linux-kernel - Re: [PATCH] lib: memcmp_nta: add timing-attack secure memcmp

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 11 Feb 2013 20:00:54 +0100
From:	Florian Weimer <fw@...eb.enyo.de>
To:	Daniel Borkmann <dborkman@...hat.com>
Cc:	gregkh@...uxfoundation.org, akpm@...ux-foundation.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] lib: memcmp_nta: add timing-attack secure memcmp

* Daniel Borkmann:

> + * memcmp_nta - memcmp that is secure against timing attacks

It's not providing an ordering, so it should not have "cmp" in the
name.

> +	for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
> +		res |= (*su1 ^ *su2);

The compiler could still short-circuit this loop.  Unlikely at
present, but this looks like a maintenance hazard.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/