[Python] POST request to google analytics API with encrypted parameters throws Invalid grant...

I am trying to generate the Access Token using Refresh token from Google Analytics API. The request which I am trying to send is encrypted using Python libraries. When I run the below code, I am getting

{'error': 'unsupported_grant_type', 'error_description':'Invalid grant_type: '}

When I run this code without encrypting the parameters, my request works fine without any issues and able to get the access token as well. I am not really sure what I am missing here. Kindly help on this issue and suggest some solutions.

import os
import requests
import json
import base64
import random
from Crypto import Random
from Crypto.Cipher import AES
from Crypto.Random import get_random_bytes
from Crypto.Util.padding import pad,unpad
import secrets

key= os.urandom(16)
iv = Random.new().read(AES.block_size)


def encrypt_data(key, data):
BS = AES.block_size
pad = lambda s: s + ((BS - len(s) % BS) * chr(BS - len(s) % BS)).encode()
cipher = AES.new(key, AES.MODE_CBC, iv)
encrypted_data = base64.b64encode(cipher.encrypt(pad(data)))
return encrypted_data


base_url = "https://accounts.google.com"
client_Id = "XXXXX"
client_secret = "YYYYY"
grant_type = "refresh_token"
refresh_token = "ZZZZZZ"
access_type="offline"

data = {"grant_type":grant_type,
"client_id":client_Id,
"client_secret":client_secret,
"refresh_token":refresh_token,
"access_type":access_type
}

encode_string = json.dumps(data).encode("utf-8")
response = requests.post(base_url+"/o/oauth2/token?",params=encrypt_data(key,encode_string)).json()
print(response.content)

Continue reading...