diff options
Diffstat (limited to 'drivers/crypto/qce/sha.c')
| -rw-r--r-- | drivers/crypto/qce/sha.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/crypto/qce/sha.c b/drivers/crypto/qce/sha.c index 7da562dca740..2813c9a27a6e 100644 --- a/drivers/crypto/qce/sha.c +++ b/drivers/crypto/qce/sha.c @@ -216,6 +216,25 @@ static int qce_ahash_update(struct ahash_request *req) /* calculate how many bytes will be hashed later */ hash_later = total % blocksize; + + /* + * At this point, there is more than one block size of data. If + * the available data to transfer is exactly a multiple of block + * size, save the last block to be transferred in qce_ahash_final + * (with the last block bit set) if this is indeed the end of data + * stream. If not this saved block will be transferred as part of + * next update. If this block is not held back and if this is + * indeed the end of data stream, the digest obtained will be wrong + * since qce_ahash_final will see that rctx->buflen is 0 and return + * doing nothing which in turn means that a digest will not be + * copied to the destination result buffer. qce_ahash_final cannot + * be made to alter this behavior and allowed to proceed if + * rctx->buflen is 0 because the crypto engine BAM does not allow + * for zero length transfers. + */ + if (!hash_later) + hash_later = blocksize; + if (hash_later) { unsigned int src_offset = req->nbytes - hash_later; scatterwalk_map_and_copy(rctx->buf, req->src, src_offset, |