Re: [secdir] sec-dir review of draft-ietf-siprec-architecture-08

"Hutton, Andrew" <> Wed, 16 October 2013 14:20 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 59F1821F9C4A; Wed, 16 Oct 2013 07:20:31 -0700 (PDT)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -2.599
X-Spam-Status: No, score=-2.599 tagged_above=-999 required=5 tests=[BAYES_00=-2.599]
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id KN507Gb+tdA4; Wed, 16 Oct 2013 07:20:26 -0700 (PDT)
Received: from ( []) by (Postfix) with ESMTP id DE89721F9CAD; Wed, 16 Oct 2013 07:20:23 -0700 (PDT)
Received: from (unknown []) by (Server) with ESMTP id 5536E23F055F; Wed, 16 Oct 2013 16:20:22 +0200 (CEST)
Received: from ([]) by ([]) with mapi id 14.03.0123.003; Wed, 16 Oct 2013 16:19:41 +0200
From: "Hutton, Andrew" <>
To: Derek Atkins <>, "" <>, "" <>
Thread-Topic: sec-dir review of draft-ietf-siprec-architecture-08
Thread-Index: AQHOvrubMf93F21HCEGJjMCkxJ10v5n3ZzNg
Date: Wed, 16 Oct 2013 14:20:21 +0000
Message-ID: <>
References: <>
In-Reply-To: <>
Accept-Language: en-US
Content-Language: en-US
x-originating-ip: []
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-Mailman-Approved-At: Wed, 16 Oct 2013 07:26:11 -0700
Cc: "" <>, "" <>, "" <>, "" <>
Subject: Re: [secdir] sec-dir review of draft-ietf-siprec-architecture-08
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: Security Area Directorate <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Wed, 16 Oct 2013 14:20:31 -0000

Hi Derek,

Thanks for your comment and sorry for taking a while to get back to you.

The security considerations section contains the following text:

" It is the responsibility of the Session Recording Server to protect
   the Replicated Media and Recording Metadata once it has been received
   and archived.  The mechanism for protecting the storage and retrieval
   from the SRS is out of scope of this work."

Personally I think this is reasonable as we never say anything in SIP related specifications what a UA should do with the media once it has been received and this work is all about delivering the media and related metadata to the recording system not what it does with it afterwards.

Is it really necessary to go any further than this?

Andy (SIPREC Co-Chair).

> -----Original Message-----
> From: Derek Atkins []
> Sent: 01 October 2013 16:34
> To:;
> Cc:;;
>;; Hutton, Andrew
> Subject: sec-dir review of draft-ietf-siprec-architecture-08
> Hi,
> I have reviewed this document as part of the security directorate's
> ongoing effort to review all IETF documents being processed by the
> IESG.  These comments were written primarily for the benefit of the
> security area directors.  Document editors and WG chairs should treat
> these comments just like any other last call comments.
>    Session recording is a critical requirement in many communications
>    environments such as call centers and financial trading.  In some of
>    these environments, all calls must be recorded for regulatory,
>    compliance, and consumer protection reasons.  Recording of a session
>    is typically performed by sending a copy of a media stream to a
>    recording device.  This document describes architectures for
>    deploying session recording solutions in an environment which is
>    based on the Session Initiation Protocol (SIP).
> Retrieving recorded media is a potential Key Management problem which
> this document completely ignores (and even claims is out of scope).
> The key used to encrypt the recorded media (whether or not the media
> is re-encrypted) must be stored and retrieved as part of the media
> retrieval.  How this important data is stored and retrieved is left
> out, leaving an implementation with no guidance on how to protect that
> valuable asset.  In fact the document completely elides the question
> of how a retriever obtains the data encryption key.  Even if it's just
> additional guidance the Security Considerations should at least
> explain the problem even if it doesn't provide a solution.
> -derek
> --
>        Derek Atkins                 617-623-3745
>        Computer and Internet Security Consultant