Re: [dss-x-comment] DSS2 SignatureAlgorithm (ETSI STF 539)

[Andreas Kuehne <kuehne@trustable.de>]

Hi Henrik,

my overall vision of a DSS server is that it provides a functionality
within a given scope and that's what the server and client agree upon.
This scope may be expressed quite obviously by a ServicePolicy. Once a
client requests e.g. a qualified seal, the server chooses a reasonable
way to fulfill this request within the given requirements. The client
usually isn't aware of all the details. If the client has more specific
requirements regarding the used algorithm and its parameters it seems to
me that initial contract between the client and server wasn't specific
enough.

The intention of the SignatureAlgorithm optional input is to give the
server a hint regarding the expected group of signature algorithms. The
explicit provisioning of algorithm parameters wasn't intended. If the
parameters are included into the interface it will introduce a lot of
additional complexity. Not only in terms of schema size, but also in
terms error handling. And the expected lifetime of the standard will
degraded due to new upcoming algorithms for signing, hashing and padding
and their parameters.

Nevertheless, if you consider explicit parameters as a important
requirement then now it's the best point in time raise your request as
DSS 2.0 is still in the Committee Draft phase.

Greetings,

Andreas 
> Hi,
>
>  
>
> We are working in the ETSI STF 539 about protocols for server signing and
> have a question about the SignatureAlgorithm element in DSS2.
>
>  
>
> The SignatureAlgorithm element is defined as a string type. How can we
> specify the use of the RSA-PSS signature algorithm which may need additional
> parameters, such as salt length and trailer field?
>
>  
>
> Best regards,
>
> Hälsningar/Regards/Grüße - Henrik
>
>
>
>
> Henrik Löfgren, CTO
>  <mailto:anders@comfact.com> henrik@comfact.com
> Tel: +46 (0)31 13 53 15 Mobile: +46 (0)768 15 98 11 
>  <http://www.comfact.com/> www.comfact.com
>
>  
>
>  
>
>

-- 
Andreas Kühne 
phone: +49 177 293 24 97 
mailto: kuehne@trustable.de

Trustable Ltd. Niederlassung Deutschland Gartenheimstr. 39C - 30659 Hannover Amtsgericht Hannover HRB 212612

Director Andreas Kühne

Company UK Company No: 5218868 Registered in England and Wales