module Gem::Security

def self.create_cert(subject, key, age = ONE_YEAR, extensions = EXTENSIONS, serial = 1)
  cert = OpenSSL::X509::Certificate.new
  cert.public_key = get_public_key(key)
  cert.version    = 2
  cert.serial     = serial
  cert.not_before = Time.now
  cert.not_after  = Time.now + age
  cert.subject    = subject
  ef = OpenSSL::X509::ExtensionFactory.new nil, cert
  cert.extensions = extensions.map do |ext_name, value|
    ef.create_extension ext_name, value
  end
  cert
end