libtommath/s_mp_get_bit.c
2019-11-04 15:41:32 +01:00

22 lines
492 B
C

#include "tommath_private.h"
#ifdef S_MP_GET_BIT_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
/* Get bit at position b and return true if the bit is 1, false if it is 0 */
bool s_mp_get_bit(const mp_int *a, int b)
{
mp_digit bit;
int limb = b / MP_DIGIT_BIT;
if (limb < 0 || limb >= a->used) {
return false;
}
bit = (mp_digit)1 << (b % MP_DIGIT_BIT);
return ((a->dp[limb] & bit) != 0u);
}
#endif