- From: Joseph M. Reagle Jr. <reagle@w3.org>
- Date: Wed, 21 Jul 1999 10:53:19 -0400
- To: <rdbrown@Globeset.com>
- Cc: "'Dan Connolly'" <connolly@w3.org>, "'IETF/W3C XML-DSig WG'" <w3c-ietf-xmldsig@w3.org>
At 07:33 PM 7/20/99 -0500, Richard D. Brown wrote: >> This also touches on the issue of being able to sign >> the original content (the PDF file) instead of the encoded >> and attached version of the original content. >> Richard: how did you propose to do this? > >If you refer to the proposal I did to Richard Himes, it consists of >packaging the encoded content of the resource and the detached signature in >a single XML document. The encoded content is encapsulated in an XML element >that displays the encoding scheme as well as the 'Web locator' associated >with the resource, whose content is being encapsulated. This proposal >assumed that the application would decode and 'cache' the packaged resources >(or at least emulate such behaviors) before verification of the Resource >elements contained in the signature Manifest. Notice that this proposal has >been made in the context of a specific application and did not try to >address the problem in general. So the XML Package includes the encoding algorithm and source locator, as well as the encoded form, which encapsulated the PDF file. Now what does the actual signature manifest locator point to: the package or the source? If the source then it might not know to look in the package; if the package, it should sign the package. Part of the issue here is to what degree does the URI speak of the location and/or encoding? ------- _XML Package (ID=package) : encoding algorithim : resource locator ____ _Encoding form _______ _PDF File (ID=source) I think my preferred solution would be a statement about a statement: (I sign (I am the package/encoded form of (I am a contractual statement))) ... ? Well, this will become much clearer once I have a data model in hand. (The encoded form is merely the value of the property "encoded as" of the actual resource, the signature is a property of the reified form of that statement... Obviously I need to think it through further.) _________________________________________________________ Joseph Reagle Jr. Policy Analyst mailto:reagle@w3.org XML-Signature Co-Chair http://w3.org/People/Reagle/
Received on Wednesday, 21 July 1999 10:53:22 UTC