On Tue, Jun 05, 2007 at 10:51:31AM -0700, Henry B. Hotz wrote: > On Jun 4, 2007, at 9:36 PM, Nicolas Williams wrote: > >On Mon, Jun 04, 2007 at 04:48:25PM -0700, Henry B. Hotz wrote: > >>If I had my way, any vendor would need to convince me that they have > >>solved the KDC robustness problem. I have a hard time imagining a > > > >The OTP robustness problem, you mean. > > Same thing if you build the OTP into the KDC. I'm not personally > interested in OTP that doesn't get you a Kerberos ticket.
No, the two are not the same thing. The KDC could have a pluggable pre-auth framework and the OTP implementation could be a third party's, as I've already explained. In that case the OTP robustness issue would be the third party's, not the KDC implementor's. Really, it would be. The same applies to OTPs and PAM, for example. Usually the way this is addressed is by having an OTP vendor provided API that sends the OTP to a remote server for verification, and that remote server is clustered. > >>Is it worth bringing this up on the IETF list? > > > >Maybe. There is an Internet OTP, after all. > > You mean RFC2289? AFAIK it doesn't address the robustness issue I And RFC4226. > mentioned, though it probably mentions the problem somewhere. At > least the SASL mech that uses it makes mention of the problem. You asked if this is worth bringing up at the IETF, and yes, because of RFC2289 and RFC4226 that would be an appropriate forum where to discuss the protocol aspects of the problem you're concerned with. The Kerberos V OTP pre-auth protocol proposal(s) need to be discussed on the IETF KRB WG list. Ideally we could get OTP vendors interested in implementing key generating OTPs and then we could spec a protocol for it and solve lots of problems. Nico --
