netdev - Re: [PATCH 2/3] xfrm: Traffic Flow Confidentiality for IPv4 ESP

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 for Android: free password hash cracker in your pocket

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

Message-ID: <1291800041.2005.25.camel@martin>
Date:	Wed, 08 Dec 2010 10:20:41 +0100
From:	Martin Willi <martin@...ongswan.org>
To:	Herbert Xu <herbert@...dor.apana.org.au>
Cc:	linux-crypto@...r.kernel.org, netdev@...r.kernel.org
Subject: Re: [PATCH 2/3] xfrm: Traffic Flow Confidentiality for IPv4 ESP

> In particular, why would we need a boundary at all? Setting it to
> anything other than the PMTU would seem to defeat the purpose of
> TFC for packets between the boundary and the PMTU.

I don't agree, this highly depends on the traffic on the SA. For a
general purpose tunnel with TCP flows, PMTU padding is fine. But if
there are only small packets (maybe SIP+RTP), padding to the PMTU is
very expensive.

The administrator setting up the SAs probably knows (or even controls
directly) what traffic it is used for, and might lower the boundary
accordingly.

Regards
Martin

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html