Hello Kevin, > > User-Agent: AnyConnect Windows 3.0.07059 > If ocserv requires XML POST submissions, I would suggest tweaking the > ocserv XML output so that it more closely resembles the structure of > the document shown above. However, requiring XML POST does break > compatibility with AnyConnect <=v2.5. we can use the User-Agent header to distinguish, sending the legacy challenge for the old clients and the XML for the newer anyconnect clients. However my assumption is that, that the problem is not the format being used, but the fact that newer AnyConnect versions use multiple TCP connections instead of one. One for the username and one for the password which is killing the state machine in src/worker-auth.c. If it helps, I can do another man in the middle attack with a fake password and post the pcap here. When you look at that you'll see that it is in fact not one TCP connection but multiple. Cheers, Thomas