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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<string[]> {
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<string> {
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<ECSignature> {
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;
}
}
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