Question

I want to use openssl_public_encrypt to encrypt data and store it in a MySQL database. Then, when I need the data, I want to SELECT it from the MySQL database and use openssl_private_decrypt to decrypt it. After it is encrypted I am using base64 to encode the data for MySQL and again to decode the data before decrypting it.

Here is the code I am using to encrypt the data and INSERT it in the database:

<?php
    require_once('default.inc.php');
    mysql_connect_selectdb($host,$username,$password,$database);
    function encrypt($string) {
    $publickey = '-----BEGIN PUBLIC KEY-----
    PUBLIC KEY HERE
    -----END PUBLIC KEY-----';
        openssl_public_encrypt($string,$encryptedstring,$publickey);
        return $encryptedstring;
    }
$number = base64_encode(encrypt('1234567890123456'));
$qry = "UPDATE table SET number='$number' WHERE id='120006'";
$result = mysql_query($qry);
if (!$result) {
    die(mysql_error());
}
?>

The default.inc.php file sets error reporting to E_ALL and also defines the mysql connect variables and the mysql_connect_selectdb() function. It inserts into the database fine and there is no output to the screen.

Here is the code I am using to SELECT it from the database and decrypt it:

<?php
require_once('default.inc.php');
mysql_connect_selectdb($host,$username,$password,$database);
$key = '-----BEGIN RSA PRIVATE KEY-----
PRIVATE KEY HERE
-----END RSA PRIVATE KEY-----';
function decrypt($string,$privatekey) {
    openssl_private_decrypt($string,$decryptedstring,$privatekey);
    return $decryptedstring;
}
$qry = "SELECT * FROM table WHERE id='120006'";
$result = mysql_query($qry);
if ($result) {
    if (mysql_numrows($result) == '1') {
        $data = mysql_fetch_assoc($result);
        $number = decrypt(base64_decode($data['number']),$key);
        echo 'Number: '.$number;
    }
    else {
    echo 'no rows';
}
}
else {
    die(mysql_error());
}
?>

There is no output to the screen other than Number:. I can’t figure out why it doesn’t decrypt. I can echo the $data['number'] straight from the database and it shows up fine as base 64 encoded data and also I can echo the data after it has been base 64 decoded and it shows up fine as binary on my screen, however when I try to decrypt it there is no output.

The MySQL field number is VARCHAR(128) (have tried VARBINARY, BINARY and BLOB), VARCHAR should be fine for base64, and it is a latin1_swedish_ci collation.

Any help would be greatly appreciated! Thanks!

Answer 1

I figured it out. The column number was a VARCHAR(128) however the length of the string being inserted was 172, so therefore the end of the string was cut off. Without the end of the string, it didn’t decrypt properly and returned NULL.