In an InfoCard Capabilities session, lead by Pamela Dingle, there was some discussion about how to do this technically. The following is a proposal for one way this might be accomplished.
The "Relying Party" would need to...
- define an XRDS file describing identity protocols supported, services provided, and other metadata
- allow for discovery of the XRDS file through normal XRI resolution (section 6)
- additionally allow for discovery by adding a
<link rel=”xrds.metadata” target=”location-of-xrds-file”/>
in the <head> section of the pages provided by the relying party
The "Identity Agent" would need to...
- look in web page dom for the xrds.metadata link
- retrieve and parse XRDS document
- find supported identity mechanisms and endpoints
- invoke card selector
- allow user to select card
- post card to endpoint specified in the XRDS document
What could the XRDS markup look like for an InfoCard relying party?
First we need to define some <Type> URIs to represent different metadata characteristics of the relying party relating to InfoCards. Here are some possible examples...
<Type>http://infocardfoundation.org/policy/1.0/login</Type>This type identifies the service/endpoint describing the claims required for login.<Type>http://infocardfoundation.org/policy/1.0/registration</Type>This type identifies the service/endpoint describing the claims required for registration.<Type>http://infocardfoundation.org/service/1.0/login</Type>This type identifies the service/endpoint where the login token should be sent.<Type>http://infocardfoundation.org/service/1.0/registration</Type>This type identifies the service/endpoint where the registration token should be sent.
An example XRDS document could look like...
<?xml version=1.0 encoding=UTF-8?>
<XRDS xmlns=xri://$xrds>
<XRD xmlns=xri://$XRD*($v*2.0) version=2.0>
<Type>xri://$xrds*simple</Type>
<!-- Service specification that identifies the endpoint of the infocard policy for login claims -->
<Service>
<Type>http://infocardfoundation.org/policy/1.0/login</Type>
<URI>http://sp.example.com/policy/login.xml</URI>
</Service>
<!-- Service specification that identifies the endpoint of the infocard policy for registration claims -->
<Service>
<Type>http://infocardfoundation.org/policy/1.0/registration</Type>
<URI>http://sp.example.com/policy/registration.xml</URI>
</Service>
<!-- Service specification that identifies the endpoint for submitting login claims -->
<Service>
<Type>http://infocardfoundation.org/service/1.0/login</Type>
<URI>http://sp.example.com/login</URI>
</Service>
<!-- Service specification that identifies the endpoint of the infocard policy for login claims -->
<Service>
<Type>http://infocardfoundation.org/service/1.0/registration</Type>
<URI>http://sp.example.com/registration</URI>
</Service>
</XRD>
</XRDS>
