Re: Redirects continued -- was: Problem with certificate on home-grown WebID

On 12/21/2011 05:19 PM, Henry Story wrote:
> 
> On 21 Dec 2011, at 16:57, Pierre-Antoine Champin wrote:
> 
>> Hi,
>>
>> I had the same misunderstanding as Sebastian, creating WebID
>>  http://champin.net/pa
>>
>> I now created
>>  http://champin.net/#pa
>> (which I too prefer, btw).
>>
>> But that one does not work with foafssl.org :-(
> 
> That's because at present it does not have redirection implemented and you resource redirects
> 
> $ curl -i  http://champin.net/ 
> HTTP/1.0 302 Found
> Server: BaseHTTP/0.3 Python/2.5.2
> Date: Wed, 21 Dec 2011 16:15:10 GMT
> Location: http://liris.cnrs.fr/~pchampin/
> Content-type: text/html
> Vary: Host


I beg to differ: http://champin.net/pa redirected as well, and it worked
(and still does)!

>> I attach the result page. It says
>>
>>  The WebId Profile must be parseable Content and transformable to an
>>  RDF graph
> 
> yep, if I were to be serious about redirects I'd have to change that to say: we don't work with
> redirects.... 
> 
> Since we are looking for use case for webids that redirect, let me ask you: why did you find
> it important to have your webid redirect?

well, essentially out of laziness: when I acquired the domain name
champin.net, I had the choice between setting up the DNS to point to the
real server, or let my registrar do the redirect.

That being said, I don't have full control on the server where my data
is actually hosted, so I'm not even sure I am in position to set up the
DNS to make champin.net accessible without any redirection. So that
would be an important reason.

  pa

> 
> 
> Henry
> 
>>
>> but RDF Validator is happy with it:
>>
>> http://www.w3.org/RDF/Validator/ARPServlet?URI=http%3A%2F%2Fchampin.net%2F&PARSE=Parse+URI%3A+&TRIPLES_AND_GRAPH=PRINT_TRIPLES&FORMAT=PNG_EMBED
>>
>> and it is recognized by https://auth.fcns.eu/
>>
>>  pa
>>
>>
>> On 12/21/2011 02:30 PM, Henry Story wrote:
>>>
>>> On 21 Dec 2011, at 14:05, Sebastian Trüg wrote:
>>>
>>>> On 12/21/2011 11:19 AM, Henry Story wrote:
>>>>>
>>>>> On 21 Dec 2011, at 09:55, Sebastian Trüg wrote:
>>>>>
>>>>>> Attached you find the result from https://foafssl.org/test/WebId. To be
>>>>>> honest I am not sure if it succeeded or not, the output confuses me. :/
>>>>>
>>>>> yes, the output of this test suite is not as well finished as the previous
>>>>> one. And there is a bug there, I'll fix.
>>>>>
>>>>> Ok, so you are using a WebID that redirects. I would suggest against it for
>>>>> two reasons:
>>>>>
>>>>> -1. It increases the verification time for the verifier: the verifier has
>>>>>   to potentially do 2 HTTP connections, and in any case it has to do back
>>>>>   and forth
>>>>> -2 It is possible that some implementations don't support redirect, as it is
>>>>>   one of these less obvious features of the web. As soon as you add complexity
>>>>>   you add ways things can go wrong, and your identity is perhaps important 
>>>>>   enough for you not to want these things to go wrong
>>>>>   (In this case my implementation does not support it. But I can add it)
>>>>> -3 We believe we have worked out the security characteristics of redirects, 
>>>>>   but they are less obvious than the simple GET and will require more work,
>>>>>   so we have no language in the spec at present covering those - it's undefined
>>>>>   one might say. In any case they confuse Peter Williams, and risk confusing
>>>>>   military grade security people a lot more. So if you want to log in to higher
>>>>>   security sites you may find redirects create confusion with those people
>>>>>   implementing them. This comes up in ISSUE-64
>>>>>   http://www.w3.org/2005/Incubator/webid/track/issues/64
>>>>>
>>>>> Does that make sense?
>>>>
>>>> Well, yes. However, I am confused. You directed me to the site which I
>>>> took this setup from.
>>>
>>> http://www.w3.org/TR/2008/NOTE-swbp-vocab-pub-20080828/
>>>
>>> Yes, it is true that the "Best Practice Recipes for Publishing RDF Vocabularies"
>>> covers two cases one of which uses a redirect. The redirect is as we mentioned
>>> may require us to think things through in a bit more detail, though I don't think
>>> it is a big issue.
>>>
>>>> Also you mentioned that it would be nicer to have
>>>> web ids like http://www.trueg.de/sebastian instead of something like
>>>> http://www.trueg.de/sebastian/foaf[#me].
>>>
>>>> So which is it? :)
>>>
>>> I think I mentioned WebIDs like 
>>>
>>> http://www.trueg.de/sebastian#me 
>>>
>>> rather than 
>>>
>>> http://www.trueg.de/sebastian.rdf#me
>>>
>>> not 
>>>
>>> http://www.trueg.de/sebastian
>>>
>>> with a redirect.
>>>
>>> I think there is a pragmatic consideration in favour of the # one to do with reduction
>>> in communication costs. 
>>>
>>> But you are right that this would do well to be more clearly specified in the 
>>> spec.
>>>
>>>>
>>>>>   So having said that there are a number of redirect types, 
>>>>> http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html
>>>>>
>>>>>  300 Multiple Choices
>>>>>  301 Moved Permanently
>>>>>  302 Found  // we can ignore this one
>>>>>  303 See Other
>>>>>  304 Not Modified
>>>>>  305 Use Proxy
>>>>>  307 Temporary Redirect
>>>>>
>>>>> and one needs to consider which of these have what types of security implications, if any.
>>>>> Perhaps there is not much more to do here than to just think it though. But if we want to
>>>>> help implementors implement the WebId protocol so that you get a consistent experience between
>>>>> each verification service, and so that you are not left out in the cold inexplicably
>>>>> some places and not others, then we need to work this out. As you see it is easier and more
>>>>> efficient to stick to #urls.
>>>>>
>>>>> The question is if there are any good rason for non #urls in our authentication use case.
>>>>
>>>> Only the prettyness of the URL which should be irrelevant in the end
>>>> since the point is to not show it to the user, right.
>>>
>>> yes, that alone would not make for a very good reason. Perhaps there are others. It would
>>> be good to collect them.
>>>
>>>> I simply followed your advise, or maybe misunderstood your advise...
>>>
>>> No you are doing well :-) You're helping us think about this issue 2^6 here. It's an important
>>> one. 
>>>
>>> Henry
>>>
>>>>
>>>> Cheers,
>>>> Sebastian
>>>>
>>>>> Henry
>>>>>
>>>>>>
>>>>>> Cheers,
>>>>>> Sebastian
>>>>>>
>>>>>> On 12/20/2011 10:44 PM, Henry Story wrote:
>>>>>>> Ok, I have updated the server to the new scala version.
>>>>>>>
>>>>>>> I hope it remains up until you read this e-mail. I am still working on the details
>>>>>>> of how to release it. But if it is still up please let me know if it works now
>>>>>>> with your key.
>>>>>>>
>>>>>>> Henry
>>>>>>> [snip]
>>>>>
>>>>> Social Web Architect
>>>>> http://bblfish.net/
>>>>>
>>>>>
>>>
>>> Social Web Architect
>>> http://bblfish.net/
>>>
>>>
>>
>> <WebId.html>
> 
> Social Web Architect
> http://bblfish.net/
> 

Received on Wednesday, 21 December 2011 17:21:15 UTC