RE: still more Digest auth questions/comments

Read carefully, both of the text samples below have a comma after H(A1).
Everything after the comma is an implicit concatenation.  I believe the
samples below are entirely correct.

-----Original Message-----
From: Dave Kristol []
Sent: Friday, April 10, 1998 8:49 AM
Subject: still more Digest auth questions/comments

3.2.1 The WWW-Authenticate Response Header

We define function KD as:
      KD(secret, data) = H(concat(secret, ":", data))

3.2.2 The Authorization Request Header

The spec. says:
    If the "qop" directive is not present (this construction is for
    compatibility with RFC 2069):

       request-digest  =
		  <"> < KD ( H(A1), unq(nonce-value) ":" H(A2) ) > <">

    see below for the defintions for A1 and A2.

    If the "qop" value is "auth":

       request-digest  = <"> < KD ( H(A1),     unq(nonce-value)
					   ":" nc-value
					   ":" unq(cnonce-value)
					   ":" unq(qop-value)
					   ":" H(A2)
				   ) <">

Note that in neither of these uses of KD() are there two arguments!

I believe the first use of KD() is actually incorrect, although the
description is inherited from RFC 2069.  I think it should be H(), not

It's not clear to me whether the other use of KD() is correct, or
whether it, too, should be H().  If it should be H() (and I think so),
then we should remove all references to KD(), which is not actually

Dave Kristol

Received on Friday, 10 April 1998 08:57:34 UTC