kc3-lang/libtommath/bn_mp_rand.c

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• Hash : c8cc3657
  Author :
  Date : 2019-05-11T09:09:12
  

  mov s_mp_rand_source_platform to separate file

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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 */
  /* SPDX-License-Identifier: Unlicense */
  
  int (*s_mp_rand_source)(void *, size_t) = s_mp_rand_source_platform;
  
  void mp_rand_source(int (*source)(void *out, size_t size))
  {
     s_mp_rand_source = (source == NULL) ? s_mp_rand_source_platform : source;
  }
  
  /* makes a pseudo-random int of a given size */
  int mp_rand_digit(mp_digit *r)
  {
     int ret = s_mp_rand_source(r, sizeof(mp_digit));
     *r &= MP_MASK;
     return ret;
  }
  
  int mp_rand(mp_int *a, int digits)
  {
     int ret, i;
  
     mp_zero(a);
  
     if (digits <= 0) {
        return MP_OKAY;
     }
  
     if ((ret = mp_grow(a, digits)) != MP_OKAY) {
        return ret;
     }
  
     if ((ret = s_mp_rand_source(a->dp, (size_t)digits * sizeof(mp_digit))) != MP_OKAY) {
        return ret;
     }
  
     /* TODO: We ensure that the highest digit is nonzero. Should this be removed? */
     while ((a->dp[digits - 1] & MP_MASK) == 0) {
        if ((ret = s_mp_rand_source(a->dp + digits - 1, sizeof(mp_digit))) != MP_OKAY) {
           return ret;
        }
     }
  
     a->used = digits;
     for (i = 0; i < digits; ++i) {
        a->dp[i] &= MP_MASK;
     }
  
     return MP_OKAY;
  }
  #endif
  

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