Random Password Generator

Generate secure random password
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// ==UserScript==
// @name         Random Password Generator
// @namespace    https://openuserjs.org/users/burn
// @version      20260207
// @description  Generate secure random password
// @copyright    2026, burn (https://openuserjs.org//users/burn)
// @license      MIT
// @match        *://*/*
// @include      *
// @grant        GM_registerMenuCommand
// @grant        GM.registerMenuCommand
// @grant        GM_setClipboard
// @grant        GM.setClipboard
// ==/UserScript==

// ==OpenUserJS==
// @author burn
// ==/OpenUserJS==

/*jshint esversion: 8 */ 
(function() {
    'use strict';
    const DBG = false;
    const SCRIPT = GM_info.script.name;
    let log = (str) => {
        DBG && console.log(GM_info.script.name + " | " + str);
    };

    function secureRandomIndex(max) {
        const range = 0xFFFFFFFF;
        const limit = range - (range % max);
        const buf = new Uint32Array(1);

        do {
            crypto.getRandomValues(buf);
        } while (buf[0] >= limit);

        return buf[0] % max;
    }

    function pick(str) {
        return str[secureRandomIndex(str.length)];
    }

    Object.defineProperty(Array.prototype, "shuffle", {
        value: function() {
            for (let i = this.length - 1; i > 0; i--) {
                const j = secureRandomIndex(i + 1);
                [this[i], this[j]] = [this[j], this[i]];
            }
            return this;
        },
        enumerable: false
    });

    function generatePassword() {
        const LEN = 19;
        const LOWER = "abcdefghijkmnopqrstuvwxyz";
        const UPPER = "ABCDEFGHJKLMNPQRSTUVWXYZ";
        const NUM = "23456789";
        const SYM = "!@#$%^&*()-_=+[]{};:,.<>?";

        const ALL = LOWER + UPPER + NUM + SYM;

        const result = new Array(
            pick(LOWER),
            pick(UPPER),
            pick(NUM),
            pick(SYM)
        );

        for (let i = result.length; i < LEN; i++) {
            result.push(pick(ALL));
            result.shuffle();
        }

        if (typeof GM_setClipboard !== "undefined") {
            GM_setClipboard(result.join(""), "text");
        } else if (typeof GM !== "undefined" && GM.setClipboard) {
            GM.setClipboard(result.join(""), "text");
        }
    }

    if (typeof GM_registerMenuCommand !== "undefined") {
        GM_registerMenuCommand("Generate Secure Password", generatePassword);
    } else if (typeof GM !== "undefined" && GM.registerMenuCommand) {
        GM.registerMenuCommand("Generate Secure Password", generatePassword);
    }
})();