Decrypt AES CBC in python

I have the following code in JS

var CryptoJS = require("crypto-js");

function DecodePara(encrypted, key, iv) {
    var key = CryptoJS.SHA256(key);
    var iv = CryptoJS.SHA256(iv);
    var decrypted = CryptoJS.AES.decrypt(encrypted, key, {
        iv: iv,
        mode: CryptoJS.mode.CBC,
        padding: CryptoJS.pad.ZeroPadding
    });
    return decrypted.toString(CryptoJS.enc.Utf8);
}

var encrypted = 'bCjzbWfj7KqtJjCvYpq7Pg=='
var key = 'SNhPDFVEQVWZjsHoyDBXfuWC'
var iv = key.substr(5, 10)

console.log(DecodePara(encrypted, key, iv))

Output = '10203050'

the return is as expected, I would like to get the same result through python, I have already performed some tests based on some research but without success.)

I have tried variations of the following code

from Crypto.Cipher import AES
from Crypto.Util.Padding import unpad
import hashlib

code = 'bCjzbWfj7KqtJjCvYpq7Pg=='

key = 'SNhPDFVEQVWZjsHoyDBXfuWC'
iv =  key[5:15]

key = hashlib.sha256(key.encode('utf-8')).hexdigest()
iv = hashlib.sha256(iv.encode('utf-8')).hexdigest()

def decrypt(encrypted,key,iv):   
  cipher = AES.new(key, AES.MODE_CBC, iv)
  decryptedtext = unpad(cipher.decrypt(encrypted), AES.block_size)
  decryptedtextP = decryptedtext.decode("UTF-8")
  return decryptedtextP

decrypted = decrypt(code,key,iv)
print(decrypted)

raise ValueError("Incorrect AES key length (%d bytes)" % len(key)) ValueError: Incorrect AES key length (64 bytes)

Solution

Consider the following in the Python code:

key and IV must not be hex encoded, i.e. hexdigest() must be replaced by digest().
the IV has to be truncated to 16 bytes (implicitly done in the CryptoJS code).
the ciphertext has to be Base64 decoded Base64 (implicitly done in the CryptoJS code).
remove the Zero padding manually, e.g. with rstrip(b'\0'), because the padding module of PyCryptodome does not support Zero padding.

The fixed code is:

from Crypto.Cipher import AES
import hashlib
import base64

code = 'bCjzbWfj7KqtJjCvYpq7Pg=='

key = 'SNhPDFVEQVWZjsHoyDBXfuWC'
iv =  key[5:15]

key = hashlib.sha256(key.encode('utf-8')).digest()              # replace hexdigest() by digest
iv = hashlib.sha256(iv.encode('utf-8')).digest()[0:16]          # replace hexdigest() by digest; truncate the IV to 16 bytes

def decrypt(encrypted,key,iv):   
  cipher = AES.new(key, AES.MODE_CBC, iv)
  decryptedtext = cipher.decrypt(base64.b64decode(encrypted))   # Base64 decode the ciphertext
  decryptedtextP = decryptedtext.rstrip(b'\0').decode("UTF-8")  # remove the Zero padding
  return decryptedtextP

decrypted = decrypt(code,key,iv)
print(decrypted) # 10203050

Keep in mind:

it's insecure to derive the IV from the key, since this results in reuse of key/IV pairs if the key is fixed. Instead, a random IV should be used for each encryption.
Zero padding is unreliable. Instead PKCS#7 padding should be used (which is also supported by PyCryptodome's padding module).
it's a vulnerability to use a digest as key derivation function. Instead, a dedicated key derivation function such as Argon2 or PBKDF2 should be applied.