diff --git a/modules/services/diskstation/getCertificate.sh b/modules/services/diskstation/getCertificate.sh
new file mode 100755
index 0000000..ced109b
--- /dev/null
+++ b/modules/services/diskstation/getCertificate.sh
@@ -0,0 +1,5 @@
+#! /usr/bin/env bash
+set -euo pipefail
+
+nix-shell -p openssl \
+    --command "openssl s_client -showcerts -connect $1 </dev/null 2>/dev/null|openssl x509 -outform PEM > $2"