MatrixSynapse/synapse/config/key.py

184 lines
7.0 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2015, 2016 OpenMarket 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 hashlib
import logging
import os
from signedjson.key import (
NACL_ED25519,
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.util.stringutils import random_string, random_string_with_symbols
from ._base import Config, ConfigError
logger = logging.getLogger(__name__)
class KeyConfig(Config):
def read_config(self, config):
self.signing_key = self.read_signing_key(config["signing_key_path"])
self.old_signing_keys = self.read_old_signing_keys(
config["old_signing_keys"]
)
self.key_refresh_interval = self.parse_duration(
config["key_refresh_interval"]
)
self.perspectives = self.read_perspectives(
config["perspectives"]
)
self.macaroon_secret_key = config.get(
"macaroon_secret_key", self.registration_shared_secret
)
if not self.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.warn("Config is missing missing macaroon_secret_key")
seed = self.signing_key[0].seed
self.macaroon_secret_key = hashlib.sha256(seed)
self.expire_access_token = config.get("expire_access_token", False)
# 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 default_config(self, config_dir_path, server_name, generate_secrets=False,
**kwargs):
base_key_name = os.path.join(config_dir_path, server_name)
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)
else:
macaroon_secret_key = "# macaroon_secret_key: <PRIVATE STRING>"
form_secret = "# form_secret: <PRIVATE STRING>"
return """\
# a secret which is used to sign access tokens. If none is specified,
# the registration_shared_secret is used, if one is given; otherwise,
# a secret key is derived from the signing key.
#
# Note that changing this will invalidate any active access tokens, so
# all clients will have to log back in.
%(macaroon_secret_key)s
# Used to enable access token expiration.
expire_access_token: False
# a secret which is used to calculate HMACs for form values, to stop
# falsification of values. Must be specified for the User Consent
# forms to work.
%(form_secret)s
## Signing Keys ##
# Path to the signing key to sign messages with
signing_key_path: "%(base_key_name)s.signing.key"
# The keys that the server used to sign messages with but won't use
# to sign new messages. E.g. it has lost its private key
old_signing_keys: {}
# "ed25519:auto":
# # Base64 encoded public key
# key: "The public part of your old signing key."
# # Millisecond POSIX timestamp when the key expired.
# expired_ts: 123456789123
# How long key response published by this server is valid for.
# Used to set the valid_until_ts in /key/v2 APIs.
# Determines how quickly servers will query to check which keys
# are still valid.
key_refresh_interval: "1d" # 1 Day.
# The trusted servers to download signing keys from.
perspectives:
servers:
"matrix.org":
verify_keys:
"ed25519:auto":
key: "Noi6WqcDj0QmPxCNQqgezwTlBKrfqehY1u2FyWP9uYw"
""" % locals()
def read_perspectives(self, perspectives_config):
servers = {}
for server_name, server_config in perspectives_config["servers"].items():
for key_id, key_data in server_config["verify_keys"].items():
if is_signing_algorithm_supported(key_id):
key_base64 = key_data["key"]
key_bytes = decode_base64(key_base64)
verify_key = decode_verify_key_bytes(key_id, key_bytes)
servers.setdefault(server_name, {})[key_id] = verify_key
return servers
def read_signing_key(self, signing_key_path):
signing_keys = self.read_file(signing_key_path, "signing_key")
try:
return read_signing_keys(signing_keys.splitlines(True))
except Exception as e:
raise ConfigError(
"Error reading signing_key: %s" % (str(e))
)
def read_old_signing_keys(self, old_signing_keys):
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 = decode_verify_key_bytes(key_id, key_bytes)
verify_key.expired_ts = 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):
signing_key_path = config["signing_key_path"]
if not self.path_exists(signing_key_path):
with open(signing_key_path, "w") 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") as signing_key_file:
write_signing_keys(
signing_key_file, (key,),
)