Python - EST 3D Secure Integration

est3d.py

#!/usr/bin/python
# -*- coding: utf-8 -*-
from django.shortcuts import redirect
from django.http import HttpResponse
import requests, hashlib, base64, time

EST_MERCHANT_ID = "400000200"
EST_3D_KEY = "TRPS0200"
EST_RETURN_URL = "http://test.domain.com/basarili"
EST_FAIL_URL = "http://test.domain.com/basarisiz"
EST_3D_URL = 'https://entegrasyon.asseco-see.com.tr/fim/est3Dgate'

def build_string(*args):
    return ''.join([str(a) for a in args])

def prepare_hash(clientid,orderid,amount,okUrl,failUrl,islemtipi,rnd,storekey):
    string_to_be_hashed = build_string(clientid,orderid,amount,okUrl,failUrl,islemtipi,rnd,storekey)
    sha1_hashed = hashlib.sha1(string_to_be_hashed).digest()
    base64_enc = base64.b64encode(sha1_hashed)
    return base64_enc

def make_3d_payment(request,order,credit_card,exp_year,exp_month,cvv,cardholder_name):
    rnd = int(round(time.time() * 1000))
    if credit_card[0] == "4":
        brand = 1
    elif credit_card[0] == "5":
        brand = 2
    elif credit_card[0] == "6":
        brand = 3
    else:
        brand = ""
    payload = {
        'clientid' : EST_MERCHANT_ID,
        'islemtipi' : 'Auth',
        'okUrl': EST_RETURN_URL,
        'failUrl': EST_FAIL_URL,
        'storetype':'3d_pay',
        'amount' :  "{0:.2f}".format(order.total_price),
        'currency' : '949',
        'cardType' : brand,
        'pan': credit_card,
        'Ecom_Payment_Card_ExpDate_Year':exp_year,
        'Ecom_Payment_Card_ExpDate_Month':exp_month,
        'cv2':cvv,
        'rnd': rnd,
        'hash': prepare_hash(EST_MERCHANT_ID,order.order_id,"{0:.2f}".format(order.total_price),EST_RETURN_URL,EST_FAIL_URL,"Auth",rnd,EST_3D_KEY),
        'oid': order.order_id,
        'lang':'tr',
    }
    resp = requests.post(EST_3D_URL, data=payload, verify=False)
    return HttpResponse(resp.text)

def finalize_3d_payment(request,result):
    order_id = result.get("oid")
    response = result.get("Response")
    if response == "Approved":
        transaction_id = result.get("TransId")
        #başarılı olarak kaydet
        return redirect("success_page")
    else:
        return redirect("checkout_page")