Rework ldap integration with ldap3

Use the pure-python ldap3 library, which eliminates the need for a
system dependency.

Offer both a `search` and `simple_bind` mode, for more sophisticated
ldap scenarios.
- `search` tries to find a matching DN within the `user_base` while
  employing the `user_filter`, then tries the bind when a single
  matching DN was found.
- `simple_bind` tries the bind against a specific DN by combining the
  localpart and `user_base`

Offer support for STARTTLS on a plain connection.

The configuration was changed to reflect these new possibilities.

Signed-off-by: Martin Weinelt <hexa@darmstadt.ccc.de>
This commit is contained in:
Martin Weinelt 2016-06-06 02:05:57 +02:00
parent 0fe0b0eeb6
commit 0a32208e5d
4 changed files with 253 additions and 64 deletions

View File

@ -13,40 +13,88 @@
# See the License for the specific language governing permissions and
# limitations under the License.
from ._base import Config
from ._base import Config, ConfigError
MISSING_LDAP3 = (
"Missing ldap3 library. This is required for LDAP Authentication."
)
class LDAPMode(object):
SIMPLE = "simple",
SEARCH = "search",
LIST = (SIMPLE, SEARCH)
class LDAPConfig(Config):
def read_config(self, config):
ldap_config = config.get("ldap_config", None)
if ldap_config:
ldap_config = config.get("ldap_config", {})
self.ldap_enabled = ldap_config.get("enabled", False)
self.ldap_server = ldap_config["server"]
self.ldap_port = ldap_config["port"]
self.ldap_tls = ldap_config.get("tls", False)
self.ldap_search_base = ldap_config["search_base"]
self.ldap_search_property = ldap_config["search_property"]
self.ldap_email_property = ldap_config["email_property"]
self.ldap_full_name_property = ldap_config["full_name_property"]
else:
self.ldap_enabled = False
self.ldap_server = None
self.ldap_port = None
self.ldap_tls = False
self.ldap_search_base = None
self.ldap_search_property = None
self.ldap_email_property = None
self.ldap_full_name_property = None
if self.ldap_enabled:
# verify dependencies are available
try:
import ldap3
ldap3 # to stop unused lint
except ImportError:
raise ConfigError(MISSING_LDAP3)
self.ldap_mode = LDAPMode.SIMPLE
# verify config sanity
self.require_keys(ldap_config, [
"uri",
"base",
"attributes",
])
self.ldap_uri = ldap_config["uri"]
self.ldap_start_tls = ldap_config.get("start_tls", False)
self.ldap_base = ldap_config["base"]
self.ldap_attributes = ldap_config["attributes"]
if "bind_dn" in ldap_config:
self.ldap_mode = LDAPMode.SEARCH
self.require_keys(ldap_config, [
"bind_dn",
"bind_password",
])
self.ldap_bind_dn = ldap_config["bind_dn"]
self.ldap_bind_password = ldap_config["bind_password"]
self.ldap_filter = ldap_config.get("filter", None)
# verify attribute lookup
self.require_keys(ldap_config['attributes'], [
"uid",
"name",
"mail",
])
def require_keys(self, config, required):
missing = [key for key in required if key not in config]
if missing:
raise ConfigError(
"LDAP enabled but missing required config values: {}".format(
", ".join(missing)
)
)
def default_config(self, **kwargs):
return """\
# ldap_config:
# enabled: true
# server: "ldap://localhost"
# port: 389
# tls: false
# search_base: "ou=Users,dc=example,dc=com"
# search_property: "cn"
# email_property: "email"
# full_name_property: "givenName"
# uri: "ldap://ldap.example.com:389"
# start_tls: true
# base: "ou=users,dc=example,dc=com"
# attributes:
# uid: "cn"
# mail: "email"
# name: "givenName"
# #bind_dn:
# #bind_password:
# #filter: "(objectClass=posixAccount)"
"""

View File

@ -20,6 +20,7 @@ from synapse.api.constants import LoginType
from synapse.types import UserID
from synapse.api.errors import AuthError, LoginError, Codes, StoreError, SynapseError
from synapse.util.async import run_on_reactor
from synapse.config.ldap import LDAPMode
from twisted.web.client import PartialDownloadError
@ -28,6 +29,12 @@ import bcrypt
import pymacaroons
import simplejson
try:
import ldap3
except ImportError:
ldap3 = None
pass
import synapse.util.stringutils as stringutils
@ -50,17 +57,20 @@ class AuthHandler(BaseHandler):
self.INVALID_TOKEN_HTTP_STATUS = 401
self.ldap_enabled = hs.config.ldap_enabled
self.ldap_server = hs.config.ldap_server
self.ldap_port = hs.config.ldap_port
self.ldap_tls = hs.config.ldap_tls
self.ldap_search_base = hs.config.ldap_search_base
self.ldap_search_property = hs.config.ldap_search_property
self.ldap_email_property = hs.config.ldap_email_property
self.ldap_full_name_property = hs.config.ldap_full_name_property
if self.ldap_enabled is True:
import ldap
logger.info("Import ldap version: %s", ldap.__version__)
if self.ldap_enabled:
if not ldap3:
raise RuntimeError(
'Missing ldap3 library. This is required for LDAP Authentication.'
)
self.ldap_mode = hs.config.ldap_mode
self.ldap_uri = hs.config.ldap_uri
self.ldap_start_tls = hs.config.ldap_start_tls
self.ldap_base = hs.config.ldap_base
self.ldap_filter = hs.config.ldap_filter
self.ldap_attributes = hs.config.ldap_attributes
if self.ldap_mode == LDAPMode.SEARCH:
self.ldap_bind_dn = hs.config.ldap_bind_dn
self.ldap_bind_password = hs.config.ldap_bind_password
self.hs = hs # FIXME better possibility to access registrationHandler later?
@ -452,40 +462,167 @@ class AuthHandler(BaseHandler):
@defer.inlineCallbacks
def _check_ldap_password(self, user_id, password):
if not self.ldap_enabled:
logger.debug("LDAP not configured")
""" Attempt to authenticate a user against an LDAP Server
and register an account if none exists.
Returns:
True if authentication against LDAP was successful
"""
if not ldap3 or not self.ldap_enabled:
defer.returnValue(False)
import ldap
logger.info("Authenticating %s with LDAP" % user_id)
try:
ldap_url = "%s:%s" % (self.ldap_server, self.ldap_port)
logger.debug("Connecting LDAP server at %s" % ldap_url)
l = ldap.initialize(ldap_url)
if self.ldap_tls:
logger.debug("Initiating TLS")
self._connection.start_tls_s()
local_name = UserID.from_string(user_id).localpart
dn = "%s=%s, %s" % (
self.ldap_search_property,
local_name,
self.ldap_search_base)
logger.debug("DN for LDAP authentication: %s" % dn)
l.simple_bind_s(dn.encode('utf-8'), password.encode('utf-8'))
if not (yield self.does_user_exist(user_id)):
handler = self.hs.get_handlers().registration_handler
user_id, access_token = (
yield handler.register(localpart=local_name)
if self.ldap_mode not in LDAPMode.LIST:
raise RuntimeError(
'Invalid ldap mode specified: {mode}'.format(
mode=self.ldap_mode
)
)
try:
server = ldap3.Server(self.ldap_uri)
logger.debug(
"Attempting ldap connection with %s",
self.ldap_uri
)
localpart = UserID.from_string(user_id).localpart
if self.ldap_mode == LDAPMode.SIMPLE:
# bind with the the local users ldap credentials
bind_dn = "{prop}={value},{base}".format(
prop=self.ldap_attributes['uid'],
value=localpart,
base=self.ldap_base
)
conn = ldap3.Connection(server, bind_dn, password)
logger.debug(
"Established ldap connection in simple mode: %s",
conn
)
if self.ldap_start_tls:
conn.start_tls()
logger.debug(
"Upgraded ldap connection in simple mode through StartTLS: %s",
conn
)
conn.bind()
elif self.ldap_mode == LDAPMode.SEARCH:
# connect with preconfigured credentials and search for local user
conn = ldap3.Connection(
server,
self.ldap_bind_dn,
self.ldap_bind_password
)
logger.debug(
"Established ldap connection in search mode: %s",
conn
)
if self.ldap_start_tls:
conn.start_tls()
logger.debug(
"Upgraded ldap connection in search mode through StartTLS: %s",
conn
)
conn.bind()
# find matching dn
query = "({prop}={value})".format(
prop=self.ldap_attributes['uid'],
value=localpart
)
if self.ldap_filter:
query = "(&{query}{filter})".format(
query=query,
filter=self.ldap_filter
)
logger.debug("ldap search filter: %s", query)
result = conn.search(self.ldap_base, query)
if result and len(conn.response) == 1:
# found exactly one result
user_dn = conn.response[0]['dn']
logger.debug('ldap search found dn: %s', user_dn)
# unbind and reconnect, rebind with found dn
conn.unbind()
conn = ldap3.Connection(
server,
user_dn,
password,
auto_bind=True
)
else:
# found 0 or > 1 results, abort!
logger.warn(
"ldap search returned unexpected (%d!=1) amount of results",
len(conn.response)
)
defer.returnValue(False)
logger.info(
"User authenticated against ldap server: %s",
conn
)
# check for existing account, if none exists, create one
if not (yield self.does_user_exist(user_id)):
# query user metadata for account creation
query = "({prop}={value})".format(
prop=self.ldap_attributes['uid'],
value=localpart
)
if self.ldap_mode == LDAPMode.SEARCH and self.ldap_filter:
query = "(&{filter}{user_filter})".format(
filter=query,
user_filter=self.ldap_filter
)
logger.debug("ldap registration filter: %s", query)
result = conn.search(
search_base=self.ldap_base,
search_filter=query,
attributes=[
self.ldap_attributes['name'],
self.ldap_attributes['mail']
]
)
if len(conn.response) == 1:
attrs = conn.response[0]['attributes']
mail = attrs[self.ldap_attributes['mail']][0]
name = attrs[self.ldap_attributes['name']][0]
# create account
registration_handler = self.hs.get_handlers().registration_handler
user_id, access_token = (
yield registration_handler.register(localpart=localpart)
)
# TODO: bind email, set displayname with data from ldap directory
logger.info(
"ldap registration successful: %d: %s (%s, %)",
user_id,
localpart,
name,
mail
)
else:
logger.warn(
"ldap registration failed: unexpected (%d!=1) amount of results",
len(result)
)
defer.returnValue(False)
defer.returnValue(True)
except ldap.LDAPError, e:
logger.warn("LDAP error: %s", e)
except ldap3.core.exceptions.LDAPException as e:
logger.warn("Error during ldap authentication: %s", e)
defer.returnValue(False)
@defer.inlineCallbacks

View File

@ -48,6 +48,9 @@ CONDITIONAL_REQUIREMENTS = {
"Jinja2>=2.8": ["Jinja2>=2.8"],
"bleach>=1.4.2": ["bleach>=1.4.2"],
},
"ldap": {
"ldap3>=1.0": ["ldap3>=1.0"],
},
}

View File

@ -56,6 +56,7 @@ def setup_test_homeserver(name="test", datastore=None, config=None, **kargs):
config.use_frozen_dicts = True
config.database_config = {"name": "sqlite3"}
config.ldap_enabled = False
if "clock" not in kargs:
kargs["clock"] = MockClock()