[Date Prev][Date Next] [Chronological] [Thread] [Top]

Re: Models: Matching Rule Uses

At 04:18 PM 2/13/2003, David Chadwick wrote:
>> >So caseIgnoreIA5Match can be used with attributes whose corresponding
>> >ASN.1 type is IA5String, but not e.g. bit string syntax.  I'm hoping
>> >that this also means that a caseIgnoreIA5Match matching rule use can
>> >only list attributes whose corresponding ASN.1 type is IA5String.
>> 
>> No, the assertion syntax and attribute value syntax can be quite
>> different.
>
>Currently this is not so.

X.501(93) does not restrict how "different" the syntaxes might
be.  It only requires that there be "rules for deriving a value of
the assertion syntax from a value of the attribute syntax, if required."

And while X.501 says these rules are to be defined as part of the matching
rule specification, I believe (as is the common practice) that new syntax
specifications may define new value derivation rules such that existing
matching rules may be re-used with the new syntax.

There are a wide variety of uses of the "core" matching rules with attribute
value syntaxes not considered by the "core" specification.

Kurt