Subject: Re: A contradiction between RFC3852 and RFC3278

From: Sean Turner <[email-masked]>
Date: Fri, 13 Mar 2009 19:56:24 -0400

Maxim,

I don't have any objection to adding the note to draft-smime-3278bis.

spt

Maxim Masiutin wrote:
> Hello Sean,
> 
> In all CMS messages that I’ve seen, when RSA algorithm is used, SignatureAlgorithm in the SignerInfo is rsaEncryption, not md5WithRSAEncryption. That’s why it made confusion when I was implementing elliptic curves.
> Maybe, if an update of RFC3852 is planned, we will add a clarification for this?
> Also, while RFC3278-bis is in the draft status, what about adding a clarification that hash in SignatureAlgorithm and DigestAlgorithm must match?
> 
>

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From: "Maxim Masiutin" <[email-masked]>
Date: Sat, 14 Mar 2009 23:43:18 +0200

Hello Sean,

Maybe we should alter the description of signatureAlgorithm in section 2.1.1 of draft-smime-3278bis, to the following:

     - signatureAlgorithm contains the signature algorithm identifier 
       (see Section 7.1.3) where the public key part of it
       is ECDSA and the hash part MUST refer to the same algorithm as 
       specified in the digestAlgorithm field. signatureAlgorithm MUST
       be one of the following ecdsa-with-SHA1, 
       ecdsa-with-SHA224, ecdsa-with-SHA256, 
       ecdsa-with-SHA384, or ecdsa-with-SHA512. 

-- 
Best regards,
Maxim Masiutin                     
Ritlabs SRL
http://www.ritlabs.com/

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From: "Maxim Masiutin" <[email-masked]>
Date: Mon, 16 Mar 2009 18:24:54 +0200

Hello Sean,

Thank you, your suggestion to add a paragraph is fine!

-- 
Best regards,
Maxim Masiutin                            mailto:[email-masked]

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From: Sean Turner <[email-masked]>
Date: Mon, 16 Mar 2009 12:10:04 -0400

Maxim,

The paragraph now says:

signatureAlgorithm contains the signature algorithm identifier (see 
Section 7.1.3): ecdsa-with-SHA1, ecdsa-with-SHA224, ecdsa-with-SHA256, 
ecdsa-with-SHA384, or ecdsa-with-SHA512.

How about we add the following to the end of it:

The hash algorithm identified in the name of the signature algorithm 
MUST be the same as the digestAlgorithm (e.g., digestAlgorithm is 
id-sha256 therefore signatureAlgorithm is ecdsa-with-SHA256).

spt