netdev - Re: Internet-Draft on Port Randomisation

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:	Tue, 9 Sep 2008 14:31:19 +0800
From:	"Eugene Teo" <eugeneteo@...nel.sg>
To:	"Stephen Hemminger" <stephen.hemminger@...tta.com>
Cc:	netdev@...r.kernel.org
Subject: Re: Internet-Draft on Port Randomisation

On Tue, Sep 9, 2008 at 12:58 PM, Stephen Hemminger
<stephen.hemminger@...tta.com> wrote:
> Eugene Teo wrote:
>>
>> Has anyone read this Internet-Draft?
>>
>> http://www.gont.com.ar/drafts/port-randomization/draft-ietf-tsvwg-port-randomization-02.txt
>>
>> In this memo, there are descriptions of four different ephemeral port
>> randomisation algorithms (see page 17).
>>
>> Algo #1 and #2 are simple port randomisation algorithms. Algo #3 is
>> what we have in Linux. The memo suggested algorithm #4, double-hash
>> randomisation algorithm, which is an improvement to algo #3 (see page
>> 15).
>>
>> Does anyone have any thought about the improved algorithm? Is this
>> worth implementing,
>
> No the added lock overhead of a global next free port array is not worth it.
> Think of big web server under
> DoS pressure. The existing port search can run in parallel, Algo #4 was
> suggested by people
> who don't work on a real SMP OS.

Thanks Stephen.

Eugene
--
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