gistfile1.rb

module Puppet::Parser::Functions
  newfunction(:aes_encrypt, :type => :rvalue) do |args|

    clear_text = args[0]
    passphrase = args[1]

     .....
  end
end



...

in manifest's init.pp :

$maven_encrypted_master_password = aes_encrypt($maven_master_password, 'settings.security')