We found the same issue, but it isn't just that ShareFile doesn't support SLO its the fact that it sends to the logout URL framed which the F5 doesn't allow. We found that in some browsers we weren't actually getting logged out with MarkD's suggestion so we point it at a generic uri "/sharefile-logout" and break out the frame and then kill the session with the following iRule:
when HTTP_REQUEST {
if {[HTTP::uri] equals "/sharefile-logout"} {
HTTP::respond 200 content "Logging out.. "
}
}
when ACCESS_ACL_ALLOWED {
if {[HTTP::uri] equals "/saml/sp/profile/post/sls/sharefile"} {
ACCESS::session remove
}
}
This worked in all browsers and versions that we tested.