(in-package :araneida) (defun make-basic-authentication-handler (realm lookup-user)   "Returns a function suitable for use as a :authentication handler for REALM.  The called should supply a function LOOKUP-USER taking two arguments NAME and PASSWORD and returning some unique user identifier"   (lambda (r arg-string)     (declare (ignore arg-string))     (seqlet ((auth (car (request-header r :authorization)))              (user (apply lookup-user                           (split (base64-decode (cadr (split auth))) nil '(#\:)))))       (cond (user              (setf (request-user r) user))             (t              (format (request-stream r) "HTTP/1.0 401 Unauthorized~%WWW-Authenticate: Basic realm=~D~%Content-type: text/html~%~%<h1>Unauthorized</h1><p>Either your browser does not support HTTP basic authentication or you have supplied an incorrect username/password for this page.  Sorry"                      realm)              (close (request-stream r))              (signal 'response-sent)))       t)))