Add parameter values to an existing tag in XML

I am trying different ways to add new values to an existing tag in my XML file.

My original XML:

<Server port="8005" shutdown="SHUTDOWN">
  <Service name="Catalina">
    <Connector port="8080" protocol="HTTP/1.1"
      connectionTimeout="20000"
      redirectPort="8443"/>
  </Service>
</Server>

I want it to transform into:

<Server port="8005" shutdown="SHUTDOWN">
  <Service name="Catalina">
    <Connector port="8080" protocol="HTTP/1.1"
      connectionTimeout="20000"
      redirectPort="8443"
      scheme="https"
      secure="true" SSLEnabled="true"
      keyAlias="tomcat" keyPass="welcome"
      keystoreFile="/data/matrix/automated-setup/openam.jks"
      keystorePass="welcome" clientAuth="false" sslProtocol="TLS"/>
  </Service>
</Server>

I don't want to use XSLT here. How can I do it using sed or awk? It has to be added under tag only