# L-37 MCS 275 Wed 14 Apr 2010 : pass_server.py

# The server receives login name.

namespass = {'A':'1','B':'2'}

from socket import *

hostname = ''   # blank for any address
number = 11267  # number for the port
buffer = 80     # size of the buffer

def connect():
   """
   Connects and returns server socket.
   """
   server_address = (hostname, number)
   server = socket(AF_INET, SOCK_STREAM)
   server.bind(server_address)
   server.listen(1)
   return server

def serve(server):
   """
   Accepts connection from a client
   and receives a login name.
   Checks if the name is a key in namespass
   and sends a reply to the client.
   If the name is a key, then the password
   sent by the client is checked and a reply
   is send back.
   """
   client, client_address = server.accept()
   name = client.recv(buffer)
   print 'received \"' + name + '\"'
   if not namespass.has_key(name):
      print 'access is denied'
      client.send('access denied')
   else:
      client.send('send password')
      pasw = client.recv(buffer) 
      print 'received \"' + pasw + '\"'
      if namespass[name] == pasw:
         print 'access is granted'
         client.send('access granted')
      else:
         print 'access is denied'
         client.send('access denied')

def main():
   """
   Simulates a simple password interaction.
   """
   server = connect()
   print 'waiting for connections'
   serve(server)
   print 'closing the server'
   server.close()

if __name__=="__main__": main()