FW: [ubl-dev] Digital Signatures

["Sylvia Webb" <swebb@gefeg.com>]

All,

Just before the holidays, this messages was posted on UBL-Dev.
Additionally, I exchanged email with Giovanni directly and he provided some
additional information and a suggested solution.

He has given his permission for me to post his messages to me to the list.
The additional project details and his proposed solution follow his initial
message. Giovanni has also volunteered to assist us when we are ready to
discuss this requirement. He is a member of the Spanish Localization
subcommittee.

Regards,
Sylvia 
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-----Original Message-----
From: Giovanni Roldan [mailto:groldan@gennassis.com] 
Sent: Friday, December 17, 2004 1:59 PM
To: ubl-dev@lists.oasis-open.org
Subject: [ubl-dev] Digital Signatures


1.- Is there available schemas in the UBL definition to digitally sing UBL
documents? (I can't see the tags and namespaces for digital signature in
schemas)

2.- Is there any way to include or to import digital signature definitions
in UBL shemas?

 
These questions raise because I'm trying to use Microsoft Infopath 2003, and
I need to use the digital signature feature that comes with this product but
I can't, the product documentation indicate:  "You cannot enable digital
signatures for a form that was designed based on an XML Schema  that does
not have a digital signature namespace" 

 
I'm working for a government project (in Ecuador- South America) so it's
very important to support digital signatures using the UBL standard and
obviously the security feature of MS InfoPath.


Saludos,

Giovanni Roldan C.
GENNASSIS
www.gennassis.com

Quito
Ecuador.

-----Mensaje original-----
De: Stephen Green [mailto:stephen_green@bristol-city.gov.uk]
Enviado el: viernes, 17 de diciembre de 2004 7:53
Para: ubl-dev@lists.oasis-open.org
Asunto: Re: [ubl-dev] Tools for database support for UBL?

Many thanks to all who replied to my question about tools and techniques for
supporting database integration with UBL and UBL-based Schemas and
instances.

It will take a while to ponder all the shared information :-)

Tim's response makes me wonder whether some of the extra information from
the conceptual model which might be necessary to properly create table
relationships could be provided in a form more accessible to a code/SQL
generator.

If anyone has any further information on how to infer (perhaps automatably)
the relationships from the xsd or spreadsheets which are machine-readable
then I'd love to hear it.

Also if anyone has any solutions for a .NET developer to use I'd love to
hear of them.

Again, thanks to everyone.

All the best

Stephen Green

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The detailed requirement for the project:

We are designing business documents (forms) based in the UBL definition for
example invoices and order (obviously). To design the forms we are using
Microsoft Infopath, Infopath produces an xml document with the information
filled in the form (the invoice); until here everything is perfect.

Infopath has a feature to sign documents using the W3C standard, now the
problem: to use these feature it's needed a schema for signatures and UBL
doesn't include a schema for signatures, that is the reason why Infopath
present the following error: 

"You cannot enable digital signatures for a form that was designed based on
an XML Schema  that does not have a digital signature namespace"

Now it's clear for me that I need to include my own signature schema (until
there is a "formal standard" for signatures schemas in UBL), as I understood
in one of the responses in this forum UBL 1.1 will include a schema; Stephen
Green suggested something like:

<?xml version="1.0"?>
<xsd:schema targetNamespace="some:urn"...   
...
namespace declarations and  includes or imports of both digital signature
and  UN/CEFACT StandardBusinessDocumentHeader Schemas ...
<xsd:complexType name="GenericHeader">
  <xsd:sequence>
    <xsd:element ref="[[ something for digital signature ]]"/>
    <xsd:element ref="sh:StandardBusinessDocument" minOccurs="0"/>
  </xsd:sequence>
</xsd:complexType>
<xsd:element name="GenericHeader" type="GenericHeader"/>
<xsd:element name=  [[ something for digital signature ]]   />
</xsd:schema>

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The solution is to add to the UBL schema, the following XML lines:

 

<xsd:element name="signature"> <!-contribution of GENNASSIS -->

   <xsd:complexType>

   <xsd:sequence>

       <xsd:any
namespace="http://www.w3.org/2000/09/xmldsig#"processContents="lax";
minOccurs="0" maxOccurs="unbounded"/>

   </xsd:sequence>

   </xsd:complexType>

</xsd:element>

 
The piece of XML should be added to any UBL schema document (maindoc) as an
additional element, for example in the Order UBL schema the signature
element should be a child element of the Order root element.
 

In the attached file you will find a complete Order UBL schema example,
which works with Microsoft InfoPath and supports digital signatures.

COMERCIUS UBL-Order-1.0.xsd