Claus Färber wrote: > Marius Scurtescu schrieb: >> The new attribute values are needed in order to signal an OpenID 2 >> provider. > > Why is this necessary? Is OpenID 2 incompatible? In other words, what > happens if an OpenID 2 Relying Party tries to talk to an OpenID 1.x > Provider? > > If the OpenID 1.x Provider just ignores additional message fields (i.e. > treats them like an unknown extension), then no new rel values are > needed. If this is not the case, maybe the OID 2 spec can be changed to > make it possible. >
One incompatibility that springs to mind is that it is permissable to talk to a 2.0 OP via a POST request with the arguments in the entity body, while a 1.1 will likely barf on this since 1.1 only allowed for GET requests with the arguments in the query string. A 2.0 RP that uses a GET request and uses extension prefixes that match the ad-hoc field names used for the 1.1 extensions could, in theory, talk to a 1.1 OP without any problems. That is, unless I've missed something. :) _______________________________________________ specs mailing list specs@openid.net http://openid.net/mailman/listinfo/specs