The signer has the fully qualified class name: org.signserver.module.jarchive.signer.JArchiveCMSSigner.
Overview
The JArchive CMS signer is a special-purpose version of the extended CMS signer with default values suitable for JAR signing. This is intended for use with client-side hashing, where a client does the hashing of the original file and requests this hash to be signed by SignServer, giving a resulting signature which is then inserted into the resulting output file by the client.