Re: [dss] Compound operation Verify & Sign

[Trevor Perrin <trevp@trevp.net>]

At 10:28 AM 10/24/2003 +0100, Nick Pope wrote:
>Content-Transfer-Encoding: 7bit
>
>Following the discussion on the <Status> element brings to mind the
>discussion we had a few meetings ago on compound (or what Ed called stacked)
>operations and particularly the ability to support a VerifyAndSign operation
>where a counter signature is applied based on whether the original signature
>is valid.
>
>I believe that such an operation is important in a number of use cases, for
>example, notarisation services.
>
>This was brought up at the F2F meeting and was included in the requirements
>document (3.9).  My recollection of the discussion on 22 Sept is that the
>only compound operation that was needed would be VerifyAndSign, although I
>see no record of it in the minutes.
>
>How do we envisage VerifyAndSign being supported in the DSS protocol?  Is
>there a way of combining the two request / response structures, or do we
>need to define a specific structure which is this combined operation?


One idea: a combined, verify-and-sign operation might just have a request 
message identical to VerifyRequest and a response message identical to 
SignResponse (see below) - in other words, a signature is *both* sent (like 
in VerifyRequest) and retrieved (like in SignResponse).

I'm sure it's more complicated than that, in terms of options, but the 
basic framework might be pretty simple..


Trevor


         <xs:element name="SignRequest">
                 <xs:complexType>
                         <xs:sequence>
                                 <xs:element ref="dss:Options" minOccurs="0"/>
                                 <xs:element ref="dss:InputDocuments"/>
                         </xs:sequence>
                 </xs:complexType>
         </xs:element>

         <xs:element name="SignResponse">
                 <xs:complexType>
                         <xs:sequence>
                                 <xs:element ref="dss:Status"/>
                                 <xs:element ref="dss:Signature" 
minOccurs="0"/>
                                 <xs:element ref="dss:Outputs" minOccurs="0"/>
                         </xs:sequence>
                 </xs:complexType>
         </xs:element>

         <xs:element name="VerifyRequest">
                 <xs:complexType>
                         <xs:sequence>
                                 <xs:element ref="dss:Options" minOccurs="0"/>
                                 <xs:element ref="dss:Signature" 
minOccurs="0"/>
                                 <xs:element ref="dss:InputDocuments"/>
                         </xs:sequence>
                 </xs:complexType>
         </xs:element>

         <xs:element name="VerifyResponse">
                 <xs:complexType>
                         <xs:sequence>
                                 <xs:element ref="dss:Status"/>
                                 <xs:element ref="dss:Outputs" minOccurs="0"/>
                         </xs:sequence>
                 </xs:complexType>
         </xs:element>