Implement MSC4009 to widen the allowed Matrix ID grammar (#15536)

Behind a configuration flag this adds + to the list of allowed
characters in Matrix IDs. The main feature this enables is
using full E.164 phone numbers as Matrix IDs.

1 files changed, 4 insertions, 2 deletions

diff --git a/synapse/handlers/sso.py b/synapse/handlers/sso.py
index 92c3742625..25fd2eb3a1 100644
--- a/synapse/handlers/sso.py
+++ b/synapse/handlers/sso.py
@@ -225,6 +225,8 @@ class SsoHandler:
 
         self._consent_at_registration = hs.config.consent.user_consent_at_registration
 
+        self._e164_mxids = hs.config.experimental.msc4009_e164_mxids
+
     def register_identity_provider(self, p: SsoIdentityProvider) -> None:
         p_id = p.idp_id
         assert p_id not in self._identity_providers
@@ -711,7 +713,7 @@ class SsoHandler:
         # Since the localpart is provided via a potentially untrusted module,
         # ensure the MXID is valid before registering.
         if not attributes.localpart or contains_invalid_mxid_characters(
-            attributes.localpart
+            attributes.localpart, self._e164_mxids
         ):
             raise MappingException("localpart is invalid: %s" % (attributes.localpart,))
 
@@ -944,7 +946,7 @@ class SsoHandler:
             localpart,
         )
 
-        if contains_invalid_mxid_characters(localpart):
+        if contains_invalid_mxid_characters(localpart, self._e164_mxids):
             raise SynapseError(400, "localpart is invalid: %s" % (localpart,))
         user_id = UserID(localpart, self._server_name).to_string()
         user_infos = await self._store.get_users_by_id_case_insensitive(user_id)