SPAKE provides additional strength to Kerberos authentication through use of elliptic curve cryptography. More information can be found at https://github.com/krb5/krb5/blob/master/doc/admin/spake.rst ; the RFC draft is at https://www.ietf.org/id/draft-ietf-kitten-krb-spake-preauth-05.txt Specifically, please backport https://github.com/freeipa/freeipa/pull/1747 to Fedora 28 and Fedora 29's freeipa. Thanks!
freeipa-4.6.90.pre2-3.fc28 has been submitted as an update to Fedora 28. https://bodhi.fedoraproject.org/updates/FEDORA-2018-93dfeefc68
master: 792adeb Enable SPAKE support using krb5.conf.d snippet 73c3495 Use shutil to copy file
freeipa-4.6.90.pre2-3.fc28 has been pushed to the Fedora 28 testing repository. If problems still persist, please make note of it in this bug report. See https://fedoraproject.org/wiki/QA:Updates_Testing for instructions on how to install test updates. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2018-93dfeefc68
freeipa-4.6.90.pre2-3.fc28 has been pushed to the Fedora 28 stable repository. If problems still persist, please make note of it in this bug report.