For openSUSE Leap 42.3 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/spins:invis:stable:samba/openSUSE_Leap_42.3/spins:invis:stable:samba.repo
zypper refresh
zypper install samba
For openSUSE Leap 42.2 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/spins:invis:stable:samba/openSUSE_Leap_42.2/spins:invis:stable:samba.repo
zypper refresh
zypper install samba
For openSUSE Leap 42.1 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/spins:invis:stable:samba/openSUSE_Leap_42.1/spins:invis:stable:samba.repo
zypper refresh
zypper install samba