mirror of
http://galexander.org/git/simplesshd.git
synced 2024-11-30 11:18:12 +00:00
28 lines
610 B
C
28 lines
610 B
C
#include "tommath_private.h"
|
|
#ifdef BN_MP_DR_IS_MODULUS_C
|
|
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
|
|
/* SPDX-License-Identifier: Unlicense */
|
|
|
|
/* determines if a number is a valid DR modulus */
|
|
mp_bool mp_dr_is_modulus(const mp_int *a)
|
|
{
|
|
int ix;
|
|
|
|
/* must be at least two digits */
|
|
if (a->used < 2) {
|
|
return MP_NO;
|
|
}
|
|
|
|
/* must be of the form b**k - a [a <= b] so all
|
|
* but the first digit must be equal to -1 (mod b).
|
|
*/
|
|
for (ix = 1; ix < a->used; ix++) {
|
|
if (a->dp[ix] != MP_MASK) {
|
|
return MP_NO;
|
|
}
|
|
}
|
|
return MP_YES;
|
|
}
|
|
|
|
#endif
|