Question

Could somebody advice me on subject “Simple encrypt/decrypt of utf-8 strings in php5 with secret key” ? Some advice on independant libraries?
(no dependancy on 32/64bit machines).

$encryptedTextUTF8 = simpleEncrypt($originalTextUTF8, $secret);
echo simpleDecrypt($encryptedTextUTF8, $secret); // outputs $originalTextUTF8

Answer 1

Using the mcrypt extension: http://us.php.net/manual/en/book.mcrypt.php
Something like the following could be feasible:

$pass      = 'password_string_to_be_encrypted';
$string    = 'password_string_to_be_decrypted';
$salt      = 'your_salt';
$pepper    = 'your_extra_salt';
$encrypted = base64_encode( mcrypt_encrypt( MCRYPT_RIJNDAEL_256, md5( $salt . $pass . $pepper ), $string, MCRYPT_MODE_CBC, md5( md5( $salt . $pass . $pepper ))));
$decrypted = rtrim( mcrypt_decrypt( MCRYPT_RIJNDAEL_256, md5($salt . $pass . $pepper), base64_decode( $string ), MCRYPT_MODE_CBC, md5( md5( $salt . $pass . $pepper))), "\0");

edit: Proven wrong, I suggest to remove the md5 part of the encryption. As to what is better, I do not know yet, but I’ll try to come update my post when I’ve had sufficient time investigating.. sorry! 🙂