{ lib, ... }:
{
  config.flake.lib.getGithubKeys =
    { username, sha256 }:
    let
      authorizedKeysFile = builtins.fetchurl {
        url = "https://github.com/${username}.keys";
        inherit sha256;
      };
      keys = lib.splitString "\n" (builtins.readFile authorizedKeysFile);
    in
    builtins.filter (s: s != "") keys;
}