Here is what we tried to do initially...
On the AEWS server, export the certificate information, which creates a cert.cer file containing the certificate for the AEWS Tomcat application. You will be asked for the keystore password. Enter changeit
keytool -export -alias tomcat -file /tmp/cert.cer -keystore /opt/CA/WorkloadAutomationAE/autouser.$AUTOSERV/webserver/conf/.keystore
You will need to make the applicable path changes for your environment - to the .keystore located under the AEWS
then import into the keystore on the machine running your REST Client.
but we ended up coding the REST Client to accept all requests (which is dangerous), but it is (REST Client) limited to our env and the Webservices and the client are secured so they cant be accessed from anywhere else except where we want to allow it from.