Many things

Change-Id: I147b761e6ba157e77bb374c3e0191533a03a92a3
diff --git a/modules/ssh.nix b/modules/ssh.nix
new file mode 100644
index 0000000..70e1ebb
--- /dev/null
+++ b/modules/ssh.nix
@@ -0,0 +1,7 @@
+{
+  services.openssh = {
+    enable = true;
+    settings.PasswordAuthentication = false;
+  };
+  networking.firewall.allowedTCPPorts = [ 22 ];
+}