Add ability to disable password auth (#2612)

* Add ability to disable password auth

* Allow disabling password authentication

roles/custom/matrix-synapse/defaults/main.yml

@@ -371,6 +371,11 @@ matrix_synapse_auto_join_rooms: []
 # automatically if they don't already exist.
 matrix_synapse_autocreate_auto_join_rooms: true
 
+# Controls whether password authentication is allowed
+# It may be useful when you've configured OAuth, SAML or CAS and want authentication
+# to happen only through them
+matrix_synapse_password_config_enabled: true
+
 # Controls password-peppering for Synapse. Not to be changed after initial setup.
 matrix_synapse_password_config_pepper: ""