mirror of
http://galexander.org/git/simplesshd.git
synced 2024-11-30 11:18:12 +00:00
35 lines
790 B
C
35 lines
790 B
C
#include "tommath_private.h"
|
|
#ifdef BN_MP_DECR_C
|
|
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
|
|
/* SPDX-License-Identifier: Unlicense */
|
|
|
|
/* Decrement "a" by one like "a--". Changes input! */
|
|
mp_err mp_decr(mp_int *a)
|
|
{
|
|
if (MP_IS_ZERO(a)) {
|
|
mp_set(a,1uL);
|
|
a->sign = MP_NEG;
|
|
return MP_OKAY;
|
|
} else if (a->sign == MP_NEG) {
|
|
mp_err err;
|
|
a->sign = MP_ZPOS;
|
|
if ((err = mp_incr(a)) != MP_OKAY) {
|
|
return err;
|
|
}
|
|
/* There is no -0 in LTM */
|
|
if (!MP_IS_ZERO(a)) {
|
|
a->sign = MP_NEG;
|
|
}
|
|
return MP_OKAY;
|
|
} else if (a->dp[0] > 1uL) {
|
|
a->dp[0]--;
|
|
if (a->dp[0] == 0u) {
|
|
mp_zero(a);
|
|
}
|
|
return MP_OKAY;
|
|
} else {
|
|
return mp_sub_d(a, 1uL,a);
|
|
}
|
|
}
|
|
#endif
|