Hi Eric,
On 2/4/21 5:48 PM, Eric Biggers wrote:
On Thu, Feb 04, 2021 at 04:43:53PM -0500, Thara Gopinath wrote:
Crypto engine BAM dma does not support 0 length data. Return unsupported
if zero length messages are passed for transformation.
Signed-off-by: Thara Gopinath <thara.gopinath@xxxxxxxxxx>
---
drivers/crypto/qce/skcipher.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/crypto/qce/skcipher.c b/drivers/crypto/qce/skcipher.c
index de1f37ed4ee6..331b3c3a5b59 100644
--- a/drivers/crypto/qce/skcipher.c
+++ b/drivers/crypto/qce/skcipher.c
@@ -8,6 +8,7 @@
#include <linux/interrupt.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
+#include <linux/errno.h>
#include <crypto/aes.h>
#include <crypto/internal/des.h>
#include <crypto/internal/skcipher.h>
@@ -260,6 +261,10 @@ static int qce_skcipher_crypt(struct skcipher_request *req, int encrypt)
rctx->flags |= encrypt ? QCE_ENCRYPT : QCE_DECRYPT;
keylen = IS_XTS(rctx->flags) ? ctx->enc_keylen >> 1 : ctx->enc_keylen;
+ /* CE does not handle 0 length messages */
+ if (!req->cryptlen)
+ return -EOPNOTSUPP;
+
For the algorithms in question, the correct behavior is to return 0.
What do you mean? The driver should return a 0 ?
Aren't the tests catching that difference?
I was anyways planning on sending an email to the list with these
queries. But since you asked, these are my observations with fuzz
testing which I have been doing quite a bit now (I am also working on
adding a few qualcomm AEAD algorithms support in mainline).
- if the generic algorithm supports 0 length messages and the
transformation I am testing does not, the test framework throws an error
and stops.
- key support mismatch between the generic algorithm vs my algorithm
/engine also does the same thing.For eg, Qualcomm CE engine does not
support any three keys being same for triple des algorithms. Where as a
two key 3des is a valid scenario for generic algorithm(k1=k3). Another
example is hardware engine not supporting AES192.
How are these scenarios usually handled ? Why not allow the test
framework to proceed with the testing if the algorithm does not support
a particular scenario ?
- Eric
--
Warm Regards
Thara
