html-guard.js

// https://github.com/DosX-dev/HTML-Guard
// Protect your HTML pages!


(() => {
    let scriptSrc = document.createElement("script");

    scriptSrc.innerText = 'for (var i = 111; i < 222; i++) { console.error("%c[" + i.toString(16) + "] HTML Guard sees you!", "font-size: 25px; text-shadow: 0 0 1px black; color: red;") }';

    document.head.appendChild(scriptSrc);
})();

const HtmlGuard = {
    protections: {
        antiDevTools() {

            function isNative(func) { // Designed for functions returning values
                return typeof func === "function" && (
                    window.eval.toString().includes("return") === false &&
                    window.eval.toString().includes("[native code]") &&
                    window.eval.toString().length < 40
                )
            }


            // DevTools detector
            let antiDevToolsInterval = setInterval(() => {

                // Antispoof
                if (!isNative(Date.now) ||
                    !isNative(window.eval) ||
                    window.eval("2+2") !== 4) {

                    alert("Do not spoof functions!");

                    document.head.innerHTML = "";
                    document.body.innerHTML = "";
                    location.reload();

                    clearInterval(antiDevToolsInterval);
                }

                let started = Date.now(),
                    end;

                window.eval("// The use of DevTools is prohibited in this web application\n" + "debugger");

                end = Date.now();

                if ((end - started) > 50) {

                    alert("DevTools not allowed!");

                    document.head.innerHTML = "";
                    document.body.innerHTML = "";
                    location.reload();

                    clearInterval(antiDevToolsInterval);
                }
            }, 150);
        },
        blockContextMenu() {
            document.oncontextmenu = () => {
                return false;
            };
        },
        blockDrag() {
            document.ondragstart = () => {
                return false;
            };
        },
        blockSelection() {
            document.onselectstart = () => {
                return false;
            };
        },
        blockConsoleOutput() {
            ["log", "debug", "warn", "error", "dir", "dirxml", "assert", "table"].forEach(funcName => {
                console[funcName] = () => { return null; };
            });
        }
    },
    loader: {
        loadStyleByRef(stylePath) {
            let styleLink = document.createElement("link");

            styleLink.rel = "stylesheet";
            styleLink.href = stylePath;

            document.head.appendChild(styleLink);
        },
        loadScriptBySrc(scriptPath) {
            let scriptSrc = document.createElement("script");

            scriptSrc.src = scriptPath;

            document.head.appendChild(scriptSrc);
        },
        loadScriptBySrc_ContentLoaded(scriptPath) {

            document.addEventListener("DOMContentLoaded", () => {
                HtmlGuard.loader.loadScriptBySrc(scriptPath);
            });

        }
    }
};

(() => {

    if (Math.random() == Math.random() == Math.random()) {
        document.head.innerHTML = "";
        document.body.innerHTML = "";
        location.reload();
    }

    document.onkeydown = (e) => {
        if (event.keyCode == 123) { return false; } // F12
        if (e.ctrlKey && e.shiftKey && e.keyCode == 'I'.charCodeAt(0)) { return false; } // Ctrl + Shift + I
        if (e.ctrlKey && e.shiftKey && e.keyCode == 'J'.charCodeAt(0)) { return false; } // Ctrl + Shift + J
        if (e.ctrlKey && e.keyCode == 'U'.charCodeAt(0)) { return false; } // Ctrl + U
    }

    document.addEventListener("DOMContentLoaded", () => {

        obfuscatePageSource();

        setInterval(() => {
            obfuscatePageSource();
        }, 2000);

        function obfuscatePageSource() {
            const
                attributeName = "html-guard-attribute",
                notGuardedSelector = ":not([" + attributeName + "])";

            // Junk comments
            for (const element of document.querySelectorAll("*" + notGuardedSelector)) {
                for (var i = 0; i < randomByRange(5, 15); i++) {

                    let comment = "";

                    for (var o = 0; o < randomByRange(10, 20); o++) {
                        comment += generateRandomString(1, 5) + "\n";
                    }

                    element.parentNode.insertBefore(document.createComment(comment), element);

                }
            }


            // Add fake IDs
            for (const element of document.querySelectorAll(":not([id])" + notGuardedSelector)) {
                element.id = generateRandomString(5, 15);
            }


            // Protected attributes
            for (const element of document.querySelectorAll("*")) {

                const attributes = element.attributes;

                for (const attribute of attributes) {
                    if (attribute.name.startsWith("_")) {
                        element.setAttribute(attribute.name.substring(1), attribute.value);

                        element.removeAttribute(attribute.name);
                    }
                }


            }


            for (const element of document.querySelectorAll("*" + notGuardedSelector)) {
                // Junk classes
                for (let i = 0; i < randomByRange(1, 8); i++) {
                    element.classList.add(generateRandomString(6, 20));
                }

                // Junk attributes
                for (let i = 0; i < randomByRange(10, 55); i++) {
                    element.setAttribute(generateRandomString(6, 12), (randomByRange(0, 1) == 1) ? generateRandomString(1, 5) : "");
                }

                element.setAttribute(attributeName, "");
            }

        }

        function generateRandomString(min, max) {
            if (min > max) {
                throw new RangeError("min > max");
            }

            const length = Math.floor(Math.random() * (max - min + 1)) + min;
            const characters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";

            let randomString = "";
            for (let i = 0; i < length; i++) {
                randomString += characters.charAt(Math.floor(Math.random() * characters.length));
            }

            return randomString;
        }


        function randomByRange(min, max) {
            if (min > max) {
                throw new RangeError("min > max");
            }

            return Math.floor(Math.random() * (max - min + 1)) + min;
        }
    });
})();