1#include <tommath.h>
2#ifdef BN_MP_TORADIX_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, tomstdenis@gmail.com, http://math.libtomcrypt.com
16 */
17
18/* stores a bignum as a ASCII string in a given radix (2..64) */
19int mp_toradix (mp_int * a, char *str, int radix)
20{
21  int     res, digs;
22  mp_int  t;
23  mp_digit d;
24  char   *_s = str;
25
26  /* check range of the radix */
27  if (radix < 2 || radix > 64) {
28    return MP_VAL;
29  }
30
31  /* quick out if its zero */
32  if (mp_iszero(a) == 1) {
33     *str++ = '0';
34     *str = '\0';
35     return MP_OKAY;
36  }
37
38  if ((res = mp_init_copy (&t, a)) != MP_OKAY) {
39    return res;
40  }
41
42  /* if it is negative output a - */
43  if (t.sign == MP_NEG) {
44    ++_s;
45    *str++ = '-';
46    t.sign = MP_ZPOS;
47  }
48
49  digs = 0;
50  while (mp_iszero (&t) == 0) {
51    if ((res = mp_div_d (&t, (mp_digit) radix, &t, &d)) != MP_OKAY) {
52      mp_clear (&t);
53      return res;
54    }
55    *str++ = mp_s_rmap[d];
56    ++digs;
57  }
58
59  /* reverse the digits of the string.  In this case _s points
60   * to the first digit [exluding the sign] of the number]
61   */
62  bn_reverse ((unsigned char *)_s, digs);
63
64  /* append a NULL so the string is properly terminated */
65  *str = '\0';
66
67  mp_clear (&t);
68  return MP_OKAY;
69}
70
71#endif
72
73/* $Source: /cvs/libtom/libtommath/bn_mp_toradix.c,v $ */
74/* $Revision: 1.3 $ */
75/* $Date: 2006/03/31 14:18:44 $ */
76