@waku/rln
Version:
RLN (Rate Limiting Nullifier) implementation for Waku
189 lines (187 loc) • 7.1 kB
JavaScript
/**
* Utilities for hex, bytes, CSPRNG.
* @module
*/
/*! noble-hashes - MIT License (c) 2022 Paul Miller (paulmillr.com) */
// We use WebCrypto aka globalThis.crypto, which exists in browsers and node.js 16+.
// node.js versions earlier than v19 don't declare it in global scope.
// For node.js, package.json#exports field mapping rewrites import
// from `crypto` to `cryptoNode`, which imports native module.
// Makes the utils un-importable in browsers without a bundler.
// Once node.js 18 is deprecated (2025-04-30), we can just drop the import.
/** Checks if something is Uint8Array. Be careful: nodejs Buffer will return true. */
function isBytes(a) {
return a instanceof Uint8Array || (ArrayBuffer.isView(a) && a.constructor.name === 'Uint8Array');
}
/** Asserts something is positive integer. */
function anumber(n) {
if (!Number.isSafeInteger(n) || n < 0)
throw new Error('positive integer expected, got ' + n);
}
/** Asserts something is Uint8Array. */
function abytes(b, ...lengths) {
if (!isBytes(b))
throw new Error('Uint8Array expected');
if (lengths.length > 0 && !lengths.includes(b.length))
throw new Error('Uint8Array expected of length ' + lengths + ', got length=' + b.length);
}
/** Asserts a hash instance has not been destroyed / finished */
function aexists(instance, checkFinished = true) {
if (instance.destroyed)
throw new Error('Hash instance has been destroyed');
if (checkFinished && instance.finished)
throw new Error('Hash#digest() has already been called');
}
/** Asserts output is properly-sized byte array */
function aoutput(out, instance) {
abytes(out);
const min = instance.outputLen;
if (out.length < min) {
throw new Error('digestInto() expects output buffer of length at least ' + min);
}
}
/** Cast u8 / u16 / u32 to u32. */
function u32(arr) {
return new Uint32Array(arr.buffer, arr.byteOffset, Math.floor(arr.byteLength / 4));
}
/** Zeroize a byte array. Warning: JS provides no guarantees. */
function clean(...arrays) {
for (let i = 0; i < arrays.length; i++) {
arrays[i].fill(0);
}
}
/** Create DataView of an array for easy byte-level manipulation. */
function createView(arr) {
return new DataView(arr.buffer, arr.byteOffset, arr.byteLength);
}
/** The rotate right (circular right shift) operation for uint32 */
function rotr(word, shift) {
return (word << (32 - shift)) | (word >>> shift);
}
/** Is current platform little-endian? Most are. Big-Endian platform: IBM */
const isLE = /* @__PURE__ */ (() => new Uint8Array(new Uint32Array([0x11223344]).buffer)[0] === 0x44)();
/** The byte swap operation for uint32 */
function byteSwap(word) {
return (((word << 24) & 0xff000000) |
((word << 8) & 0xff0000) |
((word >>> 8) & 0xff00) |
((word >>> 24) & 0xff));
}
/** In place byte swap for Uint32Array */
function byteSwap32(arr) {
for (let i = 0; i < arr.length; i++) {
arr[i] = byteSwap(arr[i]);
}
return arr;
}
const swap32IfBE = isLE
? (u) => u
: byteSwap32;
// Built-in hex conversion https://caniuse.com/mdn-javascript_builtins_uint8array_fromhex
const hasHexBuiltin = /* @__PURE__ */ (() =>
// @ts-ignore
typeof Uint8Array.from([]).toHex === 'function' && typeof Uint8Array.fromHex === 'function')();
// Array where index 0xf0 (240) is mapped to string 'f0'
const hexes = /* @__PURE__ */ Array.from({ length: 256 }, (_, i) => i.toString(16).padStart(2, '0'));
/**
* Convert byte array to hex string. Uses built-in function, when available.
* @example bytesToHex(Uint8Array.from([0xca, 0xfe, 0x01, 0x23])) // 'cafe0123'
*/
function bytesToHex(bytes) {
abytes(bytes);
// @ts-ignore
if (hasHexBuiltin)
return bytes.toHex();
// pre-caching improves the speed 6x
let hex = '';
for (let i = 0; i < bytes.length; i++) {
hex += hexes[bytes[i]];
}
return hex;
}
// We use optimized technique to convert hex string to byte array
const asciis = { _0: 48, _9: 57, A: 65, F: 70, a: 97, f: 102 };
function asciiToBase16(ch) {
if (ch >= asciis._0 && ch <= asciis._9)
return ch - asciis._0; // '2' => 50-48
if (ch >= asciis.A && ch <= asciis.F)
return ch - (asciis.A - 10); // 'B' => 66-(65-10)
if (ch >= asciis.a && ch <= asciis.f)
return ch - (asciis.a - 10); // 'b' => 98-(97-10)
return;
}
/**
* Convert hex string to byte array. Uses built-in function, when available.
* @example hexToBytes('cafe0123') // Uint8Array.from([0xca, 0xfe, 0x01, 0x23])
*/
function hexToBytes(hex) {
if (typeof hex !== 'string')
throw new Error('hex string expected, got ' + typeof hex);
// @ts-ignore
if (hasHexBuiltin)
return Uint8Array.fromHex(hex);
const hl = hex.length;
const al = hl / 2;
if (hl % 2)
throw new Error('hex string expected, got unpadded hex of length ' + hl);
const array = new Uint8Array(al);
for (let ai = 0, hi = 0; ai < al; ai++, hi += 2) {
const n1 = asciiToBase16(hex.charCodeAt(hi));
const n2 = asciiToBase16(hex.charCodeAt(hi + 1));
if (n1 === undefined || n2 === undefined) {
const char = hex[hi] + hex[hi + 1];
throw new Error('hex string expected, got non-hex character "' + char + '" at index ' + hi);
}
array[ai] = n1 * 16 + n2; // multiply first octet, e.g. 'a3' => 10*16+3 => 160 + 3 => 163
}
return array;
}
/**
* Converts string to bytes using UTF8 encoding.
* @example utf8ToBytes('abc') // Uint8Array.from([97, 98, 99])
*/
function utf8ToBytes(str) {
if (typeof str !== 'string')
throw new Error('string expected');
return new Uint8Array(new TextEncoder().encode(str)); // https://bugzil.la/1681809
}
/**
* Normalizes (non-hex) string or Uint8Array to Uint8Array.
* Warning: when Uint8Array is passed, it would NOT get copied.
* Keep in mind for future mutable operations.
*/
function toBytes(data) {
if (typeof data === 'string')
data = utf8ToBytes(data);
abytes(data);
return data;
}
/** Copies several Uint8Arrays into one. */
function concatBytes(...arrays) {
let sum = 0;
for (let i = 0; i < arrays.length; i++) {
const a = arrays[i];
abytes(a);
sum += a.length;
}
const res = new Uint8Array(sum);
for (let i = 0, pad = 0; i < arrays.length; i++) {
const a = arrays[i];
res.set(a, pad);
pad += a.length;
}
return res;
}
/** For runtime check if class implements interface */
class Hash {
}
/** Wraps hash function, creating an interface on top of it */
function createHasher(hashCons) {
const hashC = (msg) => hashCons().update(toBytes(msg)).digest();
const tmp = hashCons();
hashC.outputLen = tmp.outputLen;
hashC.blockLen = tmp.blockLen;
hashC.create = () => hashCons();
return hashC;
}
export { Hash, abytes, aexists, anumber, aoutput, byteSwap, byteSwap32, bytesToHex, clean, concatBytes, createHasher, createView, hexToBytes, isBytes, isLE, rotr, swap32IfBE, toBytes, u32, utf8ToBytes };