> >>From what I can see, the Ticket structure does not uniquely identify the > > ticket type or ticket version, so that there is no easy way for the server > > to determine what type of ticket has been submitted to it, or whether the > > client is using the recommended format or not. The server checks the mac > > in the last 20 octets, and if this is valid, then it decrypts the > > encrypted_state. However, if the client were using the same mac, but a > > different ticket format, the mac could check out, but the StatePlaintext > > would not match. A Ticket Type/Version field would make it clear to the > > server whether it is handling a Ticket of known type. > > I'm not sure I understand this, Bernard. The client doesn't need > to know anything about the ticket format or get to decide > anything about the mac. It's just the server talking to itself. The client does not need to crack the ticket. However, it is possible for the client to submit a ticket to a server that doesn't understand it. For example, wireless LAN networks can span the globe, and require many backend servers, all of which may not be located at the same location, or run the same version of the same software. However, clients may only cache tickets by SSID. If a client obtains a ticket from Server A, running software version X, and then sends it to server B, running software version Y, how is Server B supposed to figure out that it is the wrong version? _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf