Python Code:
from Crypto.Random import get_random_bytes
from Crypto.Cipher import AES
from Crypto.Util.Padding import pad
import base64
def encrypt_string(input_string, key_base64, str_iv):
try:
key = key_base64.encode('utf-8')
if str_iv:
iv = base64.b64decode(str_iv)
else:
iv = get_random_bytes(16)
cipher = AES.new(key, AES.MODE_CBC, iv)
padded_data = pad(input_string.encode(), AES.block_size)
cipher_data = cipher.encrypt(padded_data)
combined_data = iv + cipher_data
return base64.b64encode(combined_data).decode()
except Exception as e:
print(e)
if __name__ == "__main__":
key = "1bd393e7a457f9023d9ba95fffb5a2e1"
iv = "1oTOhV9xGyu1mppmWZWa5w=="
input_string = "AAAAAAA"
encrypted_data = encrypt_string(input_string, key, iv)
print("Encrypted string:", encrypted_data)`
OUTPUT : Encrypted string: 1oTOhV9xGyu1mppmWZWa5+kzveiTRzRH+gRVHx+7Ad0=
PHP code:
<?php
function encrypt_string($input_string, $key_base64, $str_iv) {
try {
$key = base64_decode($key_base64);
if ($str_iv) {
$iv = base64_decode($str_iv);
} else {
$iv = openssl_random_pseudo_bytes(16);
}
$ciphertext = openssl_encrypt($input_string, 'aes-256-cbc', $key, OPENSSL_RAW_DATA, $iv);
$combined_data = $iv . $ciphertext;
return base64_encode($combined_data);
} catch (Exception $e) {
echo $e->getMessage();
}
}
$key = "1bd393e7a457f9023d9ba95fffb5a2e1";
$iv = "1oTOhV9xGyu1mppmWZWa5w==";
$input_string = "AAAAAAA";
$encrypted_data = encrypt_string($input_string, $key, $iv);
echo "Encrypted string: " . $encrypted_data . "\n";
?>
OUTPUT: Encrypted string: 1oTOhV9xGyu1mppmWZWa53Nc8rxWTultBWLvWitUICQ=
Please, does anyone know how to make the output of these two codes the same?
If you want to get the same result then just remove the $key = base64_decode($key_base64). I did get the right result for $key = $key_base64.
Note that using the base64 encoding directly as key means that a maximum of 6 bits contain random information for each character / byte of input. So if you insert 32 characters then the key size is effectively 32 * 6 = 192 bits. That's more than enough, but clearly less than the 256 bits "promised" by AES-256.
The other issue is that CBC doesn't offer integrity / authenticity.
I'd recommend never to convert keys to strings in the first place - just keep them binary. Furthermore, if you're going to encrypt with a symmetric key then use something like NaCL or another library that performs higher level "sealing" rather than just encryption. If you want to use a password then you should use a good Password Based Key Derivation Function (PBKDF) such as PBKDF2 or Argon2.