- struct sha256_ctx *sctx = shash_desc_ctx(desc);
- unsigned int i, index, part_len;
-
- /* Compute number of bytes mod 128 */
- index = (unsigned int)((sctx->count[0] >> 3) & 0x3f);
-
- /* Update number of bits */
- if ((sctx->count[0] += (len << 3)) < (len << 3)) {
- sctx->count[1]++;
- sctx->count[1] += (len >> 29);
- }
-
- part_len = 64 - index;
-
- /* Transform as many times as possible. */
- if (len >= part_len) {
- memcpy(&sctx->buf[index], data, part_len);
- sha256_transform(sctx->state, sctx->buf);
-
- for (i = part_len; i + 63 < len; i += 64)
- sha256_transform(sctx->state, &data[i]);
- index = 0;
- } else {
- i = 0;
+ struct sha256_state *sctx = shash_desc_ctx(desc);
+ unsigned int partial, done;
+ const u8 *src;
+
+ partial = sctx->count & 0x3f;
+ sctx->count += len;
+ done = 0;
+ src = data;
+
+ if ((partial + len) > 63) {
+ if (partial) {
+ done = -partial;
+ memcpy(sctx->buf + partial, data, done + 64);
+ src = sctx->buf;
+ }
+
+ do {
+ sha256_transform(sctx->state, src);
+ done += 64;
+ src = data + done;
+ } while (done + 63 < len);
+
+ partial = 0;