keychain binary package in Ubuntu Mantic s390x

 Keychain is an OpenSSH key manager, typically run from ~/.bash_profile. When
 keychain is run, it checks for a running ssh-agent, otherwise it starts one.
 It saves the ssh-agent environment variables to ~/.keychain/\$\{HOSTNAME\}-sh,
 so that subsequent logins and non-interactive shells such as cron jobs can
 source the file and make passwordless ssh connections. In addition, when
 keychain runs, it verifies that the key files specified on the command-line
 are known to ssh-agent, otherwise it loads them, prompting you for a password
 if necessary.

Source package