c3-lang/libtommath/bn_mp_prime_is_divisible.c

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• Hash : 4e3f1344
  Author :
  Date : 2015-11-12T01:49:07
  

  provide tommath_private.h tommath.h contains declarations for the public part of the library. tommath_private.h contains the functions which are private to ltm and should not be exposed to the public.

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• bn_mp_prime_is_divisible.c

• #include <tommath_private.h>
  #ifdef BN_MP_PRIME_IS_DIVISIBLE_C
  /* LibTomMath, multiple-precision integer library -- Tom St Denis
   *
   * LibTomMath is a library that provides multiple-precision
   * integer arithmetic as well as number theoretic functionality.
   *
   * The library was designed directly after the MPI library by
   * Michael Fromberger but has been written from scratch with
   * additional optimizations in place.
   *
   * The library is free for all purposes without any express
   * guarantee it works.
   *
   * Tom St Denis, tstdenis82@gmail.com, http://libtom.org
   */
  
  /* determines if an integers is divisible by one 
   * of the first PRIME_SIZE primes or not
   *
   * sets result to 0 if not, 1 if yes
   */
  int mp_prime_is_divisible (mp_int * a, int *result)
  {
    int     err, ix;
    mp_digit res;
  
    /* default to not */
    *result = MP_NO;
  
    for (ix = 0; ix < PRIME_SIZE; ix++) {
      /* what is a mod LBL_prime_tab[ix] */
      if ((err = mp_mod_d (a, ltm_prime_tab[ix], &res)) != MP_OKAY) {
        return err;
      }
  
      /* is the residue zero? */
      if (res == 0) {
        *result = MP_YES;
        return MP_OKAY;
      }
    }
  
    return MP_OKAY;
  }
  #endif
  
  /* $Source$ */
  /* $Revision$ */
  /* $Date$ */
  

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