Para openSUSE Factory execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:wrosenauer:devel/openSUSE_Factory/home:wrosenauer:devel.repo
zypper refresh
zypper install hmaccalc
Para 15.5 execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:wrosenauer:devel/15.5/home:wrosenauer:devel.repo
zypper refresh
zypper install hmaccalc
Para 15.4 execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:wrosenauer:devel/15.4/home:wrosenauer:devel.repo
zypper refresh
zypper install hmaccalc