Implementing YADIS with no new software

Benjamin Yu benjaminlyu at
Mon Oct 31 08:40:15 PST 2005

A few things:

1. I agree with Martin's general approach-- the K.I.S.S. rule.

2. What about embedding the capabilities information in the identity URL's
document instead of linking to another static doc? I'm not saying that I am
really advocating this position, just bringing it up for a pro/con discussion.

3. Ok, YADIS is just a "Capabilities Discovery" mechanism (I don't want to
really use the word 'protocol'). It strikes me as being very similar to
"Service Discovery". What about broadening the scope to something more generic
and greater than 'just identity'?


--- Martin Atkins <mart at> wrote:

> With a few changes to the discovery mechanism, I believe that it would
> be possible to support all this YADIS business with no further
> implementation.
> There are two key changes:
> * The <link> element in the retrieved HTML document, rather than being
> required to point at an identity server, is instead specified as
> pointing at a capability document. This doesn't really change much
> except the terminology used.
> * The capability declaration document (the x-meta-identity thing) is
> extended to support the specification of a URL to use as the endpoint
> for each declared capability.
> The following scenario then becomes possible:
> * I install off-the-shelf OpenID server and LID server software onto my
> server with no modifications.
> * I create a STATIC FILE in my webroot which is an x-meta-identity
> document noting that I support both LID and OpenID and that they can be
> found at these other URLs, where my stock install server software can be
> found.
> * The HTML document at my identity URL LINKs to that static file as the
> capability document.
> Now I have an identity URL that supports both LID and OpenID without
> having to use some fancy multi-protocol identity server or do any
> programming.
> Sound good?

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