Re: [clue] Last Call: <draft-ietf-clue-rtp-mapping-10.txt> (Mapping RTP streams to CLUE Media Captures) to Proposed Standard

[Paul Kyzivat <[e-mail]>]

On 1/16/17 8:56 AM, Magnus Westerlund wrote:
> Den 2017-01-15 kl. 07:05, skrev Roni Even:
>> Hi Magnus,
>> CaptureID here is just conveying the value defined in the CLUE data model
>> and CLUE protocol defines the security consideration for conveying the
>> adertized and configured values.
>> So any security on creating is done in the protocol document
>
> Yes, it is containing a value. And the data model and protocol documents
> defines the protocol level security requirements and solution. However,
> as the CaptureID is taken out of the context of the CLUE protocol, and
> put into RTP/RTCP there needs to be consideration for the implications
> of that action.

Good point. When used within the CLUE protocol the captureID is 
protected by DTLS. RTP/RTCP presents new concerns.

	Thanks,
	Paul

> As I don't find any recommendation for how an implementation generates
> CaptureIDs I could not determine the security sensitivity of the field.
> That is why I am asking about that aspect. Please provide an analysis of
> what it may contain, i.e. worst case, and the appropriate recommendation
> for appropriately securing that field.
>
>>
>> As for the header extension, I will add some text
>
> And I think this is relevant also for SDES items in general, not only
> for the header extension. The security risks and fundamental
> requirements are shared anyway.
>
> Cheers
>
> Magnus
>
>> Roni
>>
>>> -----Original Message-----
>>> From: clue [mailto:[e-mail]] On Behalf Of Magnus Westerlund
>>> Sent: Friday, January 13, 2017 2:22 PM
>>> To: [e-mail]
>>> Cc: [e-mail]; [e-mail];
>> [e-mail]
>>> Subject: Re: [clue] Last Call: <draft-ietf-clue-rtp-mapping-10.txt>
>> (Mapping RTP
>>> streams to CLUE Media Captures) to Proposed Standard
>>>
>>> Hi,
>>>
>>> As one of IANA's expert reviewers for the two registries that this
>> document
>>> attempts to register in, I want to provide some feedback on individual
>> basis and
>>> directly.
>>>
>>> The SDES item registration of the CaptureID is fine with the exception
>> that it isn't
>>> clear on the security consideration for the CaptureID field as SDES
>>> item.
>> I fail to
>>> find any limitations or even recommendations for how the value is
>>> created
>> by
>>> the implementation. Nor does the security considerations discuss the
>> potential
>>> risk that the capture ID is privacy sensitive, like "Adrian's Mic"
>>> rather
>> than AC0
>>> as in the example in the data model document. The data model document is
>>> fairly clear on the need for confidentiality and authorization for the
>> whole data
>>> model document. However, this thinking has not been raised and clarified
>> in this
>>> specific move of the information into the RTP protocol.
>>>
>>> So, I would recommend a discussion in general if the field should have
>>> anonymous labels, that do not contain privacy information. Then one
>>> needs
>> to
>>> be clear on what requirements that puts on transporting this field in
>>> RTP.
>> And
>>> that depends on how certain one can be that it is anonymous or that
>>> it may
>>> contain sensitive information and therefore should be confidentiality
>> protected.
>>> In all cases this field needs integrity and source authentication. Which
>> should be
>>> made explicit in the security consideration. The clue mapping require
>>> implementation of SRTP with DTLS-SRTP keying, however, it fails to be
>> specific
>>> on which protection profiles that are to be supported, both for the SRTP
>> as well
>>> as the crypto functions for the key handshakes in DTLS-SRTP. Thus, I
>>> can't
>> be
>>> certain if the CaptureID will be confidentiality protected or not
>>> even in
>> RTCP.
>>>
>>> When it comes to the RTP Header Extension case, the RFC 7941 is very
>> explicit
>>> about the requirement on doing this security consideration. And I note
>> that with
>>> the above analysis of what requirements to put, one can ensure that the
>> right
>>> requirements on the CLUE system to protect any RTP header extension with
>> the
>>> CaptureID is done. I do note that if confidentiality protection is
>>> needed,
>> this
>>> means additional implementation requirement. Such needs to be defined in
>> this
>>> or referenced document if that is the case.
>>>
>>> This should be fairly straight forward to fix, but needs to be done.
>>>
>>> Cheers
>>>
>>> Magnus
>>>
>>> Den 2016-12-22 kl. 22:18, skrev The IESG:
>>>>
>>>> The IESG has received a request from the ControLling mUltiple streams
>>>> for tElepresence WG (clue) to consider the following document:
>>>> - 'Mapping RTP streams to CLUE Media Captures'
>>>>   <draft-ietf-clue-rtp-mapping-10.txt> as Proposed Standard
>>>>
>>>> The IESG plans to make a decision in the next few weeks, and solicits
>>>> final comments on this action. Please send substantive comments to the
>>>> [e-mail] mailing lists by 2017-01-12. Exceptionally, comments may
>>>> be sent to [e-mail] instead. In either case, please retain the
>>>> beginning of the Subject line to allow automated sorting.
>>>>
>>>> Abstract
>>>>
>>>>
>>>>    This document describes how the Real Time transport Protocol
>>>> (RTP) is
>>>>    used in the context of the CLUE protocol.  It also describes the
>>>>    mechanisms and recommended practice for mapping RTP media streams
>>>>    defined in SDP to CLUE Media Captures.
>>>>
>>>>
>>>>
>>>>
>>>> The file can be obtained via
>>>> https://datatracker.ietf.org/doc/draft-ietf-clue-rtp-mapping/
>>>>
>>>> IESG discussion can be tracked via
>>>> https://datatracker.ietf.org/doc/draft-ietf-clue-rtp-mapping/ballot/
>>>>
>>>>
>>>> No IPR declarations have been submitted directly on this I-D.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>>
>>> Magnus Westerlund
>>>
>>> ----------------------------------------------------------------------
>>> Services, Media and Network features, Ericsson Research EAB/TXM
>>> ----------------------------------------------------------------------
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>>>
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>>
>>
>
>