import { schemas, SchemaValidator } from '@0xproject/json-schemas'; import { Order, SignedOrder, SolidityTypes } from '@0xproject/types'; import { BigNumber } from '@0xproject/utils'; import BN = require('bn.js'); import * as ethABI from 'ethereumjs-abi'; import * as ethUtil from 'ethereumjs-util'; import * as _ from 'lodash'; import { assert } from './assert'; const INVALID_TAKER_FORMAT = 'instance.taker is not of a type(s) string'; /** * Converts BigNumber instance to BN * The only reason we convert to BN is to remain compatible with `ethABI.soliditySHA3` that * expects values of Solidity type `uint` to be passed as type `BN`. * We do not use BN anywhere else in the codebase. */ function bigNumberToBN(value: BigNumber): BN { return new BN(value.toString(), 10); } /** * Computes the orderHash for a supplied order. * @param order An object that conforms to the Order or SignedOrder interface definitions. * @return The resulting orderHash from hashing the supplied order. */ export function getOrderHashHex(order: Order | SignedOrder): string { try { assert.doesConformToSchema('order', order, schemas.orderSchema); } catch (error) { if (_.includes(error.message, INVALID_TAKER_FORMAT)) { const errMsg = 'Order taker must be of type string. If you want anyone to be able to fill an order - pass ZeroEx.NULL_ADDRESS'; throw new Error(errMsg); } throw error; } const orderParts = [ { value: order.exchangeContractAddress, type: SolidityTypes.Address }, { value: order.maker, type: SolidityTypes.Address }, { value: order.taker, type: SolidityTypes.Address }, { value: order.makerTokenAddress, type: SolidityTypes.Address }, { value: order.takerTokenAddress, type: SolidityTypes.Address }, { value: order.feeRecipient, type: SolidityTypes.Address }, { value: bigNumberToBN(order.makerTokenAmount), type: SolidityTypes.Uint256, }, { value: bigNumberToBN(order.takerTokenAmount), type: SolidityTypes.Uint256, }, { value: bigNumberToBN(order.makerFee), type: SolidityTypes.Uint256, }, { value: bigNumberToBN(order.takerFee), type: SolidityTypes.Uint256, }, { value: bigNumberToBN(order.expirationUnixTimestampSec), type: SolidityTypes.Uint256, }, { value: bigNumberToBN(order.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; } /** * 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. * Use this method when processing orderHashes submitted as user input. * @param orderHash Hex encoded orderHash. * @return Whether the supplied orderHash has the expected format. */ export function isValidOrderHash(orderHash: 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('orderHash', orderHash); const schemaValidator = new SchemaValidator(); const isValid = schemaValidator.validate(orderHash, schemas.orderHashSchema).valid; return isValid; }