Giac_maj/libtommath-0.39/bn_mp_copy.c 1.4 KB
6663b6c9   adorian   projet complet av...
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
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
  #include <tommath.h>
  #ifdef BN_MP_COPY_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://math.libtomcrypt.com
   */
  
  /* copy, b = a */
  int
  mp_copy (mp_int * a, mp_int * b)
  {
    int     res, n;
  
    /* if dst == src do nothing */
    if (a == b) {
      return MP_OKAY;
    }
  
    /* grow dest */
    if (b->alloc < a->used) {
       if ((res = mp_grow (b, a->used)) != MP_OKAY) {
          return res;
       }
    }
  
    /* zero b and copy the parameters over */
    {
      register mp_digit *tmpa, *tmpb;
  
      /* pointer aliases */
  
      /* source */
      tmpa = a->dp;
  
      /* destination */
      tmpb = b->dp;
  
      /* copy all the digits */
      for (n = 0; n < a->used; n++) {
        *tmpb++ = *tmpa++;
      }
  
      /* clear high digits */
      for (; n < b->used; n++) {
        *tmpb++ = 0;
      }
    }
  
    /* copy used count and sign */
    b->used = a->used;
    b->sign = a->sign;
    return MP_OKAY;
  }
  #endif
  
  /* $Source: /cvs/libtom/libtommath/bn_mp_copy.c,v $ */
  /* $Revision: 1.3 $ */
  /* $Date: 2006/03/31 14:18:44 $ */