crypto: sha512 - make it work, undo percpu message schedule
authorAlexey Dobriyan <adobriyan@gmail.com>
Sat, 14 Jan 2012 18:27:37 +0000 (21:27 +0300)
committerSimone Willett <swillett@nvidia.com>
Fri, 10 Feb 2012 02:20:21 +0000 (18:20 -0800)
commit34ebfc4201c63d5c1885021423678a35163c48c8
tree5fd247ab94abb5cd1c2ac9cd27a74b3b6a88a1cd
parentb51e517d28543e8ea56ae13ccf1f42c475aa3275
crypto: sha512 - make it work, undo percpu message schedule

commit 84e31fdb7c797a7303e0cc295cb9bc8b73fb872d upstream.

commit f9e2bca6c22d75a289a349f869701214d63b5060
aka "crypto: sha512 - Move message schedule W[80] to static percpu area"
created global message schedule area.

If sha512_update will ever be entered twice, hash will be silently
calculated incorrectly.

Probably the easiest way to notice incorrect hashes being calculated is
to run 2 ping floods over AH with hmac(sha512):

#!/usr/sbin/setkey -f
flush;
spdflush;
add IP1 IP2 ah 25 -A hmac-sha512 0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000025;
add IP2 IP1 ah 52 -A hmac-sha512 0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000052;
spdadd IP1 IP2 any -P out ipsec ah/transport//require;
spdadd IP2 IP1 any -P in  ipsec ah/transport//require;

XfrmInStateProtoError will start ticking with -EBADMSG being returned
from ah_input(). This never happens with, say, hmac(sha1).

With patch applied (on BOTH sides), XfrmInStateProtoError does not tick
with multiple bidirectional ping flood streams like it doesn't tick
with SHA-1.

After this patch sha512_transform() will start using ~750 bytes of stack on x86_64.
This is OK for simple loads, for something more heavy, stack reduction will be done
separatedly.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
Change-Id: I752dc16e90deb04b35202fddce818ace0b605e9d
Reviewed-on: http://git-master/r/79656
crypto/sha512_generic.c