un.rb: use OpenSSL::PKey.read instead of OpenSSL::PKey::RSA.new

Also, error out if --ssl-private-key option is not given, since
specifying only the certificate makes no sense.  [Feature #13714]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59268 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/un.rb

@@ -329,11 +329,12 @@ def httpd
       opt = options[name] and (options[name] = Integer(opt)) rescue nil
     end
     if cert = options[:SSLCertificate]
+      key = options[:SSLPrivateKey] or
+        raise "--ssl-private-key option must also be given"
       require 'webrick/https'
-      require 'openssl'
-      options[:SSLCertificate] = OpenSSL::X509::Certificate.new(File.read(cert))
       options[:SSLEnable] = true
-      options[:SSLPrivateKey] &&= OpenSSL::PKey::RSA.new(File.read(options[:SSLPrivateKey]))
+      options[:SSLCertificate] = OpenSSL::X509::Certificate.new(File.read(cert))
+      options[:SSLPrivateKey] = OpenSSL::PKey.read(File.read(key))
       options[:Port] ||= 8443   # HTTPS Alternate
     end
     options[:Port] ||= 8080     # HTTP Alternate