pb_init.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 #include <stdlib.h>
  14
  15 /* initialize a */
  16 int pb_init(pb_poly *a, mp_int *characteristic)
  17 {
  18    int x, y, err;
  19
  20    /* init characteristic */
  21    if ((err = mp_init_copy(&(a->characteristic), characteristic)) != MP_OKAY) {
  22       return err;
  23    }
  24
  25    /* now allocate an array of mp_ints */
  26    if ((a->terms = calloc(PB_TERMS, sizeof(mp_int))) == NULL) {
  27       mp_clear(&(a->characteristic));
  28       return MP_MEM;
  29    }
  30
  31    /* now initialize them all */
  32    for (x = 0; x < PB_TERMS; x++) {
  33        if ((err = mp_init(&(a->terms[x]))) != MP_OKAY) {
  34           /* free stuff */
  35           for (y = 0; y < x; y++) {
  36               mp_clear(&(a->terms[y]));
  37           }
  38           free(a->terms);
  39           mp_clear(&(a->characteristic));
  40           return err;
  41       }
  42    }
  43
  44    /* set our parameters */
  45    a->used  = 0;
  46    a->alloc = PB_TERMS;
  47    return MP_OKAY;
  48 }
  49
  50