ietf-dkim
[Top] [All Lists]

[ietf-dkim] Re: bh=; l=0;

2006-07-02 07:59:29
At 7:23 AM -0700 7/2/06, Michael Thomas wrote:
Paul Hoffman wrote:



#13 3.4.5, 3.5 and 3.7. "l=0" is allowed, but "bh=" is REQUIRED, which is a bit
of a contradiction.


"l=0;bh=;" seems valid.


It doesn't seem valid to me, and it's certainly not the natural thing that
an implementor would do which is to just take the value of SHA[1|256]_Final
and compare it against the bh= value. Leaving it as is doesn't create an
unnecessary new case.

Oh, wait; Michael is completely right here. If l=0, bh= contains the hash of a zero-length string, which has the length of a normal hash output. My apologies.

And "l=" is not mentioned when saying how to calculate
"bh=". I guess the right thing to do might be to add some mention of "l=" when
talking about calculating "bh=",


Agree.


I don't see what the problem is: l= is the canonical byte count, and that's
just as true with bh as is was before bh was invented.

The question is, what string do you hash when l= is given? I am interpreting the spec as that you has the string with the length given in l=; are you reading it as you hash the entire body regardless of the presence of l=?
_______________________________________________
NOTE WELL: This list operates according to http://mipassoc.org/dkim/ietf-list-rules.html

<Prev in Thread] Current Thread [Next in Thread>