Subject: [MSEC] GDOI Update draft

From: Yoav Nir <[email-masked]>
Date: Thu, 8 Apr 2010 14:35:19 +0300

Hi.

As I promised at the meeting, I will review this draft thoroughly, but I already have two comments

 1.  It was said in the meeting (although it's not written in the draft) that none of the known implementations have implemented the PFS extension, and so it is dropped. This is incorrect. I have checked Check Point's implementation, and it does, in fact, implement the PFS feature. What the draft says, in appendix B, is that it provides negligible value, and that the specification is faulty. These statements are true.
Much as I'd hate to deprecate running code from my own company, I agree with the reasoning in appendix B, so I'm fine with it being deprecated.

 2.  The document is missing a conformance requirements section. Although there is some conformance language in the various sections, like DES is SHOULD NOT, and AES-CBC-128 is MUST, the document is missing a centralized list of what is required, as opposed to optional, or not recommended.  I would suggest the following:

KEK_MANAGEMENT_ALGORITHM

 *   LKH - MUST  (?)

KEK_ALGORITHM

 *   DES - SHOULD NOT
 *   3DES - SHOULD
 *   AES - MUST

SIG_HASH_ALGORITHM

 *   MD5 - MUST NOT
 *   SHA1 - SHOULD NOT
 *   SHA256 - MUST

(BTW: why do you have to specify this at all?  With RSA, you're using the PKCS#1.5 format that encodes the hash algorithm anyways, so why negotiate it?)

SIG_ALGORITHM

 *   RSA - MUST

protocol

 *   ESP - MUST
 *   AH - MAY

Key download type

 *   are all three types mandatory?

And so on.

Anyway, I do promise to read this throughly soon.

Yoav