Encrypt - Decrypt AES from/to Python PyCryptodome from/to PHP openssl

encryption.php

<?php
// use to generate key : 'openssl rand -hex 32'

function my_encrypt($data, $passphrase) {
    $secret_key = hex2bin($passphrase);
    $iv = openssl_random_pseudo_bytes(openssl_cipher_iv_length('aes-256-cbc'));
    $encrypted_64 = openssl_encrypt($data, 'aes-256-cbc', $secret_key, 0, $iv);
    $iv_64 = base64_encode($iv);
    $json = new stdClass();
    $json->iv = $iv_64;
    $json->data = $encrypted_64;
    return base64_encode(json_encode($json));
} 

function my_decrypt($data, $passphrase) {
    $secret_key = hex2bin($passphrase);
    $json = json_decode(base64_decode($data));
    $iv = base64_decode($json->{'iv'});
    $encrypted_64 = $json->{'data'};
    $data_encrypted = base64_decode($encrypted_64);
    $decrypted = openssl_decrypt($data_encrypted, 'aes-256-cbc', $secret_key, OPENSSL_RAW_DATA, $iv);
    return $decrypted;
}

encryption.py

#!/usr/bin/env python3
# pip install pycryptodome

import json
import binascii
from Crypto.Cipher import AES
from Crypto import Random
import base64

def my_encrypt(data, passphrase):
    """
         Encrypt using AES-256-CBC with random/shared iv
        'passphrase' must be in hex, generate with 'openssl rand -hex 32'
    """
    try:
        key = binascii.unhexlify(passphrase)
        pad = lambda s : s+chr(16-len(s)%16)*(16-len(s)%16)
        iv = Random.get_random_bytes(16)
        cipher = AES.new(key, AES.MODE_CBC, iv)
        encrypted_64 = base64.b64encode(cipher.encrypt(pad(data).encode())).decode('ascii')
        iv_64 = base64.b64encode(iv).decode('ascii')
        json_data = {}
        json_data['iv'] = iv_64
        json_data['data'] = encrypted_64
        clean = base64.b64encode(json.dumps(json_data).encode('ascii'))
    except Exception as e:
        print("Cannot encrypt datas...")
        print(e)
        exit(1)
    return clean

def my_decrypt(data, passphrase):
    """
         Decrypt using AES-256-CBC with iv
        'passphrase' must be in hex, generate with 'openssl rand -hex 32'
        # https://stackoverflow.com/a/54166852/11061370
    """
    try:
        unpad = lambda s : s[:-s[-1]]
        key = binascii.unhexlify(passphrase)
        encrypted = json.loads(base64.b64decode(data).decode('ascii'))
        encrypted_data = base64.b64decode(encrypted['data'])
        iv = base64.b64decode(encrypted['iv'])
        cipher = AES.new(key, AES.MODE_CBC, iv)
        decrypted = cipher.decrypt(encrypted_data)
        clean = unpad(decrypted).decode('ascii').rstrip()
    except Exception as e:
        print("Cannot decrypt datas...")
        print(e)
        exit(1)
    return clean

Hello @eoli3n can you help me let me know how nonce and ctr is created in Node-js code?

i tried the code above, its working when encrypt decrypt using python..
but, when i decrypt using php the encrypted text in python.. its not working..

is anyone have the same issue ?

<?php
function decrypt($data) {
    $passphrase = '71b9111bd63e1f4d54f347938d6f2881';
    $secret_key = hex2bin($passphrase);
    $json = json_decode(base64_decode($data));
    $iv = base64_decode($json->{'iv'});
    $encrypted_64 = $json->{'data'};
    $data_encrypted = base64_decode($encrypted_64);
    $decrypted = openssl_decrypt($data_encrypted, 'AES-256-CBC', $secret_key, OPENSSL_RAW_DATA, $iv);
    
    echo $decrypted;
    return $decrypted;
}

$res = decrypt("eyJpdiI6ICJLWTBiOFNMcy9GY1c3RFY1SjI4OUJBPT0iLCAiZGF0YSI6ICI4b3M1d3J5YzdzaFU4d0NoV1RIK1NiK3FiUVhPNnRjMzBSRjllaDlCdDFVPSJ9");
echo $res;
?>

@SDAMedia you didn't give the passphrase to the function.

$res = decrypt("eyJpdiI6ICJLWTBiOFNMcy9GY1c3RFY1SjI4OUJBPT0iLCAiZGF0YSI6ICI4b3M1d3J5YzdzaFU4d0NoV1RIK1NiK3FiUVhPNnRjMzBSRjllaDlCdDFVPSJ9", "YOUR_PASSPHRASE_HERE");

the passphrase already in the function, so i'm not passing the passphrase in the function.. @eoli3n

can anyone help me..

@SDAMedia in openssl_decrypt, change the algorithm from 'AES-256-CBC' to 'AES-128-CBC'. The length of your passphrase corresponds actually to the latter.
(Compare "openssl rand -hex 32" and "openssl rand -hex 16", the number of characters in hex representation is doubled)

ah I see @mxmfrlv thank you very much, I remember when I implemented the encryption above in my python code, it's not working with hex 32, so I am using hex 16.

then when I change the algorithm from AES-256-CBC to AES-128-CBC, it's now working.

This is returning an error when I try to encrypt alphabet characters with diacritics in Python.
Example:

my_encrypt("Crème Brûlée", "hash")
# Output:
# Data must be padded to 16 byte boundary in CBC mode

Is there a way for me to have this method accept all types of characters?

Security considerations

You are aware of the fact that the parameters that you're referring to as "passphrases" are really not passphrases, but cryptographic keys, which have to consist of cryptographically strong random bytes, are you not?

You can generate symmetric encryption keys directly in your code (maybe via a separate function, e.g. generate_secure_encryption_key()) using the same way you're generating your initialization vectors, i.e. through Crypto.Random (or alternatively, os.urandom). The key needs to then be stored somewhere safe, e.g. a file readable only by its owner.

If you need to use a passphrase for encryption, such as the string "a quick brown fox jumps over the lazy dog", you need to use a key derivation function to transform your passphrase into a suitable key.