diff --git a/synapse/crypto/context_factory.py b/synapse/crypto/context_factory.py
index 2bc5cc3807..4f48e8e88d 100644
--- a/synapse/crypto/context_factory.py
+++ b/synapse/crypto/context_factory.py
@@ -24,12 +24,25 @@ from OpenSSL import SSL, crypto
from twisted.internet._sslverify import _defaultCurveName
from twisted.internet.abstract import isIPAddress, isIPv6Address
from twisted.internet.interfaces import IOpenSSLClientConnectionCreator
-from twisted.internet.ssl import CertificateOptions, ContextFactory, platformTrust
+from twisted.internet.ssl import (
+ CertificateOptions,
+ ContextFactory,
+ TLSVersion,
+ platformTrust,
+)
from twisted.python.failure import Failure
logger = logging.getLogger(__name__)
+_TLS_VERSION_MAP = {
+ "1": TLSVersion.TLSv1_0,
+ "1.1": TLSVersion.TLSv1_1,
+ "1.2": TLSVersion.TLSv1_2,
+ "1.3": TLSVersion.TLSv1_3,
+}
+
+
class ServerContextFactory(ContextFactory):
"""Factory for PyOpenSSL SSL contexts that are used to handle incoming
connections."""
@@ -43,16 +56,18 @@ class ServerContextFactory(ContextFactory):
try:
_ecCurve = crypto.get_elliptic_curve(_defaultCurveName)
context.set_tmp_ecdh(_ecCurve)
-
except Exception:
logger.exception("Failed to enable elliptic curve for TLS")
- context.set_options(SSL.OP_NO_SSLv2 | SSL.OP_NO_SSLv3)
+
+ context.set_options(
+ SSL.OP_NO_SSLv2 | SSL.OP_NO_SSLv3 | SSL.OP_NO_TLSv1 | SSL.OP_NO_TLSv1_1
+ )
context.use_certificate_chain_file(config.tls_certificate_file)
context.use_privatekey(config.tls_private_key)
# https://hynek.me/articles/hardening-your-web-servers-ssl-ciphers/
context.set_cipher_list(
- "ECDH+AESGCM:ECDH+CHACHA20:ECDH+AES256:ECDH+AES128:!aNULL:!SHA1"
+ "ECDH+AESGCM:ECDH+CHACHA20:ECDH+AES256:ECDH+AES128:!aNULL:!SHA1:!AESCCM"
)
def getContext(self):
@@ -79,10 +94,22 @@ class ClientTLSOptionsFactory(object):
# Use CA root certs provided by OpenSSL
trust_root = platformTrust()
- self._verify_ssl_context = CertificateOptions(trustRoot=trust_root).getContext()
+ # "insecurelyLowerMinimumTo" is the argument that will go lower than
+ # Twisted's default, which is why it is marked as "insecure" (since
+ # Twisted's defaults are reasonably secure). But, since Twisted is
+ # moving to TLS 1.2 by default, we want to respect the config option if
+ # it is set to 1.0 (which the alternate option, raiseMinimumTo, will not
+ # let us do).
+ minTLS = _TLS_VERSION_MAP[config.federation_client_minimum_tls_version]
+
+ self._verify_ssl = CertificateOptions(
+ trustRoot=trust_root, insecurelyLowerMinimumTo=minTLS
+ )
+ self._verify_ssl_context = self._verify_ssl.getContext()
self._verify_ssl_context.set_info_callback(self._context_info_cb)
- self._no_verify_ssl_context = CertificateOptions().getContext()
+ self._no_verify_ssl = CertificateOptions(insecurelyLowerMinimumTo=minTLS)
+ self._no_verify_ssl_context = self._no_verify_ssl.getContext()
self._no_verify_ssl_context.set_info_callback(self._context_info_cb)
def get_options(self, host):
|
