kc3-lang/libtommath/bn_mp_rand.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_rand.c

• #include <tommath_private.h>
  #ifdef BN_MP_RAND_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
   */
  
  /* makes a pseudo-random int of a given size */
  int
  mp_rand (mp_int * a, int digits)
  {
    int     res;
    mp_digit d;
  
    mp_zero (a);
    if (digits <= 0) {
      return MP_OKAY;
    }
  
    /* first place a random non-zero digit */
    do {
      d = ((mp_digit) abs (MP_GEN_RANDOM())) & MP_MASK;
    } while (d == 0);
  
    if ((res = mp_add_d (a, d, a)) != MP_OKAY) {
      return res;
    }
  
    while (--digits > 0) {
      if ((res = mp_lshd (a, 1)) != MP_OKAY) {
        return res;
      }
  
      if ((res = mp_add_d (a, ((mp_digit) abs (MP_GEN_RANDOM())), a)) != MP_OKAY) {
        return res;
      }
    }
  
    return MP_OKAY;
  }
  #endif
  
  /* $Source$ */
  /* $Revision$ */
  /* $Date$ */
  

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