Re: A tool for crafting ESP packets

From: Loki (loki@fatelabs.com)
Date: 11/25/01


Message-Id: <200111251917.fAPJHuG15355@pa-lnx01.fatelabs.com>
From: Loki <loki@fatelabs.com>
To: "Nelson Brito" <nelson@tw-award.com>, "Emre Yildirim" <emre.yildirim@us.army.mil>
Subject: Re: A tool for crafting ESP packets
Date: Sun, 25 Nov 2001 14:17:56 -0500

Nelson,
I think you are misunderstanding. AH (Authentication Header), ESP
(Encapsulating Security Payload), etc. are all headers in an IPSec packet.
There is no such thing as "sending an AH packet). When I referred to my
previous past as a tool to craft "ESP packets" I am in other words saying,
"crafting IPSec packets". As all of these headers make up the IP Security
protocol suite.

Loki
www.fatelabs.com

On Tuesday 25 September 2001 04:31 pm, Nelson Brito wrote:
> : Loki wrote:
> : > Also, AH isn't a "packet" it
> : > provides authentication mechanisms for IP datagrams and protection
>
> against
>
> : > replay attacks.
>
> So, AH and ESP is a packet, in "IPSec Securing VPNs" from RSA Press, the
> author Carlton R. Davis shays:
> pg. 199: "In tunnel mode AH is inserted before the original IP header and a
> new IP header is inserted in front of the AH."
>
> So, you'll see this "PACKET" like a "AH PACKET", am I wrong? I don't think
> so.
>
> See the diagrams:
> IPv4 Header before applying AH:
> [variable-length] [transport protocol] [transport protocol]
> [ option filed ] [ header ][ data ]
>
> IPv4 Header after apllying AH:
> [new IP Header] [ authentication ] [original IP header] [TPH] [TPD]
> [ option field ] [header, a.k.a AH] [ option field ] [ ]
> [ ]
>
> : Then "ESP" isn't really a packet either, since it's just the encrypted
> : payload. By the way, you can have a "AH" packet i.e.
>
> Good point of view. ;-)
>
> : Just my $0.02 on this.
>
> Send me the number of yours Bank account. ;-)
>
> Sem mais,

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