xca binary package in Ubuntu Oracular s390x

 XCA creates and manages Certificate authorities and helps the user to
 create and manage keys, certificates, certificate sign requests,
 certificate revocation lists etc.
 .
 All data is saved in an encrypted, portable database, and can be exported
 in various standard formats. XCA is also available for MacOS X and
 Windows systems.
 .
 For a good workflow, certificate templates can be defined to make the
 creation of new certificates an easy task.

Source package