#!/usr/bin/env python

import sys
import PAM
from getpass import getpass

def pam_conv(auth, query_list, userData):

        resp = []

        for i in range(len(query_list)):
                query, type = query_list[i]
                if type == PAM.PAM_PROMPT_ECHO_ON:
                        val = raw_input(query)
                        resp.append((val, 0))
                elif type == PAM.PAM_PROMPT_ECHO_OFF:
                        val = getpass(query)
                        resp.append((val, 0))
                elif type == PAM.PAM_PROMPT_ERROR_MSG or type == PAM.PAM_PROMPT_TEXT_INFO:
                        print query
                        resp.append(('', 0))
                else:
                        return None

        return resp

service = 'passwd'

if len(sys.argv) == 2:
        user = sys.argv[1]
else:
        user = None

auth = PAM.pam()
auth.start(service)
if user != None:
        auth.set_item(PAM.PAM_USER, user)
auth.set_item(PAM.PAM_CONV, pam_conv)
try:
        auth.authenticate()
        auth.acct_mgmt()
except PAM.error, resp:
        print('Go away! (%s)' % resp)
except:
        print('Internal error')
else:
        print('Good to go!')