Merge pull request #129 from matrix-org/key_distribution

Key distribution v2

4 files changed, 161 insertions, 50 deletions

diff --git a/synapse/config/_base.py b/synapse/config/_base.py
index 6017cb6334..b59f4e45e2 100644
--- a/synapse/config/_base.py
+++ b/synapse/config/_base.py
@@ -77,6 +77,17 @@ class Config(object):
         with open(file_path) as file_stream:
             return file_stream.read()
 
+    @classmethod
+    def read_yaml_file(cls, file_path, config_name):
+        cls.check_file(file_path, config_name)
+        with open(file_path) as file_stream:
+            try:
+                return yaml.load(file_stream)
+            except:
+                raise ConfigError(
+                    "Error parsing yaml in file %r" % (file_path,)
+                )
+
     @staticmethod
     def default_path(name):
         return os.path.abspath(os.path.join(os.path.curdir, name))
diff --git a/synapse/config/homeserver.py b/synapse/config/homeserver.py
index efbdd93c25..1c8ff38465 100644
--- a/synapse/config/homeserver.py
+++ b/synapse/config/homeserver.py
@@ -24,12 +24,13 @@ from .voip import VoipConfig
 from .registration import RegistrationConfig
 from .metrics import MetricsConfig
 from .appservice import AppServiceConfig
+from .key import KeyConfig
 
 
 class HomeServerConfig(TlsConfig, ServerConfig, DatabaseConfig, LoggingConfig,
                        RatelimitConfig, ContentRepositoryConfig, CaptchaConfig,
                        VoipConfig, RegistrationConfig,
-                       MetricsConfig, AppServiceConfig,):
+                       MetricsConfig, AppServiceConfig, KeyConfig,):
     pass
 
 
diff --git a/synapse/config/key.py b/synapse/config/key.py
new file mode 100644
index 0000000000..a2de6d5c17
--- /dev/null
+++ b/synapse/config/key.py
@@ -0,0 +1,147 @@
+# -*- coding: utf-8 -*-
+# Copyright 2015 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 os
+from ._base import Config, ConfigError
+import syutil.crypto.signing_key
+from syutil.crypto.signing_key import (
+    is_signing_algorithm_supported, decode_verify_key_bytes
+)
+from syutil.base64util import decode_base64
+
+
+class KeyConfig(Config):
+
+    def __init__(self, args):
+        super(KeyConfig, self).__init__(args)
+        self.signing_key = self.read_signing_key(args.signing_key_path)
+        self.old_signing_keys = self.read_old_signing_keys(
+            args.old_signing_key_path
+        )
+        self.key_refresh_interval = args.key_refresh_interval
+        self.perspectives = self.read_perspectives(
+            args.perspectives_config_path
+        )
+
+    @classmethod
+    def add_arguments(cls, parser):
+        super(KeyConfig, cls).add_arguments(parser)
+        key_group = parser.add_argument_group("keys")
+        key_group.add_argument("--signing-key-path",
+                               help="The signing key to sign messages with")
+        key_group.add_argument("--old-signing-key-path",
+                               help="The keys that the server used to sign"
+                                    " sign messages with but won't use"
+                                    " to sign new messages. E.g. it has"
+                                    " lost its private key")
+        key_group.add_argument("--key-refresh-interval",
+                               default=24 * 60 * 60 * 1000,  # 1 Day
+                               help="How long a key response is valid for."
+                                    " Used to set the exipiry in /key/v2/."
+                                    " Controls how frequently servers will"
+                                    " query what keys are still valid")
+        key_group.add_argument("--perspectives-config-path",
+                               help="The trusted servers to download signing"
+                                    " keys from")
+
+    def read_perspectives(self, perspectives_config_path):
+        config = self.read_yaml_file(
+            perspectives_config_path, "perspectives_config_path"
+        )
+        servers = {}
+        for server_name, server_config in 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 syutil.crypto.signing_key.read_signing_keys(
+                signing_keys.splitlines(True)
+            )
+        except Exception:
+            raise ConfigError(
+                "Error reading signing_key."
+                " Try running again with --generate-config"
+            )
+
+    def read_old_signing_keys(self, old_signing_key_path):
+        old_signing_keys = self.read_file(
+            old_signing_key_path, "old_signing_key"
+        )
+        try:
+            return syutil.crypto.signing_key.read_old_signing_keys(
+                old_signing_keys.splitlines(True)
+            )
+        except Exception:
+            raise ConfigError(
+                "Error reading old signing keys."
+            )
+
+    @classmethod
+    def generate_config(cls, args, config_dir_path):
+        super(KeyConfig, cls).generate_config(args, config_dir_path)
+        base_key_name = os.path.join(config_dir_path, args.server_name)
+
+        args.pid_file = os.path.abspath(args.pid_file)
+
+        if not args.signing_key_path:
+            args.signing_key_path = base_key_name + ".signing.key"
+
+        if not os.path.exists(args.signing_key_path):
+            with open(args.signing_key_path, "w") as signing_key_file:
+                syutil.crypto.signing_key.write_signing_keys(
+                    signing_key_file,
+                    (syutil.crypto.signing_key.generate_signing_key("auto"),),
+                )
+        else:
+            signing_keys = cls.read_file(args.signing_key_path, "signing_key")
+            if len(signing_keys.split("\n")[0].split()) == 1:
+                # handle keys in the old format.
+                key = syutil.crypto.signing_key.decode_signing_key_base64(
+                    syutil.crypto.signing_key.NACL_ED25519,
+                    "auto",
+                    signing_keys.split("\n")[0]
+                )
+                with open(args.signing_key_path, "w") as signing_key_file:
+                    syutil.crypto.signing_key.write_signing_keys(
+                        signing_key_file,
+                        (key,),
+                    )
+
+        if not args.old_signing_key_path:
+            args.old_signing_key_path = base_key_name + ".old.signing.keys"
+
+        if not os.path.exists(args.old_signing_key_path):
+            with open(args.old_signing_key_path, "w"):
+                pass
+
+        if not args.perspectives_config_path:
+            args.perspectives_config_path = base_key_name + ".perspectives"
+
+        if not os.path.exists(args.perspectives_config_path):
+            with open(args.perspectives_config_path, "w") as perspectives_file:
+                perspectives_file.write(
+                    'servers:\n'
+                    '  matrix.org:\n'
+                    '    verify_keys:\n'
+                    '      "ed25519:auto":\n'
+                    '         key: "Noi6WqcDj0QmPxCNQqgezwTlBKrfqehY1u2FyWP9uYw"\n'
+                )
diff --git a/synapse/config/server.py b/synapse/config/server.py
index d4c223f348..c25feb4c58 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -13,16 +13,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import os
-from ._base import Config, ConfigError
-import syutil.crypto.signing_key
+from ._base import Config
 
 
 class ServerConfig(Config):
     def __init__(self, args):
         super(ServerConfig, self).__init__(args)
         self.server_name = args.server_name
-        self.signing_key = self.read_signing_key(args.signing_key_path)
         self.bind_port = args.bind_port
         self.bind_host = args.bind_host
         self.unsecure_port = args.unsecure_port
@@ -53,8 +50,6 @@ class ServerConfig(Config):
                  "This is used by remote servers to connect to this server, "
                  "e.g. matrix.org, localhost:8080, etc."
         )
-        server_group.add_argument("--signing-key-path",
-                                  help="The signing key to sign messages with")
         server_group.add_argument("-p", "--bind-port", metavar="PORT",
                                   type=int, help="https port to listen on",
                                   default=8448)
@@ -83,46 +78,3 @@ class ServerConfig(Config):
                                        "Zero is used to indicate synapse "
                                        "should set the soft limit to the hard"
                                        "limit.")
-
-    def read_signing_key(self, signing_key_path):
-        signing_keys = self.read_file(signing_key_path, "signing_key")
-        try:
-            return syutil.crypto.signing_key.read_signing_keys(
-                signing_keys.splitlines(True)
-            )
-        except Exception:
-            raise ConfigError(
-                "Error reading signing_key."
-                " Try running again with --generate-config"
-            )
-
-    @classmethod
-    def generate_config(cls, args, config_dir_path):
-        super(ServerConfig, cls).generate_config(args, config_dir_path)
-        base_key_name = os.path.join(config_dir_path, args.server_name)
-
-        args.pid_file = os.path.abspath(args.pid_file)
-
-        if not args.signing_key_path:
-            args.signing_key_path = base_key_name + ".signing.key"
-
-        if not os.path.exists(args.signing_key_path):
-            with open(args.signing_key_path, "w") as signing_key_file:
-                syutil.crypto.signing_key.write_signing_keys(
-                    signing_key_file,
-                    (syutil.crypto.signing_key.generate_signing_key("auto"),),
-                )
-        else:
-            signing_keys = cls.read_file(args.signing_key_path, "signing_key")
-            if len(signing_keys.split("\n")[0].split()) == 1:
-                # handle keys in the old format.
-                key = syutil.crypto.signing_key.decode_signing_key_base64(
-                    syutil.crypto.signing_key.NACL_ED25519,
-                    "auto",
-                    signing_keys.split("\n")[0]
-                )
-                with open(args.signing_key_path, "w") as signing_key_file:
-                    syutil.crypto.signing_key.write_signing_keys(
-                        signing_key_file,
-                        (key,),
-                    )