Wireshark-dev: [Wireshark-dev] asn2wrs documentation?
From: Peter Wu <peter@xxxxxxxxxxxxx>
Date: Tue, 15 Sep 2015 13:46:40 +0200
Hi,

I am working on improving dissection support of the subjectPublicKey
field in X.509 Certificates[1]. Right now these opaque BIT STRING types
are shown as a sequence of bytes, but I would like to dissect the other
fields (like modulus and exponent for RSA and public key y for DSA).
(This work is a prerequisite for a new method of specifying RSA private
key files in the SSL preferences without having to list address+port.)

These numbers (RSA modulus, DSA y, DSS-Params p, q, g) are larger than
64-bit and therefore are forced to be displayed as FT_BYTES. The problem
that now occurs is that the original field is lost
(ber.64bit_uint_as_bytes is used instead).

To tackle that problem, I started using TYPE_ATTR, but since the fields
are still dissected as ber_integer, it does not help. I think I can use
"IMPORT_TAG", but it is not documented on the wiki[2].

Those who are familiar with the asn2wrs script, is it possible to update
the wiki? Are there other documentation resources available?
-- 
Kind regards,
Peter Wu
https://lekensteyn.nl

 [1]: https://git.lekensteyn.nl/peter/wireshark/commit/?h=lkn/x509-subjectpublickey-v2
 [2]: https://wiki.wireshark.org/Asn2wrsAuxiliary