crypto: ccm - preserve the IV buffer
authorRomain Izard <romain.izard.pro@gmail.com>
Tue, 31 Oct 2017 14:42:35 +0000 (15:42 +0100)
committerHerbert Xu <herbert@gondor.apana.org.au>
Fri, 3 Nov 2017 13:35:35 +0000 (21:35 +0800)
commit441f99c90497e15aa3ad1dbabd56187e29614348
treebc57636479d687c706c17d6818e9593b498c7f9d
parentd041b557792c85677f17e08eee535eafbd6b9aa2
crypto: ccm - preserve the IV buffer

The IV buffer used during CCM operations is used twice, during both the
hashing step and the ciphering step.

When using a hardware accelerator that updates the contents of the IV
buffer at the end of ciphering operations, the value will be modified.
In the decryption case, the subsequent setup of the hashing algorithm
will interpret the updated IV instead of the original value, which can
lead to out-of-bounds writes.

Reuse the idata buffer, only used in the hashing step, to preserve the
IV's value during the ciphering step in the decryption case.

Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
crypto/ccm.c