Initial refactor of order-utils. Move many utils from contracts into this package.

11 files changed, 478 insertions, 160 deletions

diff --git a/packages/order-utils/src/artifacts.ts b/packages/order-utils/src/artifacts.ts
new file mode 100644
index 000000000..6eb5ad0c0
--- /dev/null
+++ b/packages/order-utils/src/artifacts.ts
@@ -0,0 +1,8 @@
+import { Artifact } from '@0xproject/types';
+
+import * as Exchange from './artifacts/Exchange.json';
+import * as ISigner from './artifacts/ISigner.json';
+export const artifacts = {
+    Exchange: (Exchange as any) as Artifact,
+    ISigner: (ISigner as any) as Artifact,
+};
diff --git a/packages/order-utils/src/assert.ts b/packages/order-utils/src/assert.ts
index 5ac402e7e..07cde453a 100644
--- a/packages/order-utils/src/assert.ts
+++ b/packages/order-utils/src/assert.ts
@@ -8,8 +8,6 @@ import { BigNumber } from '@0xproject/utils';
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
 import * as _ from 'lodash';
 
-import { isValidSignature } from './signature_utils';
-
 export const assert = {
     ...sharedAssert,
     async isSenderAddressAsync(
diff --git a/packages/order-utils/src/asset_proxy_utils.ts b/packages/order-utils/src/asset_proxy_utils.ts
new file mode 100644
index 000000000..11f81c656
--- /dev/null
+++ b/packages/order-utils/src/asset_proxy_utils.ts
@@ -0,0 +1,149 @@
+import { AssetProxyId, ERC20ProxyData, ERC721ProxyData, ProxyData } from '@0xproject/types';
+import { BigNumber } from '@0xproject/utils';
+import BN = require('bn.js');
+import ethUtil = require('ethereumjs-util');
+
+const ERC20_PROXY_METADATA_BYTE_LENGTH = 21;
+const ERC721_PROXY_METADATA_BYTE_LENGTH = 53;
+
+export const assetProxyUtils = {
+    encodeAssetProxyId(assetProxyId: AssetProxyId): Buffer {
+        return ethUtil.toBuffer(assetProxyId);
+    },
+    decodeAssetProxyId(encodedAssetProxyId: Buffer): AssetProxyId {
+        return ethUtil.bufferToInt(encodedAssetProxyId);
+    },
+    encodeAddress(address: string): Buffer {
+        if (!ethUtil.isValidAddress(address)) {
+            throw new Error(`Invalid Address: ${address}`);
+        }
+        const encodedAddress = ethUtil.toBuffer(address);
+        return encodedAddress;
+    },
+    decodeAddress(encodedAddress: Buffer): string {
+        const address = ethUtil.bufferToHex(encodedAddress);
+        if (!ethUtil.isValidAddress(address)) {
+            throw new Error(`Invalid Address: ${address}`);
+        }
+        return address;
+    },
+    encodeUint256(value: BigNumber): Buffer {
+        const base = 10;
+        const formattedValue = new BN(value.toString(base));
+        const encodedValue = ethUtil.toBuffer(formattedValue);
+        // tslint:disable-next-line:custom-no-magic-numbers
+        const paddedValue = ethUtil.setLengthLeft(encodedValue, 32);
+        return paddedValue;
+    },
+    decodeUint256(encodedValue: Buffer): BigNumber {
+        const formattedValue = ethUtil.bufferToHex(encodedValue);
+        const value = new BigNumber(formattedValue, 16);
+        return value;
+    },
+    encodeERC20ProxyData(tokenAddress: string): string {
+        const encodedAssetProxyId = assetProxyUtils.encodeAssetProxyId(AssetProxyId.ERC20);
+        const encodedAddress = assetProxyUtils.encodeAddress(tokenAddress);
+        const encodedMetadata = Buffer.concat([encodedAssetProxyId, encodedAddress]);
+        const encodedMetadataHex = ethUtil.bufferToHex(encodedMetadata);
+        return encodedMetadataHex;
+    },
+    decodeERC20ProxyData(proxyData: string): ERC20ProxyData {
+        const encodedProxyMetadata = ethUtil.toBuffer(proxyData);
+        if (encodedProxyMetadata.byteLength !== ERC20_PROXY_METADATA_BYTE_LENGTH) {
+            throw new Error(
+                `Could not decode ERC20 Proxy Data. Expected length of encoded data to be 21. Got ${
+                    encodedProxyMetadata.byteLength
+                }`,
+            );
+        }
+        const encodedAssetProxyId = encodedProxyMetadata.slice(0, 1);
+        const assetProxyId = assetProxyUtils.decodeAssetProxyId(encodedAssetProxyId);
+        if (assetProxyId !== AssetProxyId.ERC20) {
+            throw new Error(
+                `Could not decode ERC20 Proxy Data. Expected Asset Proxy Id to be ERC20 (${
+                    AssetProxyId.ERC20
+                }), but got ${assetProxyId}`,
+            );
+        }
+        const encodedTokenAddress = encodedProxyMetadata.slice(1, ERC20_PROXY_METADATA_BYTE_LENGTH);
+        const tokenAddress = assetProxyUtils.decodeAddress(encodedTokenAddress);
+        const erc20ProxyData = {
+            assetProxyId,
+            tokenAddress,
+        };
+        return erc20ProxyData;
+    },
+    encodeERC721ProxyData(tokenAddress: string, tokenId: BigNumber): string {
+        const encodedAssetProxyId = assetProxyUtils.encodeAssetProxyId(AssetProxyId.ERC721);
+        const encodedAddress = assetProxyUtils.encodeAddress(tokenAddress);
+        const encodedTokenId = assetProxyUtils.encodeUint256(tokenId);
+        const encodedMetadata = Buffer.concat([encodedAssetProxyId, encodedAddress, encodedTokenId]);
+        const encodedMetadataHex = ethUtil.bufferToHex(encodedMetadata);
+        return encodedMetadataHex;
+    },
+    decodeERC721ProxyData(proxyData: string): ERC721ProxyData {
+        const encodedProxyMetadata = ethUtil.toBuffer(proxyData);
+        if (encodedProxyMetadata.byteLength !== ERC721_PROXY_METADATA_BYTE_LENGTH) {
+            throw new Error(
+                `Could not decode ERC20 Proxy Data. Expected length of encoded data to be 53. Got ${
+                    encodedProxyMetadata.byteLength
+                }`,
+            );
+        }
+        const encodedAssetProxyId = encodedProxyMetadata.slice(0, 1);
+        const assetProxyId = assetProxyUtils.decodeAssetProxyId(encodedAssetProxyId);
+        if (assetProxyId !== AssetProxyId.ERC721) {
+            throw new Error(
+                `Could not decode ERC721 Proxy Data. Expected Asset Proxy Id to be ERC721 (${
+                    AssetProxyId.ERC721
+                }), but got ${assetProxyId}`,
+            );
+        }
+        const addressOffset = 21;
+        const encodedTokenAddress = encodedProxyMetadata.slice(1, addressOffset);
+        const tokenAddress = assetProxyUtils.decodeAddress(encodedTokenAddress);
+        const encodedTokenId = encodedProxyMetadata.slice(addressOffset, ERC721_PROXY_METADATA_BYTE_LENGTH);
+        const tokenId = assetProxyUtils.decodeUint256(encodedTokenId);
+        const erc721ProxyData = {
+            assetProxyId,
+            tokenAddress,
+            tokenId,
+        };
+        return erc721ProxyData;
+    },
+    decodeProxyDataId(proxyData: string): AssetProxyId {
+        const encodedProxyMetadata = ethUtil.toBuffer(proxyData);
+        if (encodedProxyMetadata.byteLength < 1) {
+            throw new Error(
+                `Could not decode Proxy Data. Expected length of encoded data to be at least 1. Got ${
+                    encodedProxyMetadata.byteLength
+                }`,
+            );
+        }
+        const encodedAssetProxyId = encodedProxyMetadata.slice(0, 1);
+        const assetProxyId = assetProxyUtils.decodeAssetProxyId(encodedAssetProxyId);
+        return assetProxyId;
+    },
+    decodeProxyData(proxyData: string): ProxyData {
+        const assetProxyId = assetProxyUtils.decodeProxyDataId(proxyData);
+        switch (assetProxyId) {
+            case AssetProxyId.ERC20:
+                const erc20ProxyData = assetProxyUtils.decodeERC20ProxyData(proxyData);
+                const generalizedERC20ProxyData = {
+                    assetProxyId,
+                    tokenAddress: erc20ProxyData.tokenAddress,
+                };
+                return generalizedERC20ProxyData;
+            case AssetProxyId.ERC721:
+                const erc721ProxyData = assetProxyUtils.decodeERC721ProxyData(proxyData);
+                const generaliedERC721ProxyData = {
+                    assetProxyId,
+                    tokenAddress: erc721ProxyData.tokenAddress,
+                    data: erc721ProxyData.tokenId,
+                };
+                return generaliedERC721ProxyData;
+            default:
+                throw new Error(`Unrecognized asset proxy id: ${assetProxyId}`);
+        }
+    },
+};
diff --git a/packages/order-utils/src/crypto.ts b/packages/order-utils/src/crypto.ts
new file mode 100644
index 000000000..517ca2840
--- /dev/null
+++ b/packages/order-utils/src/crypto.ts
@@ -0,0 +1,46 @@
+import BN = require('bn.js');
+import ABI = require('ethereumjs-abi');
+import ethUtil = require('ethereumjs-util');
+import * as _ from 'lodash';
+
+export const crypto = {
+    /**
+     * We convert types from JS to Solidity as follows:
+     * BigNumber -> uint256
+     * number -> uint8
+     * string -> string
+     * boolean -> bool
+     * valid Ethereum address -> address
+     */
+    solSHA3(args: any[]): Buffer {
+        return crypto._solHash(args, ABI.soliditySHA3);
+    },
+    solSHA256(args: any[]): Buffer {
+        return crypto._solHash(args, ABI.soliditySHA256);
+    },
+    _solHash(args: any[], hashFunction: (types: string[], values: any[]) => Buffer): Buffer {
+        const argTypes: string[] = [];
+        _.each(args, (arg, i) => {
+            const isNumber = _.isFinite(arg);
+            if (isNumber) {
+                argTypes.push('uint8');
+            } else if (arg.isBigNumber) {
+                argTypes.push('uint256');
+                const base = 10;
+                args[i] = new BN(arg.toString(base), base);
+            } else if (ethUtil.isValidAddress(arg)) {
+                argTypes.push('address');
+            } else if (_.isString(arg)) {
+                argTypes.push('string');
+            } else if (_.isBuffer(arg)) {
+                argTypes.push('bytes');
+            } else if (_.isBoolean(arg)) {
+                argTypes.push('bool');
+            } else {
+                throw new Error(`Unable to guess arg type: ${arg}`);
+            }
+        });
+        const hash = hashFunction(argTypes, args);
+        return hash;
+    },
+};
diff --git a/packages/order-utils/src/formatters.ts b/packages/order-utils/src/formatters.ts
deleted file mode 100644
index 2b6f4ddb7..000000000
--- a/packages/order-utils/src/formatters.ts
+++ /dev/null
@@ -1,23 +0,0 @@
-import { Order, OrderAddresses, OrderValues } from '@0xproject/types';
-import { BigNumber } from '@0xproject/utils';
-
-export const formatters = {
-    getOrderAddressesAndValues(order: Order): [OrderAddresses, OrderValues] {
-        const orderAddresses: OrderAddresses = [
-            order.maker,
-            order.taker,
-            order.makerTokenAddress,
-            order.takerTokenAddress,
-            order.feeRecipient,
-        ];
-        const orderValues: OrderValues = [
-            order.makerTokenAmount,
-            order.takerTokenAmount,
-            order.makerFee,
-            order.takerFee,
-            order.expirationUnixTimestampSec,
-            order.salt,
-        ];
-        return [orderAddresses, orderValues];
-    },
-};
diff --git a/packages/order-utils/src/index.ts b/packages/order-utils/src/index.ts
index e9cea95ed..5b4e20119 100644
--- a/packages/order-utils/src/index.ts
+++ b/packages/order-utils/src/index.ts
@@ -1,11 +1,12 @@
-export { getOrderHashHex, isValidOrderHash } from './order_hash';
-export { isValidSignature, signOrderHashAsync } from './signature_utils';
+export { orderHashUtils } from './order_hash';
+export { isValidSignatureAsync, ecSignOrderHashAsync } from './signature_utils';
 export { orderFactory } from './order_factory';
 export { constants } from './constants';
+export { crypto } from './crypto';
 export { generatePseudoRandomSalt } from './salt';
 export { OrderError } from './types';
-export { formatters } from './formatters';
 export { AbstractBalanceAndProxyAllowanceFetcher } from './abstract/abstract_balance_and_proxy_allowance_fetcher';
 export { AbstractOrderFilledCancelledFetcher } from './abstract/abstract_order_filled_cancelled_fetcher';
 export { RemainingFillableCalculator } from './remaining_fillable_calculator';
 export { OrderStateUtils } from './order_state_utils';
+export { assetProxyUtils } from './asset_proxy_utils';
diff --git a/packages/order-utils/src/order_factory.ts b/packages/order-utils/src/order_factory.ts
index 2759aac81..fe341b845 100644
--- a/packages/order-utils/src/order_factory.ts
+++ b/packages/order-utils/src/order_factory.ts
@@ -2,48 +2,56 @@ import { Provider, SignedOrder } from '@0xproject/types';
 import { BigNumber } from '@0xproject/utils';
 import * as _ from 'lodash';
 
-import { getOrderHashHex } from './order_hash';
+import { orderHashUtils } from './order_hash';
 import { generatePseudoRandomSalt } from './salt';
-import { signOrderHashAsync } from './signature_utils';
+import { ecSignOrderHashAsync, getVRSHexString } from './signature_utils';
 
 const SHOULD_ADD_PERSONAL_MESSAGE_PREFIX = false;
 
 export const orderFactory = {
     async createSignedOrderAsync(
         provider: Provider,
-        maker: string,
-        taker: string,
+        makerAddress: string,
+        takerAddress: string,
+        senderAddress: string,
         makerFee: BigNumber,
         takerFee: BigNumber,
-        makerTokenAmount: BigNumber,
-        makerTokenAddress: string,
-        takerTokenAmount: BigNumber,
-        takerTokenAddress: string,
-        exchangeContractAddress: string,
-        feeRecipient: string,
-        expirationUnixTimestampSecIfExists?: BigNumber,
+        makerAssetAmount: BigNumber,
+        makerAssetData: string,
+        takerAssetAmount: BigNumber,
+        takerAssetData: string,
+        exchangeAddress: string,
+        feeRecipientAddress: string,
+        expirationTimeSecondsIfExists?: BigNumber,
     ): Promise<SignedOrder> {
         const defaultExpirationUnixTimestampSec = new BigNumber(2524604400); // Close to infinite
-        const expirationUnixTimestampSec = _.isUndefined(expirationUnixTimestampSecIfExists)
+        const expirationTimeSeconds = _.isUndefined(expirationTimeSecondsIfExists)
             ? defaultExpirationUnixTimestampSec
-            : expirationUnixTimestampSecIfExists;
+            : expirationTimeSecondsIfExists;
         const order = {
-            maker,
-            taker,
+            makerAddress,
+            takerAddress,
+            senderAddress,
             makerFee,
             takerFee,
-            makerTokenAmount,
-            takerTokenAmount,
-            makerTokenAddress,
-            takerTokenAddress,
+            makerAssetAmount,
+            takerAssetAmount,
+            makerAssetData,
+            takerAssetData,
             salt: generatePseudoRandomSalt(),
-            exchangeContractAddress,
-            feeRecipient,
-            expirationUnixTimestampSec,
+            exchangeAddress,
+            feeRecipientAddress,
+            expirationTimeSeconds,
         };
-        const orderHash = getOrderHashHex(order);
-        const ecSignature = await signOrderHashAsync(provider, orderHash, maker, SHOULD_ADD_PERSONAL_MESSAGE_PREFIX);
-        const signedOrder: SignedOrder = _.assign(order, { ecSignature });
+        const orderHash = orderHashUtils.getOrderHashHex(order);
+        const ecSignature = await ecSignOrderHashAsync(
+            provider,
+            orderHash,
+            makerAddress,
+            SHOULD_ADD_PERSONAL_MESSAGE_PREFIX,
+        );
+        const signature = getVRSHexString(ecSignature);
+        const signedOrder: SignedOrder = _.assign(order, { signature });
         return signedOrder;
     },
 };
diff --git a/packages/order-utils/src/order_hash.ts b/packages/order-utils/src/order_hash.ts
index 108344a04..3d0db5b0c 100644
--- a/packages/order-utils/src/order_hash.ts
+++ b/packages/order-utils/src/order_hash.ts
@@ -1,5 +1,5 @@
 import { schemas, SchemaValidator } from '@0xproject/json-schemas';
-import { Order, SignedOrder, SolidityTypes } from '@0xproject/types';
+import { Order, SignatureType, SignedOrder, SolidityTypes } from '@0xproject/types';
 import { BigNumber } from '@0xproject/utils';
 import BN = require('bn.js');
 import * as ethABI from 'ethereumjs-abi';
@@ -7,84 +7,110 @@ import * as ethUtil from 'ethereumjs-util';
 import * as _ from 'lodash';
 
 import { assert } from './assert';
+import { crypto } from './crypto';
 
 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 {
-    const base = 10;
-    return new BN(value.toString(), base);
-}
-
-/**
- * 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);
+export const orderHashUtils = {
+    /**
+     * 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.
+     */
+    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;
+    },
+    /**
+     * 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.
+     */
+    getOrderHashHex(order: SignedOrder | Order): 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;
         }
-        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;
-}
+        const orderHashBuff = this.getOrderHashBuff(order);
+        const orderHashHex = `0x${orderHashBuff.toString('hex')}`;
+        return orderHashHex;
+    },
+    /**
+     * Computes the orderHash for a supplied order and returns it as a Buffer
+     * @param   order   An object that conforms to the Order or SignedOrder interface definitions.
+     * @return  The resulting orderHash from hashing the supplied order as a Buffer
+     */
+    getOrderHashBuff(order: SignedOrder | Order): Buffer {
+        const makerAssetDataHash = crypto.solSHA3([ethUtil.toBuffer(order.makerAssetData)]);
+        const takerAssetDataHash = crypto.solSHA3([ethUtil.toBuffer(order.takerAssetData)]);
+
+        const orderParamsHashBuff = crypto.solSHA3([
+            order.makerAddress,
+            order.takerAddress,
+            order.feeRecipientAddress,
+            order.senderAddress,
+            order.makerAssetAmount,
+            order.takerAssetAmount,
+            order.makerFee,
+            order.takerFee,
+            order.expirationTimeSeconds,
+            order.salt,
+            makerAssetDataHash,
+            takerAssetDataHash,
+        ]);
+        const orderParamsHashHex = `0x${orderParamsHashBuff.toString('hex')}`;
+        const orderSchemaHashHex = this._getOrderSchemaHex();
+        const domainSeparatorHashHex = this._getDomainSeparatorHashHex(order.exchangeAddress);
+        const domainSeparatorSchemaHex = this._getDomainSeparatorSchemaHex();
+        const orderHashBuff = crypto.solSHA3([
+            new BigNumber(domainSeparatorSchemaHex),
+            new BigNumber(domainSeparatorHashHex),
+            new BigNumber(orderSchemaHashHex),
+            new BigNumber(orderParamsHashHex),
+        ]);
+        return orderHashBuff;
+    },
+    _getOrderSchemaHex(): string {
+        const orderSchemaHashBuff = crypto.solSHA3([
+            'Order(',
+            'address makerAddress,',
+            'address takerAddress,',
+            'address feeRecipientAddress,',
+            'address senderAddress,',
+            'uint256 makerAssetAmount,',
+            'uint256 takerAssetAmount,',
+            'uint256 makerFee,',
+            'uint256 takerFee,',
+            'uint256 expirationTimeSeconds,',
+            'uint256 salt,',
+            'bytes makerAssetData,',
+            'bytes takerAssetData,',
+            ')',
+        ]);
+        const schemaHashHex = `0x${orderSchemaHashBuff.toString('hex')}`;
+        return schemaHashHex;
+    },
+    _getDomainSeparatorSchemaHex(): string {
+        const domainSeparatorSchemaHashBuff = crypto.solSHA3(['DomainSeparator(address contract)']);
+        const schemaHashHex = `0x${domainSeparatorSchemaHashBuff.toString('hex')}`;
+        return schemaHashHex;
+    },
+    _getDomainSeparatorHashHex(exchangeAddress: string): string {
+        const domainSeparatorHashBuff = crypto.solSHA3([exchangeAddress]);
+        const domainSeparatorHashHex = `0x${domainSeparatorHashBuff.toString('hex')}`;
+        return domainSeparatorHashHex;
+    },
+};
diff --git a/packages/order-utils/src/order_state_utils.ts b/packages/order-utils/src/order_state_utils.ts
index 36171f526..61050c9d6 100644
--- a/packages/order-utils/src/order_state_utils.ts
+++ b/packages/order-utils/src/order_state_utils.ts
@@ -11,7 +11,8 @@ import * as _ from 'lodash';
 
 import { AbstractBalanceAndProxyAllowanceFetcher } from './abstract/abstract_balance_and_proxy_allowance_fetcher';
 import { AbstractOrderFilledCancelledFetcher } from './abstract/abstract_order_filled_cancelled_fetcher';
-import { getOrderHashHex } from './order_hash';
+import { assetProxyUtils } from './asset_proxy_utils';
+import { orderHashUtils } from './order_hash';
 import { RemainingFillableCalculator } from './remaining_fillable_calculator';
 
 const ACCEPTABLE_RELATIVE_ROUNDING_ERROR = 0.0001;
@@ -23,7 +24,7 @@ export class OrderStateUtils {
         const unavailableTakerTokenAmount = orderRelevantState.cancelledTakerTokenAmount.add(
             orderRelevantState.filledTakerTokenAmount,
         );
-        const availableTakerTokenAmount = signedOrder.takerTokenAmount.minus(unavailableTakerTokenAmount);
+        const availableTakerTokenAmount = signedOrder.takerAssetAmount.minus(unavailableTakerTokenAmount);
         if (availableTakerTokenAmount.eq(0)) {
             throw new Error(ExchangeContractErrs.OrderRemainingFillAmountZero);
         }
@@ -42,9 +43,9 @@ export class OrderStateUtils {
                 throw new Error(ExchangeContractErrs.InsufficientMakerFeeAllowance);
             }
         }
-        const minFillableTakerTokenAmountWithinNoRoundingErrorRange = signedOrder.takerTokenAmount
+        const minFillableTakerTokenAmountWithinNoRoundingErrorRange = signedOrder.takerAssetAmount
             .dividedBy(ACCEPTABLE_RELATIVE_ROUNDING_ERROR)
-            .dividedBy(signedOrder.makerTokenAmount);
+            .dividedBy(signedOrder.makerAssetAmount);
         if (
             orderRelevantState.remainingFillableTakerTokenAmount.lessThan(
                 minFillableTakerTokenAmountWithinNoRoundingErrorRange,
@@ -62,7 +63,7 @@ export class OrderStateUtils {
     }
     public async getOrderStateAsync(signedOrder: SignedOrder): Promise<OrderState> {
         const orderRelevantState = await this.getOrderRelevantStateAsync(signedOrder);
-        const orderHash = getOrderHashHex(signedOrder);
+        const orderHash = orderHashUtils.getOrderHashHex(signedOrder);
         try {
             OrderStateUtils._validateIfOrderIsValid(signedOrder, orderRelevantState);
             const orderState: OrderStateValid = {
@@ -82,22 +83,22 @@ export class OrderStateUtils {
     }
     public async getOrderRelevantStateAsync(signedOrder: SignedOrder): Promise<OrderRelevantState> {
         const zrxTokenAddress = this._orderFilledCancelledFetcher.getZRXTokenAddress();
-        const orderHash = getOrderHashHex(signedOrder);
+        const orderHash = orderHashUtils.getOrderHashHex(signedOrder);
         const makerBalance = await this._balanceAndProxyAllowanceFetcher.getBalanceAsync(
-            signedOrder.makerTokenAddress,
-            signedOrder.maker,
+            signedOrder.makerAssetData,
+            signedOrder.makerAddress,
         );
         const makerProxyAllowance = await this._balanceAndProxyAllowanceFetcher.getProxyAllowanceAsync(
-            signedOrder.makerTokenAddress,
-            signedOrder.maker,
+            signedOrder.makerAssetData,
+            signedOrder.makerAddress,
         );
         const makerFeeBalance = await this._balanceAndProxyAllowanceFetcher.getBalanceAsync(
             zrxTokenAddress,
-            signedOrder.maker,
+            signedOrder.makerAddress,
         );
         const makerFeeProxyAllowance = await this._balanceAndProxyAllowanceFetcher.getProxyAllowanceAsync(
             zrxTokenAddress,
-            signedOrder.maker,
+            signedOrder.makerAddress,
         );
         const filledTakerTokenAmount = await this._orderFilledCancelledFetcher.getFilledTakerAmountAsync(orderHash);
         const cancelledTakerTokenAmount = await this._orderFilledCancelledFetcher.getCancelledTakerAmountAsync(
@@ -106,8 +107,8 @@ export class OrderStateUtils {
         const unavailableTakerTokenAmount = await this._orderFilledCancelledFetcher.getUnavailableTakerAmountAsync(
             orderHash,
         );
-        const totalMakerTokenAmount = signedOrder.makerTokenAmount;
-        const totalTakerTokenAmount = signedOrder.takerTokenAmount;
+        const totalMakerTokenAmount = signedOrder.makerAssetAmount;
+        const totalTakerTokenAmount = signedOrder.takerAssetAmount;
         const remainingTakerTokenAmount = totalTakerTokenAmount.minus(unavailableTakerTokenAmount);
         const remainingMakerTokenAmount = remainingTakerTokenAmount
             .times(totalMakerTokenAmount)
@@ -115,7 +116,8 @@ export class OrderStateUtils {
         const transferrableMakerTokenAmount = BigNumber.min([makerProxyAllowance, makerBalance]);
         const transferrableFeeTokenAmount = BigNumber.min([makerFeeProxyAllowance, makerFeeBalance]);
 
-        const isMakerTokenZRX = signedOrder.makerTokenAddress === zrxTokenAddress;
+        const zrxAssetData = assetProxyUtils.encodeERC20ProxyData(zrxTokenAddress);
+        const isMakerTokenZRX = signedOrder.makerAssetData === zrxAssetData;
         const remainingFillableCalculator = new RemainingFillableCalculator(
             signedOrder,
             isMakerTokenZRX,
diff --git a/packages/order-utils/src/remaining_fillable_calculator.ts b/packages/order-utils/src/remaining_fillable_calculator.ts
index 184c13aa4..b291d8ea9 100644
--- a/packages/order-utils/src/remaining_fillable_calculator.ts
+++ b/packages/order-utils/src/remaining_fillable_calculator.ts
@@ -23,7 +23,7 @@ export class RemainingFillableCalculator {
         this._remainingMakerTokenAmount = remainingMakerTokenAmount;
         this._remainingMakerFeeAmount = remainingMakerTokenAmount
             .times(signedOrder.makerFee)
-            .dividedToIntegerBy(signedOrder.makerTokenAmount);
+            .dividedToIntegerBy(signedOrder.makerAssetAmount);
     }
     public computeRemainingMakerFillable(): BigNumber {
         if (this._hasSufficientFundsForFeeAndTransferAmount()) {
@@ -36,8 +36,8 @@ export class RemainingFillableCalculator {
     }
     public computeRemainingTakerFillable(): BigNumber {
         return this.computeRemainingMakerFillable()
-            .times(this._signedOrder.takerTokenAmount)
-            .dividedToIntegerBy(this._signedOrder.makerTokenAmount);
+            .times(this._signedOrder.takerAssetAmount)
+            .dividedToIntegerBy(this._signedOrder.makerAssetAmount);
     }
     private _hasSufficientFundsForFeeAndTransferAmount(): boolean {
         if (this._isMakerTokenZRX) {
@@ -59,7 +59,7 @@ export class RemainingFillableCalculator {
     }
     private _calculatePartiallyFillableMakerTokenAmount(): BigNumber {
         // Given an order for 200 wei for 2 ZRXwei fee, find 100 wei for 1 ZRXwei. Order ratio is then 100:1
-        const orderToFeeRatio = this._signedOrder.makerTokenAmount.dividedBy(this._signedOrder.makerFee);
+        const orderToFeeRatio = this._signedOrder.makerAssetAmount.dividedBy(this._signedOrder.makerFee);
         // The number of times the maker can fill the order, if each fill only required the transfer of a single
         // baseUnit of fee tokens.
         // Given 2 ZRXwei, the maximum amount of times Maker can fill this order, in terms of fees, is 2
@@ -81,10 +81,10 @@ export class RemainingFillableCalculator {
         // When Ratio is not fully divisible there can be remainders which cannot be represented, so they are floored.
         // This can result in a RoundingError being thrown by the Exchange Contract.
         const partiallyFillableMakerTokenAmount = fillableTimesInMakerTokenUnits
-            .times(this._signedOrder.makerTokenAmount)
+            .times(this._signedOrder.makerAssetAmount)
             .dividedToIntegerBy(this._signedOrder.makerFee);
         const partiallyFillableFeeTokenAmount = fillableTimesInFeeTokenBaseUnits
-            .times(this._signedOrder.makerTokenAmount)
+            .times(this._signedOrder.makerAssetAmount)
             .dividedToIntegerBy(this._signedOrder.makerFee);
         const partiallyFillableAmount = BigNumber.min(
             partiallyFillableMakerTokenAmount,
diff --git a/packages/order-utils/src/signature_utils.ts b/packages/order-utils/src/signature_utils.ts
index ebd636b20..106bbf4e8 100644
--- a/packages/order-utils/src/signature_utils.ts
+++ b/packages/order-utils/src/signature_utils.ts
@@ -1,28 +1,97 @@
 import { schemas } from '@0xproject/json-schemas';
-import { ECSignature, Provider } from '@0xproject/types';
+import { ECSignature, Provider, SignatureType } from '@0xproject/types';
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
 import * as ethUtil from 'ethereumjs-util';
 import * as _ from 'lodash';
 
+import { artifacts } from './artifacts';
 import { assert } from './assert';
+import { ExchangeContract } from './generated_contract_wrappers/exchange';
+import { ISignerContract } from './generated_contract_wrappers/i_signer';
 import { OrderError } from './types';
 
 /**
- * Verifies that the elliptic curve signature `signature` was generated
- * by signing `data` with the private key corresponding to the `signerAddress` address.
+ * Verifies that the provided signature is valid according to the 0x Protocol smart contracts
  * @param   data          The hex encoded data signed by the supplied signature.
  * @param   signature     An object containing the elliptic curve signature parameters.
  * @param   signerAddress The hex encoded address that signed the data, producing the supplied signature.
  * @return  Whether the signature is valid for the supplied signerAddress and data.
  */
-export function isValidSignature(data: string, signature: ECSignature, signerAddress: string): boolean {
+export async function isValidSignatureAsync(
+    provider: Provider,
+    data: string,
+    signature: string,
+    signerAddress: string,
+): Promise<boolean> {
+    const signatureTypeIndexIfExists = getSignatureTypeIndexIfExists(signature);
+    if (_.isUndefined(signatureTypeIndexIfExists)) {
+        throw new Error(`Unrecognized signatureType in signature: ${signature}`);
+    }
+
+    switch (signatureTypeIndexIfExists) {
+        case SignatureType.Illegal:
+        case SignatureType.Invalid:
+            return false;
+
+        // Question: Does it make sense to handle this?
+        case SignatureType.Caller:
+            return true;
+
+        // TODO: Rename this type to `EthSign` b/c multiple of the signature
+        // types use ECRecover...
+        case SignatureType.Ecrecover: {
+            const ecSignature = parseECSignature(signature);
+            const dataBuff = ethUtil.toBuffer(data);
+            const msgHashBuff = ethUtil.hashPersonalMessage(dataBuff);
+            const msgHash = ethUtil.bufferToHex(msgHashBuff);
+            return isValidECSignature(msgHash, ecSignature, signerAddress);
+        }
+
+        case SignatureType.EIP712: {
+            const ecSignature = parseECSignature(signature);
+            return isValidECSignature(data, ecSignature, signerAddress);
+        }
+
+        case SignatureType.Trezor: {
+            const dataBuff = ethUtil.toBuffer(data);
+            const msgHashBuff = hashTrezorPersonalMessage(dataBuff);
+            const msgHash = ethUtil.bufferToHex(msgHashBuff);
+            const ecSignature = parseECSignature(signature);
+            return isValidECSignature(msgHash, ecSignature, signerAddress);
+        }
+
+        // TODO: Rename Contract -> Wallet
+        case SignatureType.Contract: {
+            const signerContract = new ISignerContract(artifacts.ISigner.abi, signerAddress, provider);
+            const isValid = await signerContract.isValidSignature.callAsync(data, signature);
+            return isValid;
+        }
+
+        case SignatureType.PreSigned: {
+            const exchangeContract = new ExchangeContract(artifacts.Exchange.abi, signerAddress, provider);
+            const isValid = await exchangeContract.preSigned.callAsync(data, signerAddress);
+            return true;
+        }
+
+        default:
+            throw new Error(`Unhandled SignatureType: ${signatureTypeIndexIfExists}`);
+    }
+}
+
+export function getVRSHexString(ecSignature: ECSignature): string {
+    const vrs = `0x${intToHex(ecSignature.v)}${ethUtil.stripHexPrefix(ecSignature.r)}${ethUtil.stripHexPrefix(
+        ecSignature.s,
+    )}`;
+    return vrs;
+}
+
+export function isValidECSignature(data: string, signature: ECSignature, signerAddress: string): boolean {
     assert.isHexString('data', data);
     assert.doesConformToSchema('signature', signature, schemas.ecSignatureSchema);
     assert.isETHAddressHex('signerAddress', signerAddress);
     const normalizedSignerAddress = signerAddress.toLowerCase();
 
-    const dataBuff = ethUtil.toBuffer(data);
-    const msgHashBuff = ethUtil.hashPersonalMessage(dataBuff);
+    const msgHashBuff = ethUtil.toBuffer(data);
     try {
         const pubKey = ethUtil.ecrecover(
             msgHashBuff,
@@ -36,6 +105,7 @@ export function isValidSignature(data: string, signature: ECSignature, signerAdd
         return false;
     }
 }
+
 /**
  * Signs an orderHash and returns it's elliptic curve signature.
  * This method currently supports TestRPC, Geth and Parity above and below V1.6.6
@@ -48,7 +118,7 @@ export function isValidSignature(data: string, signature: ECSignature, signerAdd
  *          before sending the request.
  * @return  An object containing the Elliptic curve signature parameters generated by signing the orderHash.
  */
-export async function signOrderHashAsync(
+export async function ecSignOrderHashAsync(
     provider: Provider,
     orderHash: string,
     signerAddress: string,
@@ -76,7 +146,7 @@ export async function signOrderHashAsync(
     const validVParamValues = [27, 28];
     const ecSignatureVRS = parseSignatureHexAsVRS(signature);
     if (_.includes(validVParamValues, ecSignatureVRS.v)) {
-        const isValidVRSSignature = isValidSignature(orderHash, ecSignatureVRS, normalizedSignerAddress);
+        const isValidVRSSignature = isValidECSignature(orderHash, ecSignatureVRS, normalizedSignerAddress);
         if (isValidVRSSignature) {
             return ecSignatureVRS;
         }
@@ -84,7 +154,7 @@ export async function signOrderHashAsync(
 
     const ecSignatureRSV = parseSignatureHexAsRSV(signature);
     if (_.includes(validVParamValues, ecSignatureRSV.v)) {
-        const isValidRSVSignature = isValidSignature(orderHash, ecSignatureRSV, normalizedSignerAddress);
+        const isValidRSVSignature = isValidECSignature(orderHash, ecSignatureRSV, normalizedSignerAddress);
         if (isValidRSVSignature) {
             return ecSignatureRSV;
         }
@@ -93,6 +163,39 @@ export async function signOrderHashAsync(
     throw new Error(OrderError.InvalidSignature);
 }
 
+function hashTrezorPersonalMessage(message: Buffer): Buffer {
+    const prefix = ethUtil.toBuffer('\x19Ethereum Signed Message:\n' + String.fromCharCode(message.length));
+    return ethUtil.sha3(Buffer.concat([prefix, message]));
+}
+
+function parseECSignature(signature: string): ECSignature {
+    const signatureTypeIndexIfExists = getSignatureTypeIndexIfExists(signature);
+    const ecSignatureTypes = [SignatureType.Ecrecover, SignatureType.EIP712, SignatureType.Trezor];
+    const isECSignatureType = _.includes(ecSignatureTypes, signatureTypeIndexIfExists);
+    if (!isECSignatureType) {
+        throw new Error(`Cannot parse non-ECSignature type: ${signatureTypeIndexIfExists}`);
+    }
+
+    // tslint:disable-next-line:custom-no-magic-numbers
+    const vrsHex = `0x${signature.substr(4)}`;
+    const ecSignature = parseSignatureHexAsVRS(vrsHex);
+
+    return ecSignature;
+}
+
+function intToHex(i: number): string {
+    const hex = ethUtil.bufferToHex(ethUtil.toBuffer(i));
+    return hex;
+}
+
+function getSignatureTypeIndexIfExists(signature: string): number {
+    const unprefixedSignature = ethUtil.stripHexPrefix(signature);
+    const signatureTypeHex = unprefixedSignature.substr(0, 2);
+    const base = 16;
+    const signatureTypeInt = parseInt(signatureTypeHex, base);
+    return signatureTypeInt;
+}
+
 function parseSignatureHexAsVRS(signatureHex: string): ECSignature {
     const signatureBuffer = ethUtil.toBuffer(signatureHex);
     let v = signatureBuffer[0];