1 files changed, 41 insertions, 0 deletions
diff --git a/synapse/storage/registration.py b/synapse/storage/registration.py
index 55e4e84d71..1e3c2148f6 100644
--- a/synapse/storage/registration.py
+++ b/synapse/storage/registration.py
@@ -22,6 +22,7 @@ from six import iterkeys
 from six.moves import range
 
 from twisted.internet import defer
+from twisted.internet.defer import Deferred
 
 from synapse.api.constants import UserTypes
 from synapse.api.errors import Codes, StoreError, ThreepidValidationError
@@ -337,6 +338,26 @@ class RegistrationWorkerStore(SQLBaseStore):
 
         return self.runInteraction("get_users_by_id_case_insensitive", f)
 
+    async def get_user_by_external_id(
+        self, auth_provider: str, external_id: str
+    ) -> str:
+        """Look up a user by their external auth id
+
+        Args:
+            auth_provider: identifier for the remote auth provider
+            external_id: id on that system
+
+        Returns:
+            str|None: the mxid of the user, or None if they are not known
+        """
+        return await self._simple_select_one_onecol(
+            table="user_external_ids",
+            keyvalues={"auth_provider": auth_provider, "external_id": external_id},
+            retcol="user_id",
+            allow_none=True,
+            desc="get_user_by_external_id",
+        )
+
     @defer.inlineCallbacks
     def count_all_users(self):
         """Counts all users registered on the homeserver."""
@@ -848,6 +869,26 @@ class RegistrationStore(
         self._invalidate_cache_and_stream(txn, self.get_user_by_id, (user_id,))
         txn.call_after(self.is_guest.invalidate, (user_id,))
 
+    def record_user_external_id(
+        self, auth_provider: str, external_id: str, user_id: str
+    ) -> Deferred:
+        """Record a mapping from an external user id to a mxid
+
+        Args:
+            auth_provider: identifier for the remote auth provider
+            external_id: id on that system
+            user_id: complete mxid that it is mapped to
+        """
+        return self._simple_insert(
+            table="user_external_ids",
+            values={
+                "auth_provider": auth_provider,
+                "external_id": external_id,
+                "user_id": user_id,
+            },
+            desc="record_user_external_id",
+        )
+
     def user_set_password_hash(self, user_id, password_hash):
         """
         NB. This does *not* evict any cache because the one use for this