crypto: talitos - Fix timing leak in ESP ICV verification

Using non-constant time memcmp() makes the verification of the authentication
tag in the decrypt path vulnerable to timing attacks. Fix this by using
crypto_memneq() instead.

Cc: [email protected]
Signed-off-by: David Gstir <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>

diff --git a/drivers/crypto/talitos.c b/drivers/crypto/talitos.c
index 46f531e19ccf07e97af05c221a5bfbb0d060d0a7..b6f9f42e2985b476ecc63ac16f648535be0cddc2 100644 (file)
--- a/drivers/crypto/talitos.c
+++ b/drivers/crypto/talitos.c
@@ -977,7 +977,7 @@ static void ipsec_esp_decrypt_swauth_done(struct device *dev,
                } else
                        oicv = (char *)&edesc->link_tbl[0];
 
-               err = memcmp(oicv, icv, authsize) ? -EBADMSG : 0;
+               err = crypto_memneq(oicv, icv, authsize) ? -EBADMSG : 0;
        }
 
        kfree(edesc);