Currently it's possible to require client authentication during SSL/TLS handshake by adding needClientAuth=true query string to the respective connector URI. But it is not possible to configure revocation checking of the certificate submitted by the client.
The attached patch adds the capability by introducing a new attribute - crl - of the org.apache.activemq.spring.SpringSslContext class and updating the org.apache.activemq.spring.SpringSslContext.createTrustManagers() method to make use of the value specified for the attribute in the corresponding <sslContext /> tag as appropriate.
The code is inspired by a similar code in jetty webserver: https://github.com/eclipse/jetty.project/blob/release-9/jetty-util/src/main/java/org/eclipse/jetty/util/ssl/SslContextFactory.java#L927-L965
Please consider it for merging.