Merge pull request #909 from matrix-org/erikj/shared_secret

Add an admin option to shared secret registration (breaks backwards compat)

1 files changed, 16 insertions, 4 deletions

diff --git a/synapse/rest/client/v1/register.py b/synapse/rest/client/v1/register.py
index d791d5e07e..ce7099b18f 100644
--- a/synapse/rest/client/v1/register.py
+++ b/synapse/rest/client/v1/register.py
@@ -324,6 +324,14 @@ class RegisterRestServlet(ClientV1RestServlet):
             raise SynapseError(400, "Shared secret registration is not enabled")
 
         user = register_json["user"].encode("utf-8")
+        password = register_json["password"].encode("utf-8")
+        admin = register_json.get("admin", None)
+
+        # Its important to check as we use null bytes as HMAC field separators
+        if "\x00" in user:
+            raise SynapseError(400, "Invalid user")
+        if "\x00" in password:
+            raise SynapseError(400, "Invalid password")
 
         # str() because otherwise hmac complains that 'unicode' does not
         # have the buffer interface
@@ -331,17 +339,21 @@ class RegisterRestServlet(ClientV1RestServlet):
 
         want_mac = hmac.new(
             key=self.hs.config.registration_shared_secret,
-            msg=user,
             digestmod=sha1,
-        ).hexdigest()
-
-        password = register_json["password"].encode("utf-8")
+        )
+        want_mac.update(user)
+        want_mac.update("\x00")
+        want_mac.update(password)
+        want_mac.update("\x00")
+        want_mac.update("admin" if admin else "notadmin")
+        want_mac = want_mac.hexdigest()
 
         if compare_digest(want_mac, got_mac):
             handler = self.handlers.registration_handler
             user_id, token = yield handler.register(
                 localpart=user,
                 password=password,
+                admin=bool(admin),
             )
             self._remove_session(session)
             defer.returnValue({