ssh: Read host keys from data file; rename from openssh

common/ssh.nix

@@ -0,0 +1,21 @@
+{ config, lib, pkgs, ... }:
+
+let
+  inherit (lib) concatMapAttrs;
+  keys = import ../keys.nix;
+in
+{
+  services.openssh = {
+    enable = true;
+    settings = {
+      PasswordAuthentication = false;
+      PermitRootLogin = "no";
+    };
+  };
+
+  programs.ssh.knownHosts = concatMapAttrs
+    (host: key: {
+      "${host}.birdsong.network".publicKey = key;
+    })
+    keys.machines;
+}