More server_name validation

We need to do a bit more validation when we get a server name, but don't want
to be re-doing it all over the shop, so factor out a separate
parse_and_validate_server_name, and do the extra validation.

Also, use it to verify the server name in the config file.
pull/3483/head
Richard van der Hoff 2018-07-04 18:15:03 +01:00
parent 13f7adf84b
commit 546bc9e28b
5 changed files with 68 additions and 13 deletions

1
changelog.d/3483.feature Normal file
View File

@ -0,0 +1 @@
Reject invalid server names in homeserver.yaml

View File

@ -16,6 +16,7 @@
import logging
from synapse.http.endpoint import parse_and_validate_server_name
from ._base import Config, ConfigError
logger = logging.Logger(__name__)
@ -25,6 +26,12 @@ class ServerConfig(Config):
def read_config(self, config):
self.server_name = config["server_name"]
try:
parse_and_validate_server_name(self.server_name)
except ValueError as e:
raise ConfigError(str(e))
self.pid_file = self.abspath(config.get("pid_file"))
self.web_client = config["web_client"]
self.web_client_location = config.get("web_client_location", None)
@ -162,8 +169,8 @@ class ServerConfig(Config):
})
def default_config(self, server_name, **kwargs):
if ":" in server_name:
bind_port = int(server_name.split(":")[1])
_, bind_port = parse_and_validate_server_name(server_name)
if bind_port is not None:
unsecure_port = bind_port - 400
else:
bind_port = 8448

View File

@ -18,7 +18,7 @@ from twisted.internet import defer
from synapse.api.urls import FEDERATION_PREFIX as PREFIX
from synapse.api.errors import Codes, SynapseError, FederationDeniedError
from synapse.http.endpoint import parse_server_name
from synapse.http.endpoint import parse_and_validate_server_name
from synapse.http.server import JsonResource
from synapse.http.servlet import (
parse_json_object_from_request, parse_integer_from_args, parse_string_from_args,
@ -170,8 +170,9 @@ def _parse_auth_header(header_bytes):
return value
origin = strip_quotes(param_dict["origin"])
# ensure that the origin is a valid server name
parse_server_name(origin)
parse_and_validate_server_name(origin)
key = strip_quotes(param_dict["key"])
sig = strip_quotes(param_dict["sig"])

View File

@ -12,6 +12,8 @@
# 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
from twisted.internet.endpoints import HostnameEndpoint, wrapClientTLS
from twisted.internet import defer
from twisted.internet.error import ConnectError
@ -41,8 +43,6 @@ _Server = collections.namedtuple(
def parse_server_name(server_name):
"""Split a server name into host/port parts.
Does some basic sanity checking of the
Args:
server_name (str): server name to parse
@ -55,9 +55,6 @@ def parse_server_name(server_name):
try:
if server_name[-1] == ']':
# ipv6 literal, hopefully
if server_name[0] != '[':
raise Exception()
return server_name, None
domain_port = server_name.rsplit(":", 1)
@ -68,6 +65,46 @@ def parse_server_name(server_name):
raise ValueError("Invalid server name '%s'" % server_name)
VALID_HOST_REGEX = re.compile(
"\\A[0-9a-zA-Z.-]+\\Z",
)
def parse_and_validate_server_name(server_name):
"""Split a server name into host/port parts and do some basic validation.
Args:
server_name (str): server name to parse
Returns:
Tuple[str, int|None]: host/port parts.
Raises:
ValueError if the server name could not be parsed.
"""
host, port = parse_server_name(server_name)
# these tests don't need to be bulletproof as we'll find out soon enough
# if somebody is giving us invalid data. What we *do* need is to be sure
# that nobody is sneaking IP literals in that look like hostnames, etc.
# look for ipv6 literals
if host[0] == '[':
if host[-1] != ']':
raise ValueError("Mismatched [...] in server name '%s'" % (
server_name,
))
return host, port
# otherwise it should only be alphanumerics.
if not VALID_HOST_REGEX.match(host):
raise ValueError("Server name '%s' contains invalid characters" % (
server_name,
))
return host, port
def matrix_federation_endpoint(reactor, destination, ssl_context_factory=None,
timeout=None):
"""Construct an endpoint for the given matrix destination.

View File

@ -12,7 +12,10 @@
# 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.
from synapse.http.endpoint import parse_server_name
from synapse.http.endpoint import (
parse_server_name,
parse_and_validate_server_name,
)
from tests import unittest
@ -30,17 +33,23 @@ class ServerNameTestCase(unittest.TestCase):
for i, o in test_data.items():
self.assertEqual(parse_server_name(i), o)
def test_parse_bad_server_names(self):
def test_validate_bad_server_names(self):
test_data = [
"", # empty
"localhost:http", # non-numeric port
"1234]", # smells like ipv6 literal but isn't
"[1234",
"underscore_.com",
"percent%65.com",
"1234:5678:80", # too many colons
]
for i in test_data:
try:
parse_server_name(i)
parse_and_validate_server_name(i)
self.fail(
"Expected parse_server_name(\"%s\") to throw" % i,
"Expected parse_and_validate_server_name('%s') to throw" % (
i,
),
)
except ValueError:
pass