pb_shrink.c

   1 /* LibTomPoly, Polynomial Basis Math -- Tom St Denis
   2  *
   3  * LibTomPoly is a public domain library that provides
   4  * polynomial basis arithmetic support.  It relies on
   5  * LibTomMath for large integer support.
   6  *
   7  * This library is free for all purposes without any
   8  * express guarantee that it works.
   9  *
  10  * Tom St Denis, tomstdenis@iahu.ca, http://poly.libtomcrypt.org
  11  */
  12 #include <tompoly.h>
  13
  14 int pb_shrink(pb_poly *a)
  15 {
  16    int err, x;
  17    mp_int *tmp;
  18
  19    /* first resize the array of terms */
  20    if (a->used != a->alloc && a->used > 0) {
  21       tmp = realloc(a->terms, sizeof(mp_int) * a->used);
  22       if (tmp == NULL) {
  23          return MP_MEM;
  24       }
  25       a->terms = tmp;
  26       a->alloc = a->used;
  27    }
  28
  29    /* now shrink each mp_int */
  30    for (x = 0; x < a->used; x++) {
  31        if ((err = mp_shrink(&(a->terms[x]))) != MP_OKAY) {
  32           return err;
  33        }
  34    }
  35    return MP_OKAY;
  36 }
  37
  38