libtommath/bn_mp_xor.c
Daniel Mendler 4534056c28
use enums mp_err, mp_ord, mp_bool, mp_sign
* MP_USE_ENUMS enables enums
* Wc++-compat catches some implicit conversions if MP_USE_ENUMS is defined
* 100% backwards compatible API/ABI if MP_USE_ENUMS is not defined
2019-05-13 19:15:14 +02:00

37 lines
740 B
C

#include "tommath_private.h"
#ifdef BN_MP_XOR_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
/* XOR two ints together */
mp_err mp_xor(const mp_int *a, const mp_int *b, mp_int *c)
{
int ix, px;
mp_err res;
mp_int t;
const mp_int *x;
if (a->used > b->used) {
if ((res = mp_init_copy(&t, a)) != MP_OKAY) {
return res;
}
px = b->used;
x = b;
} else {
if ((res = mp_init_copy(&t, b)) != MP_OKAY) {
return res;
}
px = a->used;
x = a;
}
for (ix = 0; ix < px; ix++) {
t.dp[ix] ^= x->dp[ix];
}
mp_clamp(&t);
mp_exch(c, &t);
mp_clear(&t);
return MP_OKAY;
}
#endif