Re: [secdir] secdir review of draft-ietf-sipcore-sip-push-21

[Christer Holmberg <[e-mail]>]

Hi Scott,

…

>I don't want to go through the whole document again, and I don't want to make too big a
>deal of this (the RFC editor has final say) but here are a few examples of things I had to read
>more than once to understand:
>
> Because of the restrictions above, Session Initiation Protocol (SIP)
> User Agents (UAs) [RFC3261] can not be awoken, in order to send
> binding-refresh SIP REGISTER requests and to receive incoming SIP
> requests, without using a PNS to wake the UA in order to perform
> those functions.
>
> In addition to the information that needs to be
> exchanged between a device and the PNS in order to establish a push
> notification subscription, the mechanism defined in this document
> does not require any additional information to be exchanged between
> the device and the PNS.

Ok, I will look into this and see if it could be made more clear.

…

>>>Finally, I think RFC8030 has a good description of the security considerations for
>>> this use case, and
>>>should be referenced here.
>>
>> I can add a reference. However, while many of the security considerations in
>> RFC8030 probably apply to any PNS, they are still written for a specific PNS.
>
>I don't know what other documents have been produced by the WG, so maybe this is
>covered elsewhere, but there are generic security considerations that apply abstractly
>to this use case. I think this document should either point to documents that describe
>them, or explicitly describe them here. For example, 8030 lists confidentiality with respect
>to the PNS, privacy considerations, authorization, DoS, and logging risks. All of those apply
>here.

RFC 8030 defines an "IETF PNS". The Apple PNS and Android PNS are proprietary (that existed before 8030 was even published).

Also, it is important that the security considerations of 8030 mostly apply to the PNS itself. The push draft does not define a PNS (eventhough it does make some assumptions on how a PNS using the push mechanism work), but a mechanism to transport PNS-related information over SIP, so the scope is slightly different.

Regards,

Christer