Thursday, September 17, 2009

Re: [Geopriv] WG2LC: draft-ietf-geopriv-held-identity-extensions-00.txt

Correct. They would be needed if the LIS wished to use HELD as opposed to
presence.

Presence is a good example of OBO with appropriate privacy considerations
handled. The presence server is an LS, it requires appropriate
authentication and it must enforce the rules. The resulting PIDF would
include the rules.

Brian


On 9/17/09 12:39 PM, "Marc Linsner" <mlinsner@cisco.com> wrote:

> That doesn't necessarily require identity extensions. A subscribe/notify to
> tel-number@esinet-lis.com will provide the same function.
>
> -Marc-
>
>
> On 9/17/09 12:31 PM, "Brian Rosen" <br@brianrosen.net> wrote:
>
>> NENA has a use case for identity extensions.
>>
>> When a legacy TDM wireline network is transitioned to an IP based, ecrit
>> compatible emergency response systems (we call that an Emergency Services IP
>> network or ESInet), the identifier for location remains as it is today, a
>> telephone number. The LIS stores location keyed by telephone number, and
>> the emergency call specific function of the gateway that connects the legacy
>> wireline network to the ESInet must query the LIS using the telephone number
>> to get location to put on the SIP call following the rules in -phonebcp.
>> The gateway is a trusted entity, it is the UA (although it's not really the
>> target) and this is the emergency case, so the ruleset doesn't apply.
>>
>> Brian
>>
>>
>> On 9/17/09 11:20 AM, "Marc Linsner" <mlinsner@cisco.com> wrote:
>>
>>> Richard,
>>>
>>> In the context of identity-extensions, for the use case of a target
>>> discovering it's location (TDIL), which is a better descriptor than LCP, the
>>> same functions of authenticate and authorize MUST be deployed before the
>>> release of location information as is employed with the third-party or OBO
>>> use cases. The actual mechanism for authentication might differ, but none
>>> the less, just because the TDIL policy is clear and well-understood does not
>>> negate the need to authenticate the requestor, no matter how difficult that
>>> task may be. You can't apply policy until you know who you are talking to.
>>> IOW, from a trust relationship pov, the LS/LIS is simply stating, 'Sure Mr.
>>> Target, you can have your location information as soon as I verify you are
>>> indeed Mr. Target'.
>>>
>>> To create any mechanism with a lesser degree of authentication/authorization
>>> is sacrificing the security of the privacy for the end-user that this work
>>> group was created to protect.
>>>
>>> I also find zero motivation to solve these issues with threats that if we
>>> don't do it someone else will. This threat has always existed.
>>>
>>> I'm also not sure that NENA is asking for third-party/OBO, I believe it's
>>> SPs asking for it. NENA simply wants location included with call setup.
>>>
>>> -Marc-
>>>
>>>
>>>
>>>
>>> On 9/16/09 9:20 PM, "Richard Barnes" <rbarnes@bbn.com> wrote:
>>>
>>>> (Reposting under the correct thread)
>>>>
>>>> <individual-hat xmlns="urn:ietf:params:xml:ns:hats">
>>>>
>>>> I'm going to try to frame this debate a little bit.
>>>>
>>>> Let's start from the assumption that identity extensions are necessary
>>>> for third-party/OBO queries. My impression is that people are OK with
>>>> the case where identifiers are included in queries from specific,
>>>> authenticated, authorized entities (e.g., public safety authorities).
>>>>
>>>> Now, we want to make sure that these extensions are not abused to gain
>>>> unauthorized access to location. So if we were to put forward a
>>>> document defining identity extensions for third-party queries. We would
>>>> then have two options:
>>>> 1. Forbid the use of identifiers in LCP requests, or
>>>> 2. Assume that LCP usage is inevitable and require verification
>>>>
>>>> Consider case (2) first. The recommendation that we would want to make
>>>> is for the LS to verify that the identifier actually corresponds to the
>>>> target. However, the identifiers in question will necessarily not be
>>>> IP-layer identifiers (or else there would be no problem). That means
>>>> that we can't define an Internet-standard mechanism for this
>>>> verification -- mechanisms will have to be network-specific. So we're
>>>> left making a vague statement that has to be re-interpreted for each
>>>> network (or type of network). Not very satisfying, but basically all
>>>> that can be done.
>>>>
>>>> Now, in case (1), we have to come up with some standards language to
>>>> accomplish this prohibition. Following our general goal, we would want
>>>> something like, "The LS MUST authenticate requestors and apply
>>>> authorization policy to requests containing identity extensions."
>>>> However, what I've been calling the LCP Policy -- "For every location
>>>> object, the Target of that LO is authorized" -- is a valid policy. (You
>>>> might even be able to express it in common-policy, if you had one entry
>>>> per LO.) And that puts us back into case (2).
>>>>
>>>> This argument seems to me to imply that if we are to enable support for
>>>> the third party requests that the emergency services community is
>>>> requesting, then we will be stuck with the LCP usage as well, for which
>>>> we can write recommendations that are unsatisfactory, but possibly clear
>>>> enough for implementors to understand. If one accepts this implication,
>>>> we're left with a choice:
>>>> 1. Provide support for third party requests and do our best on LCP use
>>>> 2. Do nothing at all
>>>>
>>>> My impression is that if we follow course (2) and do nothing, then the
>>>> parties that are asking for us to do something (NENA, NICC, etc.) will
>>>> invent something anyway. Following course (1) would then not create
>>>> anything that wouldn't be created anyway, and it would have the
>>>> potential benefits of increasing interoperability and allowing this
>>>> group to have some say over the privacy constraints.
>>>>
>>>> So, to sum all that up, I think we should aim for some recommendations
>>>> and privacy constraints on LCP usage of identifiers and move on.
>>>>
>>>> --Richard
>>>>
>>>> </individual-hat>
>>>>
>>>>
>>>> Alissa Cooper wrote:
>>>>> All,
>>>>>
>>>>> In an effort to generate discussion and progress a bit more efficiently
>>>>> in the WG, Richard and I would like to experiment with something we're
>>>>> calling "working group second-to-last call" (WG2LC). We think the
>>>>> existing structures that set deadlines for comment (WGLC, IETF LC, etc.)
>>>>> are rather effective at motivating people to take a look at documents of
>>>>> interest, so we'd like to extend that concept a bit further. WG2LC is
>>>>> what it sounds like: an informal call for comments with a deadline,
>>>>> preceding the issuance of an official WGLC. The idea is to air some
>>>>> discussion about a document before it reaches the point of being ready
>>>>> for WGLC.
>>>>>
>>>>> As a first experiment for WG2LC, consider this a working group
>>>>> second-to-last call for comments on
>>>>>
>>>>> draft-ietf-geopriv-held-identity-extensions-00.txt
>>>>>
>>>>> Please send your comments about this document to the list by 23
>>>>> September 2009.
>>>>>
>>>>> Alissa
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Geopriv mailing list
>>>>> Geopriv@ietf.org
>>>>> https://www.ietf.org/mailman/listinfo/geopriv
>>>>>
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>
>


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