Skip to main content

Open Issues for Discovery / Webfinger

The problem: Discover information that wants to publish to the world; things like their preferred identity provider, their public avatar, public contact methods, etc. Same mechanism should basically work for or, no wheel reinvention.

The Webfinger session at the last IIW was quite productive in the sense that it produced a long list of open issues that need resolution. The whiteboard snapshot to the right (stitched together thanks to @factoryjoe) shows the list, albeit in low res form. Translating the notes, and giving my takes:

Starting assumption : Domain owners need to play along. We're not trying to handle the case where wants to be discoverable, but doesn't control and the domain owner doesn't want to implement discovery.

Open Issues

Location of host-meta data: Older spec calls for this to be at /host-meta for every domain; Mark Nottingham has updated his proposal to create a /.well-known/ directory instead and put host-meta in there; I'm +10 to that.

Should discoverers try if itself doesn't support discovery? My take: No, if doesn't provide the discovery info directly it can do a 3xx redirect to a site that does. Don't complicate the protocol.

Should discoverers try https: URLs first? My take: No; this is not confidential data, and if you want source verification, it's more complicated than just using SSL and there are other solutions coming down the pike that are better.

What should the protocol do with 3xx's? This clearly needs a working group convened to decide on the exact correct flavor of 3xx to use in different situations. But, don't screw over people who need to move web sites and who leave a 301 to point to a new location.

Should it support other name@domain identifiers beyond email? Yes, of course.

Proxy problems with Accept: & Vary for getting discovery data from top level domains: This goes away with /.well-known.

What should the exact template semantics be (just {id}, or {local} + {domain} be for mapping a name@domain ID to a URL? Doesn't matter, pick one.

Must the discovery data be signed to enable the pattern to work? No, clients should make their own security decisions based on the evidence given. Signing is a good idea; make it easy to accomplish.

We need to document best practices on doing all of this stuff. Yes.

Popular posts from this blog

Personal Web Discovery (aka Webfinger)

There's a particular discovery problem for open and distributed protocols such as OpenID, OAuth, Portable Contacts, Activity Streams, and OpenSocial.  It seems like a trivial problem, but it's one of the stumbling blocks that slows mass adoption.  We need to fix it.  So first, I'm going to name it:

The Personal Web Discovery Problem:  Given a person, how do I find out what services that person uses?
This does sound trivial, doesn't it?  And it is easy as long as you're service-centric; if you're building on top of social network X, there is no discovery problem, or at least only a trivial one that can be solved with proprietary APIs.  But what if you want to build on top of X,Y, and Z?  Well, you write code to make the user log in to each one so you can call those proprietary APIs... which means the user has to tell you their identity (and probably password) on each one... and the user has already clicked the Back button because this is complicated and annoying.

XAuth is a Lot Like Democracy

XAuth is a lot like democracy:  The worst form of user identity prefs, except for all those others that have been tried (apologies to Churchill).  I've just read Eran's rather overblown "XAuth - a Terrible, Horrible, No Good, Very Bad Idea", and I see that the same objections are being tossed around; I'm going to rebut them here to save time in the future.

Let's take this from the top.  XAuth is a proposal to let browsers remember that sites have registered themselves as a user's identity provider and let other sites know if the user has a session at that site.  In other words, it has the same information as proprietary solutions that already exist, except that it works across multiple identity providers.  It means that when you go to a new website, it doesn't have to ask you what your preferred services are, it can just look them up.  Note that this only tells the site that you have an account with Google or Yahoo or Facebook or Twitter, not what the…
Twister is interesting.  It's a decentralized "microblogging" system based on putting together existing protocols:  Bitcoin, distributed hash tables, and Bittorrent.  The most interesting part for me is using Bitcoin for user registration and spam control.  Federated systems handle this with federated trust, which is at least conceptually simple.  The Twister/Bitcoin mechanism looks intriguing though I don't know enough about Bitcoin to really comment.  Need to read further.