import * as _ from 'lodash'; import * as BigNumber from 'bignumber.js'; import {bigNumberConfigs} from './bignumber_config'; import * as ethUtil from 'ethereumjs-util'; import contract = require('truffle-contract'); import * as Web3 from 'web3'; import findVersions = require('find-versions'); import compareVersions = require('compare-versions'); import {Web3Wrapper} from './web3_wrapper'; import {constants} from './utils/constants'; import {utils} from './utils/utils'; import {assert} from './utils/assert'; import {ExchangeWrapper} from './contract_wrappers/exchange_wrapper'; import {TokenRegistryWrapper} from './contract_wrappers/token_registry_wrapper'; import {ecSignatureSchema} from './schemas/ec_signature_schema'; import {TokenWrapper} from './contract_wrappers/token_wrapper'; import {ECSignature, ZeroExError, Order, SignedOrder} from './types'; import * as ExchangeArtifacts from './artifacts/Exchange.json'; import {SchemaValidator} from './utils/schema_validator'; import {orderSchema} from './schemas/order_schemas'; // Customize our BigNumber instances bigNumberConfigs.configure(); const MAX_DIGITS_IN_UNSIGNED_256_INT = 78; export class ZeroEx { public static NULL_ADDRESS = constants.NULL_ADDRESS; public exchange: ExchangeWrapper; public tokenRegistry: TokenRegistryWrapper; public token: TokenWrapper; private web3Wrapper: Web3Wrapper; /** * Verifies that the elliptic curve signature `signature` was generated * by signing `dataHex` with the private key corresponding to the `signerAddressHex` address. */ public static isValidSignature(dataHex: string, signature: ECSignature, signerAddressHex: string): boolean { assert.isHexString('dataHex', dataHex); assert.doesConformToSchema('signature', signature, ecSignatureSchema); assert.isETHAddressHex('signerAddressHex', signerAddressHex); const dataBuff = ethUtil.toBuffer(dataHex); const msgHashBuff = ethUtil.hashPersonalMessage(dataBuff); try { const pubKey = ethUtil.ecrecover( msgHashBuff, signature.v, ethUtil.toBuffer(signature.r), ethUtil.toBuffer(signature.s)); const retrievedAddress = ethUtil.bufferToHex(ethUtil.pubToAddress(pubKey)); return retrievedAddress === signerAddressHex; } catch (err) { return false; } } /** * Generates pseudo-random 256 bit salt. * The salt is used to ensure that the 0x order generated has a unique orderHash that does * not collide with any other outstanding orders. */ public static generatePseudoRandomSalt(): BigNumber.BigNumber { // BigNumber.random returns a pseudo-random number between 0 & 1 with a passed in number of decimal places. // Source: https://mikemcl.github.io/bignumber.js/#random const randomNumber = BigNumber.random(MAX_DIGITS_IN_UNSIGNED_256_INT); const factor = new BigNumber(10).pow(MAX_DIGITS_IN_UNSIGNED_256_INT - 1); const salt = randomNumber.times(factor).round(); return salt; } /** * Checks if the supplied hex encoded order hash is valid. * Note: Valid means it has the expected format, not that an order with the orderHash exists. */ public static isValidOrderHash(orderHashHex: string): boolean { // Since this method can be called to check if any arbitrary string conforms to an orderHash's // format, we only assert that we were indeed passed a string. assert.isString('orderHashHex', orderHashHex); const isValidOrderHash = utils.isValidOrderHash(orderHashHex); return isValidOrderHash; } /** * A unit amount is defined as the amount of a token above the specified decimal places (integer part). * E.g: If a currency has 18 decimal places, 1e18 or one quintillion of the currency is equivalent * to 1 unit. */ public static toUnitAmount(amount: BigNumber.BigNumber, numDecimals: number): BigNumber.BigNumber { assert.isBigNumber('amount', amount); assert.isNumber('numDecimals', numDecimals); const aUnit = new BigNumber(10).pow(numDecimals); const unit = amount.div(aUnit); return unit; } /** * A baseUnit is defined as the smallest denomination of a token. An amount expressed in baseUnits * is the amount expressed in the smallest denomination. * E.g: 1 unit of a token with 18 decimal places is expressed in baseUnits as 1000000000000000000 */ public static toBaseUnitAmount(amount: BigNumber.BigNumber, numDecimals: number): BigNumber.BigNumber { assert.isBigNumber('amount', amount); assert.isNumber('numDecimals', numDecimals); const unit = new BigNumber(10).pow(numDecimals); const baseUnitAmount = amount.times(unit); return baseUnitAmount; } constructor(web3: Web3) { this.web3Wrapper = new Web3Wrapper(web3); this.token = new TokenWrapper(this.web3Wrapper); this.exchange = new ExchangeWrapper(this.web3Wrapper, this.token); this.tokenRegistry = new TokenRegistryWrapper(this.web3Wrapper); } /** * Sets a new provider for the web3 instance used by 0x.js */ public async setProviderAsync(provider: Web3.Provider) { this.web3Wrapper.setProvider(provider); await this.exchange.invalidateContractInstanceAsync(); this.tokenRegistry.invalidateContractInstance(); this.token.invalidateContractInstances(); } /** * Get addresses via the supplied web3 instance available for sending transactions. */ public async getAvailableAddressesAsync(): Promise { const availableAddresses = await this.web3Wrapper.getAvailableAddressesAsync(); return availableAddresses; } /** * Computes the orderHash for a given order and returns it as a hex encoded string. */ public async getOrderHashHexAsync(order: Order|SignedOrder): Promise { assert.doesConformToSchema('order', SchemaValidator.convertToJSONSchemaCompatibleObject(order as object), orderSchema); const exchangeContractAddr = await this.getExchangeAddressAsync(); const orderHashHex = utils.getOrderHashHex(order, exchangeContractAddr); return orderHashHex; } /** * Signs an orderHash and returns it's elliptic curve signature. * This method currently supports TestRPC, Geth and Parity above and below V1.6.6 */ public async signOrderHashAsync(orderHashHex: string, signerAddress: string): Promise { assert.isHexString('orderHashHex', orderHashHex); await assert.isSenderAddressAsync('signerAddress', signerAddress, this.web3Wrapper); let msgHashHex; const nodeVersion = await this.web3Wrapper.getNodeVersionAsync(); const isParityNode = utils.isParityNode(nodeVersion); if (isParityNode) { // Parity node adds the personalMessage prefix itself msgHashHex = orderHashHex; } else { const orderHashBuff = ethUtil.toBuffer(orderHashHex); const msgHashBuff = ethUtil.hashPersonalMessage(orderHashBuff); msgHashHex = ethUtil.bufferToHex(msgHashBuff); } const signature = await this.web3Wrapper.signTransactionAsync(signerAddress, msgHashHex); let signatureData; const [nodeVersionNumber] = findVersions(nodeVersion); // Parity v1.6.6 and earlier returns the signatureData as vrs instead of rsv as Geth does // Later versions return rsv but for the time being we still want to support version < 1.6.6 // Date: May 23rd 2017 const latestParityVersionWithVRS = '1.6.6'; const isVersionBeforeParityFix = compareVersions(nodeVersionNumber, latestParityVersionWithVRS) <= 0; if (isParityNode && isVersionBeforeParityFix) { const signatureBuffer = ethUtil.toBuffer(signature); let v = signatureBuffer[0]; if (v < 27) { v += 27; } signatureData = { v, r: signatureBuffer.slice(1, 33), s: signatureBuffer.slice(33, 65), }; } else { signatureData = ethUtil.fromRpcSig(signature); } const {v, r, s} = signatureData; const ecSignature: ECSignature = { v, r: ethUtil.bufferToHex(r), s: ethUtil.bufferToHex(s), }; const isValidSignature = ZeroEx.isValidSignature(orderHashHex, ecSignature, signerAddress); if (!isValidSignature) { throw new Error(ZeroExError.INVALID_SIGNATURE); } return ecSignature; } private async getExchangeAddressAsync() { const networkIdIfExists = await this.web3Wrapper.getNetworkIdIfExistsAsync(); const exchangeNetworkConfigsIfExists = _.isUndefined(networkIdIfExists) ? undefined : (ExchangeArtifacts as any).networks[networkIdIfExists]; if (_.isUndefined(exchangeNetworkConfigsIfExists)) { throw new Error(ZeroExError.CONTRACT_NOT_DEPLOYED_ON_NETWORK); } const exchangeAddress = exchangeNetworkConfigsIfExists.address; return exchangeAddress; } }