phpsecurityrandompasswords

Generating a random password in php


I am trying to generate a random password in php.

However I am getting all 'a's and the return type is of type array and I would like it to be a string. Any ideas on how to correct the code?

Thanks.

function randomPassword() {
    $alphabet = "abcdefghijklmnopqrstuwxyzABCDEFGHIJKLMNOPQRSTUWXYZ0123456789";
    for ($i = 0; $i < 8; $i++) {
        $n = rand(0, count($alphabet)-1);
        $pass[$i] = $alphabet[$n];
    }
    return $pass;
}

Solution

  • Security warning: rand() is not a cryptographically secure pseudorandom number generator. Look elsewhere for generating a cryptographically secure pseudorandom string in PHP.

    Try this (use strlen instead of count, because count on a string is always 1):

    function randomPassword() {
        $alphabet = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890';
        $pass = array(); //remember to declare $pass as an array
        $alphaLength = strlen($alphabet) - 1; //put the length -1 in cache
        for ($i = 0; $i < 8; $i++) {
            $n = rand(0, $alphaLength);
            $pass[] = $alphabet[$n];
        }
        return implode($pass); //turn the array into a string
    }
    

    Demo