How can I retrieve specific information from persistent session handler with PHP?

Question

I'm using PHP session handler to implement persistent session on my site. The problem is that at some point, I need to insert the user_key into another MySQL table and I don't know how to retrieve that information from the code.

For example, the data row into my session table is:

active|i:1487613760;user_username|s:20:"v.lima06@hotmail.com";user_key|s:8:"a5186adc";authenticated|b:1;user_name|s:12:"victor";user_email|s:20:"v.lima06@hotmail.com";remember|b:1;

and I would like to know if there is a simple way to get the user_key variable.

Sorry if it was a bit confusing.

Answer 1

First option is to unserialize this string. http://php.net/manual/en/function.unserialize.php

Second option, You can use preg_match function with the next pattern:

preg_match('/user_key\|s:\d+:"([a-zA-Z0-9]+)"/', $string, $match);

Answer 2

I cant find anywhere something to handle that format of serialized string, its not something I've seen before.

However, heres a quick function to turn it into an array (it might not be overly elegant, but I've only had 1 coffee):

$string = 'active|i:1487613760;user_username|s:20:"v.lima06@hotmail.com";user_key|s:8:"a5186adc";authenticated|b:1;user_name|s:12:"victor";user_email|s:20:"v.lima06@hotmail.com";remember|b:1;
';

$array = deserializeSessionString($string);

echo $array['user_key'];

// deserialize a session string into an array
function deserializeSessionString($string)
{
    $output = [];
    // separate the key-value pairs and iterate
    foreach(explode(';', $string) as $p) {
        // separate the identifier with the contents
        $bits = explode('|', $p);

        // conditionally store in the correct format.
        if(isset($bits[1])) {
            $test = explode(':', $bits[1]);
            switch($test[0]) {
                // int
                case 'i':
                    $output[$bits[0]] = $test[1];
                    break;
                case 's':

                    // string
                    // ignore test[1], we dont care about it
                    $output[$bits[0]] = $test[2];
                    break;

                case 'b':
                    // boolean
                     $output[$bits[0]] = ($test[1] == 1 ? true : false);
                    break;
            }
        }

    }

    return $output;
}

then you should be able to access what you need with just the key:

echo $array['user_key'];

heres an example