Source code for cherrypy.lib.auth_basic

# This file is part of CherryPy <>
# -*- coding: utf-8 -*-
# vim:ts=4:sw=4:expandtab:fileencoding=utf-8
"""HTTP Basic Authentication tool.

This module provides a CherryPy 3.x tool which implements
the server-side of HTTP Basic Access Authentication, as described in

Example usage, using the built-in checkpassword_dict function which uses a dict
as the credentials store::

    userpassdict = {'bird' : 'bebop', 'ornette' : 'wayout'}
    checkpassword = cherrypy.lib.auth_basic.checkpassword_dict(userpassdict)
    basic_auth = {'tools.auth_basic.on': True,
                  'tools.auth_basic.realm': 'earth',
                  'tools.auth_basic.checkpassword': checkpassword,
                  'tools.auth_basic.accept_charset': 'UTF-8',
    app_config = { '/' : basic_auth }


import binascii
import unicodedata
import base64

import cherrypy
from cherrypy._cpcompat import ntou, tonative

__author__ = 'visteya'
__date__ = 'April 2009'

[docs]def checkpassword_dict(user_password_dict): """Returns a checkpassword function which checks credentials against a dictionary of the form: {username : password}. If you want a simple dictionary-based authentication scheme, use checkpassword_dict(my_credentials_dict) as the value for the checkpassword argument to basic_auth(). """ def checkpassword(realm, user, password): p = user_password_dict.get(user) return p and p == password or False return checkpassword
[docs]def basic_auth(realm, checkpassword, debug=False, accept_charset='utf-8'): """A CherryPy tool which hooks at before_handler to perform HTTP Basic Access Authentication, as specified in :rfc:`2617` and :rfc:`7617`. If the request has an 'authorization' header with a 'Basic' scheme, this tool attempts to authenticate the credentials supplied in that header. If the request has no 'authorization' header, or if it does but the scheme is not 'Basic', or if authentication fails, the tool sends a 401 response with a 'WWW-Authenticate' Basic header. realm A string containing the authentication realm. checkpassword A callable which checks the authentication credentials. Its signature is checkpassword(realm, username, password). where username and password are the values obtained from the request's 'authorization' header. If authentication succeeds, checkpassword returns True, else it returns False. """ fallback_charset = 'ISO-8859-1' if '"' in realm: raise ValueError('Realm cannot contain the " (quote) character.') request = cherrypy.serving.request auth_header = request.headers.get('authorization') if auth_header is not None: # split() error, base64.decodestring() error msg = 'Bad Request' with cherrypy.HTTPError.handle((ValueError, binascii.Error), 400, msg): scheme, params = auth_header.split(' ', 1) if scheme.lower() == 'basic': charsets = accept_charset, fallback_charset decoded_params = base64.b64decode(params.encode('ascii')) decoded_params = _try_decode(decoded_params, charsets) decoded_params = ntou(decoded_params) decoded_params = unicodedata.normalize('NFC', decoded_params) decoded_params = tonative(decoded_params) username, password = decoded_params.split(':', 1) if checkpassword(realm, username, password): if debug: cherrypy.log('Auth succeeded', 'TOOLS.AUTH_BASIC') request.login = username return # successful authentication charset = accept_charset.upper() charset_declaration = ( (', charset="%s"' % charset) if charset != fallback_charset else '' ) # Respond with 401 status and a WWW-Authenticate header cherrypy.serving.response.headers['www-authenticate'] = ( 'Basic realm="%s"%s' % (realm, charset_declaration) ) raise cherrypy.HTTPError( 401, 'You are not authorized to access that resource')
[docs]def _try_decode(subject, charsets): for charset in charsets[:-1]: try: return tonative(subject, charset) except ValueError: pass return tonative(subject, charsets[-1])