module Gem::Security

def self.write pemmable, path, permissions = 0600, passphrase = nil, cipher = KEY_CIPHER
  path = File.expand_path path
  open path, 'wb', permissions do |io|
    if passphrase and cipher
      io.write pemmable.to_pem cipher, passphrase
    else
      io.write pemmable.to_pem
    end
  end
  path
end