pyramid_ldap3¶
Overview¶
pyramid_ldap3
provides LDAP authentication services for your Pyramid
application. It is a fork of the pyramid_ldap
package with the goal
of eliminating the dependency on python-ldap
and ldappool
,
replacing it with a dependency on ldap3
, which is a pure Python package
that supports both Python 2 and Python 3.
Installation¶
pyramid_ldap3
depends on the pyramid
and ldap3 packages.
When you install pyramid_ldap3
using pip (usually within a virtual
environment), these dependencies will be installed automatically as well:
$ pip install pyramid_ldap3
Setup¶
Once pyramid_ldap3
is installed, you must use the config.include
mechanism to include it into your Pyramid project’s configuration. In your
Pyramid project’s __init__.py
:
config = Configurator(.....)
config.include('pyramid_ldap3')
Alternately, instead of using the Configurator’s include
method, you can
activate Pyramid by changing your application’s .ini
file, use the
following line:
pyramid.includes = pyramid_ldap3
Once you’ve included pyramid_ldap3
, you have to call methods of the
Configurator to tell it about your LDAP server and query particulars. Here’s
an example of calling methods to create a fully-configured LDAP setup that
attempts to talk to an Active Directory server:
import ldap3
config = Configurator()
config.include('pyramid_ldap3')
config.ldap_setup(
'ldap://ldap.example.com',
bind='CN=ldap user,CN=Users,DC=example,DC=com',
passwd='ld@pu5er')
config.ldap_set_login_query(
base_dn='CN=Users,DC=example,DC=com',
filter_tmpl='(sAMAccountName=%(login)s)',
scope=ldap3.LEVEL)
config.ldap_set_groups_query(
base_dn='CN=Users,DC=example,DC=com',
filter_tmpl='(&(objectCategory=group)(member=%(userdn)s))',
scope=ldap3.SUBTREE,
cache_period=600)
Configurator Methods¶
Configuration of pyramid_ldap3
is done via the Configurator methods named
ldap_setup
, ldap_set_login_query
, and ldap_set_groups_query
. All
three of these methods should be called once (and, ideally, only once) during
the startup phase of your Pyramid application.
Configurator.ldap_setup
This Configurator method accepts arguments used to set up an LDAP connection. After you call it, you will be able to use the
pyramid_ldap3.get_ldap_connector()
API from within your application. It will return apyramid_ldap3.Connector
instance. Seepyramid_ldap3.ldap_setup()
for argument details.
Configurator.ldap_set_login_query
This configurator method accepts parameters which tell
pyramid_ldap3
how to find a user based on a login. Invoking this method allows the LDAP connector’sauthenticate
method to work. Seepyramid_ldap3.ldap_set_login_query()
for argument details.If
ldap_set_login_query
is not called, thepyramid_ldap3.Connector.authenticate()
method will not work.
Configurator.ldap_set_groups_query
This configurator method accepts parameters which tell
pyramid_ldap3
how to find groups based on a user DN. Invoking this method allows the connector’suser_groups
method to work. Seepyramid_ldap3.ldap_set_groups_query()
for argument details.If
ldap_set_groups_query
is not called, thepyramid_ldap3.Connector.user_groups()
method will not work.
Caching¶
The pyramid_ldap3.ldap_set_groups_query()
and
pyramid_ldap3.ldap_set_login_query()
methods accept a cache_period
argument. It must be an integer. If it is nonzero, the results of the
associated query will be kept in memory for a maximum of that many seconds,
after which they will be flushed.
Usage¶
Assuming LDAP server and query setup has been done (as per above),
you can begin using pyramid_ldap3
in your application.
Here’s a small application which uses the pyramid_ldap3
API:
import ldap3
from pyramid.authentication import AuthTktAuthenticationPolicy
from pyramid.authorization import ACLAuthorizationPolicy
from pyramid.view import (
view_config,
forbidden_view_config)
from pyramid.response import Response
from pyramid.httpexceptions import HTTPFound
from pyramid.security import (
Allow,
Authenticated,
remember,
forget)
from pyramid_ldap3 import (
get_ldap_connector,
groupfinder)
@view_config(route_name='login',
renderer='templates/login.pt')
@forbidden_view_config(renderer='templates/login.pt')
def login(request):
url = request.current_route_url()
login = ''
password = ''
error = ''
if 'form.submitted' in request.POST:
login = request.POST['login']
password = request.POST['password']
connector = get_ldap_connector(request)
data = connector.authenticate(login, password)
if data is not None:
dn = data[0]
headers = remember(request, dn)
return HTTPFound('/', headers=headers)
else:
error = 'Invalid credentials'
return dict(
login_url=url,
login=login,
password=password,
error=error)
@view_config(route_name='root', permission='view')
def logged_in(request):
return Response('OK')
@view_config(route_name='logout')
def logout(request):
headers = forget(request)
return Response('Logged out', headers=headers)
class RootFactory(object):
__acl__ = [(Allow, Authenticated, 'view')]
def __init__(self, request):
pass
if __name__ == '__main__':
config = Configurator(root_factory=RootFactory)
config.include('pyramid_ldap3')
config.set_authentication_policy(
AuthTktAuthenticationPolicy(
'seekr1t', callback=groupfinder))
config.set_authorization_policy(
ACLAuthorizationPolicy())
config.ldap_setup(
'ldap://ldap.example.com',
bind='CN=ldap user,CN=Users,DC=example,DC=com',
passwd='ld@pu5er')
config.ldap_set_login_query(
base_dn='CN=Users,DC=example,DC=com',
filter_tmpl='(sAMAccountName=%(login)s)',
scope=ldap3.LEVEL)
config.ldap_set_groups_query(
base_dn='CN=Users,DC=example,DC=com',
filter_tmpl='(&(objectCategory=group)(member=%(userdn)s))',
scope=ldap3.SUBTREE,
cache_period=600)
config.add_route('root', '/')
config.add_route('login', '/login')
config.add_route('logout', '/logout')
config.scan('.')
app = config.make_wsgi_app()
server = make_server('0.0.0.0', 8080, app)
server.serve_forever()
This application sets up for an LDAP server on ldap.example.com
using
pyramid_ldap3.ldap_setup()
. It passes a bind
DN and passwd
for
a user capable of doing LDAP queries.
It sets up a login query using pyramid_ldap3.ldap_set_login_query()
using a base DN of CN=Users,DC=example,DC=com
and a filter_tmpl of
(sAMAccountName=%(login)s)
. The filter template’s %(login)s
value
will be replaced with the login name provided to the
pyramid_ldap3.Connector.authenticate()
method. In this case, we’re
using Active Directory, and we’d like to use the sAMAccountName as the login
parameter (aka the “windows login name”).
The application also sets up a groups query using
pyramid_ldap3.ldap_set_groups_query()
using a base DN of
CN=Users,DC=example,DC=com
and a filter_tmpl of
(&(objectCategory=group)(member=%(userdn)s))
. The group query’s filter
template’s %(userdn)s
value will be replaced with the DN of the user provided
as the userid by the pyramid_ldap3.Connector.user_groups()
method, in
order to look up all the groups to which the user belongs. In this case,
we’re using the member
attribute to match against the DN, returning all
objects of the objectCategory=group
type as group results. Unlike the
login query, we cache the result of each search made via this query for up to
10 minutes (600 seconds) based on its cache_period
argument.
Note that this query is not recursive; only groups a user belongs to directly
will be returned. If e.g. a user belongs to a group that in itself belongs to
another group, only the first will be returned. To query user groups recursively,
including all parent groups, use the following filter template:
(&(objectCategory=group)(member:1.2.840.113556.1.4.1941:=%(userdn)s))
.
See https://msdn.microsoft.com/en-us/library/aa746475%28v=vs.85%29.aspx
The login
view is invoked when someone visits /login
or when the user
is prevented from invoking another view due to its permission settings. It
displays a login form. When the form is submitted, the view obtains the
login and password passed from the form as well as an LDAP connector instance
using the pyramid_ldap3.get_ldap_connector()
function.
The LDAP connector instance has an
authenticate()
method which accepts the login
and password. It will return a data structure containing the user’s DN as
well as the user attributes if the user exists and his password is correct.
It will return None
if the user doesn’t exist or if the user exists and
his password is incorrect. A zero length password is always considered invalid
since it is, according to the LDAP spec, a request for “unauthenticated
authentication.” Unauthenticated authentication should not be used for LDAP
based authentication.
See section 5.1.2 of RFC-4513 for a description of this behavior.
When the user’s name and password are correct, the login
view uses the
pyramid.security.remember
API to set headers indicating that the user is
logged in. The user’s id will be his LDAP DN.
We make use of a canned groupfinder
function to provide group lookup
support to the built-in AuthTktAuthenticationPolicy. This groupfinder is
called for every request that requires authentication. The groups that an
authenticated user belongs to will be the DNs of each of his LDAP groups when
you use this groupfinder. The groupfinder uses the
pyramid_ldap3.Connector.user_groups()
method and looks like this:
def groupfinder(dn, request):
connector = get_ldap_connector(request)
group_list = connector.user_groups(dn)
if group_list is None:
return None
return [dn for dn, attrs in group_list]
The effect of this configuration is that a user is unable to view the
root
view at /
until logging in with successful credentials, because
it’s protected by the view
permission, which is only granted to the
Authenticated
principal based on the root factory’s ACL.
The logout
view calls pyramid.security.forget
to obtain headers
useful for dropping the credentials.
See the sampleapp
sample application inside the pyramid_ldap3
distribution for a working example of the above application. It can be
viewed at https://github.com/Cito/pyramid_ldap3/tree/master/sampleapp .
Logging¶
pyramid_ldap3
uses the logger named pyramid_ldap3
. It sends output at
a DEBUG level useful for its own developers to see what’s happening.
Sample Application¶
pyramid_ldap3
comes with a very simple Pyramid sample application that has
just a login form and shows whether the authentication via LDAP succeeded.
The configuration file uses an online LDAP test server
provided by Forum Systems.
You can install and run the sample application (best done inside a separate virtual environment) using pip like this:
$ pip install -e .[sampleapp]
$ pserve --browser sampleapp.ini
Now you should see the login form in your browser. After entering euler
as login and invalid
as password, you should see the message
Invalid credentials
. Try again with password
as password, now you
should see the message OK
and the credentials of the logged in user
euler
, including the DN of the group mathematicians.
More Information¶
Other Versions¶
Visit https://github.com/Cito/pyramid_ldap3 to download development or tagged versions.
Reporting Bugs¶
Visit https://github.com/Cito/pyramid_ldap3/issues to report bugs.