[Cryptography Team] Team Update

[Ron Teitelbaum]

Thanks for the link, I will read through it.   

 

My thoughts were to evaluate Cees comments about ASN.1 needing to be
implementation specific, but I have a strong preference for a general
purpose solution.  There has been a lot done in the compiler area that
doesn't apply to Smalltalk.  I would at least like to add as much
functionality as the C community is getting from an ASN complier.  I'm still
speaking from ignorance here, but my first impressions are, to allow the
building of an ASN structure using ASN specific classes, and to allow the
structure to read from / write to objects through a TopLink like meta
definition attached to classes, with more information like how to navigate
links.  That way the structure could translate directly using some form of
root object to gather data.  It would seem to me that that structure would
be pretty flexible and general purpose, but it needs more flushing out.  

 

To say it again:

 

ASN notation builds ASN Structure of objects in Squeak.

ASN Structure Traverses a Root Object Meta Data Structure to retrieve data
from itself or other linked objects.

The ANS Structure Class would be responsible for BER / DER encoding.

 

The Developer / User would be responsible for running the notation to create
the structure, then defining meta data on domain objects to get and write
data based on some root object (s).

 

I'm sure you have a lot more experience with this, and I am still learning.
The parser that creates the structure would do validation which may be the
most difficult part (as Cees pointed out earlier).  Having the meta data
coordinate encoding on the ANS Structure should simplify things some, much
in the way that TopLink simplifies SQL query building.  What do you think of
the potential of the design and its ability to provide similar value as
users currently get form asn compilers?

 

Ron Teitelbaum

 

 

 

  _____  

From: Matthew S. Hamrick [mailto:mhamrick at cryptonomicon.net] 
Sent: Wednesday, November 16, 2005 1:38 PM
To: Ron at USMedRec.com; Cryptography Team Development List
Subject: Re: [Cryptography Team] Team Update

 

Hey...

 

Are we working on a general purpose ASN.1 compiler / BER codec or just
enough ASN.1 to parse certs and PKCS blobs?

 

I might recommend we design an interface for the former but simply implement
the latter. BER / DER encoding can be a little ugly at times. I've written
several "highly-focused" BER / DER decoders in Java, and can tell you that
scope creep is NOT your friend. ("Highly focused" in this context means
specific to the ASN.1 for a particular application.)

 

I think someone mentioned Dubuisson's book on ASN.1, the PDF of which is
available for free download. While I believe that Dubuisson's book is an
excellent read, there's more to ASN.1 than BER/DER encoding, and you might
wind up wasting a little bit of time by trying to implement _everything_.
You might want to check out Burt Kaliski's "Layman's guide to a subset of
ASN.1, BER, and DER". Available in text format at
ftp://ftp.rsa.com/pub/pkcs/ascii/layman.asc .

 

-Cheers!

-Matt H.

 

On Nov 15, 2005, at 7:18 PM, Ron Teitelbaum wrote:





Also once the relationship is settled we will again approach Cincom about a
port of their cryptography code. (Sean have you heard any new comments from
James?) In the mean time I am still working through ASN.1.

We have a new official Team Member: Paul Davidowitz. Paul and I have worked
before he is a very solid programmer. We have discussed ASN.1 and Paul is
working through some possible designs. Please welcome Paul to the team!

 

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