sources/ldap(major): add sync_users and sync_groups, rewrite auth_user method

This commit is contained in:
Langhammer, Jens 2019-10-11 12:53:48 +02:00
parent 44a3c7fa5f
commit 22c4fb1414
9 changed files with 222 additions and 160 deletions

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@ -1,5 +1,6 @@
"""passbook LDAP Authentication Backend"""
from django.contrib.auth.backends import ModelBackend
from django.http import HttpRequest
from structlog import get_logger
from passbook.sources.ldap.connector import Connector
@ -11,11 +12,12 @@ LOGGER = get_logger()
class LDAPBackend(ModelBackend):
"""Authenticate users against LDAP Server"""
def authenticate(self, **kwargs):
def authenticate(self, request: HttpRequest, **kwargs):
"""Try to authenticate a user via ldap"""
if 'password' not in kwargs:
return None
for source in LDAPSource.objects.filter(enabled=True):
LOGGER.debug("LDAP Auth attempt", source=source)
_ldap = Connector(source)
user = _ldap.auth_user(**kwargs)
if user:

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@ -1,19 +1,15 @@
"""Wrapper for ldap3 to easily manage user"""
from time import time
from typing import Any, Dict, Optional
import ldap3
import ldap3.core.exceptions
from structlog import get_logger
from passbook.core.models import User
from passbook.lib.config import CONFIG
from passbook.core.models import Group, User
from passbook.sources.ldap.models import LDAPSource
LOGGER = get_logger()
# USERNAME_FIELD = CONFIG.y('ldap.username_field', 'sAMAccountName')
# LOGIN_FIELD = CONFIG.y('ldap.login_field', 'userPrincipalName')
class Connector:
"""Wrapper for ldap3 to easily manage user authentication and creation"""
@ -24,178 +20,103 @@ class Connector:
def __init__(self, source: LDAPSource):
self._source = source
if not self._source.enabled:
LOGGER.debug("LDAP not Enabled")
self._server = ldap3.Server(source.server_uri) # Implement URI parsing
def bind(self):
"""Bind using Source's Credentials"""
self._connection = ldap3.Connection(self._server, raise_exceptions=True,
user=source.bind_cn,
password=source.bind_password)
user=self._source.bind_cn,
password=self._source.bind_password)
self._connection.bind()
if source.start_tls:
if self._source.start_tls:
self._connection.start_tls()
@staticmethod
def encode_pass(password: str) -> str:
def encode_pass(password: str) -> bytes:
"""Encodes a plain-text password so it can be used by AD"""
return '"{}"'.format(password).encode('utf-16-le')
def generate_filter(self, **fields):
"""Generate LDAP filter from **fields."""
filters = []
for item, value in fields.items():
filters.append("(%s=%s)" % (item, value))
ldap_filter = "(&%s)" % "".join(filters)
LOGGER.debug("Constructed filter: '%s'", ldap_filter)
return ldap_filter
@property
def base_dn_users(self) -> str:
"""Shortcut to get full base_dn for user lookups"""
return ','.join([self._source.additional_user_dn, self._source.base_dn])
def lookup(self, ldap_filter: str):
"""Search email in LDAP and return the DN.
Returns False if nothing was found."""
try:
self._connection.search(self._source.search_base, ldap_filter)
results = self._connection.response
if len(results) >= 1:
if 'dn' in results[0]:
return str(results[0]['dn'])
except ldap3.core.exceptions.LDAPNoSuchObjectResult as exc:
LOGGER.warning(exc)
return False
except ldap3.core.exceptions.LDAPInvalidDnError as exc:
LOGGER.warning(exc)
return False
return False
@property
def base_dn_groups(self) -> str:
"""Shortcut to get full base_dn for group lookups"""
return ','.join([self._source.additional_group_dn, self._source.base_dn])
def _get_or_create_user(self, user_data):
"""Returns a Django user for the given LDAP user data.
If the user does not exist, then it will be created."""
attributes = user_data.get("attributes")
if attributes is None:
LOGGER.warning("LDAP user attributes empty")
return None
# Create the user data.
field_map = {
'username': '%(' + ')s',
'name': '%(givenName)s %(sn)s',
'email': '%(mail)s',
def sync_groups(self):
"""Iterate over all LDAP Groups and create passbook_core.Group instances"""
attributes = [
'objectSid', # Used as unique Identifier
'name',
'dn',
]
groups = self._connection.extend.standard.paged_search(
search_base=self.base_dn_groups,
search_filter=self._source.group_object_filter,
search_scope=ldap3.SUBTREE,
attributes=ldap3.ALL_ATTRIBUTES)
for group in groups:
attributes = group.get('attributes', {})
_, created = Group.objects.update_or_create(
attributes__objectSid=attributes.get('objectSid', ''),
defaults=self._build_object_properties(attributes),
)
LOGGER.debug("Synced group", group=attributes.get('name', ''), created=created)
def sync_users(self):
"""Iterate over all LDAP Users and create passbook_core.User instances"""
users = self._connection.extend.standard.paged_search(
search_base=self.base_dn_users,
search_filter=self._source.user_object_filter,
search_scope=ldap3.SUBTREE,
attributes=ldap3.ALL_ATTRIBUTES)
for user in users:
attributes = user.get('attributes', {})
_, created = User.objects.update_or_create(
attributes__objectSid=attributes.get('objectSid', ''),
defaults=self._build_object_properties(attributes),
)
LOGGER.debug("Synced User", user=attributes.get('name', ''), created=created)
def sync_membership(self):
"""Iterate over all Users and assign Groups using memberOf Field"""
pass
def _build_object_properties(self, attributes: Dict[str, Any]) -> Dict[str, Dict[Any, Any]]:
properties = {
'attributes': {}
}
user_fields = {}
for dj_field, ldap_field in field_map.items():
user_fields[dj_field] = ldap_field % attributes
for mapping in self._source.property_mappings.all().select_subclasses():
properties[mapping.object_field] = attributes.get(mapping.ldap_property, '')
if 'objectSid' in attributes:
properties['attributes']['objectSid'] = attributes.get('objectSid')
properties['attributes']['distinguishedName'] = attributes.get('distinguishedName')
return properties
# Update or create the user.
user, created = User.objects.update_or_create(
defaults=user_fields,
username=user_fields.pop('username', "")
)
# Update groups
# if 'memberOf' in attributes:
# applicable_groups = LDAPGroupMapping.objects.f
# ilter(ldap_dn__in=attributes['memberOf'])
# for group in applicable_groups:
# if group.group not in user.groups.all():
# user.groups.add(group.group)
# user.save()
# If the user was created, set them an unusable password.
if created:
user.set_unusable_password()
user.save()
# All done!
LOGGER.debug("LDAP user lookup succeeded")
return user
def auth_user(self, password, **filters):
def auth_user(self, password: str, **filters: Dict[str, str]) -> Optional[User]:
"""Try to bind as either user_dn or mail with password.
Returns True on success, otherwise False"""
filters.pop('request')
if not self._source.enabled:
users = User.objects.filter(**filters)
if not users.exists():
return None
# FIXME: Adapt user_uid
# email = filters.pop(CONFIG.y('passport').get('ldap').get, '')
email = filters.pop('email')
user_dn = self.lookup(self.generate_filter(**{'email': email}))
if not user_dn:
user = users.first()
if 'distinguishedName' not in user.attributes:
LOGGER.debug("User doesn't have DN set, assuming not LDAP imported.", user=user)
return None
# Try to bind as new user
LOGGER.debug("Binding as '%s'", user_dn)
LOGGER.debug("Attempting Binding as user", user=user)
try:
temp_connection = ldap3.Connection(self._server, user=user_dn,
temp_connection = ldap3.Connection(self._server,
user=user.attributes.get('distinguishedName'),
password=password, raise_exceptions=True)
temp_connection.bind()
if self._connection.search(
search_base=self._source.search_base,
search_filter=self.generate_filter(**{'email': email}),
search_scope=ldap3.SUBTREE,
attributes=[ldap3.ALL_ATTRIBUTES, ldap3.ALL_OPERATIONAL_ATTRIBUTES],
get_operational_attributes=True,
size_limit=1,
):
response = self._connection.response[0]
# If user has no email set in AD, use UPN
if 'mail' not in response.get('attributes'):
response['attributes']['mail'] = response['attributes']['userPrincipalName']
return self._get_or_create_user(response)
LOGGER.warning("LDAP user lookup failed")
return None
return user
except ldap3.core.exceptions.LDAPInvalidCredentialsResult as exception:
LOGGER.debug("User '%s' failed to login (Wrong credentials)", user_dn)
LOGGER.debug("LDAPInvalidCredentialsResult", user=user)
except ldap3.core.exceptions.LDAPException as exception:
LOGGER.warning(exception)
return None
def _do_modify(self, diff, **fields):
"""Do the LDAP modification itself"""
user_dn = self.lookup(self.generate_filter(**fields))
try:
self._connection.modify(user_dn, diff)
except ldap3.core.exceptions.LDAPException as exception:
LOGGER.warning("Failed to modify %s ('%s'), saved to DB", user_dn, exception)
# Connector.handle_ldap_error(user_dn, LDAPModification.ACTION_MODIFY, diff)
LOGGER.debug("modified account '%s' [%s]", user_dn, ','.join(diff.keys()))
return 'result' in self._connection.result and self._connection.result['result'] == 0
def disable_user(self, **fields):
"""Disables LDAP user based on mail or user_dn.
Returns True on success, otherwise False"""
diff = {
'userAccountControl': [(ldap3.MODIFY_REPLACE, [str(66050)])],
}
return self._do_modify(diff, **fields)
def enable_user(self, **fields):
"""Enables LDAP user based on mail or user_dn.
Returns True on success, otherwise False"""
diff = {
'userAccountControl': [(ldap3.MODIFY_REPLACE, [str(66048)])],
}
return self._do_modify(diff, **fields)
def change_password(self, new_password, **fields):
"""Changes LDAP user's password based on mail or user_dn.
Returns True on success, otherwise False"""
diff = {
'unicodePwd': [(ldap3.MODIFY_REPLACE, [Connector.encode_pass(new_password)])],
}
return self._do_modify(diff, **fields)
def add_to_group(self, group_dn, **fields):
"""Adds mail or user_dn to group_dn
Returns True on success, otherwise False"""
user_dn = self.lookup(**fields)
diff = {
'member': [(ldap3.MODIFY_ADD), [user_dn]]
}
return self._do_modify(diff, user_dn=group_dn)
def remove_from_group(self, group_dn, **fields):
"""Removes mail or user_dn from group_dn
Returns True on success, otherwise False"""
user_dn = self.lookup(**fields)
diff = {
'member': [(ldap3.MODIFY_DELETE), [user_dn]]
}
return self._do_modify(diff, user_dn=group_dn)

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@ -5,7 +5,7 @@ from django.contrib.admin.widgets import FilteredSelectMultiple
from django.utils.translation import gettext_lazy as _
from passbook.admin.forms.source import SOURCE_FORM_FIELDS
from passbook.sources.ldap.models import LDAPSource
from passbook.sources.ldap.models import LDAPPropertyMapping, LDAPSource
class LDAPSourceForm(forms.ModelForm):
@ -26,6 +26,7 @@ class LDAPSourceForm(forms.ModelForm):
'group_object_filter',
'sync_groups',
'sync_parent_group',
'property_mappings',
]
widgets = {
'name': forms.TextInput(),
@ -37,7 +38,8 @@ class LDAPSourceForm(forms.ModelForm):
'additional_group_dn': forms.TextInput(),
'user_object_filter': forms.TextInput(),
'group_object_filter': forms.TextInput(),
'policies': FilteredSelectMultiple(_('policies'), False)
'policies': FilteredSelectMultiple(_('policies'), False),
'property_mappings': FilteredSelectMultiple(_('Property Mappings'), False)
}
labels = {
'server_uri': _('Server URI'),
@ -47,3 +49,17 @@ class LDAPSourceForm(forms.ModelForm):
'additional_user_dn': _('Addition User DN'),
'additional_group_dn': _('Addition Group DN'),
}
class LDAPPropertyMappingForm(forms.ModelForm):
"""LDAP Property Mapping form"""
class Meta:
model = LDAPPropertyMapping
fields = ['name', 'ldap_property', 'object_field']
widgets = {
'name': forms.TextInput(),
'ldap_property': forms.TextInput(),
'object_field': forms.TextInput(),
}

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@ -0,0 +1,17 @@
# Generated by Django 2.2.6 on 2019-10-11 08:25
from django.db import migrations
class Migration(migrations.Migration):
dependencies = [
('passbook_sources_ldap', '0001_initial'),
]
operations = [
migrations.AlterModelOptions(
name='ldappropertymapping',
options={'verbose_name': 'LDAP Property Mapping', 'verbose_name_plural': 'LDAP Property Mappings'},
),
]

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@ -0,0 +1,32 @@
# Generated by Django 2.2.6 on 2019-10-11 08:25
from django.apps.registry import Apps
from django.db import migrations
def create_default_ad_property_mappings(apps: Apps, schema_editor):
LDAPPropertyMapping = apps.get_model('passbook_sources_ldap', 'LDAPPropertyMapping')
mapping = {
'name': 'name',
'givenName': 'first_name',
'sn': 'last_name',
'sAMAccountName': 'username',
'mail': 'email'
}
for ldap_property, object_field in mapping.items():
LDAPPropertyMapping.objects.get_or_create(
ldap_property=ldap_property,
object_field=object_field,
defaults={
'name': f"Autogenerated LDAP Mapping: {ldap_property} -> {object_field}"
})
class Migration(migrations.Migration):
dependencies = [
('passbook_sources_ldap', '0002_auto_20191011_0825'),
]
operations = [
migrations.RunPython(create_default_ad_property_mappings)
]

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@ -0,0 +1,25 @@
# Generated by Django 2.2.6 on 2019-10-11 08:39
import django.core.validators
import django.db.models.deletion
from django.db import migrations, models
class Migration(migrations.Migration):
dependencies = [
('passbook_sources_ldap', '0003_auto_20191011_0825'),
]
operations = [
migrations.AlterField(
model_name='ldapsource',
name='server_uri',
field=models.TextField(validators=[django.core.validators.URLValidator(schemes=['ldap', 'ldaps'])]),
),
migrations.AlterField(
model_name='ldapsource',
name='sync_parent_group',
field=models.ForeignKey(blank=True, default=None, null=True, on_delete=django.db.models.deletion.SET_DEFAULT, to='passbook_core.Group'),
),
]

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@ -10,7 +10,7 @@ from passbook.core.models import Group, PropertyMapping, Source
class LDAPSource(Source):
"""LDAP Authentication source"""
server_uri = models.URLField(validators=[URLValidator(schemes=['ldap', 'ldaps'])])
server_uri = models.TextField(validators=[URLValidator(schemes=['ldap', 'ldaps'])])
bind_cn = models.TextField()
bind_password = models.TextField()
start_tls = models.BooleanField(default=False)
@ -23,7 +23,7 @@ class LDAPSource(Source):
group_object_filter = models.TextField()
sync_groups = models.BooleanField(default=True)
sync_parent_group = models.ForeignKey(Group, blank=True,
sync_parent_group = models.ForeignKey(Group, blank=True, null=True,
default=None, on_delete=models.SET_DEFAULT)
form = 'passbook.sources.ldap.forms.LDAPSourceForm'
@ -39,6 +39,17 @@ class LDAPSource(Source):
class LDAPPropertyMapping(PropertyMapping):
"""Map LDAP Property to User or Group object"""
ldap_property = models.TextField()
object_field = models.TextField()
form = 'passbook.sources.ldap.forms.LDAPPropertyMappingForm'
def __str__(self):
return f"LDAP Property Mapping {self.ldap_property} -> {self.object_field}"
class Meta:
verbose_name = _('LDAP Property Mapping')
verbose_name_plural = _('LDAP Property Mappings')

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@ -1,5 +1,13 @@
"""LDAP Settings"""
from celery.schedules import crontab
AUTHENTICATION_BACKENDS = [
'passbook.sources.ldap.auth.LDAPBackend',
]
CELERY_BEAT_SCHEDULE = {
'sync': {
'task': 'passbook.sources.ldap.tasks.sync',
'schedule': crontab(minute=0) # Run every hour
}
}

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@ -0,0 +1,30 @@
from passbook.root.celery import CELERY_APP
from passbook.sources.ldap.connector import Connector
from passbook.sources.ldap.models import LDAPSource
@CELERY_APP.task()
def sync_groups(source_pk: int):
"""Sync LDAP Groups on background worker"""
source = LDAPSource.objects.get(pk=source_pk)
connector = Connector(source)
connector.bind()
connector.sync_groups()
@CELERY_APP.task()
def sync_users(source_pk: int):
"""Sync LDAP Users on background worker"""
source = LDAPSource.objects.get(pk=source_pk)
connector = Connector(source)
connector.bind()
connector.sync_users()
@CELERY_APP.task()
def sync():
"""Sync all sources"""
for source in LDAPSource.objects.filter(enabled=True):
connector = Connector(source)
connector.bind()
connector.sync_users()
connector.sync_groups()
connector.sync_membership()