Raise config error if empty ca list

1 files changed, 4 insertions, 0 deletions

diff --git a/synapse/config/tls.py b/synapse/config/tls.py

index 2022da5147..e8d417d024 100644
--- a/synapse/config/tls.py
+++ b/synapse/config/tls.py
@@ -93,6 +93,10 @@ class TlsConfig(Config):
 
         # Read in and parse custom CA certificates
         if self.federation_custom_ca_list is not None:
+            if self.federation_custom_ca_list:
+                raise ConfigError("federation_custom_ca_list specified without "
+                                  "any certificate files")
+
             certs = []
             for ca_file in self.federation_custom_ca_list:
                 logger.debug("Reading custom CA certificate file: %s", ca_file)