Python Client side tool( should work in browser) to extract values from a pfx file and sign it
So, first things first: it is not usueal to have the same code to run on server side and client side.
Second thing: be aware that no authentication (or "signing") done on client side can be regarded as safe. At most, the client side can take care of closely coupling the signing with the UI to give the user dynamic feedback - but since whatever requests the client side send to the server can very easily be impersonated by an script, authentication must be performed server side for each request -  for example, a variable saying the current user has authenticated correctly can just be sent as "True", regardless of usernames and passwords actually known.
Third thing: despite all this, since there are these frameworks for using Python or a Python like language client side, it is indeed possible to have some modules in  a code base that are used both client side and server side. Of those, I am most familiar with Brython which has achieved a nice level of Python 3.x compatibility and I indeed have a project sharing code client side and server side.   
The re-used code would have to be refactored to abstract any I/O (like getting user input, or getting values from a database), of couse, since these are fundamentally different things on server side, and client side. Still, some core logic can be in place that is reused both sides. 
However third party python modules, like Pycrypto won't work client side (you could probably code a xmlrpc/jsonrpc like call to use it server side) -
and although Python's hashlib is not implemented now in Brython, the project has got a momentum that opening a feature request for at least the same codecs that exist in javascript could be fulfilled in a matter of days. 
(bugs/features requests can be open at github.com/brython-dev/brython)
(PS. I just found out, to my dismay, that currently there is no standard way to compute any hash, not even md5, in Javascript without third party modules - that just emphasize the utilities of frameworks like Brython or coffescript which can bring up a bundle of functionality in a clean way)
Client side tool to extract values such as common name serial number and public key from pfx file which is loaded by client, and then sign the public key and send to server..
I have completed the backend python code which will import modules from OpenSSL.Crypto library.. 
How to execute the same in client side?.. i.e signing operation should be done in client side, 
In google i found like Brython, skulpt, pyjams help in this.. But i m confused to start.. Any suggestions?