Stig,
I have looked a both the captures and I think that they show problems with their associated dissectors.
The patch added better/more rigorous handling of constructed ASN.1 types that are IMPLICITLY tagged, and consequently you can get away with less.
In your capture file, the IMPLICIT CONTEXT [0] tag was marked as constructed. The Wireshark ASN.1 file expected to decode this as OCTET STRING:
ISO8823-PRESENTATION.asn:
CHOICE {single-ASN1-type [0] IMPLICIT OCTET STRING,
So wireshark expects to find a constructed OCTET STRING - but it doesn't find an internal OCTET STRING tag and so you see the error in wireshark you do.
However, I believe this is because ISO8823-PRESENTATION.asn should say:
CHOICE {single-ASN1-type [0] ANY,
This much better aligns with the original ASN.1.
The ANY you provided in your example capture was indeed constructed.
Attached is a simple patch. If you concur, then I will apply it.
As for Jeff's problem, I suspect it is something similar, but I will have to do a bit more digging yet as I am not as familiar with that protocol.
Graeme
Index: asn1/pres/ISO8823-PRESENTATION.asn
===================================================================
--- asn1/pres/ISO8823-PRESENTATION.asn (revision 33367)
+++ asn1/pres/ISO8823-PRESENTATION.asn (working copy)
@@ -368,7 +368,7 @@
transfer-syntax-name Transfer-syntax-name OPTIONAL,
presentation-context-identifier Presentation-context-identifier,
presentation-data-values
- CHOICE {single-ASN1-type [0] IMPLICIT OCTET STRING,
+ CHOICE {single-ASN1-type [0] ANY,
-- [0] ABSTRACT-SYNTAX.&Type
-- (CONSTRAINED BY {
Index: asn1/pres/pres.cnf
===================================================================
--- asn1/pres/pres.cnf (revision 33367)
+++ asn1/pres/pres.cnf (working copy)
@@ -47,7 +47,6 @@
proto_item *ti = proto_tree_add_text(tree, tvb, offset, -1,"dissector is not available");
expert_add_info_format(actx->pinfo, ti, PI_UNDECODED, PI_WARN, "Dissector is not available");
}
- %(DEFAULT_BODY)s
}
#.FN_BODY PDV-list/presentation-data-values/octet-aligned