Lack of single_sign_on_service getter in Config

[Lorenzo Gil Sanchez]

It would be nice to have a single_sign_on_service in the Config class. It would be almost the same as the logout_service method of the same class. It should return the single_sign_on_service url of the entity passed as first argument with the binding passed as second argument.

When there is only one IdP in your metadata and you are writting an SP, this is not needed since the Client.authenticate method automatically discovers the single_sign_on_service location. But when there are more and Config.is_wayf_needed() returns True, then you need to pass the single_sing_on_service url to the authenticate method and I don't want to mess with the Config dictionary directly.

The other option would be that the authenticate method accepts an entityid and a binding (with a sane default) instead of a location and he would discover the location by itself.

Anyway, I'll attach a patch for the first solution, which, by the way, is commited in revision 305 of my branch:

http://bazaar.launchpad.net/~lgs/pysaml2/main/revision/305