More on DTP
I noticed a post by Paul Madsen today about the proposed DTP specification that is up on the openid.net site.
This OpenID proposal ignores existing XML-based standards that provide the very same functionality.
These alternatives are admittedly somewhat obscure in the industry, little known specs like SOAP, WS-Addressing, WS-Security, XML Signature, and XML Encryption.
First off, the DTP specification is just a proposal. It is not a formal part of OpenID yet. Also, this is a really, really rough draft of the proposal that is constantly in motion right now. The fact that it ignores other standards may be true but one of the design goals is to do for data transfer what OpenID has done for single sign-on; light-weight, simple, easy-to-implement, etc. Think of the proposal as a best-of-breed of those heavier technologies. The same can be said of OpenID as it relates to SAML, Sxip and Passport.
DTP is the natural progression of the OpenID stack (at least we’re hoping we can make it work that way). First there was discovery with Yadis, then authentication and now we’re moving up the stack to look at things like attribute exchange and data transfer. These specifications are proposals today and will continue to evolve as we see how they play out in the OpenID eco-system.
Participation is always welcome! :-)
I urge you to read and consider the following article: Don’t Invent XML Languages
It was tactful of you to mention that WS-* and XML* are bloaty towers of complexity that no-one sane wants to touch.
I recommend you not to use SOAP, as it appears to be very hard to implement. I have already tried to implement a (fairly complex) web service in SOAP using PHP, and it\’s very hard to find good, fully-supported and easy-to-use libraries, and it\’s not always that easy to know how exactly you should do things.
However, it might be a good idea to use XML, in a very simply form so it doesn\’t take up too much space. XML libraries are widely available, and as opposed to SOAP very easy to use, you can even parse simple XML without an XML parser.