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Re: LDAP Certificate transfer syntax

David:

When DAP is used, certificates come back in BER. This happens because the DAP PDU is defined in ASN.1, and the BER encoding of the PDU encodes the data too. An OCTET STRING could have been used, but this was all done before there were object that had signatures. Anyway, I see this as an opportunity to do better.

I do not know about your AC development experience, but the specifications are quite clear about the need for DER. It would be nice if the repository fetch did not force the client to restore the original DER encoding.

I agree that this is not a schema issue. However, a comment that the DER encoding applied by the signer should be preserved is all I really want. You have already fixed the problem where the repository access protocol is changing the encoding.

Russ


At 06:39 PM 4/3/2002 +0100, David Chadwick wrote: 
Russ

I dont think the issue below is one for the schema ID. The certificate
attributes in the directory should be perfectly happy to receive BER or
DER (or PER for that matter I guess). So the schema ID should allow
anything to be stored there.

Your issue is more one for the LDAP profile ID which was last updated in
January. In the profile we can suggest that clients always use DER for
encoding certificates.  But what is the common WG concensus on this? FYI
in recent work we did with attribute certificates we found we had to use
BER because the DER Java objects were too buggy.

David


"Housley, Russ" wrote:
>
> David:
>
> I would like to encourage clients to provide certificates in DER. We ought
> to tell them that there will be less work for everyone if they provide
> DER-encoded certificates. Likewise for CRLs.
>
> Russ
>
> At 10:32 PM 4/1/2002 +0100, David Chadwick wrote:
>
> >"Housley, Russ" wrote:
> > >
> > > David:
> > >
> > > Is it possible to preserve the DER encoding. If not, then the DER encoding
> > > must be restored in order to validate the signature? This just seems like
> > > wasted processing to me.
> > >
> >
> >Russ
> >
> >I quite agree. The revised text is meant to ensure that the DER or BER
> >encoding created by the client when the certificate was first sent to
> >the directory for storage is preserved as is. This is the purpose of the
> >sentence below in the revised text, viz:
> >
> > > >Servers must preserve values in this syntax exactly as given when
> > > >storing and retrieving them.
> > > >
> >
> >Perhaps I should say "as given to them by the client, when storing and
> >retrieving certificates"
> >
> >David
> >

--
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David W. Chadwick, BSc PhD
Professor of Information Systems Security
IS Institute, University of Salford, Salford M5 4WT
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