Add order signing and dispensing ability to faucet

6 files changed, 150 insertions, 38 deletions

diff --git a/packages/testnet-faucets/src/ts/global.d.ts b/packages/testnet-faucets/src/ts/global.d.ts
index 97cd35680..af9534377 100644
--- a/packages/testnet-faucets/src/ts/global.d.ts
+++ b/packages/testnet-faucets/src/ts/global.d.ts
@@ -24,3 +24,11 @@ declare module 'ethereumjs-tx' {
     }
     export = EthereumTx;
 }
+
+// Define extra params on Request for parameter extraction in middleware
+declare namespace Express {
+    export interface Request {
+        recipientAddress: string;
+        networkId: string;
+    }
+}
diff --git a/packages/testnet-faucets/src/ts/handler.ts b/packages/testnet-faucets/src/ts/handler.ts
index bf5b3e81e..7883cefd8 100644
--- a/packages/testnet-faucets/src/ts/handler.ts
+++ b/packages/testnet-faucets/src/ts/handler.ts
@@ -1,11 +1,20 @@
-import { addressUtils } from '@0xproject/utils';
+import { Order, SignedOrder, ZeroEx } from '0x.js';
+import { BigNumber } from '@0xproject/utils';
 import * as express from 'express';
 import * as _ from 'lodash';
+
+// HACK: web3 injects XMLHttpRequest into the global scope and ProviderEngine checks XMLHttpRequest
+// to know whether it is running in a browser or node environment. We need it to be undefined since
+// we are not running in a browser env.
+// Filed issue: https://github.com/ethereum/web3.js/issues/844
+(global as any).XMLHttpRequest = undefined;
+
 import ProviderEngine = require('web3-provider-engine');
 import HookedWalletSubprovider = require('web3-provider-engine/subproviders/hooked-wallet');
 import NonceSubprovider = require('web3-provider-engine/subproviders/nonce-tracker');
 import RpcSubprovider = require('web3-provider-engine/subproviders/rpc');
 
+import { configs } from './configs';
 import { EtherRequestQueue } from './ether_request_queue';
 import { idManagement } from './id_management';
 import { RequestQueue } from './request_queue';
@@ -19,32 +28,38 @@ import { ZRXRequestQueue } from './zrx_request_queue';
 // tslint:disable-next-line:ordered-imports
 import * as Web3 from 'web3';
 
-interface RequestQueueByNetworkId {
-    [networkId: string]: RequestQueue;
+interface ItemByNetworkId<T> {
+    [networkId: string]: T;
 }
 
-enum QueueType {
+enum RequestedAssetType {
     ETH = 'ETH',
+    WETH = 'WETH',
     ZRX = 'ZRX',
 }
 
-const DEFAULT_NETWORK_ID = 42; // kovan
+const TWO_DAYS_IN_MS = 1.728e8; // TODO: make this configurable
 
 export class Handler {
-    private _etherRequestQueueByNetworkId: RequestQueueByNetworkId = {};
-    private _zrxRequestQueueByNetworkId: RequestQueueByNetworkId = {};
+    private _zeroExByNetworkId: ItemByNetworkId<ZeroEx> = {};
+    private _etherRequestQueueByNetworkId: ItemByNetworkId<RequestQueue> = {};
+    private _zrxRequestQueueByNetworkId: ItemByNetworkId<RequestQueue> = {};
     constructor() {
         _.forIn(rpcUrls, (rpcUrl: string, networkId: string) => {
             const providerObj = this._createProviderEngine(rpcUrl);
             const web3 = new Web3(providerObj);
+            const zeroExConfig = {
+                networkId: +networkId,
+            };
+            const zeroEx = new ZeroEx(web3.currentProvider, zeroExConfig);
+            this._zeroExByNetworkId[networkId] = zeroEx;
             this._etherRequestQueueByNetworkId[networkId] = new EtherRequestQueue(web3);
-            this._zrxRequestQueueByNetworkId[networkId] = new ZRXRequestQueue(web3, +networkId);
+            this._zrxRequestQueueByNetworkId[networkId] = new ZRXRequestQueue(web3, zeroEx);
         });
     }
     public getQueueInfo(req: express.Request, res: express.Response) {
         res.setHeader('Content-Type', 'application/json');
         const queueInfo = _.mapValues(rpcUrls, (rpcUrl: string, networkId: string) => {
-            utils.consoleLog(networkId);
             const etherRequestQueue = this._etherRequestQueueByNetworkId[networkId];
             const zrxRequestQueue = this._zrxRequestQueueByNetworkId[networkId];
             return {
@@ -62,37 +77,83 @@ export class Handler {
         res.status(200).send(payload);
     }
     public dispenseEther(req: express.Request, res: express.Response) {
-        this._dispense(req, res, this._etherRequestQueueByNetworkId, QueueType.ETH);
+        this._dispenseAsset(req, res, this._etherRequestQueueByNetworkId, RequestedAssetType.ETH);
     }
     public dispenseZRX(req: express.Request, res: express.Response) {
-        this._dispense(req, res, this._zrxRequestQueueByNetworkId, QueueType.ZRX);
+        this._dispenseAsset(req, res, this._zrxRequestQueueByNetworkId, RequestedAssetType.ZRX);
+    }
+    public async dispenseWETHOrder(req: express.Request, res: express.Response) {
+        await this._dispenseOrder(req, res, RequestedAssetType.WETH);
     }
-    private _dispense(
+    public async dispenseZRXOrder(req: express.Request, res: express.Response, next: express.NextFunction) {
+        await this._dispenseOrder(req, res, RequestedAssetType.ZRX);
+    }
+    // tslint:disable-next-line:prefer-function-over-method
+    private _dispenseAsset(
         req: express.Request,
         res: express.Response,
-        requestQueueByNetworkId: RequestQueueByNetworkId,
-        queueType: QueueType,
+        requestQueueByNetworkId: ItemByNetworkId<RequestQueue>,
+        requestedAssetType: RequestedAssetType,
     ) {
-        const recipientAddress = req.params.recipient;
-        if (_.isUndefined(recipientAddress) || !this._isValidEthereumAddress(recipientAddress)) {
-            res.status(400).send('INVALID_RECIPIENT_ADDRESS');
-            return;
-        }
-        const networkId = _.get(req.query, 'networkId', DEFAULT_NETWORK_ID);
-        const requestQueue = _.get(requestQueueByNetworkId, networkId);
+        const requestQueue = _.get(requestQueueByNetworkId, req.networkId);
         if (_.isUndefined(requestQueue)) {
-            res.status(400).send('INVALID_NETWORK_ID');
+            res.status(400).send('UNSUPPORTED_NETWORK_ID');
             return;
         }
-        const lowerCaseRecipientAddress = recipientAddress.toLowerCase();
-        const didAddToQueue = requestQueue.add(lowerCaseRecipientAddress);
+        const didAddToQueue = requestQueue.add(req.recipientAddress);
         if (!didAddToQueue) {
             res.status(503).send('QUEUE_IS_FULL');
             return;
         }
-        utils.consoleLog(`Added ${lowerCaseRecipientAddress} to queue: ${queueType} networkId: ${networkId}`);
+        utils.consoleLog(`Added ${req.recipientAddress} to queue: ${requestedAssetType} networkId: ${req.networkId}`);
         res.status(200).end();
     }
+    private async _dispenseOrder(req: express.Request, res: express.Response, requestedAssetType: RequestedAssetType) {
+        const zeroEx = _.get(this._zeroExByNetworkId, req.networkId);
+        if (_.isUndefined(zeroEx)) {
+            res.status(400).send('UNSUPPORTED_NETWORK_ID');
+            return;
+        }
+        res.setHeader('Content-Type', 'application/json');
+        const makerTokenAddress = await zeroEx.tokenRegistry.getTokenAddressBySymbolIfExistsAsync(requestedAssetType);
+        if (_.isUndefined(makerTokenAddress)) {
+            res.status(400).send('INVALID_TOKEN');
+            return;
+        }
+        const takerTokenSymbol =
+            requestedAssetType === RequestedAssetType.WETH ? RequestedAssetType.ZRX : RequestedAssetType.WETH;
+        const takerTokenAddress = await zeroEx.tokenRegistry.getTokenAddressBySymbolIfExistsAsync(takerTokenSymbol);
+        if (_.isUndefined(takerTokenAddress)) {
+            res.status(400).send('INVALID_TOKEN');
+            return;
+        }
+        const makerTokenAmount = new BigNumber(0.1);
+        const takerTokenAmount = new BigNumber(0.1);
+        const order: Order = {
+            maker: configs.DISPENSER_ADDRESS,
+            taker: req.recipientAddress,
+            makerFee: new BigNumber(0),
+            takerFee: new BigNumber(0),
+            makerTokenAmount,
+            takerTokenAmount,
+            makerTokenAddress,
+            takerTokenAddress,
+            salt: ZeroEx.generatePseudoRandomSalt(),
+            exchangeContractAddress: zeroEx.exchange.getContractAddress(),
+            feeRecipient: ZeroEx.NULL_ADDRESS,
+            expirationUnixTimestampSec: new BigNumber(Date.now() + TWO_DAYS_IN_MS),
+        };
+        const orderHash = ZeroEx.getOrderHashHex(order);
+        const signature = await zeroEx.signOrderHashAsync(orderHash, configs.DISPENSER_ADDRESS, false);
+        const signedOrder = {
+            ...order,
+            signature,
+        };
+        const signedOrderHash = ZeroEx.getOrderHashHex(signedOrder);
+        const payload = JSON.stringify(signedOrder);
+        utils.consoleLog(`Dispensed signed order: ${payload}`);
+        res.status(200).send(payload);
+    }
     // tslint:disable-next-line:prefer-function-over-method
     private _createProviderEngine(rpcUrl: string) {
         const engine = new ProviderEngine();
@@ -106,9 +167,4 @@ export class Handler {
         engine.start();
         return engine;
     }
-    // tslint:disable-next-line:prefer-function-over-method
-    private _isValidEthereumAddress(address: string): boolean {
-        const lowercaseAddress = address.toLowerCase();
-        return addressUtils.isAddress(lowercaseAddress);
-    }
 }
diff --git a/packages/testnet-faucets/src/ts/id_management.ts b/packages/testnet-faucets/src/ts/id_management.ts
index db9b610a3..b088e6cf8 100644
--- a/packages/testnet-faucets/src/ts/id_management.ts
+++ b/packages/testnet-faucets/src/ts/id_management.ts
@@ -1,8 +1,10 @@
 import EthereumTx = require('ethereumjs-tx');
+import * as ethUtil from 'ethereumjs-util';
+import * as _ from 'lodash';
 
 import { configs } from './configs';
 
-type Callback = (err: Error | null, accounts: any) => void;
+type Callback = (err: Error | null, result: any) => void;
 
 export const idManagement = {
     getAccounts(callback: Callback) {
@@ -18,4 +20,16 @@ export const idManagement = {
         const rawTx = `0x${tx.serialize().toString('hex')}`;
         callback(null, rawTx);
     },
+    signMessage(message: object, callback: Callback) {
+        const data = _.get(message, 'data');
+        if (_.isUndefined(data)) {
+            callback(new Error('No data to sign'), null);
+        }
+        const privateKeyBuffer = new Buffer(configs.DISPENSER_PRIVATE_KEY as string, 'hex');
+        const dataBuff = ethUtil.toBuffer(data);
+        const msgHashBuff = ethUtil.hashPersonalMessage(dataBuff);
+        const sig = ethUtil.ecsign(msgHashBuff, privateKeyBuffer);
+        const rpcSig = ethUtil.toRpcSig(sig.v, sig.r, sig.s);
+        callback(null, rpcSig);
+    },
 };
diff --git a/packages/testnet-faucets/src/ts/parameter_extractor.ts b/packages/testnet-faucets/src/ts/parameter_extractor.ts
new file mode 100644
index 000000000..f3a26ae01
--- /dev/null
+++ b/packages/testnet-faucets/src/ts/parameter_extractor.ts
@@ -0,0 +1,34 @@
+import { addressUtils } from '@0xproject/utils';
+import { NextFunction, Request, Response } from 'express';
+import * as _ from 'lodash';
+
+import { configs } from './configs';
+import { rpcUrls } from './rpc_urls';
+import { utils } from './utils';
+
+const DEFAULT_NETWORK_ID = 42; // kovan
+
+export const parameterExtractor = {
+    extract(req: Request, res: Response, next: NextFunction) {
+        const recipientAddress = req.params.recipient;
+        if (_.isUndefined(recipientAddress) || !_isValidEthereumAddress(recipientAddress)) {
+            res.status(400).send('INVALID_RECIPIENT_ADDRESS');
+            return;
+        }
+        const lowerCaseRecipientAddress = recipientAddress.toLowerCase();
+        req.recipientAddress = lowerCaseRecipientAddress;
+        const networkId = _.get(req.query, 'networkId', DEFAULT_NETWORK_ID);
+        const rpcUrl = _.get(rpcUrls, networkId);
+        if (_.isUndefined(rpcUrl)) {
+            res.status(400).send('UNSUPPORTED_NETWORK_ID');
+            return;
+        }
+        req.networkId = networkId;
+        next();
+    },
+};
+
+function _isValidEthereumAddress(address: string): boolean {
+    const lowercaseAddress = address.toLowerCase();
+    return addressUtils.isAddress(lowercaseAddress);
+}
diff --git a/packages/testnet-faucets/src/ts/server.ts b/packages/testnet-faucets/src/ts/server.ts
index 26edfff5a..38c2f1428 100644
--- a/packages/testnet-faucets/src/ts/server.ts
+++ b/packages/testnet-faucets/src/ts/server.ts
@@ -3,6 +3,7 @@ import * as express from 'express';
 
 import { errorReporter } from './error_reporter';
 import { Handler } from './handler';
+import { parameterExtractor } from './parameter_extractor';
 
 // Setup the errorReporter to catch uncaught exceptions and unhandled rejections
 errorReporter.setup();
@@ -20,8 +21,10 @@ app.get('/ping', (req: express.Request, res: express.Response) => {
     res.status(200).send('pong');
 });
 app.get('/info', handler.getQueueInfo.bind(handler));
-app.get('/ether/:recipient', handler.dispenseEther.bind(handler));
-app.get('/zrx/:recipient', handler.dispenseZRX.bind(handler));
+app.get('/ether/:recipient', parameterExtractor.extract, handler.dispenseEther.bind(handler));
+app.get('/zrx/:recipient', parameterExtractor.extract, handler.dispenseZRX.bind(handler));
+app.get('/order/weth/:recipient', parameterExtractor.extract, handler.dispenseWETHOrder.bind(handler));
+app.get('/order/zrx/:recipient', parameterExtractor.extract, handler.dispenseZRXOrder.bind(handler));
 
 // Log to rollbar any errors unhandled by handlers
 app.use(errorReporter.errorHandler());
diff --git a/packages/testnet-faucets/src/ts/zrx_request_queue.ts b/packages/testnet-faucets/src/ts/zrx_request_queue.ts
index 3d73f9dd2..1a8bfe1d8 100644
--- a/packages/testnet-faucets/src/ts/zrx_request_queue.ts
+++ b/packages/testnet-faucets/src/ts/zrx_request_queue.ts
@@ -18,13 +18,10 @@ const QUEUE_INTERVAL_MS = 5000;
 
 export class ZRXRequestQueue extends RequestQueue {
     private _zeroEx: ZeroEx;
-    constructor(web3: Web3, networkId: number) {
+    constructor(web3: Web3, zeroEx: ZeroEx) {
         super(web3);
         this.queueIntervalMs = QUEUE_INTERVAL_MS;
-        const zeroExConfig = {
-            networkId,
-        };
-        this._zeroEx = new ZeroEx(web3.currentProvider, zeroExConfig);
+        this._zeroEx = zeroEx;
     }
     protected async processNextRequestFireAndForgetAsync(recipientAddress: string) {
         utils.consoleLog(`Processing ZRX ${recipientAddress}`);