init

static/js/base64.js

@@ -0,0 +1,37 @@
+function unescapeBase64Url(str) {
+  return (str + '==='.slice((str.length + 3) % 4))
+    .replace(/-/g, '+')
+    .replace(/_/g, '/')
+}
+
+function escapeBase64Url(str) {
+  return str.replace(/\+/g, '-').replace(/\//g, '_').replace(/=/g, '')
+}
+
+const uint8ToBase64 = (function (exports) {
+  'use strict'
+
+  var fromCharCode = String.fromCharCode
+  var encode = function encode(uint8array) {
+    var output = []
+
+    for (var i = 0, length = uint8array.length; i < length; i++) {
+      output.push(fromCharCode(uint8array[i]))
+    }
+
+    return btoa(output.join(''))
+  }
+
+  var asCharCode = function asCharCode(c) {
+    return c.charCodeAt(0)
+  }
+
+  var decode = function decode(chars) {
+    return Uint8Array.from(atob(chars), asCharCode)
+  }
+
+  exports.decode = decode
+  exports.encode = encode
+
+  return exports
+})({})

static/js/dhke.js

@@ -0,0 +1,31 @@
+async function hashToCurve(secretMessage) {
+  let point
+  while (!point) {
+    const hash = await nobleSecp256k1.utils.sha256(secretMessage)
+    const hashHex = nobleSecp256k1.utils.bytesToHex(hash)
+    const pointX = '02' + hashHex
+    try {
+      point = nobleSecp256k1.Point.fromHex(pointX)
+    } catch (error) {
+      secretMessage = await nobleSecp256k1.utils.sha256(secretMessage)
+    }
+  }
+  return point
+}
+
+async function step1Alice(secretMessage) {
+  secretMessage = uint8ToBase64.encode(secretMessage)
+  secretMessage = new TextEncoder().encode(secretMessage)
+  const Y = await hashToCurve(secretMessage)
+  const r_bytes = nobleSecp256k1.utils.randomPrivateKey()
+  const r = bytesToNumber(r_bytes)
+  const P = nobleSecp256k1.Point.fromPrivateKey(r)
+  const B_ = Y.add(P)
+  return {B_: B_.toHex(true), r: nobleSecp256k1.utils.bytesToHex(r_bytes)}
+}
+
+function step3Alice(C_, r, A) {
+  const rInt = bytesToNumber(r)
+  const C = C_.subtract(A.multiply(rInt))
+  return C
+}

static/js/utils.js

@@ -0,0 +1,23 @@
+function splitAmount(value) {
+  const chunks = []
+  for (let i = 0; i < 32; i++) {
+    const mask = 1 << i
+    if ((value & mask) !== 0) chunks.push(Math.pow(2, i))
+  }
+  return chunks
+}
+
+function bytesToNumber(bytes) {
+  return hexToNumber(nobleSecp256k1.utils.bytesToHex(bytes))
+}
+
+function bigIntStringify(key, value) {
+  return typeof value === 'bigint' ? value.toString() : value
+}
+
+function hexToNumber(hex) {
+  if (typeof hex !== 'string') {
+    throw new TypeError('hexToNumber: expected string, got ' + typeof hex)
+  }
+  return BigInt(`0x${hex}`)
+}