MatrixSynapse/synapse/config/tls.py

299 lines
12 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2014-2016 OpenMarket Ltd
#
# 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 logging
import os
import warnings
from datetime import datetime
from hashlib import sha256
from unpaddedbase64 import encode_base64
from OpenSSL import crypto
from synapse.config._base import Config, ConfigError
logger = logging.getLogger(__name__)
class TlsConfig(Config):
def read_config(self, config):
acme_config = config.get("acme", None)
if acme_config is None:
acme_config = {}
self.acme_enabled = acme_config.get("enabled", False)
self.acme_url = acme_config.get(
"url", u"https://acme-v01.api.letsencrypt.org/directory"
)
self.acme_port = acme_config.get("port", 80)
self.acme_bind_addresses = acme_config.get("bind_addresses", ['::', '0.0.0.0'])
self.acme_reprovision_threshold = acme_config.get("reprovision_threshold", 30)
self.tls_certificate_file = self.abspath(config.get("tls_certificate_path"))
self.tls_private_key_file = self.abspath(config.get("tls_private_key_path"))
if self.has_tls_listener():
if not self.tls_certificate_file:
raise ConfigError(
"tls_certificate_path must be specified if TLS-enabled listeners are "
"configured."
)
if not self.tls_private_key_file:
raise ConfigError(
"tls_certificate_path must be specified if TLS-enabled listeners are "
"configured."
)
self._original_tls_fingerprints = config.get("tls_fingerprints", [])
if self._original_tls_fingerprints is None:
self._original_tls_fingerprints = []
self.tls_fingerprints = list(self._original_tls_fingerprints)
# This config option applies to non-federation HTTP clients
# (e.g. for talking to recaptcha, identity servers, and such)
# It should never be used in production, and is intended for
# use only when running tests.
self.use_insecure_ssl_client_just_for_testing_do_not_use = config.get(
"use_insecure_ssl_client_just_for_testing_do_not_use"
)
self.tls_certificate = None
self.tls_private_key = None
def is_disk_cert_valid(self, allow_self_signed=True):
"""
Is the certificate we have on disk valid, and if so, for how long?
Args:
allow_self_signed (bool): Should we allow the certificate we
read to be self signed?
Returns:
int: Days remaining of certificate validity.
None: No certificate exists.
"""
if not os.path.exists(self.tls_certificate_file):
return None
try:
with open(self.tls_certificate_file, 'rb') as f:
cert_pem = f.read()
except Exception:
logger.exception("Failed to read existing certificate off disk!")
raise
try:
tls_certificate = crypto.load_certificate(crypto.FILETYPE_PEM, cert_pem)
except Exception:
logger.exception("Failed to parse existing certificate off disk!")
raise
if not allow_self_signed:
if tls_certificate.get_subject() == tls_certificate.get_issuer():
raise ValueError(
"TLS Certificate is self signed, and this is not permitted"
)
# YYYYMMDDhhmmssZ -- in UTC
expires_on = datetime.strptime(
tls_certificate.get_notAfter().decode('ascii'), "%Y%m%d%H%M%SZ"
)
now = datetime.utcnow()
days_remaining = (expires_on - now).days
return days_remaining
def read_certificate_from_disk(self, require_cert_and_key):
"""
Read the certificates and private key from disk.
Args:
require_cert_and_key (bool): set to True to throw an error if the certificate
and key file are not given
"""
if require_cert_and_key:
self.tls_private_key = self.read_tls_private_key()
self.tls_certificate = self.read_tls_certificate()
elif self.tls_certificate_file:
# we only need the certificate for the tls_fingerprints. Reload it if we
# can, but it's not a fatal error if we can't.
try:
self.tls_certificate = self.read_tls_certificate()
except Exception as e:
logger.info(
"Unable to read TLS certificate (%s). Ignoring as no "
"tls listeners enabled.", e,
)
self.tls_fingerprints = list(self._original_tls_fingerprints)
if self.tls_certificate:
# Check that our own certificate is included in the list of fingerprints
# and include it if it is not.
x509_certificate_bytes = crypto.dump_certificate(
crypto.FILETYPE_ASN1, self.tls_certificate
)
sha256_fingerprint = encode_base64(sha256(x509_certificate_bytes).digest())
sha256_fingerprints = set(f["sha256"] for f in self.tls_fingerprints)
if sha256_fingerprint not in sha256_fingerprints:
self.tls_fingerprints.append({u"sha256": sha256_fingerprint})
def default_config(self, config_dir_path, server_name, **kwargs):
base_key_name = os.path.join(config_dir_path, server_name)
tls_certificate_path = base_key_name + ".tls.crt"
tls_private_key_path = base_key_name + ".tls.key"
# this is to avoid the max line length. Sorrynotsorry
proxypassline = (
'ProxyPass /.well-known/acme-challenge '
'http://localhost:8009/.well-known/acme-challenge'
)
return (
"""\
## TLS ##
# PEM-encoded X509 certificate for TLS.
# This certificate, as of Synapse 1.0, will need to be a valid and verifiable
# certificate, signed by a recognised Certificate Authority.
#
# See 'ACME support' below to enable auto-provisioning this certificate via
# Let's Encrypt.
#
# tls_certificate_path: "%(tls_certificate_path)s"
# PEM-encoded private key for TLS
# tls_private_key_path: "%(tls_private_key_path)s"
# ACME support: This will configure Synapse to request a valid TLS certificate
# for your configured `server_name` via Let's Encrypt.
#
# Note that provisioning a certificate in this way requires port 80 to be
# routed to Synapse so that it can complete the http-01 ACME challenge.
# By default, if you enable ACME support, Synapse will attempt to listen on
# port 80 for incoming http-01 challenges - however, this will likely fail
# with 'Permission denied' or a similar error.
#
# There are a couple of potential solutions to this:
#
# * If you already have an Apache, Nginx, or similar listening on port 80,
# you can configure Synapse to use an alternate port, and have your web
# server forward the requests. For example, assuming you set 'port: 8009'
# below, on Apache, you would write:
#
# %(proxypassline)s
#
# * Alternatively, you can use something like `authbind` to give Synapse
# permission to listen on port 80.
#
acme:
# ACME support is disabled by default. Uncomment the following line
# (and tls_certificate_path and tls_private_key_path above) to enable it.
#
# enabled: true
# Endpoint to use to request certificates. If you only want to test,
# use Let's Encrypt's staging url:
# https://acme-staging.api.letsencrypt.org/directory
#
# url: https://acme-v01.api.letsencrypt.org/directory
# Port number to listen on for the HTTP-01 challenge. Change this if
# you are forwarding connections through Apache/Nginx/etc.
#
# port: 80
# Local addresses to listen on for incoming connections.
# Again, you may want to change this if you are forwarding connections
# through Apache/Nginx/etc.
#
# bind_addresses: ['::', '0.0.0.0']
# How many days remaining on a certificate before it is renewed.
#
# reprovision_threshold: 30
# List of allowed TLS fingerprints for this server to publish along
# with the signing keys for this server. Other matrix servers that
# make HTTPS requests to this server will check that the TLS
# certificates returned by this server match one of the fingerprints.
#
# Synapse automatically adds the fingerprint of its own certificate
# to the list. So if federation traffic is handled directly by synapse
# then no modification to the list is required.
#
# If synapse is run behind a load balancer that handles the TLS then it
# will be necessary to add the fingerprints of the certificates used by
# the loadbalancers to this list if they are different to the one
# synapse is using.
#
# Homeservers are permitted to cache the list of TLS fingerprints
# returned in the key responses up to the "valid_until_ts" returned in
# key. It may be necessary to publish the fingerprints of a new
# certificate and wait until the "valid_until_ts" of the previous key
# responses have passed before deploying it.
#
# You can calculate a fingerprint from a given TLS listener via:
# openssl s_client -connect $host:$port < /dev/null 2> /dev/null |
# openssl x509 -outform DER | openssl sha256 -binary | base64 | tr -d '='
# or by checking matrix.org/federationtester/api/report?server_name=$host
#
tls_fingerprints: []
# tls_fingerprints: [{"sha256": "<base64_encoded_sha256_fingerprint>"}]
"""
% locals()
)
def read_tls_certificate(self):
"""Reads the TLS certificate from the configured file, and returns it
Also checks if it is self-signed, and warns if so
Returns:
OpenSSL.crypto.X509: the certificate
"""
cert_path = self.tls_certificate_file
logger.info("Loading TLS certificate from %s", cert_path)
cert_pem = self.read_file(cert_path, "tls_certificate_path")
cert = crypto.load_certificate(crypto.FILETYPE_PEM, cert_pem)
# Check if it is self-signed, and issue a warning if so.
if cert.get_issuer() == cert.get_subject():
warnings.warn(
(
"Self-signed TLS certificates will not be accepted by Synapse 1.0. "
"Please either provide a valid certificate, or use Synapse's ACME "
"support to provision one."
)
)
return cert
def read_tls_private_key(self):
"""Reads the TLS private key from the configured file, and returns it
Returns:
OpenSSL.crypto.PKey: the private key
"""
private_key_path = self.tls_private_key_file
logger.info("Loading TLS key from %s", private_key_path)
private_key_pem = self.read_file(private_key_path, "tls_private_key_path")
return crypto.load_privatekey(crypto.FILETYPE_PEM, private_key_pem)