blob: 1cc47f19694d46eb4cd3b566cc19965015795fe1 (
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
|
#include <tommath.h>
#ifdef BN_MP_RAND_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@iahu.ca, http://math.libtomcrypt.org
*/
/* makes a pseudo-random int of a given size */
int
mp_rand (mp_int * a, int digits)
{
int res;
mp_digit d;
mp_zero (a);
if (digits <= 0) {
return MP_OKAY;
}
/* first place a random non-zero digit */
do {
d = ((mp_digit) abs (rand ()));
} while (d == 0);
if ((res = mp_add_d (a, d, a)) != MP_OKAY) {
return res;
}
while (digits-- > 0) {
if ((res = mp_lshd (a, 1)) != MP_OKAY) {
return res;
}
if ((res = mp_add_d (a, ((mp_digit) abs (rand ())), a)) != MP_OKAY) {
return res;
}
}
return MP_OKAY;
}
#endif
|
