1 files changed, 133 insertions, 0 deletions
diff --git a/synapse/config/key.py b/synapse/config/key.py
new file mode 100644
index 0000000000..0494c0cb77
--- /dev/null
+++ b/synapse/config/key.py
@@ -0,0 +1,133 @@
+# -*- 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
+from synapse.util.stringutils import random_string
+
+
+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"]
+        )
+
+    def default_config(self, config_dir_path, server_name):
+        base_key_name = os.path.join(config_dir_path, server_name)
+        return """\
+        ## 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 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_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 os.path.exists(signing_key_path):
+            with open(signing_key_path, "w") as signing_key_file:
+                key_id = "a_" + random_string(4)
+                syutil.crypto.signing_key.write_signing_keys(
+                    signing_key_file,
+                    (syutil.crypto.signing_key.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 = syutil.crypto.signing_key.decode_signing_key_base64(
+                    syutil.crypto.signing_key.NACL_ED25519,
+                    key_id,
+                    signing_keys.split("\n")[0]
+                )
+                with open(signing_key_path, "w") as signing_key_file:
+                    syutil.crypto.signing_key.write_signing_keys(
+                        signing_key_file,
+                        (key,),
+                    )