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Re: ACTION-764: Review placement of base64 alg in 1.1/2.0, should it be under transforms?

From: Cantor, Scott E. <cantor.2@osu.edu>
Date: Tue, 11 Jan 2011 01:25:00 +0000
To: Brian LaMacchia <bal@microsoft.com>, "public-xmlsec@w3.org" <public-xmlsec@w3.org>
Message-ID: <C95119E8.2D0F%cantor.2@osu.edu>
>ACTION-764 asks whether we should re-classify Base64 as a Transform
>Algorithm from an Encoding Algorithm in the required algorithms list (in,
>e.g., XMLDSIG 1.1 Section 6.1).
> 
>Looking at XMLDSIG 1.1 and XMLENC 1.1, it appears that we use the same
>Base64 URI in both ³encoding algorithm² and ³transform algorithm²
>contexts, and the URI is a valid in both.
>For example,  in XMLDSIG 1.1 Section 4.6, there's an
> example in the text where we talk about putting a PNG image in an
><Object> element and identifying it with encoding=<the base64 encoding
>URI>.  And we have a defined Encoding attribute on Object in the schema.
> (We use a similar example in XMLENC Section
> 3.1 EncryptedType.)

At least in the XML Signature case, Encoding there is advisory only and
does not connote processing semantics. OTOH, the base64 transform does. So
at the very least, that algorithm URI is perhaps both an "encoding" (which
does not seem to be normative concept) and a Transform, and ought be
listed as both. If I were to pick one, that one would be the Transform.

> 
>I havenıt checked in 2.0 yet, but given the existing usage in 1.1 Iım not
>sure Iıd move it under Transforms.

I think I would do that or duplicate it and provide more context for what
an "Encoding Algorithm" means. I'm not as concerned about that for 1.x,
it's an old issue there.

-- Scott
Received on Tuesday, 11 January 2011 01:25:31 GMT

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