Пример #1
0
static void
table_init (const struct ecc_curve *ecc,
	    mp_limb_t *table, unsigned bits,
	    int initial, const mp_limb_t *p,
	    mp_limb_t *scratch)
{
  unsigned size = 1 << bits;
  unsigned j;

  mpn_zero (TABLE(0), 3*ecc->size);
  ecc_a_to_j (ecc, initial, TABLE(1), p);

  for (j = 2; j < size; j += 2)
    {
      ecc_dup_jj (ecc, TABLE(j), TABLE(j/2), scratch);
      ecc_add_jja (ecc, TABLE(j+1), TABLE(j), TABLE(1), scratch);
    }  
}
Пример #2
0
void
ecc_mul_a (const struct ecc_curve *ecc,
	   int initial, mp_limb_t *r,
	   const mp_limb_t *np, const mp_limb_t *p,
	   mp_limb_t *scratch)
{
#define tp scratch
#define pj (scratch + 3*ecc->size)
#define scratch_out (scratch + 6*ecc->size)

  int is_zero;

  unsigned i;

  ecc_a_to_j (ecc, initial, pj, p);
  mpn_zero (r, 3*ecc->size);
  
  for (i = ecc->size, is_zero = 1; i-- > 0; )
    {
      mp_limb_t w = np[i];
      mp_limb_t bit;

      for (bit = (mp_limb_t) 1 << (GMP_NUMB_BITS - 1);
	   bit > 0;
	   bit >>= 1)
	{
	  int digit;

	  ecc_dup_jj (ecc, r, r, scratch_out);
	  ecc_add_jja (ecc, tp, r, pj, scratch_out);

	  digit = (w & bit) > 0;
	  /* If is_zero is set, r is the zero point,
	     and ecc_add_jja produced garbage. */
	  cnd_copy (is_zero, tp, pj, 3*ecc->size);
	  is_zero &= ~digit;
	  /* If we had a one-bit, use the sum. */
	  cnd_copy (digit, r, tp, 3*ecc->size);
	}
    }
}
Пример #3
0
static void
bench_add_jja (void *p)
{
  struct ecc_ctx *ctx = (struct ecc_ctx *) p;
  ecc_add_jja (ctx->ecc, ctx->rp, ctx->ap, ctx->bp, ctx->tp);
}