CODEWITHSUNDEEP
phpunique-key
Jack Ottermans
Jack Ottermans

Reputation: 139

Generate an unique ID to append behind an url

I've found this stack overflow page with the PHP function below and it works perfectly but I don't have enough user reputation to comment on that page and ask for help so that's why I created a new question about this.

Let's say I use the function in my code below to generate a 6 or 8 character key how much chance do I have that this function will generate the same key twice? Is it once every thousand / million / billion times ?

Thank you..

function crypto_rand_secure($min, $max) {
        $range = $max - $min;
        if ($range < 0) return $min; // not so random...
        $log = log($range, 2);
        $bytes = (int) ($log / 8) + 1; // length in bytes
        $bits = (int) $log + 1; // length in bits
        $filter = (int) (1 << $bits) - 1; // set all lower bits to 1
        do {
            $rnd = hexdec(bin2hex(openssl_random_pseudo_bytes($bytes)));
            $rnd = $rnd & $filter; // discard irrelevant bits
        } while ($rnd >= $range);
        return $min + $rnd;
}

function getToken($length){
    $token = "";
    $codeAlphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    $codeAlphabet.= "abcdefghijklmnopqrstuvwxyz";
    $codeAlphabet.= "0123456789";
    for($i=0;$i<$length;$i++){
        $token .= $codeAlphabet[crypto_rand_secure(0,strlen($codeAlphabet))];
    }
    return $token;
}

Upvotes: 0

Views: 659

Answers (1)

Grim...
Grim...

Reputation: 16953

If all you need is a unique ID, you can just use the uniqid() function.

Upvotes: 2

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