| Message ID | 20210120184843.3217775-3-thara.gopinath@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Regression fixes/clean ups in the Qualcomm crypto engine driver | expand |
On Wed 20 Jan 12:48 CST 2021, Thara Gopinath wrote: > 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. > Please drop "drivers: " from $subject. Apart from that this looks good. Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Regards, Bjorn > Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org> > --- > drivers/crypto/qce/sha.c | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/drivers/crypto/qce/sha.c b/drivers/crypto/qce/sha.c > index 08aed03e2b59..dd263c5e4dd8 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, > -- > 2.25.1 >
diff --git a/drivers/crypto/qce/sha.c b/drivers/crypto/qce/sha.c index 08aed03e2b59..dd263c5e4dd8 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,
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. Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org> --- drivers/crypto/qce/sha.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) -- 2.25.1