c3-lang/libtommath/bn_mp_get_bit.c

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• Hash : e45f75fd
  Author :
  Date : 2019-04-13T08:46:57
  

  deprecate DIGIT_BIT, use MP_DIGIT_BIT

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• bn_mp_get_bit.c

• #include "tommath_private.h"
  #ifdef BN_MP_GET_BIT_C
  
  /* LibTomMath, multiple-precision integer library -- Tom St Denis */
  /* SPDX-License-Identifier: Unlicense */
  
  /* Checks the bit at position b and returns MP_YES
     if the bit is 1, MP_NO if it is 0 and MP_VAL
     in case of error */
  int mp_get_bit(const mp_int *a, int b)
  {
     int limb;
     mp_digit bit, isset;
  
     if (b < 0) {
        return MP_VAL;
     }
  
     limb = b / MP_DIGIT_BIT;
  
     if (limb >= a->used) {
        return MP_NO;
     }
  
     bit = (mp_digit)(1) << (b % MP_DIGIT_BIT);
  
     isset = a->dp[limb] & bit;
     return (isset != 0u) ? MP_YES : MP_NO;
  }
  
  #endif
  

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