Very, Very simple authentication framework

This framework is based on the idea that when a user logs in, a user variable is set in the session. Say, something like this:

    def login(self, name,password):
        # todo: validate password
        # but you should be able to do so yourself.. 
        toSession(user=name) # assumes correct password, whatever it is
        # for debugging purposes
        # get the referer
        url = cpg.request.headerMap.get('Referer','/main')
        # move over there!
        httptools.redirect(url)
        # well, i used xyaptuTemplate, so i'll have to set this as well :)
        cpg.response.xyaptuTemplate.noFooter = True
        cpg.response.xyaptuTemplate.noHeader = True

    login = expose(login) 
    # or, if you use the checkAuth method, you should simple .expose=True it...
    # else, some unauthorized user might never authorize him/herself because he/she
    # is unauthorized :)

Sample code:

The following only allows the administrator to be logged in. One could have similar methods only available (like maintaining an order/shopping cart/whatever) for other, validated users.

class AdminNews(object):
    def newNewsItem(self,title,text,public):
        pass # stripped the code
    newNewsItem = adminOnly(newNewsItem)        

    def index(self):
        # sample code
        yield "templates/admin.news.index.html"
    index = adminOnly(index)

class AdminInstellingen(object):
    def index(self):
        # again, sample code
        yield "templates/admin.instellingen.index.html"
    index = adminOnly(index)

The code:

def checkAuth():
    # this is called default before the actual method is called, 
    # when a method is exposed using
    #    methodname = expose(methodname)
    # one could add basic checking in here
    pass 

def expose(func, preFunc=checkAuth, postFunc=None):
    def helper(*p,**kwp):
        if preFunc:
           preFunc()
        result = func(*p,**kwp)
        if postFunc:
           postFunc()
        return result   
    helper.exposed = True
    return helper

def adminOnly(func):
    def checkIsAdminOrRaiseError():
        if fromSession('user') != 'admin':
            raise NotFound
    return expose(func,preFunc = checkIsAdminOrRaiseError)
    
def validCustomerOnly(func):
    def checkIsValidUserOrRaiseError():
        # check if it's a valid customer number
        # see this as sample code :))
        if fromSession('user') not in cpg.root.dataprovider.debtors:
            raise NotFound
    return expose(func,preFunc = checkIsValidUserOrRaiseError)