WEB/Sammlung/auth.py
darthsandmann c9f3117da1 Sammlung
2016-10-16 21:53:15 +02:00

138 lines
4.6 KiB
Python

# -*- encoding: UTF-8 -*-
#
# Form based authentication for CherryPy. Requires the
# Session tool to be loaded.
#
import cherrypy
SESSION_KEY = '_cp_username'
def check_credentials(username, password):
"""Verifies credentials for username and password.
Returns None on success or a string describing the error on failure"""
# Adapt to your needs
if username in ('joe', 'steve') and password == 'secret':
return None
else:
return u"Incorrect username or password."
# An example implementation which uses an ORM could be:
# u = User.get(username)
# if u is None:
# return u"Username %s is unknown to me." % username
# if u.password != md5.new(password).hexdigest():
# return u"Incorrect password"
def check_auth(*args, **kwargs):
"""A tool that looks in config for 'auth.require'. If found and it
is not None, a login is required and the entry is evaluated as a list of
conditions that the user must fulfill"""
conditions = cherrypy.request.config.get('auth.require', None)
if conditions is not None:
username = cherrypy.session.get(SESSION_KEY)
if username:
cherrypy.request.login = username
for condition in conditions:
# A condition is just a callable that returns true or false
if not condition():
raise cherrypy.HTTPRedirect("/auth/login")
else:
raise cherrypy.HTTPRedirect("/auth/login")
cherrypy.tools.auth = cherrypy.Tool('before_handler', check_auth)
def require(*conditions):
"""A decorator that appends conditions to the auth.require config
variable."""
def decorate(f):
if not hasattr(f, '_cp_config'):
f._cp_config = dict()
if 'auth.require' not in f._cp_config:
f._cp_config['auth.require'] = []
f._cp_config['auth.require'].extend(conditions)
return f
return decorate
# Conditions are callables that return True
# if the user fulfills the conditions they define, False otherwise
#
# They can access the current username as cherrypy.request.login
#
# Define those at will however suits the application.
def member_of(groupname):
def check():
# replace with actual check if <username> is in <groupname>
return cherrypy.request.login == 'joe' and groupname == 'admin'
return check
def name_is(reqd_username):
return lambda: reqd_username == cherrypy.request.login
# These might be handy
def any_of(*conditions):
"""Returns True if any of the conditions match"""
def check():
for c in conditions:
if c():
return True
return False
return check
# By default all conditions are required, but this might still be
# needed if you want to use it inside of an any_of(...) condition
def all_of(*conditions):
"""Returns True if all of the conditions match"""
def check():
for c in conditions:
if not c():
return False
return True
return check
# Controller to provide login and logout actions
class AuthController(object):
def on_login(self, username):
"""Called on successful login"""
def on_logout(self, username):
"""Called on logout"""
def get_loginform(self, username, msg="Enter login information", from_page="/"):
return """<html><body>
<form method="post" action="/auth/login">
<input type="hidden" name="from_page" value="%(from_page)s" />
%(msg)s<br />
Username: <input type="text" name="username" value="%(username)s" /><br />
Password: <input type="password" name="password" /><br />
<input type="submit" value="Log in" />
</body></html>""" % locals()
@cherrypy.expose
def login(self, username=None, password=None, from_page="/"):
if username is None or password is None:
return self.get_loginform("", from_page=from_page)
error_msg = check_credentials(username, password)
if error_msg:
return self.get_loginform(username, error_msg, from_page)
else:
cherrypy.session[SESSION_KEY] = cherrypy.request.login = username
self.on_login(username)
raise cherrypy.HTTPRedirect(from_page or "/")
@cherrypy.expose
def logout(self, from_page="/"):
sess = cherrypy.session
username = sess.get(SESSION_KEY, None)
sess[SESSION_KEY] = None
if username:
cherrypy.request.login = None
self.on_logout(username)
raise cherrypy.HTTPRedirect(from_page or "/")