From: pgut001@cs.auckland.ac.nz
Date: Sat, 18 May 1996 16:06:07 +0800
To: cypherpunks@toad.com
Subject: Re: Any DLL's that handle Public Key Encryption or Key Exchange?
Message-ID: <199605180202.OAA09277@cs26.cs.auckland.ac.nz>
MIME-Version: 1.0
Content-Type: text/plain


Death rays from Mars made Bill Stewart <stewarts@ix.netcom.com> write:
 
>There's an RSAEURO drop-in clone of RSAREF that's on ftp.ox.ac.uk, so you
>could write a version of your software that lets Yankees and non-Yankees drop
>in whichever version is appropriate without worrying about patent or copyright
>problems.
 
I've already got a nice fast RSA implementation, so I think I'll stick with
that.  Besides, I'm not terribly keen on using a library which has stolen code
in it.
 
If anyone wants to create an RSAREF version, all you need to do is replace one
module (lib_rsa.c) with an RSAREF-compatible version (that's why I mentioned
plug-in encryption modules in the docs - you just unplug the existing code and
plug in RSAREF instead).  What you need to do is use RSAPublicBlock() and
RSAPrivateBlock(), the rest is just wrapper code which you can base on the
existing lib_rsa.c.  My estimate is that it's about an afternoons work.
 
>Any RSAREF system used in the US has the problem that it's limited to the
>"official" interfaces, which means you can't do fully general RSA without
>permission.
 
I got permission from RSADSI to bypass the official interface to RSAREF for
HPACK, my archiver which has PGP-compatible encryption, in 1993.  However I
suspect getting permission for the same thing in a general-purpose library,
especially one which has RC2, RC4, and DESX[1] in it, may be difficult since
parts of the library are essentially a free version of BSAFE (not by design,
they just ended up that way).
 
[1] Well, it will have DESX once I can get some test vectors to make sure I've
    got it right.  Does anyone have some I can use?
 
Peter.