1 files changed, 105 insertions, 0 deletions
diff --git a/packages/contracts/util/order.ts b/packages/contracts/util/order.ts
new file mode 100644
index 000000000..b42149d38
--- /dev/null
+++ b/packages/contracts/util/order.ts
@@ -0,0 +1,105 @@
+import { BigNumber } from '@0xproject/utils';
+import { Web3Wrapper } from '@0xproject/web3-wrapper';
+import ethUtil = require('ethereumjs-util');
+import * as _ from 'lodash';
+
+import { crypto } from './crypto';
+import { OrderParams } from './types';
+
+export class Order {
+    public params: OrderParams;
+    private _web3Wrapper: Web3Wrapper;
+    constructor(web3Wrapper: Web3Wrapper, params: OrderParams) {
+        this.params = params;
+        this._web3Wrapper = web3Wrapper;
+    }
+    public isValidSignature() {
+        const { v, r, s } = this.params;
+        if (_.isUndefined(v) || _.isUndefined(r) || _.isUndefined(s)) {
+            throw new Error('Cannot call isValidSignature on unsigned order');
+        }
+        const orderHash = this._getOrderHash();
+        const msgHash = ethUtil.hashPersonalMessage(ethUtil.toBuffer(orderHash));
+        try {
+            const pubKey = ethUtil.ecrecover(msgHash, v, ethUtil.toBuffer(r), ethUtil.toBuffer(s));
+            const recoveredAddress = ethUtil.bufferToHex(ethUtil.pubToAddress(pubKey));
+            return recoveredAddress === this.params.maker;
+        } catch (err) {
+            return false;
+        }
+    }
+    public async signAsync() {
+        const orderHash = this._getOrderHash();
+        const signature = await this._web3Wrapper.signTransactionAsync(this.params.maker, orderHash);
+        const { v, r, s } = ethUtil.fromRpcSig(signature);
+        this.params = _.assign(this.params, {
+            orderHashHex: orderHash,
+            v,
+            r: ethUtil.bufferToHex(r),
+            s: ethUtil.bufferToHex(s),
+        });
+    }
+    public createFill(takerTokenFillAmount?: BigNumber) {
+        const fill = {
+            orderAddresses: [
+                this.params.maker,
+                this.params.taker,
+                this.params.makerToken,
+                this.params.takerToken,
+                this.params.feeRecipient,
+            ],
+            orderValues: [
+                this.params.makerTokenAmount,
+                this.params.takerTokenAmount,
+                this.params.makerFee,
+                this.params.takerFee,
+                this.params.expirationTimestampInSec,
+                this.params.salt,
+            ],
+            takerTokenFillAmount: takerTokenFillAmount || this.params.takerTokenAmount,
+            v: this.params.v,
+            r: this.params.r,
+            s: this.params.s,
+        };
+        return fill;
+    }
+    public createCancel(takerTokenCancelAmount?: BigNumber) {
+        const cancel = {
+            orderAddresses: [
+                this.params.maker,
+                this.params.taker,
+                this.params.makerToken,
+                this.params.takerToken,
+                this.params.feeRecipient,
+            ],
+            orderValues: [
+                this.params.makerTokenAmount,
+                this.params.takerTokenAmount,
+                this.params.makerFee,
+                this.params.takerFee,
+                this.params.expirationTimestampInSec,
+                this.params.salt,
+            ],
+            takerTokenCancelAmount: takerTokenCancelAmount || this.params.takerTokenAmount,
+        };
+        return cancel;
+    }
+    private _getOrderHash(): string {
+        const orderHash = crypto.solSHA3([
+            this.params.exchangeContractAddress,
+            this.params.maker,
+            this.params.taker,
+            this.params.makerToken,
+            this.params.takerToken,
+            this.params.feeRecipient,
+            this.params.makerTokenAmount,
+            this.params.takerTokenAmount,
+            this.params.makerFee,
+            this.params.takerFee,
+            this.params.expirationTimestampInSec,
+            this.params.salt,
+        ]);
+        const orderHashHex = ethUtil.bufferToHex(orderHash);
+        return orderHashHex;
+    }
+}