[v2.6.34-stable 212/213] crypto: sha512 - Fix byte counter overflow in SHA-512

From: Paul Gortmaker
Date: Wed Feb 05 2014 - 15:08:44 EST

From: Kent Yoder <key@xxxxxxxxxxxxxxxxxx>

This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.

commit 25c3d30c918207556ae1d6e663150ebdf902186b upstream.

The current code only increments the upper 64 bits of the SHA-512 byte
counter when the number of bytes hashed happens to hit 2^64 exactly.

This patch increments the upper 64 bits whenever the lower 64 bits

Signed-off-by: Kent Yoder <key@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
crypto/sha512_generic.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crypto/sha512_generic.c b/crypto/sha512_generic.c
index 9ed9f60316e5..899b2fa24e50 100644
--- a/crypto/sha512_generic.c
+++ b/crypto/sha512_generic.c
@@ -177,7 +177,7 @@ sha512_update(struct shash_desc *desc, const u8 *data, unsigned int len)
index = sctx->count[0] & 0x7f;

/* Update number of bytes */
- if (!(sctx->count[0] += len))
+ if ((sctx->count[0] += len) < len)

part_len = 128 - index;

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/