RE: Question about signing document header with XML Signature

Srinivas -

The most general answer to your question is that there is nothing about an
XML signature <Reference> element that distinguishes between a header and a
body, or any other data.

The reason why I say this is because you specify the reference to be
digested with a URI fragment and it is de-referenced from there.

If you are performing a same-document detached signature (which is common
with a SOAP message), the URI attribute value for the <Reference> element
will be #foo where foo is the element with the Id value of foo. In your
case, foo is the Body.

In many cases the body of a SOAP document may have an Id. 

For the case of a SOAP message header, the header may not have an Id
attribute, so you must use an XPath expression in that case. Either way, you
still use a <Reference> element, but simply change the URI based on the
target to digest if needed. For the case of the XPath transform it would be
the empty quotes "" denoting the entire node-set with a filter over it for
the header.

Blake Dournaee
Senior Security Architect
Sarvega, Inc.

-----Original Message-----
From: w3c-ietf-xmldsig-request@w3.org
[mailto:w3c-ietf-xmldsig-request@w3.org] On Behalf Of Srinivas
Sent: Wednesday, August 25, 2004 3:05 PM
To: w3c-ietf-xmldsig@w3.org
Subject: Question about signing document header with XML Signature


Hi,
I wonder if the gurus out in XML land could throw some
light on this matter. I am using XML Signature to sign
a message. I had no trouble with figuring out the use
of XML Signature for signing the message body.

Next, what I wanted to find out was, can I use a
similar technique to sign the message header too?
Meaning, am I correct in concluding that there is no
difference in the usage of XML Signature for signing
either the message body or the message header?

Thanks for you assistance,
-Ravi


		
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Received on Wednesday, 25 August 2004 22:32:20 UTC