bug?: erroneous start time for max renewable life check

[Richard Johnson]

On Wed, Jun 09, 2010 at 12:15:36PM -0400, Greg Hudson wrote:
> I think the most practical fix for your problem is to make the Heimdal
> KDC more forgiving--it should not squash the validity end time of the
> ticket simply because it calculated a lower maximum renewable end time.

Thanks for the more precise ID of the problem.  The Heimdal KDC should
probably use a more reasonable start time if it's going to calculate
lifetimes.

> If I were a Heimdal developer, I'd propose removing this line from
> krb5tgs.c:
> 
>         et.endtime = min(et.endtime, *et.renew_till);

Thanks.  I'll test it and pursue that fix or a similar one.

> I'm certainly happy to change the MIT krb5 client code to not request
> renewable service tickets, and I'll bring that up on the krbdev list.
> But it's much easier to change your KDC than to change your OS-native
> client code on every client.

Jeffrey Altman pointed out that my assumption of always having the TGT
around when using the ftp service ticket is incorrect.  Having a renewable
service ticket without requiring keeping/passing around the TGT can be
safer, and I'd thus be hesitant to have others lose that option.


Richard