Re: Adding a pointer to a WebID in a GPG pubkey

I think the main topic here is WebID discovery by embedding a triple
pointing to a WebID inside a GPG key. You can also consider it as an
alternative authentication method, specific to GPG's web of trust, since
you would use GPG keys instead of certificates. It is very similar to
WebID-TLS, where your public key (which is published on a key repository)
contains a pointer to your WebID profile, and your profile document
contains an RDF representation of the public key.

Andrei


On Tue, Aug 27, 2013 at 7:58 PM, Melvin Carvalho
<melvincarvalho@gmail.com>wrote:

>
>
>
> On 27 August 2013 17:13, Olivier Berger <
> olivier.berger@telecom-sudparis.eu> wrote:
>
>> Hi.
>>
>> I've been discussing web of trust with Andrei and others, in the context
>> of the Debian project, which already relies a lot on the GPG/OpenPGP web
>> of trust.
>>
>> So I've been wondering how to add a WebID pointer in a pubkey. However,
>> there doesn't seem to be some easily manageable way to add RDF to a key
>> (or at least I didn't discover it)... and I thought that a QR code as a
>> photo ID in the pubkey could be something to test out.
>>
>> So I've played a bit with the script below, and produced a QR code JPEG
>> that I added to my key. See my pubkey at [0].
>>
>> Once decoded, it provides with a basic triple :
>>  <> <http://xmlns.com/wot/0.1/identity> <
>> http://www-public.telecom-sudparis.eu/~berger_o/foaf.rdf#me>
>>
>> Maybe there would be a better way to encode this... or another ontology
>> ?
>>
>> In reverse, my WebID points to the pubkey.
>>
>>
>> The script :
>>
>>  webid=http://www-public.telecom-sudparis.eu/~berger_o/foaf.rdf#me
>>  echo '<> <http://xmlns.com/wot/0.1/identity> <'$webid'>' | qrencode -t
>> EPS -o webid.eps
>>  #convert -verbose -monochrome -define jpeg:extent=1kb -strip -set
>> comment "WebID link as RDF" webid.eps webid.jpg
>>  convert -monochrome -quality "5%" -strip -set comment "WebID link as
>> RDF" webid.eps webid.jpg
>>
>> Note that using 5% quality seemed to allow the qr code to be decoded by
>> zbarimg, while producing a JPEG image small enough for GPG to add it
>> without complaining on the file size. YMMV.
>>
>>
>> Would this be an interesting step to promote WebID, by taking adventage
>> of the existing GPG web of trust ?
>>
>
> Does GPG "certificate" allow you to link to a URL anywhere?  I think the
> keyserver field might allow an HTTP URL.
>
> I've seen people tag a URL on the end of a PEM encoded key, but it's not
> exactly standard.
>
> My avatar in facebook contains a QR code pointer to my homepage (which
> contains my key)
>
> Is there anything the equivalent of subjectAlternativeName in GPG ... or
> maybe ive misunderstood the problem?
>
>
>>
>> What do you think.
>>
>> Best regards,
>>
>> [0] http://www-public.it-sudparis.eu/~berger_o/info/pubkey/pubkey.txt
>> --
>> Olivier BERGER
>> http://www-public.telecom-sudparis.eu/~berger_o/ - OpenPGP-Id:
>> 2048R/5819D7E8
>> Ingenieur Recherche - Dept INF
>> Institut Mines-Telecom, Telecom SudParis, Evry (France)
>>
>>
>>
>