sign

# File lib/rubygems/security/signer.rb, line 102
  def sign data
    return unless @key

    raise Gem::Security::Exception, 'no certs provided' if @cert_chain.empty?

    if @cert_chain.length == 1 and @cert_chain.last.not_after < Time.now then
      re_sign_key
    end

    full_name = extract_name @cert_chain.last

    Gem::Security::SigningPolicy.verify @cert_chain, @key, {}, {}, full_name

    @key.sign @digest_algorithm.new, data
  end