So I return to the lists here somewhat sheepishly to admit that the problem was solved simply by adding the reCaptcha domain to our EZproxy stanza with the magic Javascript directives:

  DJ recaptcha.net
  HJ recaptcha.net

One of those must, I'm guessing, fetch the reCaptcha Javascript without an HTTP referrer, or possible even using the original vendor site's domain in the referrer, since that's the only way it will work.  Either way, solved our problem.

ezproxy++

--Dave

==================
David Walker
Library Web Services Manager
California State University
http://xerxes.calstate.edu
________________________________________
From: Walker, David
Sent: Tuesday, August 25, 2009 12:33 PM
To: [log in to unmask]
Cc: [log in to unmask]
Subject: EzProxy and recaptcha

Casting a net far and wide on this, sorry.

We're using EZproxy to proxy a website that also happens to have reCaptcha on it.

I guess reCaptcha keys are tied to domain names, so when the Javascript is brought into the page via the <script /> tag, it sees that the page is 'proxy.example.edu' instead of 'www.vendorsite.com', and we end-up with an error from reCaptcha saying:

   This reCAPTCHA key isn't authorized for the given domain.

That all makes sense.  But can anyone fathom a workaround?

--Dave


==================
David Walker
Library Web Services Manager
California State University
http://xerxes.calstate.edu