1 #include "tommath_private.h"
2 #ifdef BN_MP_DR_IS_MODULUS_C
3 /* LibTomMath, multiple-precision integer library -- Tom St Denis */
4 /* SPDX-License-Identifier: Unlicense */
6 /* determines if a number is a valid DR modulus */
7 mp_bool mp_dr_is_modulus(const mp_int *a)
11 /* must be at least two digits */
16 /* must be of the form b**k - a [a <= b] so all
17 * but the first digit must be equal to -1 (mod b).
19 for (ix = 1; ix < a->used; ix++) {
20 if (a->dp[ix] != MP_MASK) {