Unrecognized application tags throw an error instead of creating a generic object

[point-source]

The current implementation of the ASN1Parser checks to see if the tag is primitive or application. If the tag is application, it checks to see if it is based on a sequence. If so, it parses as a sequence. If not, it throws an error. What's strange is that if the tag is neither primitive nor application (and is thus either context-specific or universal), the parser goes ahead and creates a generic ASN1Object.

Is there a reason why we allow generic objects in context-specific or universal space but not within application space? From what I understand, application are any tags that might exist in say LDAP but not in SNMP or vice-versa. I assume that means that an LDAP tag may have the same code as an SNMP tag but mean different things. I have struggled to find documentation to confirm/deny this.

If this is not the case, and all application-based tags are unique/reserved, I would like to add additional tags to this library so they may be recognized. If this is the case, and application tags may mean different things to different applications, then I propose we allow generic objects to be created when an application tag is not recognized.

Relevant code here: https://github.com/wstrange/asn1lib/blob/master/lib/asn1parser.dart#L57

[wstrange]

The ASN1 spec is very non obvious to me - but what you are proposing makes sense. I can retest the dartdap ldap library if you create a new version. LDAP is a pretty good way of shaking out encoding problems.