Generate a random token. From: https://stackoverflow.com/questions/3290283/what-is-a-good-way-to-produce-a-random-site-salt-to-be-used-in-creating-passwo/3291689#3291689

random-token.php.php

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=32){
  $token = "";
  $codeAlphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
  $codeAlphabet.= "abcdefghijklmnopqrstuvwxyz";
  $codeAlphabet.= "0123456789";
  for($i=0;$i<$length;$i++){
    $token .= $codeAlphabet[crypto_rand_secure(0,strlen($codeAlphabet))];
  }
  return $token;
}

$x = getToken();
echo $x;