encrypt decrypt php

function encrypt_decrypt($string, $action = 'encrypt')
{
    $encrypt_method = "AES-256-CBC";
    $secret_key = 'AA74CDCC2BBRT935136HH7B63C27'; // user define private key
    $secret_iv = '5fgf5HJ5g27'; // user define secret key
    $key = hash('sha256', $secret_key);
    $iv = substr(hash('sha256', $secret_iv), 0, 16); // sha256 is hash_hmac_algo
    if ($action == 'encrypt') {
        $output = openssl_encrypt($string, $encrypt_method, $key, 0, $iv);
        $output = base64_encode($output);
    } else if ($action == 'decrypt') {
        $output = openssl_decrypt(base64_decode($string), $encrypt_method, $key, 0, $iv);
    }
    return $output;
}
 
echo "Your Encrypted password is = ". $pwd = encrypt_decrypt('spaceo', 'encrypt');
echo "Your Decrypted password is = ". encrypt_decrypt($pwd, 'decrypt');
function encrypt($plaintext, $password) {
    $method = "AES-256-CBC";
    $key = hash('sha256', $password, true);
    $iv = openssl_random_pseudo_bytes(16);

    $ciphertext = openssl_encrypt($plaintext, $method, $key, OPENSSL_RAW_DATA, $iv);
    $hash = hash_hmac('sha256', $ciphertext . $iv, $key, true);

    return $iv . $hash . $ciphertext;
}

function decrypt($ivHashCiphertext, $password) {
    $method = "AES-256-CBC";
    $iv = substr($ivHashCiphertext, 0, 16);
    $hash = substr($ivHashCiphertext, 16, 32);
    $ciphertext = substr($ivHashCiphertext, 48);
    $key = hash('sha256', $password, true);

    if (!hash_equals(hash_hmac('sha256', $ciphertext . $iv, $key, true), $hash)) return null;

    return openssl_decrypt($ciphertext, $method, $key, OPENSSL_RAW_DATA, $iv);
}

//Example usage:
$encrypted = encrypt('Plaintext string.', 'password'); // this yields a binary string

echo decrypt($encrypted, 'password');
// decrypt($encrypted, 'wrong password') === null