Expose eth_signTypedData functionality for order signing

1 files changed, 49 insertions, 1 deletions

diff --git a/packages/order-utils/src/signature_utils.ts b/packages/order-utils/src/signature_utils.ts
index 3b656d3fc..05c673ae2 100644
--- a/packages/order-utils/src/signature_utils.ts
+++ b/packages/order-utils/src/signature_utils.ts
@@ -1,5 +1,5 @@
 import { schemas } from '@0xproject/json-schemas';
-import { ECSignature, SignatureType, SignerType, ValidatorSignature } from '@0xproject/types';
+import { ECSignature, Order, SignatureType, SignerType, ValidatorSignature } from '@0xproject/types';
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
 import { Provider } from 'ethereum-types';
 import * as ethUtil from 'ethereumjs-util';
@@ -7,9 +7,11 @@ import * as _ from 'lodash';
 
 import { artifacts } from './artifacts';
 import { assert } from './assert';
+import { EIP712_DOMAIN_NAME, EIP712_DOMAIN_SCHEMA, EIP712_DOMAIN_VERSION } from './eip712_utils';
 import { ExchangeContract } from './generated_contract_wrappers/exchange';
 import { IValidatorContract } from './generated_contract_wrappers/i_validator';
 import { IWalletContract } from './generated_contract_wrappers/i_wallet';
+import { EIP712_ORDER_SCHEMA } from './order_hash';
 import { OrderError } from './types';
 import { utils } from './utils';
 
@@ -192,6 +194,52 @@ export const signatureUtils = {
         }
     },
     /**
+     * Signs an order using `eth_signTypedData` and returns it's elliptic curve signature and signature type.
+     * This method currently supports Ganache.
+     * @param   order The Order to sign.
+     * @param   signerAddress   The hex encoded Ethereum address you wish to sign it with. This address
+     *          must be available via the Provider supplied to 0x.js.
+     * @return  A hex encoded string containing the Elliptic curve signature generated by signing the orderHash and the Signature Type.
+     */
+    async ecSignOrderAsync(provider: Provider, order: Order, signerAddress: string): Promise<string> {
+        assert.isWeb3Provider('provider', provider);
+        assert.isETHAddressHex('signerAddress', signerAddress);
+        const web3Wrapper = new Web3Wrapper(provider);
+        await assert.isSenderAddressAsync('signerAddress', signerAddress, web3Wrapper);
+        const normalizedSignerAddress = signerAddress.toLowerCase();
+        const typedData = {
+            types: {
+                EIP712Domain: EIP712_DOMAIN_SCHEMA.parameters,
+                Order: EIP712_ORDER_SCHEMA.parameters,
+            },
+            domain: {
+                name: EIP712_DOMAIN_NAME,
+                version: EIP712_DOMAIN_VERSION,
+                verifyingContract: order.exchangeAddress,
+            },
+            message: {
+                ...order,
+                salt: order.salt.toString(),
+                makerFee: order.makerFee.toString(),
+                takerFee: order.takerFee.toString(),
+                makerAssetAmount: order.makerAssetAmount.toString(),
+                takerAssetAmount: order.takerAssetAmount.toString(),
+                expirationTimeSeconds: order.expirationTimeSeconds.toString(),
+            },
+            primaryType: 'Order',
+        };
+        const signature = await web3Wrapper.signTypedDataAsync(normalizedSignerAddress, typedData);
+        const ecSignatureRSV = parseSignatureHexAsRSV(signature);
+        const signatureBuffer = Buffer.concat([
+            ethUtil.toBuffer(ecSignatureRSV.v),
+            ethUtil.toBuffer(ecSignatureRSV.r),
+            ethUtil.toBuffer(ecSignatureRSV.s),
+            ethUtil.toBuffer(SignatureType.EIP712),
+        ]);
+        const signatureHex = `0x${signatureBuffer.toString('hex')}`;
+        return signatureHex;
+    },
+    /**
      * Signs an orderHash and returns it's elliptic curve signature and signature type.
      * This method currently supports TestRPC, Geth and Parity above and below V1.6.6
      * @param   orderHash       Hex encoded orderHash to sign.