Edi Weitz edi@agharta.de writes:
I have a question regarding authorization; The goal of having authorization is to provide restricted access to a set of pages. The example in test.lisp on gives access to one page, which is the one generated by the authorization-page function itself.
How would I go about using authroization to restrict access to a set of pages, perhaps even including static ones? Should I set it up so that a prefix of the URIs of that set always leads to a handler which calls authorization? In that case, how would such a handler look like?
TBNL currently doesn't have code to automate that. You can, of course, use Apache's facilities and ignore TBNL. Or you might want to do something like this (untested)
(defmacro with-authorization ((authorizer) &body body) (with-unique-names (user password) `(multiple-value-bind (,user ,password) (authorization) (cond ((funcall ,authorizer ,user ,password) ,@body) (t (require-authorization))))))
(defun my-authorizer (user password) (and (string= user "foo") (string= password "bar")))
and then
(defun page () (with-authorization (#'my-authorizer) (with-html (:html (:head (:title "Blabla")) (:body "More bla")))))
Another option would be to let the first dispatcher in the list of dispatchers do the following:
If URL doesn't need authorization just return NIL so the next dispatcher has its turn.
If URL needs authorization and user is authorized also return NIL.
Otherwise dispatch to a fixed handler which just calls REQUIRE-AUTHORIZATION.
Does that help?
Yes, I believe so. I think my insufficient understanding of the underlying HTTP mechanism led me to believe it was more complicated than it apparently is.
Am I correct now to believe that it is in reality Apache which takes care of the authorization, so that once a user gave a proper username and password, he will be authorized for the rest of his session? So all that needs to be done is for each and every handler of access restricted pages to call tbnl:authorization and check for valid username and passwords?
If the above is correct, then any misconceptions has been cleared up on my part. Both you and Stefan gave me some good suggestions for what to try. I suspect that the with-authorization macro is the simplest solution if the number of access restricted pages are small, which they are in my case, so maybe I will go with that. I'll experiment with it tonight.
Björn