Those of you with win2000 based DNS servers might be interested to know that I have just successfully sent a TSIG-GSS dynamic DNS update to a win2000 server from a Linux box, using a kerberos ticket from MIT kerberos. This is an important piece of the netbiosless support that is being added to Samba.
Thus far I have only sent successful updates using des-cbc-crc tickets. I would prefer to be able to use hmac-md5 tickets as that is what win2000 uses, but I haven't been able to get that to work yet. I'm guessing there may be a bug in the MIT hmac-md5 implementation, or at least a difference between the MIT and Microsoft implementations. The MIT library can certainly generate and use hmac-md5 tickets for other things (we use them in Samba ADS support all the time) so I suspect the problem is in using them for signing (like in calls to gss_get_mic()). My current test implementation is a mish-mash of perl and C, using the Net::DNS perl module for DNS packet construction and C to interface to the MIT kerberos GSSAPI library. I'm still thinking about how I will put this into a more palatable form, the choices seem to be to either cleanup my perl code a bit or try to modify the bind-9 nsupdate utility to handle the necessary TKEY requests. I originally started on this project with the aim of updating the bind-9 code but I've found it fairly hard to work out how to extend it, which is why I switched to the Net::DNS module. If anyone out there knows the bind-9 code really well and wants to help me produce a patch to that then please let me know. Cheers, Tridge
