diff options
| -rw-r--r-- | changelog.d/9240.misc | 1 | ||||
| -rw-r--r-- | docs/sample_config.yaml | 8 | ||||
| -rw-r--r-- | synapse/config/repository.py | 19 | ||||
| -rw-r--r-- | synapse/config/server.py | 99 | ||||
| -rw-r--r-- | tests/config/test_server.py | 61 |
5 files changed, 160 insertions, 28 deletions
diff --git a/changelog.d/9240.misc b/changelog.d/9240.misc new file mode 100644 index 0000000000..850201f6cd --- /dev/null +++ b/changelog.d/9240.misc @@ -0,0 +1 @@ +Deny access to additional IP addresses by default. diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml index 6d265d2972..0e323846fa 100644 --- a/docs/sample_config.yaml +++ b/docs/sample_config.yaml @@ -169,6 +169,7 @@ pid_file: DATADIR/homeserver.pid # - '100.64.0.0/10' # - '192.0.0.0/24' # - '169.254.0.0/16' +# - '192.88.99.0/24' # - '198.18.0.0/15' # - '192.0.2.0/24' # - '198.51.100.0/24' @@ -177,6 +178,9 @@ pid_file: DATADIR/homeserver.pid # - '::1/128' # - 'fe80::/10' # - 'fc00::/7' +# - '2001:db8::/32' +# - 'ff00::/8' +# - 'fec0::/10' # List of IP address CIDR ranges that should be allowed for federation, # identity servers, push servers, and for checking key validity for @@ -994,6 +998,7 @@ media_store_path: "DATADIR/media_store" # - '100.64.0.0/10' # - '192.0.0.0/24' # - '169.254.0.0/16' +# - '192.88.99.0/24' # - '198.18.0.0/15' # - '192.0.2.0/24' # - '198.51.100.0/24' @@ -1002,6 +1007,9 @@ media_store_path: "DATADIR/media_store" # - '::1/128' # - 'fe80::/10' # - 'fc00::/7' +# - '2001:db8::/32' +# - 'ff00::/8' +# - 'fec0::/10' # List of IP address CIDR ranges that the URL preview spider is allowed # to access even if they are specified in url_preview_ip_range_blacklist. diff --git a/synapse/config/repository.py b/synapse/config/repository.py index 850ac3ebd6..fcaea8fb93 100644 --- a/synapse/config/repository.py +++ b/synapse/config/repository.py @@ -17,9 +17,7 @@ import os from collections import namedtuple from typing import Dict, List -from netaddr import IPSet - -from synapse.config.server import DEFAULT_IP_RANGE_BLACKLIST +from synapse.config.server import DEFAULT_IP_RANGE_BLACKLIST, generate_ip_set from synapse.python_dependencies import DependencyException, check_requirements from synapse.util.module_loader import load_module @@ -187,16 +185,17 @@ class ContentRepositoryConfig(Config): "to work" ) - self.url_preview_ip_range_blacklist = IPSet( - config["url_preview_ip_range_blacklist"] - ) - # we always blacklist '0.0.0.0' and '::', which are supposed to be # unroutable addresses. - self.url_preview_ip_range_blacklist.update(["0.0.0.0", "::"]) + self.url_preview_ip_range_blacklist = generate_ip_set( + config["url_preview_ip_range_blacklist"], + ["0.0.0.0", "::"], + config_path=("url_preview_ip_range_blacklist",), + ) - self.url_preview_ip_range_whitelist = IPSet( - config.get("url_preview_ip_range_whitelist", ()) + self.url_preview_ip_range_whitelist = generate_ip_set( + config.get("url_preview_ip_range_whitelist", ()), + config_path=("url_preview_ip_range_whitelist",), ) self.url_preview_url_blacklist = config.get("url_preview_url_blacklist", ()) diff --git a/synapse/config/server.py b/synapse/config/server.py index 47a0370173..b5e82ba3d0 100644 --- a/synapse/config/server.py +++ b/synapse/config/server.py @@ -15,6 +15,7 @@ # See the License for the specific language governing permissions and # limitations under the License. +import itertools import logging import os.path import re @@ -23,7 +24,7 @@ from typing import Any, Dict, Iterable, List, Optional, Set import attr import yaml -from netaddr import IPSet +from netaddr import AddrFormatError, IPNetwork, IPSet from synapse.api.room_versions import KNOWN_ROOM_VERSIONS from synapse.util.stringutils import parse_and_validate_server_name @@ -40,6 +41,66 @@ logger = logging.Logger(__name__) # in the list. DEFAULT_BIND_ADDRESSES = ["::", "0.0.0.0"] + +def _6to4(network: IPNetwork) -> IPNetwork: + """Convert an IPv4 network into a 6to4 IPv6 network per RFC 3056.""" + + # 6to4 networks consist of: + # * 2002 as the first 16 bits + # * The first IPv4 address in the network hex-encoded as the next 32 bits + # * The new prefix length needs to include the bits from the 2002 prefix. + hex_network = hex(network.first)[2:] + hex_network = ("0" * (8 - len(hex_network))) + hex_network + return IPNetwork( + "2002:%s:%s::/%d" % (hex_network[:4], hex_network[4:], 16 + network.prefixlen,) + ) + + +def generate_ip_set( + ip_addresses: Optional[Iterable[str]], + extra_addresses: Optional[Iterable[str]] = None, + config_path: Optional[Iterable[str]] = None, +) -> IPSet: + """ + Generate an IPSet from a list of IP addresses or CIDRs. + + Additionally, for each IPv4 network in the list of IP addresses, also + includes the corresponding IPv6 networks. + + This includes: + + * IPv4-Compatible IPv6 Address (see RFC 4291, section 2.5.5.1) + * IPv4-Mapped IPv6 Address (see RFC 4291, section 2.5.5.2) + * 6to4 Address (see RFC 3056, section 2) + + Args: + ip_addresses: An iterable of IP addresses or CIDRs. + extra_addresses: An iterable of IP addresses or CIDRs. + config_path: The path in the configuration for error messages. + + Returns: + A new IP set. + """ + result = IPSet() + for ip in itertools.chain(ip_addresses or (), extra_addresses or ()): + try: + network = IPNetwork(ip) + except AddrFormatError as e: + raise ConfigError( + "Invalid IP range provided: %s." % (ip,), config_path + ) from e + result.add(network) + + # It is possible that these already exist in the set, but that's OK. + if ":" not in str(network): + result.add(IPNetwork(network).ipv6(ipv4_compatible=True)) + result.add(IPNetwork(network).ipv6(ipv4_compatible=False)) + result.add(_6to4(network)) + + return result + + +# IP ranges that are considered private / unroutable / don't make sense. DEFAULT_IP_RANGE_BLACKLIST = [ # Localhost "127.0.0.0/8", @@ -53,6 +114,8 @@ DEFAULT_IP_RANGE_BLACKLIST = [ "192.0.0.0/24", # Link-local networks. "169.254.0.0/16", + # Formerly used for 6to4 relay. + "192.88.99.0/24", # Testing networks. "198.18.0.0/15", "192.0.2.0/24", @@ -66,6 +129,12 @@ DEFAULT_IP_RANGE_BLACKLIST = [ "fe80::/10", # Unique local addresses. "fc00::/7", + # Testing networks. + "2001:db8::/32", + # Multicast. + "ff00::/8", + # Site-local addresses + "fec0::/10", ] DEFAULT_ROOM_VERSION = "6" @@ -294,17 +363,15 @@ class ServerConfig(Config): ) # Attempt to create an IPSet from the given ranges - try: - self.ip_range_blacklist = IPSet(ip_range_blacklist) - except Exception as e: - raise ConfigError("Invalid range(s) provided in ip_range_blacklist.") from e + # Always blacklist 0.0.0.0, :: - self.ip_range_blacklist.update(["0.0.0.0", "::"]) + self.ip_range_blacklist = generate_ip_set( + ip_range_blacklist, ["0.0.0.0", "::"], config_path=("ip_range_blacklist",) + ) - try: - self.ip_range_whitelist = IPSet(config.get("ip_range_whitelist", ())) - except Exception as e: - raise ConfigError("Invalid range(s) provided in ip_range_whitelist.") from e + self.ip_range_whitelist = generate_ip_set( + config.get("ip_range_whitelist", ()), config_path=("ip_range_whitelist",) + ) # The federation_ip_range_blacklist is used for backwards-compatibility # and only applies to federation and identity servers. If it is not given, @@ -312,14 +379,12 @@ class ServerConfig(Config): federation_ip_range_blacklist = config.get( "federation_ip_range_blacklist", ip_range_blacklist ) - try: - self.federation_ip_range_blacklist = IPSet(federation_ip_range_blacklist) - except Exception as e: - raise ConfigError( - "Invalid range(s) provided in federation_ip_range_blacklist." - ) from e # Always blacklist 0.0.0.0, :: - self.federation_ip_range_blacklist.update(["0.0.0.0", "::"]) + self.federation_ip_range_blacklist = generate_ip_set( + federation_ip_range_blacklist, + ["0.0.0.0", "::"], + config_path=("federation_ip_range_blacklist",), + ) self.start_pushers = config.get("start_pushers", True) diff --git a/tests/config/test_server.py b/tests/config/test_server.py index a10d017120..98af7aa675 100644 --- a/tests/config/test_server.py +++ b/tests/config/test_server.py @@ -15,7 +15,8 @@ import yaml -from synapse.config.server import ServerConfig, is_threepid_reserved +from synapse.config._base import ConfigError +from synapse.config.server import ServerConfig, generate_ip_set, is_threepid_reserved from tests import unittest @@ -128,3 +129,61 @@ class ServerConfigTestCase(unittest.TestCase): ) self.assertEqual(conf["listeners"], expected_listeners) + + +class GenerateIpSetTestCase(unittest.TestCase): + def test_empty(self): + ip_set = generate_ip_set(()) + self.assertFalse(ip_set) + + ip_set = generate_ip_set((), ()) + self.assertFalse(ip_set) + + def test_generate(self): + """Check adding IPv4 and IPv6 addresses.""" + # IPv4 address + ip_set = generate_ip_set(("1.2.3.4",)) + self.assertEqual(len(ip_set.iter_cidrs()), 4) + + # IPv4 CIDR + ip_set = generate_ip_set(("1.2.3.4/24",)) + self.assertEqual(len(ip_set.iter_cidrs()), 4) + + # IPv6 address + ip_set = generate_ip_set(("2001:db8::8a2e:370:7334",)) + self.assertEqual(len(ip_set.iter_cidrs()), 1) + + # IPv6 CIDR + ip_set = generate_ip_set(("2001:db8::/104",)) + self.assertEqual(len(ip_set.iter_cidrs()), 1) + + # The addresses can overlap OK. + ip_set = generate_ip_set(("1.2.3.4", "::1.2.3.4")) + self.assertEqual(len(ip_set.iter_cidrs()), 4) + + def test_extra(self): + """Extra IP addresses are treated the same.""" + ip_set = generate_ip_set((), ("1.2.3.4",)) + self.assertEqual(len(ip_set.iter_cidrs()), 4) + + ip_set = generate_ip_set(("1.1.1.1",), ("1.2.3.4",)) + self.assertEqual(len(ip_set.iter_cidrs()), 8) + + # They can duplicate without error. + ip_set = generate_ip_set(("1.2.3.4",), ("1.2.3.4",)) + self.assertEqual(len(ip_set.iter_cidrs()), 4) + + def test_bad_value(self): + """An error should be raised if a bad value is passed in.""" + with self.assertRaises(ConfigError): + generate_ip_set(("not-an-ip",)) + + with self.assertRaises(ConfigError): + generate_ip_set(("1.2.3.4/128",)) + + with self.assertRaises(ConfigError): + generate_ip_set((":::",)) + + # The following get treated as empty data. + self.assertFalse(generate_ip_set(None)) + self.assertFalse(generate_ip_set({})) |