Basic OpenSSL-based package signing class.
Creates a new signer with an RSA key or path to a key, and a certificate chain containing X509 certificates, encoding certificates or paths to certificates.
 
               # File rubygems/security/signer.rb, line 33
def initialize key, cert_chain, passphrase = nil
  @cert_chain = cert_chain
  @key        = key
  unless @key then
    default_key  = File.join Gem.default_key_path
    @key = default_key if File.exist? default_key
  end
  unless @cert_chain then
    default_cert = File.join Gem.default_cert_path
    @cert_chain = [default_cert] if File.exist? default_cert
  end
  @digest_algorithm = Gem::Security::DIGEST_ALGORITHM
  @digest_name      = Gem::Security::DIGEST_NAME
  @key = OpenSSL::PKey::RSA.new File.read(@key), passphrase if
    @key and not OpenSSL::PKey::RSA === @key
  if @cert_chain then
    @cert_chain = @cert_chain.compact.map do |cert|
      next cert if OpenSSL::X509::Certificate === cert
      cert = File.read cert if File.exist? cert
      OpenSSL::X509::Certificate.new cert
    end
    load_cert_chain
  end
end
             
            Sign data with given digest algorithm
 
               # File 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