Re: Empty IA5String

[John McMeeking <jmcmeek@us.ibm.com>]

On a personal note, I've always found the notion of an zero-length value
hard to digest.  I could really use a real world example (not in the
drafts, just to help me accept the concept) where a zero-length value has a
different meaning than no value.

Otherwise, from the perspective of not breaking existing implementations
(or applications), since zero-length values are valid for several syntaxes
(distinguished name, octet string, IA5 string), unless someone can make a
good argument for zero-length values being an error in the current RFC, I
don't think we should change it.


John  McMeeking


owner-ietf-ldapbis@OpenLDAP.org wrote on 11/09/2004 07:19:03 AM:

> Steven Legg writes:
> >Hallvard B Furuseth wrote:
> >>[Syntaxes] section 3.3.15 says an IA5 String may be empty.
> >>
> >> Why is that, when Directory String and Printable String may not?
> >
> > The Directory String and Printable String syntaxes derive from syntaxes
> > in X.520 that have been constrained to have at least one character.
> > The IA5 String syntax does not have a counterpart in X.520 so it
doesn't
> > need to be constrained for interoperability reasons.
> > (...)
> > The working group needs to decide whether to restrict IA5 String to at
> > least one character, or to allow empty strings to compare true.
>
> My vote from an LDAP viewpoint would be minimal change, i.e. do not
> disallow empty IA5 Strings.
>
> OTOH, if an X.500 implementor wants to support IA5 String, maybe the
> reason why X.500 requires 1+ characters in the other string syntaxes,
> also would make the same restriction preferable in IA5 String?
>
> --
> Hallvard