Mercurial > dropbear
comparison libtommath/bn_s_mp_get_bit.c @ 1739:13d834efc376 fuzz
merge from main
| author | Matt Johnston <matt@ucc.asn.au> |
|---|---|
| date | Thu, 15 Oct 2020 19:55:15 +0800 |
| parents | 1051e4eea25a |
| children |
comparison
equal
deleted
inserted
replaced
| 1562:768ebf737aa0 | 1739:13d834efc376 |
|---|---|
| 1 #include "tommath_private.h" | |
| 2 #ifdef BN_S_MP_GET_BIT_C | |
| 3 | |
| 4 /* LibTomMath, multiple-precision integer library -- Tom St Denis */ | |
| 5 /* SPDX-License-Identifier: Unlicense */ | |
| 6 | |
| 7 /* Get bit at position b and return MP_YES if the bit is 1, MP_NO if it is 0 */ | |
| 8 mp_bool s_mp_get_bit(const mp_int *a, unsigned int b) | |
| 9 { | |
| 10 mp_digit bit; | |
| 11 int limb = (int)(b / MP_DIGIT_BIT); | |
| 12 | |
| 13 if (limb >= a->used) { | |
| 14 return MP_NO; | |
| 15 } | |
| 16 | |
| 17 bit = (mp_digit)1 << (b % MP_DIGIT_BIT); | |
| 18 return ((a->dp[limb] & bit) != 0u) ? MP_YES : MP_NO; | |
| 19 } | |
| 20 | |
| 21 #endif |