# 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
from typing import List, Optional, Pattern
from OpenSSL import SSL, crypto
from twisted.internet._sslverify import Certificate, trustRootFromCertificates
from synapse.config._base import Config, ConfigError
from synapse.util import glob_to_regex
logger = logging.getLogger(__name__)
class TlsConfig(Config):
section = "tls"
def read_config(self, config: dict, config_dir_path: str, **kwargs):
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.root.server.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_private_key_path must be specified if TLS-enabled listeners are "
"configured."
)
# Whether to verify certificates on outbound federation traffic
self.federation_verify_certificates = config.get(
"federation_verify_certificates", True
)
# Minimum TLS version to use for outbound federation traffic
self.federation_client_minimum_tls_version = str(
config.get("federation_client_minimum_tls_version", 1)
)
if self.federation_client_minimum_tls_version not in ["1", "1.1", "1.2", "1.3"]:
raise ConfigError(
"federation_client_minimum_tls_version must be one of: 1, 1.1, 1.2, 1.3"
)
# Prevent people shooting themselves in the foot here by setting it to
# the biggest number blindly
if self.federation_client_minimum_tls_version == "1.3":
if getattr(SSL, "OP_NO_TLSv1_3", None) is None:
raise ConfigError(
"federation_client_minimum_tls_version cannot be 1.3, "
"your OpenSSL does not support it"
)
# Whitelist of domains to not verify certificates for
fed_whitelist_entries = config.get(
"federation_certificate_verification_whitelist", []
)
if fed_whitelist_entries is None:
fed_whitelist_entries = []
# Support globs (*) in whitelist values
self.federation_certificate_verification_whitelist: List[Pattern] = []
for entry in fed_whitelist_entries:
try:
entry_regex = glob_to_regex(entry.encode("ascii").decode("ascii"))
except UnicodeEncodeError:
raise ConfigError(
"IDNA domain names are not allowed in the "
"federation_certificate_verification_whitelist: %s" % (entry,)
)
# Convert globs to regex
self.federation_certificate_verification_whitelist.append(entry_regex)
# List of custom certificate authorities for federation traffic validation
custom_ca_list = config.get("federation_custom_ca_list", None)
# Read in and parse custom CA certificates
self.federation_ca_trust_root = None
if custom_ca_list is not None:
if len(custom_ca_list) == 0:
# A trustroot cannot be generated without any CA certificates.
# Raise an error if this option has been specified without any
# corresponding certificates.
raise ConfigError(
"federation_custom_ca_list specified without "
"any certificate files"
)
certs = []
for ca_file in custom_ca_list:
logger.debug("Reading custom CA certificate file: %s", ca_file)
content = self.read_file(ca_file, "federation_custom_ca_list")
# Parse the CA certificates
try:
cert_base = Certificate.loadPEM(content)
certs.append(cert_base)
except Exception as e:
raise ConfigError(
"Error parsing custom CA certificate file %s: %s" % (ca_file, e)
)
self.federation_ca_trust_root = trustRootFromCertificates(certs)
# 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: Optional[crypto.X509] = None
self.tls_private_key: Optional[crypto.PKey] = None
def read_certificate_from_disk(self):
"""
Read the certificates and private key from disk.
"""
self.tls_private_key = self.read_tls_private_key()
self.tls_certificate = self.read_tls_certificate()
def generate_config_section(
self,
config_dir_path,
server_name,
data_dir_path,
tls_certificate_path,
tls_private_key_path,
**kwargs,
):
"""If the TLS paths are not specified the default will be certs in the
config directory"""
base_key_name = os.path.join(config_dir_path, server_name)
if bool(tls_certificate_path) != bool(tls_private_key_path):
raise ConfigError(
"Please specify both a cert path and a key path or neither."
)
tls_enabled = "" if tls_certificate_path and tls_private_key_path else "#"
if not tls_certificate_path:
tls_certificate_path = base_key_name + ".tls.crt"
if not tls_private_key_path:
tls_private_key_path = base_key_name + ".tls.key"
# flake8 doesn't recognise that variables are used in the below string
_ = tls_enabled
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.
#
# Be sure to use a `.pem` file that includes the full certificate chain including
# any intermediate certificates (for instance, if using certbot, use
# `fullchain.pem` as your certificate, not `cert.pem`).
#
%(tls_enabled)stls_certificate_path: "%(tls_certificate_path)s"
# PEM-encoded private key for TLS
#
%(tls_enabled)stls_private_key_path: "%(tls_private_key_path)s"
# Whether to verify TLS server certificates for outbound federation requests.
#
# Defaults to `true`. To disable certificate verification, uncomment the
# following line.
#
#federation_verify_certificates: false
# The minimum TLS version that will be used for outbound federation requests.
#
# Defaults to `1`. Configurable to `1`, `1.1`, `1.2`, or `1.3`. Note
# that setting this value higher than `1.2` will prevent federation to most
# of the public Matrix network: only configure it to `1.3` if you have an
# entirely private federation setup and you can ensure TLS 1.3 support.
#
#federation_client_minimum_tls_version: 1.2
# Skip federation certificate verification on the following whitelist
# of domains.
#
# This setting should only be used in very specific cases, such as
# federation over Tor hidden services and similar. For private networks
# of homeservers, you likely want to use a private CA instead.
#
# Only effective if federation_verify_certicates is `true`.
#
#federation_certificate_verification_whitelist:
# - lon.example.com
# - "*.domain.com"
# - "*.onion"
# List of custom certificate authorities for federation traffic.
#
# This setting should only normally be used within a private network of
# homeservers.
#
# Note that this list will replace those that are provided by your
# operating environment. Certificates must be in PEM format.
#
#federation_custom_ca_list:
# - myCA1.pem
# - myCA2.pem
# - myCA3.pem
"""
# Lowercase the string representation of boolean values
% {
x[0]: str(x[1]).lower() if isinstance(x[1], bool) else x[1]
for x in locals().items()
}
)
def read_tls_certificate(self) -> crypto.X509:
"""Reads the TLS certificate from the configured file, and returns it
Returns:
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.encode())
return cert
def read_tls_private_key(self) -> crypto.PKey:
"""Reads the TLS private key from the configured file, and returns it
Returns:
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)