From 5997a245c77b754fb8ef807043066fcfde64858c Mon Sep 17 00:00:00 2001
From: Lars Persson <lars.persson@axis.com>
Date: Wed, 23 Jan 2019 12:59:45 +0100
Subject: [PATCH] crypto: axis - use a constant time tag compare
Avoid plain memcmp() on the AEAD tag value as this could leak
information through a timing side channel.
Signed-off-by: Lars Persson <larper@axis.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---
drivers/crypto/axis/artpec6_crypto.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/crypto/axis/artpec6_crypto.c b/drivers/crypto/axis/artpec6_crypto.c
index 5089ad2c49f91..109efab6a9df2 100644
--- a/drivers/crypto/axis/artpec6_crypto.c
+++ b/drivers/crypto/axis/artpec6_crypto.c
@@ -2201,9 +2201,9 @@ static void artpec6_crypto_complete_aead(struct crypto_async_request *req)
areq->assoclen + areq->cryptlen -
authsize);
- if (memcmp(req_ctx->decryption_tag,
- input_tag,
- authsize)) {
+ if (crypto_memneq(req_ctx->decryption_tag,
+ input_tag,
+ authsize)) {
pr_debug("***EBADMSG:\n");
print_hex_dump_debug("ref:", DUMP_PREFIX_ADDRESS, 32, 1,
input_tag, authsize, true);
--
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