3.8 Emacs Lisp reCAPTCHA library
================================

This library allows interaction with Google's reCAPTCHA service

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   • reCAPTCHA: verifies that the user as correctly introduced the
     CAPTCHA.
   • reCAPTCHA mailhide: used to encrypt email addresses in webpages,
     and decrypt them after a successful CAPTCHA.

   The main entry points are:

   • recaptcha-html: outputs the HTML code that needs to be included in
     a webpage to display the CAPTCHA.
   • recaptcha-verify: takes as input the challenge (i.e.  what the user
     wrote) and validates the CAPTCHA.
   • recaptcha-mailhide-html: outputs the HTML to show an email address.

   It was written primarily to be used with Elnode (1), a non-blocking
webserver written in Emacs Lisp:

     ;; The following code can be used to quickly test the code, it is
     ;; based on elnode (and thus requires it of course). After evaluating
     ;; it http://localhost:8009/recaptcha and http://localhost:8009/mailhide/
     ;; are listening, each testing a particular functionality.
     ;;
     ;; (defun root-handler (httpcon)
     ;;   (elnode-hostpath-dispatcher httpcon
                                      '(("^.*//recaptcha/\\(.*\\)" . recaptcha-handler)
     ;; 				("^.*//mailhide/\\(.*\\)" . mailhide-handler))))
     ;;
     ;; (elnode-start 'root-handler :port 8009)

   For the code, go to the GitHub repository (2).

   ---------- Footnotes ----------

   (1) Elnode (https://www.emacswiki.org/emacs/Elnode)

   (2) GitHub repository (https://github.com/fsmunoz/recaptcha)