You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

102 lines
3.6 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2019 The Matrix.org Foundation C.I.C.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import re
import string
import saml2.response
__version__ = "0.0.1"
class SamlMappingProvider(object):
def __init__(self):
mxid_localpart_allowed_characters = set(
"_-./=" + string.ascii_lowercase + string.digits
)
self._dot_replace_pattern = re.compile(
("[^%s]" % (re.escape("".join(mxid_localpart_allowed_characters)),))
)
self._multiple_to_single_dot_pattern = re.compile(r"\.{2,}")
self._string_end_dot_pattern = re.compile(r"\.$")
self._mxid_source_attribute = None
def saml_response_to_user_attributes(
self,
saml_response: saml2.response.AuthnResponse,
failures: int = 0,
) -> dict:
"""Maps some text from a SAML response to attributes of a new user
Args:
saml_response: A SAML auth response object
failures: How many times a call to this function with this
saml_response has resulted in a failure
Returns:
dict: A dict containing new user attributes. Possible keys:
* mxid_localpart (str): Required. The localpart of the user's mxid
* displayname (str): The displayname of the user
"""
# The calling function will catch the KeyError if this fails
mxid_source = saml_response.ava[self._mxid_source_attribute][0]
# Truncate the username to the first found '@' character to prevent complete
# emails being leaked
pos = mxid_source.find("@")
if pos >= 0:
mxid_source = mxid_source[:pos]
mxid_localpart = self._dotreplace_for_mxid(mxid_source)
# Append suffix integer if last call to this function failed to produce
# a usable mxid
localpart = mxid_localpart + (str(failures) if failures else "")
# Retrieve the display name from the saml response
displayname = saml_response.ava.get("displayName", [None])[0]
return {
"mxid_localpart": localpart,
"displayname": displayname,
}
def _dotreplace_for_mxid(self, username: str) -> str:
"""Replace non-allowed mxid characters with a '.'
Args:
username (str): The username to process
Returns:
str: The processed username
"""
username = username.lower()
username = self._dot_replace_pattern.sub(".", username)
# regular mxids aren't allowed to start with an underscore either
username = re.sub("^_", "", username)
# Change all instances of multiple dots together into a single dot
username = self._multiple_to_single_dot_pattern.sub(".", username)
# Remove any trailing dots
username = self._string_end_dot_pattern.sub("", username)
return username
def parse_config(self, config):
"""Parse the dict provided by the homeserver config"""
self._mxid_source_attribute = config.get("mxid_source_attribute", "uid")