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Wireshark-dev: Re: [Wireshark-dev] asn2wrs - BER and AUTOMATIC TAGS question

From: "Martin Peylo" <martinmeis@xxxxxxxxxxxxxx>
Date: Wed, 21 Nov 2007 14:59:27 +0100
Hi Thomas,

thanks a lot for the fast answer!
As you said, I had to insert "[n] IMPLICIT" into each sequence element
to make it work.

Best regards,
Martin

On Nov 20, 2007 7:41 PM, Kukosa, Tomas <tomas.kukosa@xxxxxxxxxxx> wrote:
> Hi,
>
> unfortunately the asn2wrs does not support AUTOMATIC TAGS now.
> The mentioned example is a PER example where tags are not importatnt, i.e. missing AUTOMATIC TAGS support is not a problem.
> I am going to implement it but I am not sure when.
>
> The only way how it can be solved now is to put tags into asn.1 source manually.
>
> regards,
>   Tomas
>
>
> ________________________________
>
> Od: wireshark-dev-bounces@xxxxxxxxxxxxx za uživatele Martin Peylo
> Odesláno: út 20.11.2007 19:16
> Komu: Developer support list for Wireshark
> Předmět: [Wireshark-dev] asn2wrs - BER and AUTOMATIC TAGS question
>
>
>
>
> Hi,
>
> I have to create a dissector for a (not that well designed)
> proprietary ASN.1 defined protocol. It uses BER for encoding.
>
> It is defined with "AUTOMATIC TAGS" which means that the components of
> all constructed types (e.g. SEQUENCEs) are automatically tagged as
> CONTEXT-SPECIFIC starting from 0 and increment by one at each
> successive component.
>
> When I use my newly created plugin on traces, Wireshark complains e.g.
> that it finds 0x80 (first context-specific component) instead of 0x02
> (UNIVERSAL INTEGER).
>
> Now my question:
> Is there any switch I have to use to dissect this kind of encoding or
> is it just not possible so far? The example I found on
> <http://wiki.wireshark.org/FooPage> also uses "AUTOMATIC TAGS".
>
> Best regards,
> Martin
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