Re: Genart last call review of draft-ietf-httpbis-origin-frame-04

Works for me.

   Brian

On 28/11/2017 13:33, Mark Nottingham wrote:
> Thanks again. Please see:
>  https://github.com/httpwg/http-extensions/commit/871a80d12aa
> 
> 
>> On 27 Nov 2017, at 1:05 pm, Brian E Carpenter <brian.e.carpenter@gmail.com> wrote:
>> 
>> Hi Mark,
>> 
>> On 27/11/2017 12:38, Mark Nottingham wrote:
>>> Hi Brian,
>>> 
>>> Thanks for the review. Responses below.
>>> 
>>>> On 26 Nov 2017, at 2:44 pm, Brian Carpenter <brian.e.carpenter@gmail.com> wrote:
>>> [...]
>>>> Minor Issues:
>>>> -------------
>>>> 
>>>>> 2.1.  Syntax
>>>> ...
>>>>> Origin: An OPTIONAL sequence of characters ... that the
>>>>> sender believes this connection is or could be authoritative for.
>>>> 
>>>> So, that implies that all data in the ORIGIN frame might be false.
>>>> Doesn't that deserve a bit of a health warning at the beginning of the
>>>> Security Considerations?
>>> 
>>> The first paragraph of SC is already:
>>> 
>>> """
>>>  Clients that blindly trust the ORIGIN frame's contents will be
>>>  vulnerable to a large number of attacks.  See Section 2.4 for mitigations.
>>> """
>>> 
>>> What would you suggest?
>>> 
>>>> Also, using the word "believes" of a server
>>>> is strange. How would the server acquire uncertain knowledge in the
>>>> first place, and what algorithm would decide what it "believes"?
>>> 
>>> This is to emphasise that ORIGIN is advisory only -- it does not constitute proof (crypto does that).
>> 
>> Right. But I think it's the anthropomorphic choice of word that triggered me. If you said "that the sender asserts this connection is or could be authoritative for" I think I'd have nothing further to say, since it's clearly an assertion that needs to be checked.
>> 
>>> 
>>>> Appendix A doesn't show any sign of a client checking whether an
>>>> Origin-Entry is real.
>>> 
>>> As per Section 2.4, it isn't checked when the origin set is created or updated; it's checked when the value is used.
>> 
>> OK
>> 
>>> 
>>> 
>>>>> 2.3.  The Origin Set
>>>> ...
>>>>> o  Host: the value sent in Server Name Indication (SNI, [RFC6066]
>>>>>   Section 3), converted to lower case
>>>> 
>>>> In that reference:
>>>> 
>>>>>> Literal IPv4 and IPv6 addresses are not permitted in "HostName".
>>>> 
>>>> Is that an intended or unintended restriction for the ORIGIN frame?
>>>> In any case it should probably be mentioned explicitly to avoid confusion.
>>>> (If IPv6 literals were allowed, they might be very convenient for server
>>>> load balancing. But RFC6066 excludes that.)
>>> 
>>> Good catch. I don't think there's cause for confusion here (the text there isn't about what can go on the wire), but there is a corner case we haven't covered (when a client that supports SNI omits it because it's an IP literal). 
>>> 
>>> My inclination there is to say that the host is the SNI value or the server IP if SNI is missing; what do people think?
>> 
>>> From this reviewer's peanut gallery seat, that makes sense.
>> 
>>  Brian
>> 
>>> 
>>> Cheers,
>>> 
>>> --
>>> Mark Nottingham   https://www.mnot.net/
>>> 
>>> 
> 
> --
> Mark Nottingham   https://www.mnot.net/
> 
> 

Received on Tuesday, 28 November 2017 10:26:56 UTC