[xsd-users] [Q] XSD in combination with Apache Xml Security

[Alexander Petry]

Hello list!

I  am  currently  working on  a  project  that  is  going  to use  XML  in
combination with the XML security specifications ([1] and [2]). The Apache
Foundation  implemented   both  specs  (XML  Digital   Signature  and  XML
Encryption) in the  XML Security Library ([3]). Under  Debian this library
can be installed via apt-get install libxml-security-c{12,-dev}.

The problem  I am  facing right  now is how  to combine  the xsd-generated
classes with this library. My document structure looks something like
that:

<xbe:message>
  <xbe:header>
     ...
     <dsig:Signature>
        ...
     </dsig:Signature>
  </xbe:header>

  <xbe:body>
     ...
  </xbe:body>
</xbe:message>

Building and  parsing of simple  "xbe:message" objects works, but  I don't
know how I  am supposed to integrate the  'dsig:Signature' part correctly,
the examples in [3] are not that obvious (at least to me). The steps I
tried so far have been:

    1. create the in-memory representation of a 'xbe:message'
    2. serialize the message to a DOMDocument
    3. find the 'xbe:header' element
    4. create a Signature object (via library calls) and append it to the
       header element
    5. sign the document
    6. write the (signed) document to a file
    7. read the file and validate the signature (fails!)

Did somebody  already implement something like  that and is  able to share
the code? Is there a known procedure how to integrate other libraries that
modify the DOM tree with xsd? I am grateful for any hints.

Best regards,
Alex

References:
        [1] http://www.w3.org/TR/xmldsig-core/
        [2] http://www.w3.org/TR/xmlenc-core/
        [3] http://santuario.apache.org/index.html