Move the configuration file handling code into a separate module

sydent/config/__init__.py

@@ -14,6 +14,7 @@
 
 from configparser import ConfigParser
 
+from sydent.config.crypto import CryptoConfig
 from sydent.config.database import DatabaseConfig
 
 
@@ -29,8 +30,12 @@ class SydentConfig:
 
     def __init__(self):
         self.database = DatabaseConfig()
+        self.crypto = CryptoConfig()
 
-        self.config_sections = [self.database]
+        self.config_sections = [
+            self.database,
+            self.crypto,
+        ]
 
     def _parse_config(self, cfg: ConfigParser) -> None:
         """
@@ -42,10 +47,17 @@ def _parse_config(self, cfg: ConfigParser) -> None:
         for section in self.config_sections:
             section.parse_config(cfg)
 
-    def parse_from_config_parser(self, cfg: ConfigParser) -> None:
+    def parse_from_config_parser(self, cfg: ConfigParser) -> bool:
         """
         Parse the configuration from a ConfigParser object
 
         :param cfg: the configuration to be parsed
+        ...
+        :return: Whether or not cfg has been changed and needs saving
         """
         self._parse_config(cfg)
+
+        # TODO: Don't alter config file when starting Sydent unless
+        #       user has asked for this specifially (e.g. on first
+        #       run only, or when specify --generate-config)
+        return self.crypto.save_key

sydent/sign/ed25519.py → sydent/config/crypto.py

@@ -1,4 +1,4 @@
-# Copyright 2014 OpenMarket Ltd
+# Copyright 2021 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.
@@ -12,53 +12,60 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+
 import logging
+from typing import TYPE_CHECKING
 
-import nacl.encoding
-import nacl.exceptions
-import nacl.signing
+import nacl
 import signedjson.key
 
+if TYPE_CHECKING:
+    from configparser import ConfigParser
+
 logger = logging.getLogger(__name__)
 
 
-class SydentEd25519:
-    def __init__(self, syd):
-        self.sydent = syd
+class CryptoConfig:
+    def parse_config(self, cfg: "ConfigParser") -> None:
+        """
+        Parse the crypto section of the config
+        :param cfg: the configuration to be parsed
+        """
 
-        save_key = False
+        signing_key_str = cfg.get("crypto", "ed25519.signingkey")
+        signing_key_parts = signing_key_str.split(" ")
 
-        sk_str = self.sydent.cfg.get("crypto", "ed25519.signingkey")
-        sk_parts = sk_str.split(" ")
+        self.save_key = False
 
-        if sk_str == "":
+        if signing_key_str == "":
             logger.info(
                 "This server does not yet have an ed25519 signing key. "
-                + "Creating one and saving it in the config file."
+                "Creating one and saving it in the config file."
             )
+
             self.signing_key = signedjson.key.generate_signing_key("0")
-            save_key = True
-        elif len(sk_parts) == 1:
+
+            self.save_key = True
+        elif len(signing_key_parts) == 1:
             # old format key
             logger.info("Updating signing key format: brace yourselves")
+
             self.signing_key = nacl.signing.SigningKey(
-                sk_str, encoder=nacl.encoding.HexEncoder
+                signing_key_str, encoder=nacl.encoding.HexEncoder
             )
             self.signing_key.version = "0"
             self.signing_key.alg = signedjson.key.NACL_ED25519
 
-            save_key = True
+            self.save_key = True
         else:
             self.signing_key = signedjson.key.decode_signing_key_base64(
-                sk_parts[0], sk_parts[1], sk_parts[2]
+                signing_key_parts[0], signing_key_parts[1], signing_key_parts[2]
             )
 
-        if save_key:
-            sk_str = "%s %s %s" % (
+        if self.save_key:
+            signing_key_str = "%s %s %s" % (
                 self.signing_key.alg,
                 self.signing_key.version,
                 signedjson.key.encode_signing_key_base64(self.signing_key),
             )
-            self.sydent.cfg.set("crypto", "ed25519.signingkey", sk_str)
-            self.sydent.save_config()
-            logger.info("Key saved")
+            cfg.set("crypto", "ed25519.signingkey", signing_key_str)

sydent/sydent.py

@@ -69,7 +69,6 @@
 from sydent.http.servlets.v1_servlet import V1Servlet
 from sydent.http.servlets.v2_servlet import V2Servlet
 from sydent.replication.pusher import Pusher
-from sydent.sign.ed25519 import SydentEd25519
 from sydent.threepid.bind import ThreepidBinder
 from sydent.util.hash import sha256_and_url_safe_base64
 from sydent.util.ip_range import DEFAULT_IP_RANGE_BLACKLIST, generate_ip_set
@@ -326,7 +325,7 @@ def __init__(
         self.validators.msisdn = MsisdnValidator(self)
 
         self.keyring = Keyring()
-        self.keyring.ed25519 = SydentEd25519(self).signing_key
+        self.keyring.ed25519 = self.config.crypto.signing_key
         self.keyring.ed25519.alg = "ed25519"
 
         self.sig_verifier = Verifier(self)
@@ -610,7 +609,11 @@ def run_gc():
     setup_logging(cfg)
 
     sydent_config = SydentConfig()
-    sydent_config.parse_from_config_parser(cfg)
+    cfg_needs_saving = sydent_config.parse_from_config_parser(cfg)
 
     syd = Sydent(cfg, sydent_config=sydent_config)
+
+    if cfg_needs_saving:
+        syd.save_config()
+
     syd.run()