edge-core-js/lib/core/login/splitting.js

Edge account & wallet management library

import { asMaybe } from 'cleaners'
import { base64 } from 'rfc4648'







import { hmacSha256 } from '../../util/crypto/hashes'
import { utf8 } from '../../util/encoding'
import { changeWalletStates } from '../account/account-files'
import { waitForCurrencyWallet } from '../currency/currency-selectors'
import { applyKit } from '../login/login'
import {
  getCurrencyTools,
  maybeFindCurrencyPluginId
} from '../plugins/plugins-selectors'

import { makeKeysKit } from './keys'
import { asEdgeStorageKeys, wasEdgeStorageKeys } from './storage-keys'

export async function listSplittableWalletTypes(
  ai,
  accountId,
  walletId
) {
  const { allWalletInfosFull } = ai.props.state.accounts[accountId]

  // Find the wallet we are going to split:
  const walletInfo = allWalletInfosFull.find(
    walletInfo => walletInfo.id === walletId
  )
  if (walletInfo == null) throw new Error(`Invalid wallet id ${walletId}`)
  const pluginId = maybeFindCurrencyPluginId(
    ai.props.state.plugins.currency,
    walletInfo.type
  )
  if (pluginId == null) return []

  // Get the list of available types:
  const tools = await getCurrencyTools(ai, pluginId)
  if (tools.getSplittableTypes == null) return []
  const types = await tools.getSplittableTypes(walletInfo)

  // Filter out wallet types we have already split:
  return types.filter(type => {
    const newWalletInfo = makeSplitWalletInfo(walletInfo, type)
    const existingWalletInfo = allWalletInfosFull.find(
      walletInfo => walletInfo.id === newWalletInfo.id
    )
    // We can split the wallet if it doesn't exist, or is deleted:
    return (
      existingWalletInfo == null ||
      existingWalletInfo.archived ||
      existingWalletInfo.deleted
    )
  })
}

export function makeSplitWalletInfo(
  walletInfo,
  newWalletType
) {
  const { id, type, keys } = walletInfo

  const cleanKeys = asMaybe(asEdgeStorageKeys)(keys)
  if (cleanKeys == null) {
    throw new Error(`Wallet ${id} is not a splittable type`)
  }

  const { dataKey, syncKey } = cleanKeys
  const xorKey = xorData(
    hmacSha256(utf8.parse(type), dataKey),
    hmacSha256(utf8.parse(newWalletType), dataKey)
  )

  // Fix the id:
  const newWalletId = xorData(base64.parse(id), xorKey)
  const newSyncKey = xorData(syncKey, xorKey.subarray(0, syncKey.length))

  // Fix the keys:
  const networkName = type.replace(/wallet:/, '').replace('-', '')
  const newNetworkName = newWalletType.replace(/wallet:/, '').replace('-', '')
  const newKeys = wasEdgeStorageKeys({
    dataKey,
    syncKey: newSyncKey
  })
  for (const key of Object.keys(keys)) {
    const newKey = key === networkName + 'Key' ? newNetworkName + 'Key' : key
    if (newKeys[newKey] != null) continue
    newKeys[newKey] = keys[key]
  }

  return {
    id: base64.stringify(newWalletId),
    keys: newKeys,
    type: newWalletType
  }
}

export async function splitWalletInfo(
  ai,
  accountId,
  walletId,
  newWalletType
) {
  const accountState = ai.props.state.accounts[accountId]
  const { allWalletInfosFull, sessionKey } = accountState

  // Find the wallet we are going to split:
  const walletInfo = allWalletInfosFull.find(
    walletInfo => walletInfo.id === walletId
  )
  if (walletInfo == null) throw new Error(`Invalid wallet id ${walletId}`)

  // Handle BCH / BTC+segwit special case:
  if (
    newWalletType === 'wallet:bitcoincash' &&
    walletInfo.type === 'wallet:bitcoin' &&
    walletInfo.keys.format === 'bip49'
  ) {
    throw new Error(
      'Cannot split segwit-format Bitcoin wallets to Bitcoin Cash'
    )
  }

  // Handle BitcoinABC/SV replay protection:
  const needsProtection =
    newWalletType === 'wallet:bitcoinsv' &&
    walletInfo.type === 'wallet:bitcoincash'
  if (needsProtection) {
    const oldWallet = ai.props.output.currency.wallets[walletId].walletApi
    if (oldWallet == null) throw new Error('Missing Wallet')
    await protectBchWallet(oldWallet)
  }

  // See if the wallet has already been split:
  const newWalletInfo = makeSplitWalletInfo(walletInfo, newWalletType)
  const existingWalletInfo = allWalletInfosFull.find(
    walletInfo => walletInfo.id === newWalletInfo.id
  )
  if (existingWalletInfo != null) {
    if (existingWalletInfo.archived || existingWalletInfo.deleted) {
      // Simply undelete the existing wallet:
      const walletInfos = {}
      walletInfos[newWalletInfo.id] = {
        archived: false,
        deleted: false,
        migratedFromWalletId: undefined
      }
      await changeWalletStates(ai, accountId, walletInfos)
      return walletInfo.id
    }
    if (needsProtection) return newWalletInfo.id
    throw new Error('This wallet has already been split')
  }

  // Add the keys to the login:
  const kit = makeKeysKit(ai, sessionKey, [newWalletInfo])
  await applyKit(ai, sessionKey, kit)

  // Try to copy metadata on a best-effort basis.
  // In the future we should clone the repo instead:
  try {
    const wallet = await waitForCurrencyWallet(ai, newWalletInfo.id)
    const oldWallet = ai.props.output.currency.wallets[walletId].walletApi
    if (oldWallet != null) {
      if (oldWallet.name != null) await wallet.renameWallet(oldWallet.name)
      if (oldWallet.fiatCurrencyCode != null) {
        await wallet.setFiatCurrencyCode(oldWallet.fiatCurrencyCode)
      }
    }
  } catch (error) {
    ai.props.onError(error)
  }

  return newWalletInfo.id
}

async function protectBchWallet(wallet) {
  const bchCurrency = { currencyCode: 'BCH', tokenId: null }

  // Create a UTXO which can be spend only on the ABC network
  const spendInfoSplit = {
    ...bchCurrency,
    spendTargets: [
      {
        nativeAmount: '10000',
        otherParams: { script: { type: 'replayProtection' } },
        publicAddress: ''
      }
    ],
    metadata: {},
    networkFeeOption: 'high'
  }
  const splitTx = await wallet.makeSpend(spendInfoSplit)
  const signedSplitTx = await wallet.signTx(splitTx)
  const broadcastedSplitTx = await wallet.broadcastTx(signedSplitTx)
  await wallet.saveTx(broadcastedSplitTx)

  // Taint the rest of the wallet using the UTXO from before
  const { publicAddress } = await wallet.getReceiveAddress(bchCurrency)
  const spendInfoTaint = {
    ...bchCurrency,
    metadata: {
      name: 'Replay Protection Tx',
      notes:
        'This transaction is to protect your BCH wallet from unintentionally spending BSV funds. Please wait for the transaction to confirm before making additional transactions using this BCH wallet.'
    },
    networkFeeOption: 'high',
    spendTargets: [{ publicAddress, nativeAmount: '0' }]
  }
  const maxAmount = await wallet.getMaxSpendable(spendInfoTaint)
  spendInfoTaint.spendTargets[0].nativeAmount = maxAmount
  const taintTx = await wallet.makeSpend(spendInfoTaint)
  const signedTaintTx = await wallet.signTx(taintTx)
  const broadcastedTaintTx = await wallet.broadcastTx(signedTaintTx)
  await wallet.saveTx(broadcastedTaintTx)
}

/**
 * Combines two byte arrays via the XOR operation.
 */
function xorData(a, b) {
  if (a.length !== b.length) {
    throw new Error(`Array lengths do not match: ${a.length}, ${b.length}`)
  }

  const out = new Uint8Array(a.length)
  for (let i = 0; i < a.length; ++i) {
    out[i] = a[i] ^ b[i]
  }
  return out
}