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Re: Empty IA5String




Kurt,

Another data point ...

Component matching allows any string matching rule to be applied to any
string component of any ASN.1 type. There is nothing to prevent those
string components having zero length. We might be able to force the
IA5 String syntax to have at least one character but we can't do the
same for every string component of every ASN.1 type.

Regards,
Steven

Kurt D. Zeilenga wrote:
At 11:41 AM 11/10/2004, Hallvard B Furuseth wrote:

Kurt D. Zeilenga writes:

I assume what you mean here is that you are increasing
believing that LDAPprep should be redesigned to accept
as input an zero-length string and output a zero-length
string for this input.

This would require a major redesign of the algorithm.

Why? Just put the zero-length shortcut you gave at the top of stringprep algorithm instead of in the matching rule(s) which uses it:


Even if we presume that the proper LDAPprep("") output is "",
specifying this in the I-D would require significant revision
of the text.  And, if we presume that LDAPprep("") output for
some character string matching rules is not "", the I-D would
require significant redesign.

In short, LDAPprep was designed for X.520-based matching rules.
It wasn't designed to handle empty inputs and redesigning it
to handle such inputs is, IMO, non-trivial.

However, before we consider any change to LDAPprep, we first
must reach consensus the semantics of empty values in IA5
Strings.  I note as well that I intend to argue that IA5
Strings, as specified in RFC 1274, were intended to be
non-empty and expected in many to be non-empty and that by
allowing non-empty values in IA5 string will lead to far
more problems than it will resolve.

Kurt