Subject: Re: draft-ietf-krb-wg-pkinit-alg-agility-02 review

From: Love Hörnquist Åstrand <[email-masked]>
Date: Mon, 9 Jul 2007 11:17:45 +0200

2 apr 2007 kl. 09.15 skrev Shawn M Emery:

>
> Here is my review of draft-ietf-krb-wg-pkinit-alg-agility-02:

Sorry for the late resonse, I was on vacation and though Larry would  
pick it up since he had current document.

Fixed all nits.

> Are there any length limits for the Introductions?

Maybe it should be limited.

> Don't nonces in the protocol negate the affect of potential  
> collisions?

Even if the checksum is a easy to collide ?

> 6. KDF agility
>
> New update drafts have to be created as new KDFs become available?

Yes.

> Why are the "...," strings defined?

Because that is how you mark where the orignal structure started.

> What if the id request is disjoint from the supported list by the  
> server?

Good question. Presumably an error code is returned, I added the  
following text.

"If no acceptable KDF is found, the error KDC_ERR_NO_ACCEPTABLE_KDF  
(82).

    PKINIT introduces the following new error code:
    o  KDC_ERR_NO_ACCEPTABLE_KDF 82
"

> Why is pkinit-kdf-ah-sha256 the limiting algorithm?

Seems like a acceptable choice at the time, and still does.

> 7. Security Considerations
>
> Should we add a sentence that talks about policy?  For example:
>
> Client policy can dictate whether new hash algorithms can be used  
> by rejecting KDC replies that do not have a KDF field.  KDCs can  
> also enforce the use of new hash algorithms by rejecting client  
> requests that do not include supportedKDFs.

This is what the whole document is about, we need to write more about  
this ?

Thanks,
Love