widget signature proposal - Identifier and Created Signature property

I propose we add the following to the Widgets Signature 1.1. This is    
in response to Thomas Roessler review comments, see http://lists.w3.org/Archives/Public/public-webapps/2009JanMar/0547.html

Proposal - Add the following to the latest editor's draft http://dev.w3.org/2006/waf/widgets-digsig/

(1) In Section 5.1, Use of XML Signature in Widgets

Add to bullet list:

+ Each Signature MUST contain  a dsp:Identifier signature properties  
element compliant with XML Signature Properties [XMLSec-Properties]  
and this specification.

+ Each Signature MUST contain  a dsp:Created signature properties  
element compliant with XML Signature Properties [XMLSec-Properties]  
and this specification.

(2) Add new section 5.5 and 5.6:

5.5 Identifier Signature Property

The dsp:Identifier signature property is intended to be used to  
uniquely identify the signature to enable signature management. It  
MUST be unique for a given signer.

5.6 Created Signature Property

The dsp:Created signature property provides the time of signature   
creation and is intended to be used to provide additional information  
associated with signatures. It is a wall clock timestamp as noted in  
XML Signature Properties.

To give just one example of use, assume a distributor's signing  
process is found to be broken, but it's not practical to exchange the  
signature key. Being able to weed out all signatures made before a  
particular date might turn out really important in this context.

(2) Update 7.2 Signature Generation to add the following at the end:

The current wall time MUST be placed in the dsp:Created signature   
property upon signature generation. The granularity of this time need   
not be finer than to the minute. The time SHOULD reflect the time that  
signature generation completes.

A unique identifier string for the signature MUST be placed in the   
dsp:Identifier signature property by the signer. This MUST be a  
unique  signing string for all signatures created by the signer.

(3) Update 7.3 Signature Validation to add after the second sentence a  
new paragraph:

The Created Signature Property value MUST represent a timestamp  
earlier than the current time, to the nearest minute, according to  
wall clock time.  There MUST NOT be more than one such value in the  
signature.

---
In addition to these changes in Widget Signature, the latest Editors
Draft of XML Signature Properties reflects the addition on the new  
Identifier [1] and Created [2] Signature properties.

Please review and indicate any suggestions for  those as well.

Thanks

regards, Frederick

Frederick Hirsch
Nokia

[1] http://www.w3.org/2008/xmlsec/Drafts/xmldsig-properties/Overview.html#identifier-property

[2] http://www.w3.org/2008/xmlsec/Drafts/xmldsig-properties/Overview.html#created-property

Received on Tuesday, 10 March 2009 16:20:50 UTC