mirror of
https://mau.dev/maunium/synapse.git
synced 2024-10-01 01:36:05 -04:00
400 lines
15 KiB
Python
400 lines
15 KiB
Python
# Copyright 2015, 2016 OpenMarket Ltd
|
|
# Copyright 2019 The Matrix.org Foundation C.I.C.
|
|
#
|
|
# 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 hashlib
|
|
import logging
|
|
import os
|
|
from typing import TYPE_CHECKING, Any, Dict, Iterator, List, Optional
|
|
|
|
import attr
|
|
import jsonschema
|
|
from signedjson.key import (
|
|
NACL_ED25519,
|
|
SigningKey,
|
|
VerifyKey,
|
|
decode_signing_key_base64,
|
|
decode_verify_key_bytes,
|
|
generate_signing_key,
|
|
is_signing_algorithm_supported,
|
|
read_signing_keys,
|
|
write_signing_keys,
|
|
)
|
|
from unpaddedbase64 import decode_base64
|
|
|
|
from synapse.types import JsonDict
|
|
from synapse.util.stringutils import random_string, random_string_with_symbols
|
|
|
|
from ._base import Config, ConfigError
|
|
|
|
if TYPE_CHECKING:
|
|
from signedjson.key import VerifyKeyWithExpiry
|
|
|
|
INSECURE_NOTARY_ERROR = """\
|
|
Your server is configured to accept key server responses without signature
|
|
validation or TLS certificate validation. This is likely to be very insecure. If
|
|
you are *sure* you want to do this, set 'accept_keys_insecurely' on the
|
|
keyserver configuration."""
|
|
|
|
RELYING_ON_MATRIX_KEY_ERROR = """\
|
|
Your server is configured to accept key server responses without TLS certificate
|
|
validation, and which are only signed by the old (possibly compromised)
|
|
matrix.org signing key 'ed25519:auto'. This likely isn't what you want to do,
|
|
and you should enable 'federation_verify_certificates' in your configuration.
|
|
|
|
If you are *sure* you want to do this, set 'accept_keys_insecurely' on the
|
|
trusted_key_server configuration."""
|
|
|
|
TRUSTED_KEY_SERVER_NOT_CONFIGURED_WARN = """\
|
|
Synapse requires that a list of trusted key servers are specified in order to
|
|
provide signing keys for other servers in the federation.
|
|
|
|
This homeserver does not have a trusted key server configured in
|
|
homeserver.yaml and will fall back to the default of 'matrix.org'.
|
|
|
|
Trusted key servers should be long-lived and stable which makes matrix.org a
|
|
good choice for many admins, but some admins may wish to choose another. To
|
|
suppress this warning, the admin should set 'trusted_key_servers' in
|
|
homeserver.yaml to their desired key server and 'suppress_key_server_warning'
|
|
to 'true'.
|
|
|
|
In a future release the software-defined default will be removed entirely and
|
|
the trusted key server will be defined exclusively by the value of
|
|
'trusted_key_servers'.
|
|
--------------------------------------------------------------------------------"""
|
|
|
|
TRUSTED_KEY_SERVER_CONFIGURED_AS_M_ORG_WARN = """\
|
|
This server is configured to use 'matrix.org' as its trusted key server via the
|
|
'trusted_key_servers' config option. 'matrix.org' is a good choice for a key
|
|
server since it is long-lived, stable and trusted. However, some admins may
|
|
wish to use another server for this purpose.
|
|
|
|
To suppress this warning and continue using 'matrix.org', admins should set
|
|
'suppress_key_server_warning' to 'true' in homeserver.yaml.
|
|
--------------------------------------------------------------------------------"""
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
|
|
@attr.s(slots=True, auto_attribs=True)
|
|
class TrustedKeyServer:
|
|
# name of the server.
|
|
server_name: str
|
|
|
|
# map from key id to key object, or None to disable signature verification.
|
|
verify_keys: Optional[Dict[str, VerifyKey]] = None
|
|
|
|
|
|
class KeyConfig(Config):
|
|
section = "key"
|
|
|
|
def read_config(
|
|
self, config: JsonDict, config_dir_path: str, **kwargs: Any
|
|
) -> None:
|
|
# the signing key can be specified inline or in a separate file
|
|
if "signing_key" in config:
|
|
self.signing_key = read_signing_keys([config["signing_key"]])
|
|
else:
|
|
assert config_dir_path is not None
|
|
signing_key_path = config.get("signing_key_path")
|
|
if signing_key_path is None:
|
|
signing_key_path = os.path.join(
|
|
config_dir_path, config["server_name"] + ".signing.key"
|
|
)
|
|
|
|
self.signing_key = self.read_signing_keys(signing_key_path, "signing_key")
|
|
|
|
self.old_signing_keys = self.read_old_signing_keys(
|
|
config.get("old_signing_keys")
|
|
)
|
|
self.key_refresh_interval = self.parse_duration(
|
|
config.get("key_refresh_interval", "1d")
|
|
)
|
|
|
|
suppress_key_server_warning = config.get("suppress_key_server_warning", False)
|
|
key_server_signing_keys_path = config.get("key_server_signing_keys_path")
|
|
if key_server_signing_keys_path:
|
|
self.key_server_signing_keys = self.read_signing_keys(
|
|
key_server_signing_keys_path, "key_server_signing_keys_path"
|
|
)
|
|
else:
|
|
self.key_server_signing_keys = list(self.signing_key)
|
|
|
|
# if neither trusted_key_servers nor perspectives are given, use the default.
|
|
if "perspectives" not in config and "trusted_key_servers" not in config:
|
|
logger.warning(TRUSTED_KEY_SERVER_NOT_CONFIGURED_WARN)
|
|
key_servers = [{"server_name": "matrix.org"}]
|
|
else:
|
|
key_servers = config.get("trusted_key_servers", [])
|
|
|
|
if not isinstance(key_servers, list):
|
|
raise ConfigError(
|
|
"trusted_key_servers, if given, must be a list, not a %s"
|
|
% (type(key_servers).__name__,)
|
|
)
|
|
|
|
# merge the 'perspectives' config into the 'trusted_key_servers' config.
|
|
key_servers.extend(_perspectives_to_key_servers(config))
|
|
|
|
if not suppress_key_server_warning and "matrix.org" in (
|
|
s["server_name"] for s in key_servers
|
|
):
|
|
logger.warning(TRUSTED_KEY_SERVER_CONFIGURED_AS_M_ORG_WARN)
|
|
|
|
# list of TrustedKeyServer objects
|
|
self.key_servers = list(
|
|
_parse_key_servers(
|
|
key_servers, self.root.tls.federation_verify_certificates
|
|
)
|
|
)
|
|
|
|
macaroon_secret_key: Optional[str] = config.get(
|
|
"macaroon_secret_key", self.root.registration.registration_shared_secret
|
|
)
|
|
|
|
if not macaroon_secret_key:
|
|
# Unfortunately, there are people out there that don't have this
|
|
# set. Lets just be "nice" and derive one from their secret key.
|
|
logger.warning("Config is missing macaroon_secret_key")
|
|
seed = bytes(self.signing_key[0])
|
|
self.macaroon_secret_key = hashlib.sha256(seed).digest()
|
|
else:
|
|
self.macaroon_secret_key = macaroon_secret_key.encode("utf-8")
|
|
|
|
# a secret which is used to calculate HMACs for form values, to stop
|
|
# falsification of values
|
|
self.form_secret = config.get("form_secret", None)
|
|
|
|
def generate_config_section(
|
|
self,
|
|
config_dir_path: str,
|
|
server_name: str,
|
|
generate_secrets: bool = False,
|
|
**kwargs: Any,
|
|
) -> str:
|
|
base_key_name = os.path.join(config_dir_path, server_name)
|
|
macaroon_secret_key = ""
|
|
form_secret = ""
|
|
|
|
if generate_secrets:
|
|
macaroon_secret_key = 'macaroon_secret_key: "%s"' % (
|
|
random_string_with_symbols(50),
|
|
)
|
|
form_secret = 'form_secret: "%s"' % random_string_with_symbols(50)
|
|
|
|
return (
|
|
"""\
|
|
%(macaroon_secret_key)s
|
|
%(form_secret)s
|
|
signing_key_path: "%(base_key_name)s.signing.key"
|
|
trusted_key_servers:
|
|
- server_name: "matrix.org"
|
|
"""
|
|
% locals()
|
|
)
|
|
|
|
def read_signing_keys(self, signing_key_path: str, name: str) -> List[SigningKey]:
|
|
"""Read the signing keys in the given path.
|
|
|
|
Args:
|
|
signing_key_path
|
|
name: Associated config key name
|
|
|
|
Returns:
|
|
The signing keys read from the given path.
|
|
"""
|
|
|
|
signing_keys = self.read_file(signing_key_path, name)
|
|
try:
|
|
loaded_signing_keys = read_signing_keys(
|
|
[
|
|
signing_key_line
|
|
for signing_key_line in signing_keys.splitlines(keepends=False)
|
|
if signing_key_line.strip()
|
|
]
|
|
)
|
|
|
|
if not loaded_signing_keys:
|
|
raise ConfigError(f"No signing keys in file {signing_key_path}")
|
|
|
|
return loaded_signing_keys
|
|
except Exception as e:
|
|
raise ConfigError("Error reading %s: %s" % (name, str(e)))
|
|
|
|
def read_old_signing_keys(
|
|
self, old_signing_keys: Optional[JsonDict]
|
|
) -> Dict[str, "VerifyKeyWithExpiry"]:
|
|
if old_signing_keys is None:
|
|
return {}
|
|
keys = {}
|
|
for key_id, key_data in old_signing_keys.items():
|
|
if is_signing_algorithm_supported(key_id):
|
|
key_base64 = key_data["key"]
|
|
key_bytes = decode_base64(key_base64)
|
|
verify_key: "VerifyKeyWithExpiry" = decode_verify_key_bytes(key_id, key_bytes) # type: ignore[assignment]
|
|
verify_key.expired = key_data["expired_ts"]
|
|
keys[key_id] = verify_key
|
|
else:
|
|
raise ConfigError(
|
|
"Unsupported signing algorithm for old key: %r" % (key_id,)
|
|
)
|
|
return keys
|
|
|
|
def generate_files(self, config: Dict[str, Any], config_dir_path: str) -> None:
|
|
if "signing_key" in config:
|
|
return
|
|
|
|
signing_key_path = config.get("signing_key_path")
|
|
if signing_key_path is None:
|
|
signing_key_path = os.path.join(
|
|
config_dir_path, config["server_name"] + ".signing.key"
|
|
)
|
|
|
|
if not self.path_exists(signing_key_path):
|
|
print("Generating signing key file %s" % (signing_key_path,))
|
|
with open(
|
|
signing_key_path, "w", opener=lambda p, f: os.open(p, f, mode=0o640)
|
|
) as signing_key_file:
|
|
key_id = "a_" + random_string(4)
|
|
write_signing_keys(signing_key_file, (generate_signing_key(key_id),))
|
|
else:
|
|
signing_keys = self.read_file(signing_key_path, "signing_key")
|
|
if len(signing_keys.split("\n")[0].split()) == 1:
|
|
# handle keys in the old format.
|
|
key_id = "a_" + random_string(4)
|
|
key = decode_signing_key_base64(
|
|
NACL_ED25519, key_id, signing_keys.split("\n")[0]
|
|
)
|
|
with open(
|
|
signing_key_path, "w", opener=lambda p, f: os.open(p, f, mode=0o640)
|
|
) as signing_key_file:
|
|
write_signing_keys(signing_key_file, (key,))
|
|
|
|
|
|
def _perspectives_to_key_servers(config: JsonDict) -> Iterator[JsonDict]:
|
|
"""Convert old-style 'perspectives' configs into new-style 'trusted_key_servers'
|
|
|
|
Returns an iterable of entries to add to trusted_key_servers.
|
|
"""
|
|
|
|
# 'perspectives' looks like:
|
|
#
|
|
# {
|
|
# "servers": {
|
|
# "matrix.org": {
|
|
# "verify_keys": {
|
|
# "ed25519:auto": {
|
|
# "key": "Noi6WqcDj0QmPxCNQqgezwTlBKrfqehY1u2FyWP9uYw"
|
|
# }
|
|
# }
|
|
# }
|
|
# }
|
|
# }
|
|
#
|
|
# 'trusted_keys' looks like:
|
|
#
|
|
# [
|
|
# {
|
|
# "server_name": "matrix.org",
|
|
# "verify_keys": {
|
|
# "ed25519:auto": "Noi6WqcDj0QmPxCNQqgezwTlBKrfqehY1u2FyWP9uYw",
|
|
# }
|
|
# }
|
|
# ]
|
|
|
|
perspectives_servers = config.get("perspectives", {}).get("servers", {})
|
|
|
|
for server_name, server_opts in perspectives_servers.items():
|
|
trusted_key_server_entry = {"server_name": server_name}
|
|
verify_keys = server_opts.get("verify_keys")
|
|
if verify_keys is not None:
|
|
trusted_key_server_entry["verify_keys"] = {
|
|
key_id: key_data["key"] for key_id, key_data in verify_keys.items()
|
|
}
|
|
yield trusted_key_server_entry
|
|
|
|
|
|
TRUSTED_KEY_SERVERS_SCHEMA = {
|
|
"$schema": "http://json-schema.org/draft-04/schema#",
|
|
"description": "schema for the trusted_key_servers setting",
|
|
"type": "array",
|
|
"items": {
|
|
"type": "object",
|
|
"properties": {
|
|
"server_name": {"type": "string"},
|
|
"verify_keys": {
|
|
"type": "object",
|
|
# each key must be a base64 string
|
|
"additionalProperties": {"type": "string"},
|
|
},
|
|
},
|
|
"required": ["server_name"],
|
|
},
|
|
}
|
|
|
|
|
|
def _parse_key_servers(
|
|
key_servers: List[Any], federation_verify_certificates: bool
|
|
) -> Iterator[TrustedKeyServer]:
|
|
try:
|
|
jsonschema.validate(key_servers, TRUSTED_KEY_SERVERS_SCHEMA)
|
|
except jsonschema.ValidationError as e:
|
|
raise ConfigError(
|
|
"Unable to parse 'trusted_key_servers': {}".format(
|
|
e.message # noqa: B306, jsonschema.ValidationError.message is a valid attribute
|
|
)
|
|
)
|
|
|
|
for server in key_servers:
|
|
server_name = server["server_name"]
|
|
result = TrustedKeyServer(server_name=server_name)
|
|
|
|
verify_keys: Optional[Dict[str, str]] = server.get("verify_keys")
|
|
if verify_keys is not None:
|
|
result.verify_keys = {}
|
|
for key_id, key_base64 in verify_keys.items():
|
|
if not is_signing_algorithm_supported(key_id):
|
|
raise ConfigError(
|
|
"Unsupported signing algorithm on key %s for server %s in "
|
|
"trusted_key_servers" % (key_id, server_name)
|
|
)
|
|
try:
|
|
key_bytes = decode_base64(key_base64)
|
|
verify_key = decode_verify_key_bytes(key_id, key_bytes)
|
|
except Exception as e:
|
|
raise ConfigError(
|
|
"Unable to parse key %s for server %s in "
|
|
"trusted_key_servers: %s" % (key_id, server_name, e)
|
|
)
|
|
|
|
result.verify_keys[key_id] = verify_key
|
|
|
|
if not federation_verify_certificates and not server.get(
|
|
"accept_keys_insecurely"
|
|
):
|
|
_assert_keyserver_has_verify_keys(result)
|
|
|
|
yield result
|
|
|
|
|
|
def _assert_keyserver_has_verify_keys(trusted_key_server: TrustedKeyServer) -> None:
|
|
if not trusted_key_server.verify_keys:
|
|
raise ConfigError(INSECURE_NOTARY_ERROR)
|
|
|
|
# also check that they are not blindly checking the old matrix.org key
|
|
if trusted_key_server.server_name == "matrix.org" and any(
|
|
key_id == "ed25519:auto" for key_id in trusted_key_server.verify_keys
|
|
):
|
|
raise ConfigError(RELYING_ON_MATRIX_KEY_ERROR)
|