Pure python crypto

[Michael Gilfix]

On Wed, Apr 17 @ 14:17, Paul Rubin wrote:
> Michael Gilfix <mgilfix at eecs.tufts.edu> writes:
> >   The nice thing about blowfish is its simplicity. I started thinking
> > about implementing DES and 3DES though and its ugly. 
> 
> Blowfish isn't so simple to implement in Python, plus the key setup
> is awfully slow.

  Well, I'll have to post it when I return home to Canada. Not a good
idea to distribute it in the US :) I can send you a copy if you're in
the US if you email me directly.

> >   I was thinking that it might be nice to have an 'ssh' module or
> > 'sftp' module. Specifically, I wanted sftp for an application and
> > couldn't find any such modules. For portability reasons, it might
> > be nice to have a pure python module, however, it would require
> > some tweaking I'm sure.
> 
> I think RC4 coded in Python would run much faster than Blowfish coded
> in Python.  SSH can use RC4.  I don't know what SFTP is.
> 
> FWIW, I coded RC4 in Python a while back and if I remember correctly,
> got about 100k/sec throughput on a P3-750.  That's sort of marginal
> for (say) sftp over ADSL.  Using the SHA-OFB hack that I described,
> I got about 400-500k/sec.  

 Do you still have a copy of this? I would be nice to assemble a suite
that can be used to create a pure python implementation of SSH (which
could also use wrappers to C implementations that exist as well).  I
wish I had a better idea of what was out there module-wise though.

 SFTP is essentially the ftp protocol written on top of SSH. Very
handy as you have all the functionality of FTP except encrypted.

                    -- Mike

-- 
Michael Gilfix
mgilfix at eecs.tufts.edu

For my gpg public key:
http://www.eecs.tufts.edu/~mgilfix/contact.html