Reorganise, move code to not be split between haproxy and src folder

src/js/challenge.js

@@ -0,0 +1,158 @@
+function updateElem(selector, text) {
+	document.querySelector(selector)
+		.innerText = text;
+}
+
+function insertError(str) {
+	const ring = document.querySelector('.lds-ring');
+	const captcha = document.querySelector('#captcha');
+	(ring || captcha).insertAdjacentHTML('afterend', `<p class="red">Error: ${str}</p>`);
+	ring && ring.remove();
+	captcha && captcha.remove();
+	updateElem('.powstatus', '');
+}
+
+function finishRedirect() {
+	window.location=location.search.slice(1)+location.hash || "/";
+}
+
+const wasmSupported = (() => {
+    try {
+        if (typeof WebAssembly === "object"
+            && typeof WebAssembly.instantiate === "function") {
+            const module = new WebAssembly.Module(Uint8Array.of(0x0, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00));
+            if (module instanceof WebAssembly.Module)
+                return new WebAssembly.Instance(module) instanceof WebAssembly.Instance;
+        }
+    } catch (e) {
+		console.error(e);
+    }
+    return false;
+})();
+
+function postResponse(powResponse, captchaResponse) {
+	const body = {
+		'pow_response': powResponse,
+	};
+	if (captchaResponse) {
+		body['h-captcha-response'] = captchaResponse;
+		body['g-recaptcha-response'] = captchaResponse;
+	}
+	fetch('/.basedflare/bot-check', {
+		method: 'POST',
+		headers: {
+		  'Content-Type': 'application/x-www-form-urlencoded',
+		},
+		body: new URLSearchParams(body),
+		redirect: 'manual',
+	}).then(res => {
+		const s = res.status;
+		if (s >= 400 && s < 500) {
+			return insertError('bad challenge response request.');
+		} else if (s >= 500) {
+			return insertError('server responded with error.');
+		}
+		finishRedirect();
+	}).catch(() => {
+		insertError('failed to send challenge response.');
+	});
+}
+
+const powFinished = new Promise((resolve, reject) => {
+	window.addEventListener('DOMContentLoaded', async () => {
+		if (!wasmSupported) {
+			return insertError('browser does not support WebAssembly.');
+		}
+		const { time, kb, pow, diff } = document.querySelector('[data-pow]').dataset;
+		const argonOpts = {
+			time: time,
+			mem: kb,
+			hashLen: 32,
+			parallelism: 1,
+			type: argon2.ArgonType.Argon2id,
+		};
+		console.log('Got pow', pow, 'with difficulty', diff);
+		const eHashes = Math.pow(16, Math.floor(diff/8)) * ((diff%8)*2);
+		const diffString = '0'.repeat(Math.floor(diff/8));
+		const combined = pow;
+		const [userkey, challenge] = combined.split("#");
+		const start = Date.now();
+		if (window.Worker) {
+			const cpuThreads = window.navigator.hardwareConcurrency;
+			const isTor = location.hostname.endsWith('.onion');
+			/* Try to use all threads on tor, because tor limits threads for anti fingerprinting but this
+			   makes it awfully slow because workerThreads will always be = 1 */
+			const workerThreads = isTor ? cpuThreads : Math.max(Math.ceil(cpuThreads/2),cpuThreads-1);
+			let finished = false;
+			const messageHandler = (e) => {
+				if (e.data.length === 1) {
+					const totalHashes = e.data[0]; //assumes all worker threads are same speed
+					const elapsedSec = Math.floor((Date.now()-start)/1000);
+					const hps = Math.floor(totalHashes/elapsedSec);
+					const requiredSec = Math.floor(eHashes/hps) * 1.5; //estimate 1.5x time
+					const remainingSec = Math.max(0, Math.floor(requiredSec-elapsedSec)); //dont show negative time
+					return updateElem('.powstatus', `Proof-of-work: ${hps}H/s, ~${remainingSec}s remaining`);
+				}
+				if (finished) { return; }
+				finished = true;
+				const hasCaptcha = document.getElementById('captcha');
+				updateElem('.powstatus', `Found proof-of-work solution.${!hasCaptcha?' Submitting...':''}`);
+				workers.forEach(w => w.terminate());
+				const [workerId, answer] = e.data;
+				console.log('Worker', workerId, 'returned answer', answer, 'in', Date.now()-start+'ms');
+				const dummyTime = 5000 - (Date.now()-start);
+				window.setTimeout(() => {
+					resolve(`${combined}#${answer}`);
+				}, dummyTime);
+			}
+			const workers = [];
+			for (let i = 0; i < workerThreads; i++) {
+				const argonWorker = new Worker('/.basedflare/js/worker.js');
+				argonWorker.onmessage = messageHandler;
+				workers.push(argonWorker);
+			}
+			for (let i = 0; i < workerThreads; i++) {
+				await new Promise(res => setTimeout(res, 100));
+				workers[i].postMessage([userkey, challenge, diff, diffString, argonOpts, i, workerThreads]);
+			}
+		} else {
+			console.warn('No webworker support, running in main/UI thread!');
+			let i = 0;
+			const start = Date.now();
+			while(true) {
+				const hash = await argon2.hash({
+					pass: challenge + i.toString(),
+					salt: userkey,
+					...argonOpts,
+				});
+				if (hash.hashHex.startsWith(diffString)
+					&& ((parseInt(hash.hashHex[diffString.length],16) &
+						0xff >> (((diffString.length+1)*8)-diff)) === 0)) {
+					console.log('Main thread found solution:', hash.hashHex, 'in', (Date.now()-start)+'ms');
+					break;
+				}
+				++i;
+			}
+			const dummyTime = 5000 - (Date.now()-start);
+			window.setTimeout(() => {
+				resolve(`${combined}#${i}`);
+			}, dummyTime);
+		}
+	});
+}).then((powResponse) => {
+	const hasCaptchaForm = document.getElementById('captcha');
+	if (!hasCaptchaForm) {
+		postResponse(powResponse);
+	}
+	return powResponse;
+});
+
+function onCaptchaSubmit(captchaResponse) {
+	const captchaElem = document.querySelector('[data-sitekey]');
+	captchaElem.insertAdjacentHTML('afterend', `<div class="lds-ring"><div></div><div></div><div></div><div></div></div>`);
+	captchaElem.remove();
+	powFinished.then((powResponse) => {
+		postResponse(powResponse, captchaResponse);
+	});
+}
+