krb5_rd_cred checks IP address.

[Nicolas Williams]

On Fri, Feb 08, 2002 at 08:15:28AM -0800, Booker C. Bense wrote:
> On Thu, 7 Feb 2002, Sam Hartman wrote:
> 
> > I'm not really sure what good this check does other than to screw over
> > NAT users.  Even if we pretend that we actually still care about IP
> > address authentication what is the harm of accepting tickets from
> > someone provided that they work?
> 
> - I can't see one. The whole rational for the IP check is to make
> replay attacks harder, but I don't grok how that would even apply
> in this situation.

I thought limiting the use of stolen creds was one of the rationales for
having those IP address checks... Of course, if you steal forwardable
creds you probably have access to the host where they must be used and
then you can do whatever you want...

> >
> > I'm really not sure how to go about fixing this problem.  I could see
> > solving in several ways and am not sure which one the community
> > prefers.  Do we remove the check on the source address?
> 
> - I would vote for this option. The IP checks have always seemed to
> me to be the wrong solution to replay attacks, it doesn't really
> solve the problem. A session key cache does.
> 
> - Booker C. Bense



Nico
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