Checksumming updates
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/crc/sha256.c b/crc/sha256.c
index 3a72a5b..ae9ff4d 100644
--- a/crc/sha256.c
+++ b/crc/sha256.c
@@ -237,37 +237,57 @@
sctx->state[5] = H5;
sctx->state[6] = H6;
sctx->state[7] = H7;
- sctx->count[0] = sctx->count[1] = 0;
+ sctx->count = 0;
}
void fio_sha256_update(struct fio_sha256_ctx *sctx, const uint8_t *data,
unsigned int len)
{
- unsigned int i, idx, part_len;
+ unsigned int partial, done;
+ const uint8_t *src;
- /* Compute number of bytes mod 128 */
- idx = (unsigned int)((sctx->count[0] >> 3) & 0x3f);
+ partial = sctx->count & 0x3f;
+ sctx->count += len;
+ done = 0;
+ src = data;
- /* Update number of bits */
- if ((sctx->count[0] += (len << 3)) < (len << 3)) {
- sctx->count[1]++;
- sctx->count[1] += (len >> 29);
+ 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;
}
+ memcpy(sctx->buf + partial, src, len - done);
+}
- part_len = 64 - idx;
+void fio_sha256_final(struct fio_sha256_ctx *sctx)
+{
+ uint64_t bits;
+ unsigned int index, pad_len;
+ int i;
+ static const uint8_t padding[64] = { 0x80, };
- /* Transform as many times as possible. */
- if (len >= part_len) {
- memcpy(&sctx->buf[idx], data, part_len);
- sha256_transform(sctx->state, sctx->buf);
+ /* Save number of bits */
+ bits = sctx->count << 3;
- for (i = part_len; i + 63 < len; i += 64)
- sha256_transform(sctx->state, &data[i]);
- idx = 0;
- } else {
- i = 0;
- }
-
- /* Buffer remaining input */
- memcpy(&sctx->buf[idx], &data[i], len-i);
+ /* Pad out to 56 mod 64. */
+ index = sctx->count & 0x3f;
+ pad_len = (index < 56) ? (56 - index) : ((64+56) - index);
+ fio_sha256_update(sctx, padding, pad_len);
+
+ /* Append length (before padding) */
+ fio_sha256_update(sctx, (const uint8_t *)&bits, sizeof(bits));
+
+ /* Store state in digest */
+ for (i = 0; i < 8; i++)
+ sctx->buf[i] = sctx->state[i];
}