Bottom Responder

bottom-responder.php

<?php
/**
 * Usage: Run this from the command line to generate a secure passphrase in the format
 * of stereotypical bottom keymashing.
 *
 * php bottom-responder.php | xclip
 *
 * Why? Because furries ruin everything, including bottom jokes.
 */
function random_str(int $length, string $charset): string {
    $c = strlen($charset) - 1;
    if ($c < 1) {
        throw new RangeException("Dumb");
    }
    $pieces = [];
    for ($i = 0; $i < $length; ++$i) {
        $x = random_int(0, $c);
        array_push($pieces, $charset[$x]);
    }
    return implode($pieces);
}

/*
8 home row characters + 8 to 12 random letters + 4 home row characters

Entropy estimates

Lower end: 26.575 + 38.864 + 13.288 -> 78 bits
Upper end: 26.575 + 58.296 + 13.288 -> 98 bits
*/

$x = random_int(8, 12);
echo random_str(8, 'asdfghjkl;') . random_str($x, 'qwertyuiopasdfghjkl;zxcvbnm,.') . random_str(8, 'asdfghjkl;');

Demo: https://3v4l.org/crGhX