Fonepay transaction verification

fonepay_verification.py

import requests
import hashlib
import hmac
import base64
import json

from django.conf import settings

def base64(st):
    return base64.b64encode(st.encode('utf-8')).decode('utf-8')

def verify(params):
    
    auth_str = '{}:{}'.format(settings.FONEPAY_USERNAME, settings.FONEPAY_PASSWORD) 
    auth_str = 'Basic {}'.format(base64(auth_str))
    
    concat = '{},{},{},{},{},{{"prn": "{}","merchantCode": "{}","amount": "{}"}}'. \
        format(settings.FONEPAY_USERNAME,
               settings.FONEPAY_PASSWORD, 'POST',
               'application/json',
               '/merchant/merchantDetailsForThirdParty/txnVerification',
               params['PRN'],
               settings.FONEPAY_MERCHANT_CODE,
               int(float(self.amount)),
               ).encode('utf8')

    sign = hmac.new(settings.FONEPAY_SECRET.encode('utf8'), concat, hashlib.sha512).hexdigest()
    
    headers = {
        'Content-Type': 'application/json',
        'Authorization': auth_str,
        'auth': sign,
    }

    data = {"prn": params['PRN'], "merchantCode": settings.FONEPAY_MERCHANT_CODE, "amount": self.amount}
    response = requests.post(settings.FONEPAY_VERIFICATION_URL, data=json.dumps(data), headers=headers)