init

utils/crypto.js

@@ -0,0 +1,101 @@
+import crypto from 'crypto'
+import { BN, toBN } from 'web3-utils'
+
+import { pedersen } from '@/services'
+
+const CUT_LENGTH = 31
+
+export function parseNote(note) {
+  const [, currency, amount, netId, hexNote] = note.split('-')
+
+  return {
+    ...parseHexNote(hexNote),
+    netId,
+    amount,
+    currency
+  }
+}
+
+export function parseHexNote(hexNote) {
+  const buffNote = Buffer.from(hexNote.slice(2), 'hex')
+
+  const commitment = buffPedersenHash(buffNote)
+
+  const nullifierBuff = buffNote.slice(0, CUT_LENGTH)
+  const nullifierHash = BigInt(buffPedersenHash(nullifierBuff))
+  const nullifier = BigInt(leInt2Buff(buffNote.slice(0, CUT_LENGTH)))
+
+  const secret = BigInt(leInt2Buff(buffNote.slice(CUT_LENGTH, CUT_LENGTH * 2)))
+
+  return {
+    secret,
+    nullifier,
+    commitment,
+    nullifierBuff,
+    nullifierHash,
+    commitmentHex: toFixedHex(commitment),
+    nullifierHex: toFixedHex(nullifierHash)
+  }
+}
+
+export function leInt2Buff(value) {
+  return new BN(value, 16, 'le')
+}
+
+export function randomBN(nbytes = 31) {
+  return toBN(leInt2Buff(crypto.randomBytes(nbytes)).toString())
+}
+
+export function buffPedersenHash(buffer) {
+  const [hash] = pedersen.unpackPoint(buffer)
+  return pedersen.toStringBuffer(hash)
+}
+
+export function toFixedHex(value, length = 32) {
+  const isBuffer = value instanceof Buffer
+
+  const str = isBuffer ? value.toString('hex') : BigInt(value).toString(16)
+  return '0x' + str.padStart(length * 2, '0')
+}
+
+export const isEmptyArray = (arr) => !Array.isArray(arr) || !arr.length
+
+export function packEncryptedMessage(encryptedMessage) {
+  const nonceBuf = Buffer.from(encryptedMessage.nonce, 'base64')
+  const ephemPublicKeyBuf = Buffer.from(encryptedMessage.ephemPublicKey, 'base64')
+  const ciphertextBuf = Buffer.from(encryptedMessage.ciphertext, 'base64')
+  const messageBuff = Buffer.concat([
+    Buffer.alloc(24 - nonceBuf.length),
+    nonceBuf,
+    Buffer.alloc(32 - ephemPublicKeyBuf.length),
+    ephemPublicKeyBuf,
+    ciphertextBuf
+  ])
+  return '0x' + messageBuff.toString('hex')
+}
+
+export function unpackEncryptedMessage(encryptedMessage) {
+  if (encryptedMessage.slice(0, 2) === '0x') {
+    encryptedMessage = encryptedMessage.slice(2)
+  }
+  const messageBuff = Buffer.from(encryptedMessage, 'hex')
+  const nonceBuf = messageBuff.slice(0, 24)
+  const ephemPublicKeyBuf = messageBuff.slice(24, 56)
+  const ciphertextBuf = messageBuff.slice(56)
+  return {
+    version: 'x25519-xsalsa20-poly1305',
+    nonce: nonceBuf.toString('base64'),
+    ephemPublicKey: ephemPublicKeyBuf.toString('base64'),
+    ciphertext: ciphertextBuf.toString('base64')
+  }
+}
+
+export function checkCommitments(events = []) {
+  events.forEach(({ leafIndex }, i) => {
+    // TODO reload events, need for if infura provider missing events
+    if (leafIndex !== i) {
+      console.error(`Missing deposit event for deposit #${i}`)
+      throw new Error(window.$nuxt.$t('failedToFetchAllDepositEvents'))
+    }
+  })
+}