import * as _ from 'lodash'; import * as BigNumber from 'bignumber.js'; import * as ethUtil from 'ethereumjs-util'; import contract = require('truffle-contract'); import * as Web3 from 'web3'; import * as ethABI from 'ethereumjs-abi'; import {Web3Wrapper} from './web3_wrapper'; import {constants} from './utils/constants'; import {utils} from './utils/utils'; import {assert} from './utils/assert'; import findVersions = require('find-versions'); import compareVersions = require('compare-versions'); import {ExchangeWrapper} from './contract_wrappers/exchange_wrapper'; import {TokenRegistryWrapper} from './contract_wrappers/token_registry_wrapper'; import {ecSignatureSchema} from './schemas/ec_signature_schema'; import {SolidityTypes, ECSignature, ZeroExError} from './types'; const MAX_DIGITS_IN_UNSIGNED_256_INT = 78; export class ZeroEx { public exchange: ExchangeWrapper; public tokenRegistry: TokenRegistryWrapper; private web3Wrapper: Web3Wrapper; /** * Computes the orderHash given the order parameters and returns it as a hex encoded string. */ public static getOrderHashHex(exchangeContractAddr: string, makerAddr: string, takerAddr: string, tokenMAddress: string, tokenTAddress: string, feeRecipient: string, valueM: BigNumber.BigNumber, valueT: BigNumber.BigNumber, makerFee: BigNumber.BigNumber, takerFee: BigNumber.BigNumber, expiration: BigNumber.BigNumber, salt: BigNumber.BigNumber): string { takerAddr = _.isEmpty(takerAddr) ? constants.NULL_ADDRESS : takerAddr ; assert.isETHAddressHex('exchangeContractAddr', exchangeContractAddr); assert.isETHAddressHex('makerAddr', makerAddr); assert.isETHAddressHex('takerAddr', takerAddr); assert.isETHAddressHex('tokenMAddress', tokenMAddress); assert.isETHAddressHex('tokenTAddress', tokenTAddress); assert.isETHAddressHex('feeRecipient', feeRecipient); assert.isBigNumber('valueM', valueM); assert.isBigNumber('valueT', valueT); assert.isBigNumber('makerFee', makerFee); assert.isBigNumber('takerFee', takerFee); assert.isBigNumber('expiration', expiration); assert.isBigNumber('salt', salt); const orderParts = [ {value: exchangeContractAddr, type: SolidityTypes.address}, {value: makerAddr, type: SolidityTypes.address}, {value: takerAddr, type: SolidityTypes.address}, {value: tokenMAddress, type: SolidityTypes.address}, {value: tokenTAddress, type: SolidityTypes.address}, {value: feeRecipient, type: SolidityTypes.address}, {value: utils.bigNumberToBN(valueM), type: SolidityTypes.uint256}, {value: utils.bigNumberToBN(valueT), type: SolidityTypes.uint256}, {value: utils.bigNumberToBN(makerFee), type: SolidityTypes.uint256}, {value: utils.bigNumberToBN(takerFee), type: SolidityTypes.uint256}, {value: utils.bigNumberToBN(expiration), type: SolidityTypes.uint256}, {value: utils.bigNumberToBN(salt), type: SolidityTypes.uint256}, ]; const types = _.map(orderParts, o => o.type); const values = _.map(orderParts, o => o.value); const hashBuff = ethABI.soliditySHA3(types, values); const hashHex = ethUtil.bufferToHex(hashBuff); return hashHex; } /** * Verifies that the elliptic curve signature `signature` was generated * by signing `data` 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 order hash is valid */ public static isValidOrderHash(orderHash: string): boolean { assert.isString('orderHash', orderHash); const isValid = /^0x[0-9A-F]{64}$/i.test(orderHash); return isValid; } /** * 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, decimals: number): BigNumber.BigNumber { assert.isBigNumber('amount', amount); assert.isNumber('decimals', decimals); const aUnit = new BigNumber(10).pow(decimals); 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, decimals: number): BigNumber.BigNumber { assert.isBigNumber('amount', amount); assert.isNumber('decimals', decimals); const unit = new BigNumber(10).pow(decimals); const baseUnitAmount = amount.times(unit); return baseUnitAmount; } constructor(web3: Web3) { this.web3Wrapper = new Web3Wrapper(web3); this.exchange = new ExchangeWrapper(this.web3Wrapper); this.tokenRegistry = new TokenRegistryWrapper(this.web3Wrapper); } /** * Sets a new provider for the web3 instance used by 0x.js internally and invalidates any instantiated * contract instances created with the old provider. */ public setProvider(provider: Web3.Provider) { this.web3Wrapper.setProvider(provider); this.exchange.invalidateContractInstance(); } /** * 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): Promise { assert.isHexString('orderHashHex', orderHashHex); 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 makerAddressIfExists = await this.web3Wrapper.getSenderAddressIfExistsAsync(); if (_.isUndefined(makerAddressIfExists)) { throw new Error(ZeroExError.USER_HAS_NO_ASSOCIATED_ADDRESSES); } const signature = await this.web3Wrapper.signTransactionAsync(makerAddressIfExists, 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, makerAddressIfExists); if (!isValidSignature) { throw new Error(ZeroExError.INVALID_SIGNATURE); } return ecSignature; } }