Re: [secdir] SECDIR Review of draft-ietf-dime-local-keytran-11.txt

[Glen Zorn <[e-mail]>]

On 7/14/2011 3:05 AM, Phillip Hallam-Baker wrote:

> I have reviewed this document as part of the security directorate's
> ongoing effort to review all IETF documents being processed by the
> IESG. Document editors and WG chairs should treat these comments just
> like any other last call comments.
> 
> SECURITY
> 
> There is no substantive security considerations, only a redirect to the
> previous drafts.
> 
> This is somewhat problematic given that this is a document defining new
> formats for key transport.

If it is problematic then it would be quite helpful to say what exactly
the problem is.  Has the nature of cryptographic keys or Diameter
changed fundamentally since the publication of RFC 4072?  If not, what
is the problem?

> 
> 
> Minor
> 
> 3.1.4.  Key-Lifetime AVP
> 
> The Key-Lifetime AVP (AVP Code <AC4>) is of type Unsigned32 and
> represents the period of time (in seconds) for which the contents of the
> Keying-Material AVP (Section 3.1.3) is valid.
> 
> If the key lifetime is really expected to be 2^32, i.e. 136 years

They are most certainly not.

> then
> we should probably expect quite a bit more mechanism here.
> 
> The delta encoding avoids millennium bug type problems (we.. maybe, it
> probably just means that code will start to fail in 2032 or so when
> people start specifying key lifetimes that cause signed 32 bit time to
> wrap.) but it means that the start of the period is not fixed in time.
> 
> I think that at a minimum we need to have a security consideration
> pointing out that there is an issue here. What happens if these messages
> are proxied or cached in some fashion (OK it may not be in the protocol
> now, but can we guarantee it never will be?)
> 
> Its probably not worth fixing since the protocols themselves are full of
> the same issue but it should be called out as an SC.
> 
> 
> 
> -- 
> Website: http://hallambaker.com/
>