Canonicalization, XAdES

Hello,

I want to explain my problems by means 
of an example, which I have found in this mailing list: 
http://lists.w3.org/Archives/Public/w3c-ietf-xmldsig/2003OctDec/0014.html

I want to canonicalize the same element from the same doc as the guy in that 
posting.
I'm using a sample-prog of the IBM XML-Security Suit 
(http://www.trl.ibm.com/projects/xml/xss4j/docs/c14n.html) to canonicalize a 
subset of a xml-doc. The command is: 
"... xpath-expression < example.xml > canonicalized.xml"
Unfortunately, I can't figure out the proper xpath-expression to obtain the 
desired result (which means in this case "<Object 
xmlns="http://www.w3.org/2000/09/xmldsig#" Id="object">some
text</Object>"). Could someone reveal the expression for this example to me?

...but even if I had that result, the trouble would go on:
If I didn't misunderstand it, on the above mentioned desired result the hash 
and base64 should be performed. I try to do that with an openssl-command:
echo -e '<Object xmlns= ... ' | openssl sha1 -binary | openssl base64
...but the result differs from the right one given in the posting. So what's 
still wrong here?

What I want to do in the end, is to timestamp particular elements in view of 
XAdES-complience... So another question is, how to 
cope with multiple inputs for a hash calculation, like you find them in 
XAdES-X and A. W3C says this: 
http://www.w3.org/TR/XAdES/#Qualifying_properties_syntax_Auxiliary_syntax_The_TimeStampType_data_type
Could someone explain this a little more detailed... e.g. how do I get the 
octet-concatenation?

And last but not least: A HashDataInfo element does not mandatorily have a 
corresponding Transforms-element as a child. If there is such an element, it 
also can specify a canonicalization-algorithm as transform-method. Does this 
mean, that an element referenced in HashDataInfo without transform or with 
another transform-method than canonicalization must not be canonicalized? 

Any help is very appreciated.

Thomas

Received on Wednesday, 21 January 2004 15:04:22 UTC