Hi,
I'm trying to test AEAD based HMAC (sha1-96) with NULL encryption using a
modified tcrypt module.
I'm using a 2.6.27.4 kernel on an armv5te platform.
I hit a BUG() at crypto/scatterwalk.c:37 that indicates that the scatterlist
length is zero.
I've traced this back to crypto/authenc.c function crypto_authenc_genicv()...
There is a call to authenc_chain(cipher, dst, vdst == iv + ivsize);
It seems the test vdst == iv + ivsize fails. Does anyone know the purpose of
the test ? I think it is trying to check that the end of the IV field matches
something in the reg->dst scatterlist ?
authenc_chain() is...
static void authenc_chain(struct scatterlist *head, struct scatterlist *sg,
int chain)
{
if (chain) {
head->length += sg->length;
sg = scatterwalk_sg_next(sg);
}
if (sg)
scatterwalk_sg_chain(head, 2, sg);
else
sg_mark_end(head);
}
Therefore the value of chain is 0 and this causes authenc_chain() to not
update the length in head eg. chiper[0] scatterlist.
Can anyone please tell me what authenc_chain() is trying to do ?
Is there a "special" relationship to create the IV buffer with respect to the
dst scatterlist within tcrypt so that chain = 1 ? If I use ESP4 in IPsec
instead of tcrypt, then chain does equal 1.
Thanks for any info ?
Regards,
Dean Jenkins
MontaVista Software
--
To unsubscribe from this list: send the line "unsubscribe linux-crypto" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
