[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: comment on draft-ietf-ltans-dssc-01.txt



How about something like the following to avoid multiple instances of an alg
ID:

> AlgorithmValidityInfo ::= SEQUENCE {
> 	identifier  AlgorithmIdentifier,
> 	constraints SEQUENCE OF Constraint
	}

	Constraint::= SEQUENCE {
	parameter  CHOICE {
>                         exact  [0] OCTET STRING,
>                         min    [1] OCTET STRING,
>                         max    [2] OCTET STRING,
>                         range  [3] Range,
>                         other  [4] OtherConstraints}
> 	validity    Validity OPTIONAL,
> 	information Information OPTIONAL }


> -----Original Message-----
> From: owner-ietf-ltans@xxxxxxxxxxxx 
> [mailto:owner-ietf-ltans@xxxxxxxxxxxx] On Behalf Of Thomas Kunz
> Sent: Wednesday, December 05, 2007 11:02 AM
> To: Turner, Sean P.
> Cc: ietf-ltans@xxxxxxx
> Subject: Re: comment on draft-ietf-ltans-dssc-01.txt
> 
> The problem with your suggested syntax is the definition of 
> the our constraints. If we used the RFC3280 
> AlgorithmIdentifier structure, we would integrate the 
> constraints as follows:
> 
> AlgorithmValidityInfo ::= SEQUENCE {
> 	identifier  AlgorithmIdentifier,
> 	constraint  CHOICE {
>                         exact  [0] OCTET STRING,
>                         min    [1] OCTET STRING,
>                         max    [2] OCTET STRING,
>                         range  [3] Range,
>                         other  [4] OtherConstraints
> 	validity    Validity OPTIONAL,
> 	information Information OPTIONAL }
> 
> It's not possible to determine constraints for more than one 
> parameter (e.g. p > 1024 and q > 160 in case of DSA).
> Additionally defining ranges is impossible (e.g. modulus < 
> 2048 and modulus > 1024).
> 
> 
> so & tk
> 
> 
> Turner, Sean P. schrieb:
> > I'm only commenting on the Parameter structure in the 
> ASN.1. I think 
> > that it might be better to change Algorithm to be a sequence of 
> > algorithmIdentifier, validity, and information - call it 
> > AlgorithmValidityInfo. I suggest this for two reasons:
> > 
> > 1. The AlgorithmIdentifier structure that is used to assign an 
> > algorithm's object identifier also define the parameters. So it 
> > probably makes sense to reuse this structure.
> > 
> > 2. The parameters structures for some of the newer 
> algorithms is quite 
> > complicated. For example,  RSASSA-PSS [RFC4055] and ECC 
> Algs [RFC3279] 
> > aren't just an OID they are nested structure.
> > 
> > (not sure how to do it in XML)
> > 
> > Replace:
> > 
> > Algorithm ::= SEQUENCE {
> >         algorithmIdentifier  AlgID,
> >         parameters           [0] SEQUENCE OF Parameter  OPTIONAL,
> >         validity             [1] Validity,
> >         information          [2] SEQUENCE OF UTF8String OPTIONAL
> >    }
> > 
> >    AlgID ::= SEQUENCE {
> >         name  UTF8String,
> >         oid   [0] SEQUENCE OF OBJECT IDENTIFIER OPTIONAL,
> >         uri   [1] SEQUENCE OF IA5String OPTIONAL
> >    }
> > 
> >    Parameter ::= SEQUENCE {
> >         name        UTF8String,
> >         constraint  CHOICE {
> >                       exact  [0] OCTET STRING,
> >                       min    [1] OCTET STRING,
> >                       max    [2] OCTET STRING,
> >                       range  [3] Range,
> >                       other  [4] OtherConstraints
> >         }
> >    }
> > 
> > With:
> > 
> > AlgorithmValidityInfo ::= SEQUENCE {
> >  identifier  AlgorithmIdentifier,
> >  validity    Validity OPTIONAL,
> >  information Information OPTIONAL }
> > 
> > Validity ::= SEQUENCE {
> >   start  [0] GeneralizedTime OPTIONAL,
> >   end    [1] GeneralizedTime OPTIONAL }
> > 
> > Information ::= SEQUENCE SIZE (1..MAX) OF UTF8String
> > 
> > -- From RFC3280
> > AlgorithmIdentifier  ::=  SEQUENCE  {
> >      algorithm               OBJECT IDENTIFIER,
> >      parameters              ANY DEFINED BY algorithm OPTIONAL  }
> >                                 -- contains a value of the type
> >                                 -- registered for use with the
> >                                 -- algorithm object identifier value
> > 
> > spt
> > 
> > 
> 

Attachment: smime.p7s
Description: S/MIME cryptographic signature