blob: bb8af882e98094772a7abff9a19d40a6aadddc48 (
plain)
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
69
70
71
72
73
|
#include "tommath_private.h"
#ifdef BN_MP_TORADIX_N_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
/* stores a bignum as a ASCII string in a given radix (2..64)
*
* Stores upto maxlen-1 chars and always a NULL byte
*/
mp_err mp_toradix_n(const mp_int *a, char *str, int radix, int maxlen)
{
int digs;
mp_err err;
mp_int t;
mp_digit d;
char *_s = str;
/* check range of the maxlen, radix */
if ((maxlen < 2) || (radix < 2) || (radix > 64)) {
return MP_VAL;
}
/* quick out if its zero */
if (MP_IS_ZERO(a)) {
*str++ = '0';
*str = '\0';
return MP_OKAY;
}
if ((err = mp_init_copy(&t, a)) != MP_OKAY) {
return err;
}
/* if it is negative output a - */
if (t.sign == MP_NEG) {
/* we have to reverse our digits later... but not the - sign!! */
++_s;
/* store the flag and mark the number as positive */
*str++ = '-';
t.sign = MP_ZPOS;
/* subtract a char */
--maxlen;
}
digs = 0;
while (!MP_IS_ZERO(&t)) {
if (--maxlen < 1) {
/* no more room */
break;
}
if ((err = mp_div_d(&t, (mp_digit)radix, &t, &d)) != MP_OKAY) {
mp_clear(&t);
return err;
}
*str++ = mp_s_rmap[d];
++digs;
}
/* reverse the digits of the string. In this case _s points
* to the first digit [exluding the sign] of the number
*/
s_mp_reverse((unsigned char *)_s, digs);
/* append a NULL so the string is properly terminated */
*str = '\0';
mp_clear(&t);
return MP_OKAY;
}
#endif
|
