diff --git a/changelog.d/4384.feature b/changelog.d/4384.feature
new file mode 100644
index 0000000000..daedcd58c4
--- /dev/null
+++ b/changelog.d/4384.feature
@@ -0,0 +1 @@
+Synapse can now automatically provision TLS certificates via ACME (the protocol used by CAs like Let's Encrypt).
diff --git a/scripts-dev/build_debian_packages b/scripts-dev/build_debian_packages
index 577d93e6f6..6b9be99060 100755
--- a/scripts-dev/build_debian_packages
+++ b/scripts-dev/build_debian_packages
@@ -10,12 +10,12 @@
# can be passed on the commandline for debugging.
import argparse
-from concurrent.futures import ThreadPoolExecutor
import os
import signal
import subprocess
import sys
import threading
+from concurrent.futures import ThreadPoolExecutor
DISTS = (
"debian:stretch",
diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index f3ac3d19f0..ffc49d77cc 100755
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -13,10 +13,12 @@
# 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 gc
import logging
import os
import sys
+import traceback
from six import iteritems
@@ -324,17 +326,12 @@ def setup(config_options):
events.USE_FROZEN_DICTS = config.use_frozen_dicts
- tls_server_context_factory = context_factory.ServerContextFactory(config)
- tls_client_options_factory = context_factory.ClientTLSOptionsFactory(config)
-
database_engine = create_engine(config.database_config)
config.database_config["args"]["cp_openfun"] = database_engine.on_new_connection
hs = SynapseHomeServer(
config.server_name,
db_config=config.database_config,
- tls_server_context_factory=tls_server_context_factory,
- tls_client_options_factory=tls_client_options_factory,
config=config,
version_string="Synapse/" + get_version_string(synapse),
database_engine=database_engine,
@@ -361,12 +358,53 @@ def setup(config_options):
logger.info("Database prepared in %s.", config.database_config['name'])
hs.setup()
- hs.start_listening()
+ @defer.inlineCallbacks
def start():
- hs.get_pusherpool().start()
- hs.get_datastore().start_profiling()
- hs.get_datastore().start_doing_background_updates()
+ try:
+ # Check if the certificate is still valid.
+ cert_days_remaining = hs.config.is_disk_cert_valid()
+
+ if hs.config.acme_enabled:
+ # If ACME is enabled, we might need to provision a certificate
+ # before starting.
+ acme = hs.get_acme_handler()
+
+ # Start up the webservices which we will respond to ACME
+ # challenges with.
+ yield acme.start_listening()
+
+ # We want to reprovision if cert_days_remaining is None (meaning no
+ # certificate exists), or the days remaining number it returns
+ # is less than our re-registration threshold.
+ if (cert_days_remaining is None) or (
+ not cert_days_remaining > hs.config.acme_reprovision_threshold
+ ):
+ yield acme.provision_certificate()
+
+ # Read the certificate from disk and build the context factories for
+ # TLS.
+ hs.config.read_certificate_from_disk()
+ hs.tls_server_context_factory = context_factory.ServerContextFactory(config)
+ hs.tls_client_options_factory = context_factory.ClientTLSOptionsFactory(
+ config
+ )
+
+ # It is now safe to start your Synapse.
+ hs.start_listening()
+ hs.get_pusherpool().start()
+ hs.get_datastore().start_profiling()
+ hs.get_datastore().start_doing_background_updates()
+ except Exception as e:
+ # If a DeferredList failed (like in listening on the ACME listener),
+ # we need to print the subfailure explicitly.
+ if isinstance(e, defer.FirstError):
+ e.subFailure.printTraceback(sys.stderr)
+ sys.exit(1)
+
+ # Something else went wrong when starting. Print it and bail out.
+ traceback.print_exc(file=sys.stderr)
+ sys.exit(1)
reactor.callWhenRunning(start)
diff --git a/synapse/config/_base.py b/synapse/config/_base.py
index fd2d6d52ef..5858fb92b4 100644
--- a/synapse/config/_base.py
+++ b/synapse/config/_base.py
@@ -367,7 +367,7 @@ class Config(object):
if not keys_directory:
keys_directory = os.path.dirname(config_files[-1])
- config_dir_path = os.path.abspath(keys_directory)
+ self.config_dir_path = os.path.abspath(keys_directory)
specified_config = {}
for config_file in config_files:
@@ -379,7 +379,7 @@ class Config(object):
server_name = specified_config["server_name"]
config_string = self.generate_config(
- config_dir_path=config_dir_path,
+ config_dir_path=self.config_dir_path,
data_dir_path=os.getcwd(),
server_name=server_name,
generate_secrets=False,
diff --git a/synapse/config/tls.py b/synapse/config/tls.py
index bb8952c672..a75e233aa0 100644
--- a/synapse/config/tls.py
+++ b/synapse/config/tls.py
@@ -13,60 +13,110 @@
# See the License for the specific language governing permissions and
# limitations under the License.
+import logging
import os
+from datetime import datetime
from hashlib import sha256
from unpaddedbase64 import encode_base64
from OpenSSL import crypto
-from ._base import Config
+from synapse.config._base import Config
+
+logger = logging.getLogger()
class TlsConfig(Config):
def read_config(self, config):
- self.tls_certificate = self.read_tls_certificate(
- config.get("tls_certificate_path")
- )
- self.tls_certificate_file = config.get("tls_certificate_path")
+ acme_config = config.get("acme", {})
+ self.acme_enabled = acme_config.get("enabled", False)
+ self.acme_url = acme_config.get(
+ "url", "https://acme-v01.api.letsencrypt.org/directory"
+ )
+ self.acme_port = acme_config.get("port", 8449)
+ self.acme_bind_addresses = acme_config.get("bind_addresses", ["127.0.0.1"])
+ self.acme_reprovision_threshold = acme_config.get("reprovision_threshold", 30)
+
+ self.tls_certificate_file = os.path.abspath(config.get("tls_certificate_path"))
+ self.tls_private_key_file = os.path.abspath(config.get("tls_private_key_path"))
+ self._original_tls_fingerprints = config["tls_fingerprints"]
+ self.tls_fingerprints = list(self._original_tls_fingerprints)
self.no_tls = config.get("no_tls", False)
- if self.no_tls:
- self.tls_private_key = None
- else:
- self.tls_private_key = self.read_tls_private_key(
- config.get("tls_private_key_path")
- )
+ # 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):
+ """
+ Is the certificate we have on disk valid, and if so, for how long?
+
+ 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
+
+ # 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
- self.tls_fingerprints = config["tls_fingerprints"]
+ def read_certificate_from_disk(self):
+ """
+ Read the certificates from disk.
+ """
+ self.tls_certificate = self.read_tls_certificate(self.tls_certificate_file)
+
+ if not self.no_tls:
+ self.tls_private_key = self.read_tls_private_key(self.tls_private_key_file)
+
+ self.tls_fingerprints = list(self._original_tls_fingerprints)
# 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
+ 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})
- # 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"
- )
-
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"
- return """\
+ return (
+ """\
# PEM encoded X509 certificate for TLS.
# You can replace the self-signed certificate that synapse
# autogenerates on launch with your own SSL certificate + key pair
@@ -107,7 +157,24 @@ class TlsConfig(Config):
#
tls_fingerprints: []
# tls_fingerprints: [{"sha256": "<base64_encoded_sha256_fingerprint>"}]
- """ % locals()
+
+ ## Support for ACME certificate auto-provisioning.
+ # acme:
+ # enabled: false
+ ## ACME path.
+ ## If you only want to test, use the staging url:
+ ## https://acme-staging.api.letsencrypt.org/directory
+ # url: 'https://acme-v01.api.letsencrypt.org/directory'
+ ## Port number (to listen for the HTTP-01 challenge).
+ ## Using port 80 requires utilising something like authbind, or proxying to it.
+ # port: 8449
+ ## Hosts to bind to.
+ # bind_addresses: ['127.0.0.1']
+ ## How many days remaining on a certificate before it is renewed.
+ # reprovision_threshold: 30
+ """
+ % locals()
+ )
def read_tls_certificate(self, cert_path):
cert_pem = self.read_file(cert_path, "tls_certificate")
diff --git a/synapse/handlers/acme.py b/synapse/handlers/acme.py
new file mode 100644
index 0000000000..73ea7ed018
--- /dev/null
+++ b/synapse/handlers/acme.py
@@ -0,0 +1,147 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 New Vector 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 attr
+from zope.interface import implementer
+
+from twisted.internet import defer
+from twisted.internet.endpoints import serverFromString
+from twisted.python.filepath import FilePath
+from twisted.python.url import URL
+from twisted.web import server, static
+from twisted.web.resource import Resource
+
+logger = logging.getLogger(__name__)
+
+try:
+ from txacme.interfaces import ICertificateStore
+
+ @attr.s
+ @implementer(ICertificateStore)
+ class ErsatzStore(object):
+ """
+ A store that only stores in memory.
+ """
+
+ certs = attr.ib(default=attr.Factory(dict))
+
+ def store(self, server_name, pem_objects):
+ self.certs[server_name] = [o.as_bytes() for o in pem_objects]
+ return defer.succeed(None)
+
+
+except ImportError:
+ # txacme is missing
+ pass
+
+
+class AcmeHandler(object):
+ def __init__(self, hs):
+ self.hs = hs
+ self.reactor = hs.get_reactor()
+
+ @defer.inlineCallbacks
+ def start_listening(self):
+
+ # Configure logging for txacme, if you need to debug
+ # from eliot import add_destinations
+ # from eliot.twisted import TwistedDestination
+ #
+ # add_destinations(TwistedDestination())
+
+ from txacme.challenges import HTTP01Responder
+ from txacme.service import AcmeIssuingService
+ from txacme.endpoint import load_or_create_client_key
+ from txacme.client import Client
+ from josepy.jwa import RS256
+
+ self._store = ErsatzStore()
+ responder = HTTP01Responder()
+
+ self._issuer = AcmeIssuingService(
+ cert_store=self._store,
+ client_creator=(
+ lambda: Client.from_url(
+ reactor=self.reactor,
+ url=URL.from_text(self.hs.config.acme_url),
+ key=load_or_create_client_key(
+ FilePath(self.hs.config.config_dir_path)
+ ),
+ alg=RS256,
+ )
+ ),
+ clock=self.reactor,
+ responders=[responder],
+ )
+
+ well_known = Resource()
+ well_known.putChild(b'acme-challenge', responder.resource)
+ responder_resource = Resource()
+ responder_resource.putChild(b'.well-known', well_known)
+ responder_resource.putChild(b'check', static.Data(b'OK', b'text/plain'))
+
+ srv = server.Site(responder_resource)
+
+ listeners = []
+
+ for host in self.hs.config.acme_bind_addresses:
+ logger.info(
+ "Listening for ACME requests on %s:%s", host, self.hs.config.acme_port
+ )
+ endpoint = serverFromString(
+ self.reactor, "tcp:%s:interface=%s" % (self.hs.config.acme_port, host)
+ )
+ listeners.append(endpoint.listen(srv))
+
+ # Make sure we are registered to the ACME server. There's no public API
+ # for this, it is usually triggered by startService, but since we don't
+ # want it to control where we save the certificates, we have to reach in
+ # and trigger the registration machinery ourselves.
+ self._issuer._registered = False
+ yield self._issuer._ensure_registered()
+
+ # Return a Deferred that will fire when all the servers have started up.
+ yield defer.DeferredList(listeners, fireOnOneErrback=True, consumeErrors=True)
+
+ @defer.inlineCallbacks
+ def provision_certificate(self):
+
+ logger.warning("Reprovisioning %s", self.hs.hostname)
+
+ try:
+ yield self._issuer.issue_cert(self.hs.hostname)
+ except Exception:
+ logger.exception("Fail!")
+ raise
+ logger.warning("Reprovisioned %s, saving.", self.hs.hostname)
+ cert_chain = self._store.certs[self.hs.hostname]
+
+ try:
+ with open(self.hs.config.tls_private_key_file, "wb") as private_key_file:
+ for x in cert_chain:
+ if x.startswith(b"-----BEGIN RSA PRIVATE KEY-----"):
+ private_key_file.write(x)
+
+ with open(self.hs.config.tls_certificate_file, "wb") as certificate_file:
+ for x in cert_chain:
+ if x.startswith(b"-----BEGIN CERTIFICATE-----"):
+ certificate_file.write(x)
+ except Exception:
+ logger.exception("Failed saving!")
+ raise
+
+ defer.returnValue(True)
diff --git a/synapse/python_dependencies.py b/synapse/python_dependencies.py
index 882e844eb1..756721e304 100644
--- a/synapse/python_dependencies.py
+++ b/synapse/python_dependencies.py
@@ -79,6 +79,10 @@ CONDITIONAL_REQUIREMENTS = {
# ConsentResource uses select_autoescape, which arrived in jinja 2.9
"resources.consent": ["Jinja2>=2.9"],
+ # ACME support is required to provision TLS certificates from authorities
+ # that use the protocol, such as Let's Encrypt.
+ "acme": ["txacme>=0.9.2"],
+
"saml2": ["pysaml2>=4.5.0"],
"url_preview": ["lxml>=3.5.0"],
"test": ["mock>=2.0"],
diff --git a/synapse/server.py b/synapse/server.py
index 9985687b95..c8914302cf 100644
--- a/synapse/server.py
+++ b/synapse/server.py
@@ -46,6 +46,7 @@ from synapse.federation.transport.client import TransportLayerClient
from synapse.groups.attestations import GroupAttestationSigning, GroupAttestionRenewer
from synapse.groups.groups_server import GroupsServerHandler
from synapse.handlers import Handlers
+from synapse.handlers.acme import AcmeHandler
from synapse.handlers.appservice import ApplicationServicesHandler
from synapse.handlers.auth import AuthHandler, MacaroonGenerator
from synapse.handlers.deactivate_account import DeactivateAccountHandler
@@ -129,6 +130,7 @@ class HomeServer(object):
'sync_handler',
'typing_handler',
'room_list_handler',
+ 'acme_handler',
'auth_handler',
'device_handler',
'e2e_keys_handler',
@@ -310,6 +312,9 @@ class HomeServer(object):
def build_e2e_room_keys_handler(self):
return E2eRoomKeysHandler(self)
+ def build_acme_handler(self):
+ return AcmeHandler(self)
+
def build_application_service_api(self):
return ApplicationServiceApi(self)
|
