[galaxy-dev] FTP service for galaxy with external authentication via SAML using shibboleth

Hi, I'm currently solving a problem with authentication to FTP service for users of our galaxy server. We've successfully established an authentication via shibboleth behind Nginx (not very easy, but doable :) but that also means that ProFTPD is not working anymore, as it doesn't support SAML authentication. So my question is obvious, I'm looking for an easy and free FTP server with SAML support, can anybody help me with an advice? I've already found CompleteFTP and CrushFTP but both are paid and one is Windows-only allegedly. So how do you - people using external authentication via SAML - do this? Thanks in advance for any kind of useful advice. Best wishes, Martin Demko