My website is built in Wordpress and we are collecting personal information that I will need to place in my database. Here is my php so far for the insertion:
//defined in wp-config.php
$key = KEY_ENCRYPT;
function encrypt($text)
{
return trim(base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, $text, MCRYPT_MODE_ECB, mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB), MCRYPT_RAND))));
}
if($_POST){
//POST object placed in variables
$user_domain = $_POST['domain'];
$s_user = $_POST['s-username'];
$s_pass = $_POST['s-password'];
$w_user = $_POST['w-username'];
$w_pass = $_POST['w-password'];
//encrypting data
$encrypted_server_username = encrypt($s_user);
$encrypted_server_password = encrypt($s_pass);
$encrypted_wordpress_username = encrypt($w_user);
$encrypted_wordpress_password = encrypt($w_pass);
//set up array for options table
$user_website_data = array(
'domain'=>$user_domain,
'server_username'=>$encrypted_server_username,
'server_password'=>$encrypted_server_password,
'wordpress_username'=>$encrypted_wordpress_username,
'wordpress_password'=>$encrypted_wordpress_password
);
update_option($user_domain . '_website_data', $user_website_data);
This code successfully stores the information in an array. You can even see this code working and the process at http://thewpvalet.staging.wpengine.com/sign-up/?plan=basic. Please use 4242424242424242 as the CC number to test.
Now I'm trying to implement the decode on the backend admin area so that I can search by domain and pull up credentials. This is my code:
if(isset($_POST['domain'])){
function decrypt($text)
{
$key = KEY_ENCRYPT;
return trim(mcrypt_decrypt(MCRYPT_RIJNDAEL_256, $key, base64_decode($text), MCRYPT_MODE_ECB, mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB), MCRYPT_RAND)));
}
$search_domain = $_POST['domain'];
$url_removal = array("http://","www.");
$clean_search_domain = str_replace($url_removal, '', $search_domain);
$user_options = get_option($search_domain.'_website_data');
echo '<strong>Login Information:</strong></br>' .
'Domain:' . $user_options['domain'] . '</br>' .
'Server Username:' . decrypt($user_options['server_username']) . '</br>';
}
This returns mcrypt_decrypt() [function.mcrypt-decrypt]: Size of key is too large for this algorithm in /nas/wp/www/staging/thewpvalet/wp-content/plugins/user-info/index.php on line 43
Any idea what I could be doing wrong here?
Any idea what I could be doing wrong here?
Yes, the thing you're doing wrong is rolling your own cryptography. Let's add some whitespace and look at your function in detail:
/**
* THIS CODE IS INSECURE. DO NOT USE IT. PURGE IT FROM YOUR CODEBASE!
*/
function encrypt($text)
{
return trim(
base64_encode(
mcrypt_encrypt(
MCRYPT_RIJNDAEL_256, // Non-standard block cipher; not AES
$key,
$text,
MCRYPT_MODE_ECB, // ECB mode is insecure
mcrypt_create_iv( // ECB mode doesn't use an IV anyway
mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB),
MCRYPT_RAND // you want MCRYPT_DEV_URANDOM
)
)
)
);
}
You're generating an IV (insecurely) with ECB mode (which discards the IV anyway), for a non-standard Rijndael variant, and you're not employing message authentication. Encryption without message authentication is a fatal mistake.
Marc B, the key is 34 characters long
If you're using MCRYPT_RIJNDAEL_256 or AES (which is exclusively MCRYPT_RIJNDAEL_128 by the way; mcrypt is considered harmful), these are the only acceptable key sizes:
The reason you are getting the error is that 34 is an invalid input. This likely means that you are using a human-readable password instead of encryption key.
TL;DR: Don't roll your own crypto, use a well-studied implementation instead. defuse/php-encryption and Zend\Crypt are your best bet.