[Fwd: Re: [ietf-dkim] canonicalized null body and dkim]

Mon Dec 18 10:41:27 PST 2006

I agree that this clarification should be added whenever we
get a consensus on what to say.

Can we also include the actual sha256 digest resulting (which
goes into bh=, or am I confused?) when we do this? That way
coders can check that they've gotten the right answer.

So the new note might go something like:

"With simple c14n the following examples all result in
the same body hash which has the value..."

S.

Mark Delany wrote:
> Charles Lindsey wrote:
> 
>> Now apply simple canonicalization to all those cases, using:
>>
>>    "In more formal terms, the "simple" body canonicalization algorithm
>>     converts "0*CRLF" at the end of the body to a single "CRLF"."
>>
>> Making the entirely reasonable assumption that "body" means exactly 
>> what RFC 2822 defines it to mean, then here is what gets hashed in all 
>> of those cases:
>>
> 
> (Did you mean to include Last-Header: in the following examples?)
> 
>> 1) ordinary message with <body> of 1 non-empty line:
>> ---------------------
>> barbazCRLF
>> ---------------------
>>
>> 2) <body> consisting of 2 empty lines
>> ---------------------
>> CRLF
>> ---------------------
>>
>> 3) <body> consisting of 1 empty line
>> ---------------------
>> CRLF
>> ---------------------
>>
>> 4) <body> containing no lines
>> ---------------------
>> CRLF
>> ---------------------
>>
>> 5) message with absent <body>
>> ---------------------
>> ---------------------
>>
>> That is undoubtedly what the "formal terms" in dkim-base undoubtedly SAY.
>>
>> It is NOT what the "informal" words in dkim-base say.
>> It is NOT what version -01 of DK says.
>> It is NOT what version -06 of DK says.
>> It is NOT what Eric's three examples claim.
>> It is entirely possible that is is NOT what dkim-base was INTENDED to 
>> say.
> 
> I believe the intent is that 2, 3, 4 and 5 all canonicalize to the same 
> content for c=simple, namely to match 5) as:
> 
> -------------------------------
> Last-Header: foobarCRLF
> -------------------------------
> 
> 
> Mark.
> 
> 
> Mark.
> 
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