+ num_val += (size_t)1 << (wsize[i] - 1);
+ wNAF[i + 1] = NULL; /* make sure we always have a pivot */
+ wNAF[i] = compute_wNAF((i < num ? scalars[i] : scalar), wsize[i], &wNAF_len[i]);
+ if (wNAF[i] == NULL)
+ goto err;
+ if (wNAF_len[i] > max_len)
+ max_len = wNAF_len[i];
+ }
+
+ if (numblocks)
+ {
+ /* we go here iff scalar != NULL */
+
+ if (pre_comp == NULL)
+ {
+ if (num_scalar != 1)
+ {
+ ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+ /* we have already generated a wNAF for 'scalar' */
+ }
+ else
+ {
+ signed char *tmp_wNAF = NULL;
+ size_t tmp_len = 0;
+
+ if (num_scalar != 0)
+ {
+ ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+
+ /* use the window size for which we have precomputation */
+ wsize[num] = pre_comp->w;
+ tmp_wNAF = compute_wNAF(scalar, wsize[num], &tmp_len);
+ if (!tmp_wNAF)
+ goto err;
+
+ if (tmp_len <= max_len)
+ {
+ /* One of the other wNAFs is at least as long
+ * as the wNAF belonging to the generator,
+ * so wNAF splitting will not buy us anything. */
+
+ numblocks = 1;
+ totalnum = num + 1; /* don't use wNAF splitting */
+ wNAF[num] = tmp_wNAF;
+ wNAF[num + 1] = NULL;
+ wNAF_len[num] = tmp_len;
+ if (tmp_len > max_len)
+ max_len = tmp_len;
+ /* pre_comp->points starts with the points that we need here: */
+ val_sub[num] = pre_comp->points;
+ }
+ else
+ {
+ /* don't include tmp_wNAF directly into wNAF array
+ * - use wNAF splitting and include the blocks */
+
+ signed char *pp;
+ EC_POINT **tmp_points;
+
+ if (tmp_len < numblocks * blocksize)
+ {
+ /* possibly we can do with fewer blocks than estimated */
+ numblocks = (tmp_len + blocksize - 1) / blocksize;
+ if (numblocks > pre_comp->numblocks)
+ {
+ ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+ totalnum = num + numblocks;
+ }
+
+ /* split wNAF in 'numblocks' parts */
+ pp = tmp_wNAF;
+ tmp_points = pre_comp->points;
+
+ for (i = num; i < totalnum; i++)
+ {
+ if (i < totalnum - 1)
+ {
+ wNAF_len[i] = blocksize;
+ if (tmp_len < blocksize)
+ {
+ ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+ tmp_len -= blocksize;
+ }
+ else
+ /* last block gets whatever is left
+ * (this could be more or less than 'blocksize'!) */
+ wNAF_len[i] = tmp_len;
+
+ wNAF[i + 1] = NULL;
+ wNAF[i] = OPENSSL_malloc(wNAF_len[i]);
+ if (wNAF[i] == NULL)
+ {
+ ECerr(EC_F_EC_WNAF_MUL, ERR_R_MALLOC_FAILURE);
+ OPENSSL_free(tmp_wNAF);
+ goto err;
+ }
+ memcpy(wNAF[i], pp, wNAF_len[i]);
+ if (wNAF_len[i] > max_len)
+ max_len = wNAF_len[i];
+
+ if (*tmp_points == NULL)
+ {
+ ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR);
+ OPENSSL_free(tmp_wNAF);
+ goto err;
+ }
+ val_sub[i] = tmp_points;
+ tmp_points += pre_points_per_block;
+ pp += blocksize;
+ }
+ OPENSSL_free(tmp_wNAF);
+ }
+ }