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 {ECSignatureSchema} from './schemas/ec_signature_schema';
import {SolidityTypes, ECSignature, ZeroExError} from './types';
const MAX_DIGITS_IN_UNSIGNED_256_INT = 78;
export class ZeroEx {
public web3Wrapper: Web3Wrapper;
public exchange: ExchangeWrapper;
/**
* 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);
}
/**
* Signs an orderHash and returns it's ECSignature
* This method currently supports TestRPC, Geth and Parity above and below V1.6.6
*/
public async signOrderHashAsync(orderHashHex: string): Promise<ECSignature> {
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;
}
}
