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annotate libtommath/bn_s_mp_get_bit.c @ 1890:45e552ee4391

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merge
author Matt Johnston <matt@ucc.asn.au>
date Tue, 22 Mar 2022 16:17:47 +0800
parents 1051e4eea25a
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
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1692
1051e4eea25a Update LibTomMath to 1.2.0 (#84)
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1 #include "tommath_private.h"
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2 #ifdef BN_S_MP_GET_BIT_C
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3
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4 /* LibTomMath, multiple-precision integer library -- Tom St Denis */
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5 /* SPDX-License-Identifier: Unlicense */
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6
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7 /* Get bit at position b and return MP_YES if the bit is 1, MP_NO if it is 0 */
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8 mp_bool s_mp_get_bit(const mp_int *a, unsigned int b)
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9 {
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10 mp_digit bit;
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11 int limb = (int)(b / MP_DIGIT_BIT);
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12
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13 if (limb >= a->used) {
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14 return MP_NO;
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15 }
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16
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17 bit = (mp_digit)1 << (b % MP_DIGIT_BIT);
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18 return ((a->dp[limb] & bit) != 0u) ? MP_YES : MP_NO;
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19 }
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20
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21 #endif