[PYTHON-CRYPTO] DES3.py on Vista Question

[SUBSCRIBE PYTHON-CRYPTO Anonymous]

Greetings, 

I will say first that this forum may be more advanced than where I ought to
be, and if this is the case I welcome suggestions for other places to find
the answer to my query.

Second, I will give a quick background on my current application.
I have written a signal-processing and data visualization package primarily
in matlab.  In future, I would like to migrate this to python, but for now
it stands in matlab.

I am currently working to distribute this package.  It is comprised of
several data processing and plotting utilities which the user calls from
their machine.  The data however are warehoused by a university server, and
need to be downloaded before analysis can begin.  The sorts of data we are
talking about are continuously recorded sensors, sampling at 40Hz, for many
years.  A particular user is typically only interested in small segments of
the data stream, and it is not practical for me to put up a mirror pointing
to all the data.  The server has a utility for queing segments of data which
a user finds interesting.

I have put together some python codes which operate on the server.  Based on
a few user defined parameters, they retrieve a collection of files from the
database, together with relevant metadata for processing.  The files are
housed in a scratch directory before being sftp-ed to the user's machine.

My problem is that I am looking for a general way that someone using my
codes can execute their data-retrieval requests and transfer data from the
server to their personal machines.

In the past, for my own use, I simply set up SSH with public-private key
encryption on whichever linux machine I am using, and place the commands I
want to execute remotely in a script, and then execute the commands remotely
using ssh.

The problem is that some of the people wanting the software are using
Windows Vista.  I spent some time researching this, and it appears that if I
shell the client-commands in python, and use the Paramiko package, I ought
to be able to provide the users with the functionality that I would like,
i.e. a user can register with me, and I can issue them a key, and they can
run the data retrieval command from their machine.

My first question would be: is that correct?  Or should be looking into
using PERL or some other language.

My second question is more technical:

I have invested a significant amount of time in trying to install python
with the paramiko package on a vista machine.  I installed python 2.5, and
was able to run some basic commands and import standard packages (e.g. os).
 When I attempt to import paramiko however, I have had many errors, most of
which seem to have to do with upper and lower case letters from the auto
install.  I have hacked around by changing the source code, for example:  
from paramiko.folder import file
to 
from Paramiko.Folder import File

At the end of this, I am now receiving the following error:


>>> import Paramiko
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "__init__.py", line 69, in <module>
    from transport import randpool, SecurityOptions, Transport
  File "transport.py", line 37, in <module>
    from Paramiko.dsskey import DSSKey
  File "C:\Python25\Paramiko\dsskey.py", line 31, in <module>
    from Paramiko.pkey import PKey
  File "C:\Python25\Paramiko\pkey.py", line 28, in <module>
    from Crypto.Cipher import DES3
ImportError: cannot import name DES3
>>>

The DES3 error it would seem to me would be because there is no DES3.py in
my Crypto.Cipher diectory.
I have read up on DES3 a little, and have a vague notion that it combines
three usages of an encryption algorithm which alone is too small and simple
to be safely used.  Should there be a DES3.py in my Crypto.Cipher?  I cannot
find any reference to that effect on the web.  It occurs to me that I may
want to install this package on linux, and see it work properly, then return
to this Vista experiment, but I though perhaps someone had installed this on
a Vista machine before and run into a similar challenge.

Thanks for your time, 
Klive