feat: Replace aCAPTCHA with official ALTCHA (altcha.org) Proof-of-Work web component widget

2026-07-31 11:39:29 +02:00
parent 6ef74c7cf4
commit 83c782c469
417 changed files with 100543 additions and 317 deletions
@@ -0,0 +1,110 @@
+import wasmJson from "../wasm/crc64.wasm.json";
+import {
+	type IHasher,
+	type IWASMInterface,
+	WASMInterface,
+} from "./WASMInterface";
+import lockedCreate from "./lockedCreate";
+import Mutex from "./mutex";
+import type { IDataType } from "./util";
+
+const mutex = new Mutex();
+let wasmCache: IWASMInterface = null;
+const polyBuffer = new Uint8Array(8);
+
+function parsePoly(poly: string) {
+	const errText = "Polynomial must be provided as a 16 char long hex string";
+
+	if (typeof poly !== "string" || poly.length !== 16) {
+		return { hi: 0, lo: 0, err: new Error(errText) };
+	}
+
+	const hi = Number(`0x${poly.slice(0, 8)}`);
+	const lo = Number(`0x${poly.slice(8)}`);
+
+	if (Number.isNaN(hi) || Number.isNaN(lo)) {
+		return { hi, lo, err: new Error(errText) };
+	}
+
+	return { hi, lo, err: null };
+}
+
+function writePoly(arr: ArrayBuffer, lo: number, hi: number) {
+	// write in little-endian format
+	const buffer = new DataView(arr);
+	buffer.setUint32(0, lo, true);
+	buffer.setUint32(4, hi, true);
+}
+
+/**
+ * Calculates CRC-64 hash
+ * @param data Input data (string, Buffer or TypedArray)
+ * @param polynomial Input polynomial (defaults to 'c96c5795d7870f42' - ECMA)
+ * @returns Computed hash as a hexadecimal string
+ */
+export function crc64(
+	data: IDataType,
+	polynomial = "c96c5795d7870f42",
+): Promise<string> {
+	const { hi, lo, err } = parsePoly(polynomial);
+	if (err !== null) {
+		return Promise.reject(err);
+	}
+
+	if (wasmCache === null) {
+		return lockedCreate(mutex, wasmJson, 8).then((wasm) => {
+			wasmCache = wasm;
+			writePoly(polyBuffer.buffer, lo, hi);
+			wasmCache.writeMemory(polyBuffer);
+			return wasmCache.calculate(data);
+		});
+	}
+
+	try {
+		writePoly(polyBuffer.buffer, lo, hi);
+		wasmCache.writeMemory(polyBuffer);
+		const hash = wasmCache.calculate(data);
+		return Promise.resolve(hash);
+	} catch (err) {
+		return Promise.reject(err);
+	}
+}
+
+/**
+ * Creates a new CRC-64 hash instance
+ * @param polynomial Input polynomial (defaults to 'c96c5795d7870f42' - ECMA)
+ */
+export function createCRC64(polynomial = "c96c5795d7870f42"): Promise<IHasher> {
+	const { hi, lo, err } = parsePoly(polynomial);
+	if (err !== null) {
+		return Promise.reject(err);
+	}
+
+	return WASMInterface(wasmJson, 8).then((wasm) => {
+		const instanceBuffer = new Uint8Array(8);
+		writePoly(instanceBuffer.buffer, lo, hi);
+		wasm.writeMemory(instanceBuffer);
+		wasm.init();
+		const obj: IHasher = {
+			init: () => {
+				wasm.writeMemory(instanceBuffer);
+				wasm.init();
+				return obj;
+			},
+			update: (data) => {
+				wasm.update(data);
+				return obj;
+			},
+			// biome-ignore lint/suspicious/noExplicitAny: Conflict with IHasher type
+			digest: (outputType) => wasm.digest(outputType) as any,
+			save: () => wasm.save(),
+			load: (data) => {
+				wasm.load(data);
+				return obj;
+			},
+			blockSize: 8,
+			digestSize: 8,
+		};
+		return obj;
+	});
+}