Merge pull request #2610 from 0xProject/feat/zero-ex/meta-transactions

EP: MetaTransactions

contracts/zero-ex/CHANGELOG.json

@@ -9,6 +9,10 @@
             {
                 "note": "Export `AffiliateFeeTransformerContract`",
                 "pr": 2622
+            },
+            {
+                "note": "Add `MetaTransactions` and `SignatureValidator` features",
+                "pr": 2610
             }
         ]
     },

contracts/zero-ex/contracts/src/ZeroEx.sol

@@ -34,11 +34,12 @@ contract ZeroEx {
 
     /// @dev Construct this contract and register the `Bootstrap` feature.
     ///      After constructing this contract, `bootstrap()` should be called
-    ///      to seed the initial feature set.
+    ///      by `bootstrap()` to seed the initial feature set.
-    constructor() public {
+    /// @param bootstrapper Who can call `bootstrap()`.
+    constructor(address bootstrapper) public {
         // Temporarily create and register the bootstrap feature.
         // It will deregister itself after `bootstrap()` has been called.
-        Bootstrap bootstrap = new Bootstrap(msg.sender);
+        Bootstrap bootstrap = new Bootstrap(bootstrapper);
         LibProxyStorage.getStorage().impls[bootstrap.bootstrap.selector] =
             address(bootstrap);
     }

contracts/zero-ex/contracts/src/errors/LibMetaTransactionsRichErrors.sol

@@ -0,0 +1,174 @@
+/*
+
+  Copyright 2020 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.6.5;
+
+
+library LibMetaTransactionsRichErrors {
+
+    // solhint-disable func-name-mixedcase
+
+    function InvalidMetaTransactionsArrayLengthsError(
+        uint256 mtxCount,
+        uint256 signatureCount
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("InvalidMetaTransactionsArrayLengthsError(uint256,uint256)")),
+            mtxCount,
+            signatureCount
+        );
+    }
+
+    function MetaTransactionUnsupportedFunctionError(
+        bytes32 mtxHash,
+        bytes4 selector
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("MetaTransactionUnsupportedFunctionError(bytes32,bytes4)")),
+            mtxHash,
+            selector
+        );
+    }
+
+    function MetaTransactionWrongSenderError(
+        bytes32 mtxHash,
+        address sender,
+        address expectedSender
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("MetaTransactionWrongSenderError(bytes32,address,address)")),
+            mtxHash,
+            sender,
+            expectedSender
+        );
+    }
+
+    function MetaTransactionExpiredError(
+        bytes32 mtxHash,
+        uint256 time,
+        uint256 expirationTime
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("MetaTransactionExpiredError(bytes32,uint256,uint256)")),
+            mtxHash,
+            time,
+            expirationTime
+        );
+    }
+
+    function MetaTransactionGasPriceError(
+        bytes32 mtxHash,
+        uint256 gasPrice,
+        uint256 minGasPrice,
+        uint256 maxGasPrice
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("MetaTransactionGasPriceError(bytes32,uint256,uint256,uint256)")),
+            mtxHash,
+            gasPrice,
+            minGasPrice,
+            maxGasPrice
+        );
+    }
+
+    function MetaTransactionInsufficientEthError(
+        bytes32 mtxHash,
+        uint256 ethBalance,
+        uint256 ethRequired
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("MetaTransactionInsufficientEthError(bytes32,uint256,uint256)")),
+            mtxHash,
+            ethBalance,
+            ethRequired
+        );
+    }
+
+    function MetaTransactionInvalidSignatureError(
+        bytes32 mtxHash,
+        bytes memory signature,
+        bytes memory errData
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("MetaTransactionInvalidSignatureError(bytes32,bytes,bytes)")),
+            mtxHash,
+            signature,
+            errData
+        );
+    }
+
+    function MetaTransactionAlreadyExecutedError(
+        bytes32 mtxHash,
+        uint256 executedBlockNumber
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("MetaTransactionAlreadyExecutedError(bytes32,uint256)")),
+            mtxHash,
+            executedBlockNumber
+        );
+    }
+
+    function MetaTransactionCallFailedError(
+        bytes32 mtxHash,
+        bytes memory callData,
+        bytes memory returnData
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("MetaTransactionCallFailedError(bytes32,bytes,bytes)")),
+            mtxHash,
+            callData,
+            returnData
+        );
+    }
+}

contracts/zero-ex/contracts/src/errors/LibSignatureRichErrors.sol

@@ -0,0 +1,52 @@
+/*
+
+  Copyright 2020 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.6.5;
+
+
+library LibSignatureRichErrors {
+
+    enum SignatureValidationErrorCodes {
+        ALWAYS_INVALID,
+        INVALID_LENGTH,
+        UNSUPPORTED,
+        ILLEGAL,
+        WRONG_SIGNER
+    }
+
+    // solhint-disable func-name-mixedcase
+
+    function SignatureValidationError(
+        SignatureValidationErrorCodes code,
+        bytes32 hash,
+        address signerAddress,
+        bytes memory signature
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("SignatureValidationError(uint8,bytes32,address,bytes)")),
+            code,
+            hash,
+            signerAddress,
+            signature
+        );
+    }
+}

contracts/zero-ex/contracts/src/features/IMetaTransactions.sol

@@ -0,0 +1,127 @@
+/*
+
+  Copyright 2020 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.6.5;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
+
+
+/// @dev Meta-transactions feature.
+interface IMetaTransactions {
+
+    /// @dev Describes an exchange proxy meta transaction.
+    struct MetaTransactionData {
+        // Signer of meta-transaction. On whose behalf to execute the MTX.
+        address signer;
+        // Required sender, or NULL for anyone.
+        address sender;
+        // Minimum gas price.
+        uint256 minGasPrice;
+        // Maximum gas price.
+        uint256 maxGasPrice;
+        // MTX is invalid after this time.
+        uint256 expirationTimeSeconds;
+        // Nonce to make this MTX unique.
+        uint256 salt;
+        // Encoded call data to a function on the exchange proxy.
+        bytes callData;
+        // Amount of ETH to attach to the call.
+        uint256 value;
+        // ERC20 fee `signer` pays `sender`.
+        IERC20TokenV06 feeToken;
+        // ERC20 fee amount.
+        uint256 feeAmount;
+    }
+
+    /// @dev Emitted whenever a meta-transaction is executed via
+    ///      `executeMetaTransaction()` or `executeMetaTransactions()`.
+    /// @param hash The meta-transaction hash.
+    /// @param selector The selector of the function being executed.
+    /// @param signer Who to execute the meta-transaction on behalf of.
+    /// @param sender Who executed the meta-transaction.
+    event MetaTransactionExecuted(
+        bytes32 hash,
+        bytes4 indexed selector,
+        address signer,
+        address sender
+    );
+
+    /// @dev Execute a single meta-transaction.
+    /// @param mtx The meta-transaction.
+    /// @param signature The signature by `mtx.signer`.
+    /// @return returnResult The ABI-encoded result of the underlying call.
+    function executeMetaTransaction(
+        MetaTransactionData calldata mtx,
+        bytes calldata signature
+    )
+        external
+        payable
+        returns (bytes memory returnResult);
+
+    /// @dev Execute multiple meta-transactions.
+    /// @param mtxs The meta-transactions.
+    /// @param signatures The signature by each respective `mtx.signer`.
+    /// @return returnResults The ABI-encoded results of the underlying calls.
+    function batchExecuteMetaTransactions(
+        MetaTransactionData[] calldata mtxs,
+        bytes[] calldata signatures
+    )
+        external
+        payable
+        returns (bytes[] memory returnResults);
+
+    /// @dev Execute a meta-transaction via `sender`. Privileged variant.
+    ///      Only callable from within.
+    /// @param sender Who is executing the meta-transaction..
+    /// @param mtx The meta-transaction.
+    /// @param signature The signature by `mtx.signer`.
+    /// @return returnResult The ABI-encoded result of the underlying call.
+    function _executeMetaTransaction(
+        address sender,
+        MetaTransactionData calldata mtx,
+        bytes calldata signature
+    )
+        external
+        payable
+        returns (bytes memory returnResult);
+
+    /// @dev Get the block at which a meta-transaction has been executed.
+    /// @param mtx The meta-transaction.
+    /// @return blockNumber The block height when the meta-transactioin was executed.
+    function getMetaTransactionExecutedBlock(MetaTransactionData calldata mtx)
+        external
+        view
+        returns (uint256 blockNumber);
+
+    /// @dev Get the block at which a meta-transaction hash has been executed.
+    /// @param mtxHash The meta-transaction hash.
+    /// @return blockNumber The block height when the meta-transactioin was executed.
+    function getMetaTransactionHashExecutedBlock(bytes32 mtxHash)
+        external
+        view
+        returns (uint256 blockNumber);
+
+    /// @dev Get the EIP712 hash of a meta-transaction.
+    /// @param mtx The meta-transaction.
+    /// @return mtxHash The EIP712 hash of `mtx`.
+    function getMetaTransactionHash(MetaTransactionData calldata mtx)
+        external
+        view
+        returns (bytes32 mtxHash);
+}

contracts/zero-ex/contracts/src/features/ISignatureValidator.sol

@@ -0,0 +1,63 @@
+/*
+
+  Copyright 2020 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.6.5;
+pragma experimental ABIEncoderV2;
+
+
+/// @dev Feature for validating signatures.
+interface ISignatureValidator {
+
+   /// @dev Allowed signature types.
+    enum SignatureType {
+        Illegal,                     // 0x00, default value
+        Invalid,                     // 0x01
+        EIP712,                      // 0x02
+        EthSign,                     // 0x03
+        NSignatureTypes              // 0x04, number of signature types. Always leave at end.
+    }
+
+    /// @dev Validate that `hash` was signed by `signer` given `signature`.
+    ///      Reverts otherwise.
+    /// @param hash The hash that was signed.
+    /// @param signer The signer of the hash.
+    /// @param signature The signature. The last byte of this signature should
+    ///        be a member of the `SignatureType` enum.
+    function validateHashSignature(
+        bytes32 hash,
+        address signer,
+        bytes calldata signature
+    )
+        external
+        view;
+
+    /// @dev Check that `hash` was signed by `signer` given `signature`.
+    /// @param hash The hash that was signed.
+    /// @param signer The signer of the hash.
+    /// @param signature The signature. The last byte of this signature should
+    ///        be a member of the `SignatureType` enum.
+    /// @return isValid `true` on success.
+    function isValidHashSignature(
+        bytes32 hash,
+        address signer,
+        bytes calldata signature
+    )
+        external
+        view
+        returns (bool isValid);
+}

contracts/zero-ex/contracts/src/features/MetaTransactions.sol

@@ -0,0 +1,436 @@
+/*
+
+  Copyright 2020 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.6.5;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
+import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
+import "../errors/LibMetaTransactionsRichErrors.sol";
+import "../fixins/FixinCommon.sol";
+import "../fixins/FixinEIP712.sol";
+import "../migrations/LibMigrate.sol";
+import "../storage/LibMetaTransactionsStorage.sol";
+import "./IMetaTransactions.sol";
+import "./ITransformERC20.sol";
+import "./ISignatureValidator.sol";
+import "./ITokenSpender.sol";
+import "./IFeature.sol";
+
+
+/// @dev MetaTransactions feature.
+contract MetaTransactions is
+    IFeature,
+    IMetaTransactions,
+    FixinCommon,
+    FixinEIP712
+{
+    using LibBytesV06 for bytes;
+    using LibRichErrorsV06 for bytes;
+
+    /// @dev Intermediate state vars to avoid stack overflows.
+    struct ExecuteState {
+        address sender;
+        bytes32 hash;
+        MetaTransactionData mtx;
+        bytes signature;
+        bytes4 selector;
+        uint256 selfBalance;
+        uint256 executedBlockNumber;
+    }
+
+    struct TransformERC20Args {
+        IERC20TokenV06 inputToken;
+        IERC20TokenV06 outputToken;
+        uint256 inputTokenAmount;
+        uint256 minOutputTokenAmount;
+        ITransformERC20.Transformation[] transformations;
+    }
+
+    /// @dev Name of this feature.
+    string public constant override FEATURE_NAME = "MetaTransactions";
+    /// @dev Version of this feature.
+    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
+    /// @dev EIP712 typehash of the `MetaTransactionData` struct.
+    bytes32 public immutable MTX_EIP712_TYPEHASH = keccak256(
+        "MetaTransactionData("
+            "address signer,"
+            "address sender,"
+            "uint256 minGasPrice,"
+            "uint256 maxGasPrice,"
+            "uint256 expirationTimeSeconds,"
+            "uint256 salt,"
+            "bytes callData,"
+            "uint256 value,"
+            "address feeToken,"
+            "uint256 feeAmount"
+        ")"
+    );
+
+    constructor(address zeroExAddress)
+        public
+        FixinCommon()
+        FixinEIP712(zeroExAddress)
+    {
+        // solhint-disable-next-line no-empty-blocks
+    }
+
+    /// @dev Initialize and register this feature.
+    ///      Should be delegatecalled by `Migrate.migrate()`.
+    /// @return success `LibMigrate.SUCCESS` on success.
+    function migrate()
+        external
+        returns (bytes4 success)
+    {
+        _registerFeatureFunction(this.executeMetaTransaction.selector);
+        _registerFeatureFunction(this.batchExecuteMetaTransactions.selector);
+        _registerFeatureFunction(this._executeMetaTransaction.selector);
+        _registerFeatureFunction(this.getMetaTransactionExecutedBlock.selector);
+        _registerFeatureFunction(this.getMetaTransactionHashExecutedBlock.selector);
+        _registerFeatureFunction(this.getMetaTransactionHash.selector);
+        return LibMigrate.MIGRATE_SUCCESS;
+    }
+
+    /// @dev Execute a single meta-transaction.
+    /// @param mtx The meta-transaction.
+    /// @param signature The signature by `mtx.signer`.
+    /// @return returnResult The ABI-encoded result of the underlying call.
+    function executeMetaTransaction(
+        MetaTransactionData memory mtx,
+        bytes memory signature
+    )
+        public
+        payable
+        override
+        returns (bytes memory returnResult)
+    {
+        return _executeMetaTransactionPrivate(
+            msg.sender,
+            mtx,
+            signature
+        );
+    }
+
+    /// @dev Execute multiple meta-transactions.
+    /// @param mtxs The meta-transactions.
+    /// @param signatures The signature by each respective `mtx.signer`.
+    /// @return returnResults The ABI-encoded results of the underlying calls.
+    function batchExecuteMetaTransactions(
+        MetaTransactionData[] memory mtxs,
+        bytes[] memory signatures
+    )
+        public
+        payable
+        override
+        returns (bytes[] memory returnResults)
+    {
+        if (mtxs.length != signatures.length) {
+            LibMetaTransactionsRichErrors.InvalidMetaTransactionsArrayLengthsError(
+                mtxs.length,
+                signatures.length
+            ).rrevert();
+        }
+        returnResults = new bytes[](mtxs.length);
+        for (uint256 i = 0; i < mtxs.length; ++i) {
+            returnResults[i] = _executeMetaTransactionPrivate(
+                msg.sender,
+                mtxs[i],
+                signatures[i]
+            );
+        }
+    }
+
+    /// @dev Execute a meta-transaction via `sender`. Privileged variant.
+    ///      Only callable from within.
+    /// @param sender Who is executing the meta-transaction..
+    /// @param mtx The meta-transaction.
+    /// @param signature The signature by `mtx.signer`.
+    /// @return returnResult The ABI-encoded result of the underlying call.
+    function _executeMetaTransaction(
+        address sender,
+        MetaTransactionData memory mtx,
+        bytes memory signature
+    )
+        public
+        payable
+        override
+        onlySelf
+        returns (bytes memory returnResult)
+    {
+        return _executeMetaTransactionPrivate(sender, mtx, signature);
+    }
+
+    /// @dev Get the block at which a meta-transaction has been executed.
+    /// @param mtx The meta-transaction.
+    /// @return blockNumber The block height when the meta-transactioin was executed.
+    function getMetaTransactionExecutedBlock(MetaTransactionData memory mtx)
+        public
+        override
+        view
+        returns (uint256 blockNumber)
+    {
+        return getMetaTransactionHashExecutedBlock(getMetaTransactionHash(mtx));
+    }
+
+    /// @dev Get the block at which a meta-transaction hash has been executed.
+    /// @param mtxHash The meta-transaction hash.
+    /// @return blockNumber The block height when the meta-transactioin was executed.
+    function getMetaTransactionHashExecutedBlock(bytes32 mtxHash)
+        public
+        override
+        view
+        returns (uint256 blockNumber)
+    {
+        return LibMetaTransactionsStorage.getStorage().mtxHashToExecutedBlockNumber[mtxHash];
+    }
+
+    /// @dev Get the EIP712 hash of a meta-transaction.
+    /// @param mtx The meta-transaction.
+    /// @return mtxHash The EIP712 hash of `mtx`.
+    function getMetaTransactionHash(MetaTransactionData memory mtx)
+        public
+        override
+        view
+        returns (bytes32 mtxHash)
+    {
+        return _getEIP712Hash(keccak256(abi.encode(
+            MTX_EIP712_TYPEHASH,
+            mtx.signer,
+            mtx.sender,
+            mtx.minGasPrice,
+            mtx.maxGasPrice,
+            mtx.expirationTimeSeconds,
+            mtx.salt,
+            keccak256(mtx.callData),
+            mtx.value,
+            mtx.feeToken,
+            mtx.feeAmount
+        )));
+    }
+
+    /// @dev Execute a meta-transaction by `sender`. Low-level, hidden variant.
+    /// @param sender Who is executing the meta-transaction..
+    /// @param mtx The meta-transaction.
+    /// @param signature The signature by `mtx.signer`.
+    /// @return returnResult The ABI-encoded result of the underlying call.
+    function _executeMetaTransactionPrivate(
+        address sender,
+        MetaTransactionData memory mtx,
+        bytes memory signature
+    )
+        private
+        returns (bytes memory returnResult)
+    {
+        ExecuteState memory state;
+        state.sender = sender;
+        state.hash = getMetaTransactionHash(mtx);
+        state.mtx = mtx;
+        state.signature = signature;
+
+        _validateMetaTransaction(state);
+
+        // Mark the transaction executed.
+        assert(block.number > 0);
+        LibMetaTransactionsStorage.getStorage()
+            .mtxHashToExecutedBlockNumber[state.hash] = block.number;
+
+        // Execute the call based on the selector.
+        state.selector = mtx.callData.readBytes4(0);
+        if (state.selector == ITransformERC20.transformERC20.selector) {
+            returnResult = _executeTransformERC20Call(state);
+        } else {
+            LibMetaTransactionsRichErrors
+                .MetaTransactionUnsupportedFunctionError(state.hash, state.selector)
+                .rrevert();
+        }
+        // Pay the fee to the sender.
+        if (mtx.feeAmount > 0) {
+            ITokenSpender(address(this))._spendERC20Tokens(
+                mtx.feeToken,
+                mtx.signer, // From the signer.
+                sender, // To the sender.
+                mtx.feeAmount
+            );
+        }
+        emit MetaTransactionExecuted(
+            state.hash,
+            state.selector,
+            mtx.signer,
+            mtx.sender
+        );
+    }
+
+    /// @dev Validate that a meta-transaction is executable.
+    function _validateMetaTransaction(ExecuteState memory state)
+        private
+        view
+    {
+        // Must be from the required sender, if set.
+        if (state.mtx.sender != address(0) && state.mtx.sender != state.sender) {
+            LibMetaTransactionsRichErrors
+                .MetaTransactionWrongSenderError(
+                    state.hash,
+                    state.sender,
+                    state.mtx.sender
+                ).rrevert();
+        }
+        // Must not be expired.
+        if (state.mtx.expirationTimeSeconds <= block.timestamp) {
+            LibMetaTransactionsRichErrors
+                .MetaTransactionExpiredError(
+                    state.hash,
+                    block.timestamp,
+                    state.mtx.expirationTimeSeconds
+                ).rrevert();
+        }
+        // Must have a valid gas price.
+        if (state.mtx.minGasPrice > tx.gasprice || state.mtx.maxGasPrice < tx.gasprice) {
+            LibMetaTransactionsRichErrors
+                .MetaTransactionGasPriceError(
+                    state.hash,
+                    tx.gasprice,
+                    state.mtx.minGasPrice,
+                    state.mtx.maxGasPrice
+                ).rrevert();
+        }
+        // Must have enough ETH.
+        state.selfBalance  = address(this).balance;
+        if (state.mtx.value > state.selfBalance) {
+            LibMetaTransactionsRichErrors
+                .MetaTransactionInsufficientEthError(
+                    state.hash,
+                    state.selfBalance,
+                    state.mtx.value
+                ).rrevert();
+        }
+        // Must be signed by signer.
+        try
+            ISignatureValidator(address(this))
+                .validateHashSignature(state.hash, state.mtx.signer, state.signature)
+        {}
+        catch (bytes memory err) {
+            LibMetaTransactionsRichErrors
+                .MetaTransactionInvalidSignatureError(
+                    state.hash,
+                    state.signature,
+                    err
+                ).rrevert();
+        }
+        // Transaction must not have been already executed.
+        state.executedBlockNumber = LibMetaTransactionsStorage
+            .getStorage().mtxHashToExecutedBlockNumber[state.hash];
+        if (state.executedBlockNumber != 0) {
+            LibMetaTransactionsRichErrors
+                .MetaTransactionAlreadyExecutedError(
+                    state.hash,
+                    state.executedBlockNumber
+                ).rrevert();
+        }
+    }
+
+    /// @dev Execute a `ITransformERC20.transformERC20()` meta-transaction call
+    ///      by decoding the call args and translating the call to the internal
+    ///      `ITransformERC20._transformERC20()` variant, where we can override
+    ///      the taker address.
+    function _executeTransformERC20Call(ExecuteState memory state)
+        private
+        returns (bytes memory returnResult)
+    {
+        // HACK(dorothy-zbornak): `abi.decode()` with the individual args
+        // will cause a stack overflow. But we can prefix the call data with an
+        // offset to transform it into the encoding for the equivalent single struct arg,
+        // since decoding a single struct arg consumes far less stack space than
+        // decoding multiple struct args.
+
+        // Where the encoding for multiple args (with the seleector ommitted)
+        // would typically look like:
+        // | argument                 |  offset |
+        // |--------------------------|---------|
+        // | inputToken               |       0 |
+        // | outputToken              |      32 |
+        // | inputTokenAmount         |      64 |
+        // | minOutputTokenAmount     |      96 |
+        // | transformations (offset) |     128 | = 32
+        // | transformations (data)   |     160 |
+
+        // We will ABI-decode a single struct arg copy with the layout:
+        // | argument                 |  offset |
+        // |--------------------------|---------|
+        // | (arg 1 offset)           |       0 | = 32
+        // | inputToken               |      32 |
+        // | outputToken              |      64 |
+        // | inputTokenAmount         |      96 |
+        // | minOutputTokenAmount     |     128 |
+        // | transformations (offset) |     160 | = 32
+        // | transformations (data)   |     192 |
+
+        TransformERC20Args memory args;
+        {
+            bytes memory encodedStructArgs = new bytes(state.mtx.callData.length - 4 + 32);
+            // Copy the args data from the original, after the new struct offset prefix.
+            bytes memory fromCallData = state.mtx.callData;
+            assert(fromCallData.length >= 4);
+            uint256 fromMem;
+            uint256 toMem;
+            assembly {
+                // Prefix the original calldata with a struct offset,
+                // which is just one word over.
+                mstore(add(encodedStructArgs, 32), 32)
+                // Copy everything after the selector.
+                fromMem := add(fromCallData, 36)
+                // Start copying after the struct offset.
+                toMem := add(encodedStructArgs, 64)
+            }
+            LibBytesV06.memCopy(toMem, fromMem, fromCallData.length - 4);
+            // Decode call args for `ITransformERC20.transformERC20()` as a struct.
+            args = abi.decode(encodedStructArgs, (TransformERC20Args));
+        }
+        // Call `ITransformERC20._transformERC20()` (internal variant).
+        return _callSelf(
+            state.hash,
+            abi.encodeWithSelector(
+                ITransformERC20._transformERC20.selector,
+                keccak256(state.mtx.callData),
+                state.mtx.signer, // taker is mtx signer
+                args.inputToken,
+                args.outputToken,
+                args.inputTokenAmount,
+                args.minOutputTokenAmount,
+                args.transformations
+            ),
+            state.mtx.value
+        );
+    }
+
+    /// @dev Make an arbitrary internal, meta-transaction call.
+    ///      Warning: Do not let unadulerated `callData` into this function.
+    function _callSelf(bytes32 hash, bytes memory callData, uint256 value)
+        private
+        returns (bytes memory returnResult)
+    {
+        bool success;
+        (success, returnResult) = address(this).call{value: value}(callData);
+        if (!success) {
+            LibMetaTransactionsRichErrors.MetaTransactionCallFailedError(
+                hash,
+                callData,
+                returnResult
+            ).rrevert();
+        }
+    }
+}

contracts/zero-ex/contracts/src/features/Ownable.sol

@@ -37,19 +37,15 @@ contract Ownable is
     FixinCommon
 {
 
-    // solhint-disable
     /// @dev Name of this feature.
     string public constant override FEATURE_NAME = "Ownable";
     /// @dev Version of this feature.
     uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
-    /// @dev The deployed address of this contract.
-    address immutable private _implementation;
-    // solhint-enable
 
     using LibRichErrorsV06 for bytes;
 
-    constructor() public {
+    constructor() public FixinCommon() {
-        _implementation = address(this);
+        // solhint-disable-next-line no-empty-blocks
     }
 
     /// @dev Initializes this feature. The intial owner will be set to this (ZeroEx)

contracts/zero-ex/contracts/src/features/SignatureValidator.sol

@@ -0,0 +1,260 @@
+/*
+
+  Copyright 2020 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.6.5;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
+import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
+import "../errors/LibSignatureRichErrors.sol";
+import "../fixins/FixinCommon.sol";
+import "../migrations/LibMigrate.sol";
+import "./ISignatureValidator.sol";
+import "./IFeature.sol";
+
+
+/// @dev Feature for validating signatures.
+contract SignatureValidator is
+    IFeature,
+    ISignatureValidator,
+    FixinCommon
+{
+    using LibBytesV06 for bytes;
+    using LibRichErrorsV06 for bytes;
+
+    /// @dev Name of this feature.
+    string public constant override FEATURE_NAME = "SignatureValidator";
+    /// @dev Version of this feature.
+    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
+
+    constructor() public FixinCommon() {
+        // solhint-disable-next-line no-empty-blocks
+    }
+
+    /// @dev Initialize and register this feature.
+    ///      Should be delegatecalled by `Migrate.migrate()`.
+    /// @return success `LibMigrate.SUCCESS` on success.
+    function migrate()
+        external
+        returns (bytes4 success)
+    {
+        _registerFeatureFunction(this.validateHashSignature.selector);
+        _registerFeatureFunction(this.isValidHashSignature.selector);
+        return LibMigrate.MIGRATE_SUCCESS;
+    }
+
+    /// @dev Validate that `hash` was signed by `signer` given `signature`.
+    ///      Reverts otherwise.
+    /// @param hash The hash that was signed.
+    /// @param signer The signer of the hash.
+    /// @param signature The signature. The last byte of this signature should
+    ///        be a member of the `SignatureType` enum.
+    function validateHashSignature(
+        bytes32 hash,
+        address signer,
+        bytes memory signature
+    )
+        public
+        override
+        view
+    {
+        SignatureType signatureType = _readValidSignatureType(
+            hash,
+            signer,
+            signature
+        );
+
+        // TODO: When we support non-hash signature types, assert that
+        // `signatureType` is only `EIP712` or `EthSign` here.
+
+        _validateHashSignatureTypes(
+            signatureType,
+            hash,
+            signer,
+            signature
+        );
+    }
+
+    /// @dev Check that `hash` was signed by `signer` given `signature`.
+    /// @param hash The hash that was signed.
+    /// @param signer The signer of the hash.
+    /// @param signature The signature. The last byte of this signature should
+    ///        be a member of the `SignatureType` enum.
+    /// @return isValid `true` on success.
+    function isValidHashSignature(
+        bytes32 hash,
+        address signer,
+        bytes calldata signature
+    )
+        external
+        view
+        override
+        returns (bool isValid)
+    {
+        try this.validateHashSignature(hash, signer, signature) {
+            isValid = true;
+        } catch (bytes memory) {
+            isValid = false;
+        }
+    }
+
+    /// @dev Validates a hash-only signature type. Low-level, hidden variant.
+    /// @param signatureType The type of signature to check.
+    /// @param hash The hash that was signed.
+    /// @param signer The signer of the hash.
+    /// @param signature The signature. The last byte of this signature should
+    ///        be a member of the `SignatureType` enum.
+    function _validateHashSignatureTypes(
+        SignatureType signatureType,
+        bytes32 hash,
+        address signer,
+        bytes memory signature
+    )
+        private
+        pure
+    {
+        address recovered = address(0);
+        if (signatureType == SignatureType.Invalid) {
+            // Always invalid signature.
+            // Like Illegal, this is always implicitly available and therefore
+            // offered explicitly. It can be implicitly created by providing
+            // a correctly formatted but incorrect signature.
+            LibSignatureRichErrors.SignatureValidationError(
+                LibSignatureRichErrors.SignatureValidationErrorCodes.ALWAYS_INVALID,
+                hash,
+                signer,
+                signature
+            ).rrevert();
+        } else if (signatureType == SignatureType.EIP712) {
+            // Signature using EIP712
+            if (signature.length != 66) {
+                LibSignatureRichErrors.SignatureValidationError(
+                    LibSignatureRichErrors.SignatureValidationErrorCodes.INVALID_LENGTH,
+                    hash,
+                    signer,
+                    signature
+                ).rrevert();
+            }
+            uint8 v = uint8(signature[0]);
+            bytes32 r = signature.readBytes32(1);
+            bytes32 s = signature.readBytes32(33);
+            recovered = ecrecover(
+                hash,
+                v,
+                r,
+                s
+            );
+        } else if (signatureType == SignatureType.EthSign) {
+            // Signed using `eth_sign`
+            if (signature.length != 66) {
+                LibSignatureRichErrors.SignatureValidationError(
+                    LibSignatureRichErrors.SignatureValidationErrorCodes.INVALID_LENGTH,
+                    hash,
+                    signer,
+                    signature
+                ).rrevert();
+            }
+            uint8 v = uint8(signature[0]);
+            bytes32 r = signature.readBytes32(1);
+            bytes32 s = signature.readBytes32(33);
+            recovered = ecrecover(
+                keccak256(abi.encodePacked(
+                    "\x19Ethereum Signed Message:\n32",
+                    hash
+                )),
+                v,
+                r,
+                s
+            );
+        } else {
+            // This should never happen.
+            revert('SignatureValidator/ILLEGAL_CODE_PATH');
+        }
+        if (recovered == address(0) || signer != recovered) {
+            LibSignatureRichErrors.SignatureValidationError(
+                LibSignatureRichErrors.SignatureValidationErrorCodes.WRONG_SIGNER,
+                hash,
+                signer,
+                signature
+            ).rrevert();
+        }
+    }
+
+    /// @dev Reads the `SignatureType` from the end of a signature and validates it.
+    function _readValidSignatureType(
+        bytes32 hash,
+        address signer,
+        bytes memory signature
+    )
+        private
+        pure
+        returns (SignatureType signatureType)
+    {
+        // Read the signatureType from the signature
+        signatureType = _readSignatureType(
+            hash,
+            signer,
+            signature
+        );
+
+        // Ensure signature is supported
+        if (uint8(signatureType) >= uint8(SignatureType.NSignatureTypes)) {
+            LibSignatureRichErrors.SignatureValidationError(
+                LibSignatureRichErrors.SignatureValidationErrorCodes.UNSUPPORTED,
+                hash,
+                signer,
+                signature
+            ).rrevert();
+        }
+
+        // Always illegal signature.
+        // This is always an implicit option since a signer can create a
+        // signature array with invalid type or length. We may as well make
+        // it an explicit option. This aids testing and analysis. It is
+        // also the initialization value for the enum type.
+        if (signatureType == SignatureType.Illegal) {
+            LibSignatureRichErrors.SignatureValidationError(
+                LibSignatureRichErrors.SignatureValidationErrorCodes.ILLEGAL,
+                hash,
+                signer,
+                signature
+            ).rrevert();
+        }
+    }
+
+    /// @dev Reads the `SignatureType` from the end of a signature.
+    function _readSignatureType(
+        bytes32 hash,
+        address signer,
+        bytes memory signature
+    )
+        private
+        pure
+        returns (SignatureType sigType)
+    {
+        if (signature.length == 0) {
+            LibSignatureRichErrors.SignatureValidationError(
+                LibSignatureRichErrors.SignatureValidationErrorCodes.INVALID_LENGTH,
+                hash,
+                signer,
+                signature
+            ).rrevert();
+        }
+        return SignatureType(uint8(signature[signature.length - 1]));
+    }
+}

contracts/zero-ex/contracts/src/features/SimpleFunctionRegistry.sol

@@ -35,19 +35,15 @@ contract SimpleFunctionRegistry is
     ISimpleFunctionRegistry,
     FixinCommon
 {
-    // solhint-disable
     /// @dev Name of this feature.
     string public constant override FEATURE_NAME = "SimpleFunctionRegistry";
     /// @dev Version of this feature.
     uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
-    /// @dev The deployed address of this contract.
-    address private immutable _implementation;
-    // solhint-enable
 
     using LibRichErrorsV06 for bytes;
 
-    constructor() public {
+    constructor() public FixinCommon() {
-        _implementation = address(this);
+        // solhint-disable-next-line no-empty-blocks
     }
 
     /// @dev Initializes this feature, registering its own functions.

contracts/zero-ex/contracts/src/features/TokenSpender.sol

@@ -44,14 +44,12 @@ contract TokenSpender is
     string public constant override FEATURE_NAME = "TokenSpender";
     /// @dev Version of this feature.
     uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
-    /// @dev The implementation address of this feature.
-    address private immutable _implementation;
     // solhint-enable
 
     using LibRichErrorsV06 for bytes;
 
-    constructor() public {
+    constructor() public FixinCommon() {
-        _implementation = address(this);
+        // solhint-disable-next-line no-empty-blocks
     }
 
     /// @dev Initialize and register this feature. Should be delegatecalled
@@ -59,14 +57,14 @@ contract TokenSpender is
     /// @param allowanceTarget An `allowanceTarget` instance, configured to have
     ///        the ZeroeEx contract as an authority.
     /// @return success `MIGRATE_SUCCESS` on success.
-    function migrate(IAllowanceTarget allowanceTarget) external returns (bytes4 success) {
+    function migrate(IAllowanceTarget allowanceTarget)
+        external
+        returns (bytes4 success)
+    {
         LibTokenSpenderStorage.getStorage().allowanceTarget = allowanceTarget;
-        ISimpleFunctionRegistry(address(this))
+        _registerFeatureFunction(this.getAllowanceTarget.selector);
-            .extend(this.getAllowanceTarget.selector, _implementation);
+        _registerFeatureFunction(this._spendERC20Tokens.selector);
-        ISimpleFunctionRegistry(address(this))
+        _registerFeatureFunction(this.getSpendableERC20BalanceOf.selector);
-            .extend(this._spendERC20Tokens.selector, _implementation);
-        ISimpleFunctionRegistry(address(this))
-            .extend(this.getSpendableERC20BalanceOf.selector, _implementation);
         return LibMigrate.MIGRATE_SUCCESS;
     }
 

contracts/zero-ex/contracts/src/features/TransformERC20.sol

@@ -52,39 +52,32 @@ contract TransformERC20 is
         uint256 takerOutputTokenBalanceAfter;
     }
 
-    // solhint-disable
     /// @dev Name of this feature.
     string public constant override FEATURE_NAME = "TransformERC20";
     /// @dev Version of this feature.
     uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 1, 0);
-    /// @dev The implementation address of this feature.
-    address private immutable _implementation;
-    // solhint-enable
 
     using LibSafeMathV06 for uint256;
     using LibRichErrorsV06 for bytes;
 
-    constructor() public {
+    constructor() public FixinCommon() {
-        _implementation = address(this);
+        // solhint-disable-next-line no-empty-blocks
     }
 
     /// @dev Initialize and register this feature.
     ///      Should be delegatecalled by `Migrate.migrate()`.
     /// @param transformerDeployer The trusted deployer for transformers.
     /// @return success `LibMigrate.SUCCESS` on success.
-    function migrate(address transformerDeployer) external returns (bytes4 success) {
+    function migrate(address transformerDeployer)
-        ISimpleFunctionRegistry(address(this))
+        external
-            .extend(this.getTransformerDeployer.selector, _implementation);
+        returns (bytes4 success)
-        ISimpleFunctionRegistry(address(this))
+    {
-            .extend(this.createTransformWallet.selector, _implementation);
+        _registerFeatureFunction(this.getTransformerDeployer.selector);
-        ISimpleFunctionRegistry(address(this))
+        _registerFeatureFunction(this.createTransformWallet.selector);
-            .extend(this.getTransformWallet.selector, _implementation);
+        _registerFeatureFunction(this.getTransformWallet.selector);
-        ISimpleFunctionRegistry(address(this))
+        _registerFeatureFunction(this.setTransformerDeployer.selector);
-            .extend(this.setTransformerDeployer.selector, _implementation);
+        _registerFeatureFunction(this.transformERC20.selector);
-        ISimpleFunctionRegistry(address(this))
+        _registerFeatureFunction(this._transformERC20.selector);
-            .extend(this.transformERC20.selector, _implementation);
-        ISimpleFunctionRegistry(address(this))
-            .extend(this._transformERC20.selector, _implementation);
         this.createTransformWallet();
         LibTransformERC20Storage.getStorage().transformerDeployer = transformerDeployer;
         return LibMigrate.MIGRATE_SUCCESS;
@@ -191,6 +184,7 @@ contract TransformERC20 is
         Transformation[] memory transformations
     )
         public
+        virtual
         override
         payable
         onlySelf

contracts/zero-ex/contracts/src/fixins/FixinCommon.sol

@@ -23,13 +23,17 @@ import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
 import "../errors/LibCommonRichErrors.sol";
 import "../errors/LibOwnableRichErrors.sol";
 import "../features/IOwnable.sol";
+import "../features/ISimpleFunctionRegistry.sol";
 
 
 /// @dev Common feature utilities.
-contract FixinCommon {
+abstract contract FixinCommon {
 
     using LibRichErrorsV06 for bytes;
 
+    /// @dev The implementation address of this feature.
+    address internal immutable _implementation;
+
     /// @dev The caller must be this contract.
     modifier onlySelf() virtual {
         if (msg.sender != address(this)) {
@@ -52,6 +56,21 @@ contract FixinCommon {
         _;
     }
 
+    constructor() internal {
+        // Remember this feature's original address.
+        _implementation = address(this);
+    }
+
+    /// @dev Registers a function implemented by this feature at `_implementation`.
+    ///      Can and should only be called within a `migrate()`.
+    /// @param selector The selector of the function whose implementation
+    ///        is at `_implementation`.
+    function _registerFeatureFunction(bytes4 selector)
+        internal
+    {
+        ISimpleFunctionRegistry(address(this)).extend(selector, _implementation);
+    }
+
     /// @dev Encode a feature version as a `uint256`.
     /// @param major The major version number of the feature.
     /// @param minor The minor version number of the feature.

contracts/zero-ex/contracts/src/fixins/FixinEIP712.sol

@@ -0,0 +1,69 @@
+/*
+
+  Copyright 2020 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.6.5;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
+import "../errors/LibCommonRichErrors.sol";
+import "../errors/LibOwnableRichErrors.sol";
+import "../features/IOwnable.sol";
+
+
+/// @dev EIP712 helpers for features.
+abstract contract FixinEIP712 {
+
+    /// @dev The domain hash separator for the entire exchange proxy.
+    bytes32 public immutable EIP712_DOMAIN_SEPARATOR;
+
+    constructor(address zeroExAddress) internal {
+        // Compute `EIP712_DOMAIN_SEPARATOR`
+        {
+            uint256 chainId;
+            assembly { chainId := chainid() }
+            EIP712_DOMAIN_SEPARATOR = keccak256(
+                abi.encode(
+                    keccak256(
+                        "EIP712Domain("
+                            "string name,"
+                            "string version,"
+                            "uint256 chainId,"
+                            "address verifyingContract"
+                        ")"
+                    ),
+                    keccak256("ZeroEx"),
+                    keccak256("1.0.0"),
+                    chainId,
+                    zeroExAddress
+                )
+            );
+        }
+    }
+
+    function _getEIP712Hash(bytes32 structHash)
+        internal
+        view
+        returns (bytes32 eip712Hash)
+    {
+        return keccak256(abi.encodePacked(
+            hex"1901",
+            EIP712_DOMAIN_SEPARATOR,
+            structHash
+        ));
+    }
+}

contracts/zero-ex/contracts/src/migrations/FullMigration.sol

@@ -23,6 +23,8 @@ import "../ZeroEx.sol";
 import "../features/IOwnable.sol";
 import "../features/TokenSpender.sol";
 import "../features/TransformERC20.sol";
+import "../features/SignatureValidator.sol";
+import "../features/MetaTransactions.sol";
 import "../external/AllowanceTarget.sol";
 import "./InitialMigration.sol";
 
@@ -38,6 +40,8 @@ contract FullMigration {
         Ownable ownable;
         TokenSpender tokenSpender;
         TransformERC20 transformERC20;
+        SignatureValidator signatureValidator;
+        MetaTransactions metaTransactions;
     }
 
     /// @dev Parameters needed to initialize features.
@@ -45,42 +49,56 @@ contract FullMigration {
         address transformerDeployer;
     }
 
-    /// @dev The allowed caller of `deploy()`.
+    /// @dev The allowed caller of `initializeZeroEx()`.
-    address public immutable deployer;
+    address public immutable initializeCaller;
     /// @dev The initial migration contract.
     InitialMigration private _initialMigration;
 
-    /// @dev Instantiate this contract and set the allowed caller of `deploy()`
+    /// @dev Instantiate this contract and set the allowed caller of `initializeZeroEx()`
-    ///      to `deployer`.
+    ///      to `initializeCaller`.
-    /// @param deployer_ The allowed caller of `deploy()`.
+    /// @param initializeCaller_ The allowed caller of `initializeZeroEx()`.
-    constructor(address payable deployer_)
+    constructor(address payable initializeCaller_)
         public
     {
-        deployer = deployer_;
+        initializeCaller = initializeCaller_;
         // Create an initial migration contract with this contract set to the
-        // allowed deployer.
+        // allowed `initializeCaller`.
         _initialMigration = new InitialMigration(address(this));
     }
 
-    /// @dev Deploy the `ZeroEx` contract with the full feature set,
+    /// @dev Retrieve the bootstrapper address to use when constructing `ZeroEx`.
+    /// @return bootstrapper The bootstrapper address.
+    function getBootstrapper()
+        external
+        view
+        returns (address bootstrapper)
+    {
+        return address(_initialMigration);
+    }
+
+    /// @dev Initialize the `ZeroEx` contract with the full feature set,
     ///      transfer ownership to `owner`, then self-destruct.
     /// @param owner The owner of the contract.
+    /// @param zeroEx The instance of the ZeroEx contract. ZeroEx should
+    ///        been constructed with this contract as the bootstrapper.
     /// @param features Features to add to the proxy.
-    /// @return zeroEx The deployed and configured `ZeroEx` contract.
+    /// @return _zeroEx The configured ZeroEx contract. Same as the `zeroEx` parameter.
     /// @param migrateOpts Parameters needed to initialize features.
-    function deploy(
+    function initializeZeroEx(
         address payable owner,
+        ZeroEx zeroEx,
         Features memory features,
         MigrateOpts memory migrateOpts
     )
         public
-        returns (ZeroEx zeroEx)
+        returns (ZeroEx _zeroEx)
     {
-        require(msg.sender == deployer, "FullMigration/INVALID_SENDER");
+        require(msg.sender == initializeCaller, "FullMigration/INVALID_SENDER");
 
         // Perform the initial migration with the owner set to this contract.
-        zeroEx = _initialMigration.deploy(
+        _initialMigration.initializeZeroEx(
             address(uint160(address(this))),
+            zeroEx,
             InitialMigration.BootstrapFeatures({
                 registry: features.registry,
                 ownable: features.ownable
@@ -95,9 +113,11 @@ contract FullMigration {
 
         // Self-destruct.
         this.die(owner);
+
+        return zeroEx;
     }
 
-    /// @dev Destroy this contract. Only callable from ourselves (from `deploy()`).
+    /// @dev Destroy this contract. Only callable from ourselves (from `initializeZeroEx()`).
     /// @param ethRecipient Receiver of any ETH in this contract.
     function die(address payable ethRecipient)
         external
@@ -153,5 +173,27 @@ contract FullMigration {
                 address(this)
             );
         }
+        // SignatureValidator
+        {
+            // Register the feature.
+            ownable.migrate(
+                address(features.signatureValidator),
+                abi.encodeWithSelector(
+                    SignatureValidator.migrate.selector
+                ),
+                address(this)
+            );
+        }
+        // MetaTransactions
+        {
+            // Register the feature.
+            ownable.migrate(
+                address(features.metaTransactions),
+                abi.encodeWithSelector(
+                    MetaTransactions.migrate.selector
+                ),
+                address(this)
+            );
+        }
     }
 }

contracts/zero-ex/contracts/src/migrations/InitialMigration.sol

@@ -35,36 +35,39 @@ contract InitialMigration {
         Ownable ownable;
     }
 
-    /// @dev The allowed caller of `deploy()`. In production, this would be
+    /// @dev The allowed caller of `initializeZeroEx()`. In production, this would be
     ///      the governor.
-    address public immutable deployer;
+    address public immutable initializeCaller;
     /// @dev The real address of this contract.
     address private immutable _implementation;
 
-    /// @dev Instantiate this contract and set the allowed caller of `deploy()`
+    /// @dev Instantiate this contract and set the allowed caller of `initializeZeroEx()`
-    ///      to `deployer_`.
+    ///      to `initializeCaller_`.
-    /// @param deployer_ The allowed caller of `deploy()`.
+    /// @param initializeCaller_ The allowed caller of `initializeZeroEx()`.
-    constructor(address deployer_) public {
+    constructor(address initializeCaller_) public {
-        deployer = deployer_;
+        initializeCaller = initializeCaller_;
         _implementation = address(this);
     }
 
-    /// @dev Deploy the `ZeroEx` contract with the minimum feature set,
+    /// @dev Initialize the `ZeroEx` contract with the minimum feature set,
     ///      transfers ownership to `owner`, then self-destructs.
-    ///      Only callable by `deployer` set in the contstructor.
+    ///      Only callable by `initializeCaller` set in the contstructor.
     /// @param owner The owner of the contract.
+    /// @param zeroEx The instance of the ZeroEx contract. ZeroEx should
+    ///        been constructed with this contract as the bootstrapper.
     /// @param features Features to bootstrap into the proxy.
-    /// @return zeroEx The deployed and configured `ZeroEx` contract.
+    /// @return _zeroEx The configured ZeroEx contract. Same as the `zeroEx` parameter.
-    function deploy(address payable owner, BootstrapFeatures memory features)
+    function initializeZeroEx(
+        address payable owner,
+        ZeroEx zeroEx,
+        BootstrapFeatures memory features
+    )
         public
         virtual
-        returns (ZeroEx zeroEx)
+        returns (ZeroEx _zeroEx)
     {
-        // Must be called by the allowed deployer.
+        // Must be called by the allowed initializeCaller.
-        require(msg.sender == deployer, "InitialMigration/INVALID_SENDER");
+        require(msg.sender == initializeCaller, "InitialMigration/INVALID_SENDER");
-
-        // Deploy the ZeroEx contract, setting ourselves as the bootstrapper.
-        zeroEx = new ZeroEx();
 
         // Bootstrap the initial feature set.
         IBootstrap(address(zeroEx)).bootstrap(
@@ -75,6 +78,8 @@ contract InitialMigration {
         // Self-destruct. This contract should not hold any funds but we send
         // them to the owner just in case.
         this.die(owner);
+
+        return zeroEx;
     }
 
     /// @dev Sets up the initial state of the `ZeroEx` contract.

contracts/zero-ex/contracts/src/storage/LibMetaTransactionsStorage.sol

@@ -0,0 +1,44 @@
+/*
+
+  Copyright 2020 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.6.5;
+pragma experimental ABIEncoderV2;
+
+import "./LibStorage.sol";
+
+
+/// @dev Storage helpers for the `MetaTransactions` feature.
+library LibMetaTransactionsStorage {
+
+    /// @dev Storage bucket for this feature.
+    struct Storage {
+        // The block number when a hash was executed.
+        mapping (bytes32 => uint256) mtxHashToExecutedBlockNumber;
+    }
+
+    /// @dev Get the storage bucket for this contract.
+    function getStorage() internal pure returns (Storage storage stor) {
+        uint256 storageSlot = LibStorage.getStorageSlot(
+            LibStorage.StorageId.MetaTransactions
+        );
+        // Dip into assembly to change the slot pointed to by the local
+        // variable `stor`.
+        // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
+        assembly { stor_slot := storageSlot }
+    }
+}

contracts/zero-ex/contracts/src/storage/LibStorage.sol

@@ -34,7 +34,8 @@ library LibStorage {
         SimpleFunctionRegistry,
         Ownable,
         TokenSpender,
-        TransformERC20
+        TransformERC20,
+        MetaTransactions
     }
 
     /// @dev Get the storage slot given a storage ID. We assign unique, well-spaced

contracts/zero-ex/contracts/src/storage/LibTransformERC20Storage.sol

@@ -23,7 +23,7 @@ import "./LibStorage.sol";
 import "../external/IFlashWallet.sol";
 
 
-/// @dev Storage helpers for the `TokenSpender` feature.
+/// @dev Storage helpers for the `TransformERC20` feature.
 library LibTransformERC20Storage {
 
     /// @dev Storage bucket for this feature.

contracts/zero-ex/contracts/test/TestMetaTransactionsTransformERC20Feature.sol

@@ -0,0 +1,71 @@
+/*
+
+  Copyright 2020 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.6.5;
+pragma experimental ABIEncoderV2;
+
+import "../src/features/TransformERC20.sol";
+
+
+contract TestMetaTransactionsTransformERC20Feature is
+    TransformERC20
+{
+    event TransformERC20Called(
+        address sender,
+        uint256 value,
+        bytes32 callDataHash,
+        address taker,
+        IERC20TokenV06 inputToken,
+        IERC20TokenV06 outputToken,
+        uint256 inputTokenAmount,
+        uint256 minOutputTokenAmount,
+        Transformation[] transformations
+    );
+
+    function _transformERC20(
+        bytes32 callDataHash,
+        address payable taker,
+        IERC20TokenV06 inputToken,
+        IERC20TokenV06 outputToken,
+        uint256 inputTokenAmount,
+        uint256 minOutputTokenAmount,
+        Transformation[] memory transformations
+    )
+        public
+        override
+        payable
+        returns (uint256 outputTokenAmount)
+    {
+        if (msg.value == 666) {
+            revert('FAIL');
+        }
+
+        emit TransformERC20Called(
+            msg.sender,
+            msg.value,
+            callDataHash,
+            taker,
+            inputToken,
+            outputToken,
+            inputTokenAmount,
+            minOutputTokenAmount,
+            transformations
+        );
+        return 1337;
+    }
+}

contracts/zero-ex/package.json

@@ -39,9 +39,9 @@
         "publish:private": "yarn build && gitpkg publish"
     },
     "config": {
-        "publicInterfaceContracts": "ZeroEx,FullMigration,InitialMigration,IFlashWallet,IAllowanceTarget,IERC20Transformer,IOwnable,ISimpleFunctionRegistry,ITokenSpender,ITransformERC20,FillQuoteTransformer,PayTakerTransformer,WethTransformer,Ownable,SimpleFunctionRegistry,TransformERC20,TokenSpender,AffiliateFeeTransformer",
+        "publicInterfaceContracts": "ZeroEx,FullMigration,InitialMigration,IFlashWallet,IAllowanceTarget,IERC20Transformer,IOwnable,ISimpleFunctionRegistry,ITokenSpender,ITransformERC20,FillQuoteTransformer,PayTakerTransformer,WethTransformer,Ownable,SimpleFunctionRegistry,TransformERC20,TokenSpender,AffiliateFeeTransformer,SignatureValidator,MetaTransactions",
         "abis:comment": "This list is auto-generated by contracts-gen. Don't edit manually.",
-        "abis": "./test/generated-artifacts/@(AffiliateFeeTransformer|AllowanceTarget|Bootstrap|FillQuoteTransformer|FixinCommon|FixinGasToken|FlashWallet|FullMigration|IAllowanceTarget|IBootstrap|IERC20Bridge|IERC20Transformer|IExchange|IFeature|IFlashWallet|IGasToken|IOwnable|ISimpleFunctionRegistry|ITestSimpleFunctionRegistryFeature|ITokenSpender|ITransformERC20|InitialMigration|LibBootstrap|LibCommonRichErrors|LibERC20Transformer|LibMigrate|LibOwnableRichErrors|LibOwnableStorage|LibProxyRichErrors|LibProxyStorage|LibSimpleFunctionRegistryRichErrors|LibSimpleFunctionRegistryStorage|LibSpenderRichErrors|LibStorage|LibTokenSpenderStorage|LibTransformERC20RichErrors|LibTransformERC20Storage|LibWalletRichErrors|Ownable|PayTakerTransformer|SimpleFunctionRegistry|TestCallTarget|TestDelegateCaller|TestFillQuoteTransformerBridge|TestFillQuoteTransformerExchange|TestFillQuoteTransformerHost|TestFullMigration|TestInitialMigration|TestMigrator|TestMintTokenERC20Transformer|TestMintableERC20Token|TestSimpleFunctionRegistryFeatureImpl1|TestSimpleFunctionRegistryFeatureImpl2|TestTokenSpender|TestTokenSpenderERC20Token|TestTransformERC20|TestTransformerBase|TestTransformerDeployerTransformer|TestTransformerHost|TestWeth|TestWethTransformerHost|TestZeroExFeature|TokenSpender|TransformERC20|Transformer|TransformerDeployer|WethTransformer|ZeroEx).json"
+        "abis": "./test/generated-artifacts/@(AffiliateFeeTransformer|AllowanceTarget|Bootstrap|FillQuoteTransformer|FixinCommon|FixinEIP712|FixinGasToken|FlashWallet|FullMigration|IAllowanceTarget|IBootstrap|IERC20Bridge|IERC20Transformer|IExchange|IFeature|IFlashWallet|IGasToken|IMetaTransactions|IOwnable|ISignatureValidator|ISimpleFunctionRegistry|ITestSimpleFunctionRegistryFeature|ITokenSpender|ITransformERC20|InitialMigration|LibBootstrap|LibCommonRichErrors|LibERC20Transformer|LibMetaTransactionsRichErrors|LibMetaTransactionsStorage|LibMigrate|LibOwnableRichErrors|LibOwnableStorage|LibProxyRichErrors|LibProxyStorage|LibSignatureRichErrors|LibSimpleFunctionRegistryRichErrors|LibSimpleFunctionRegistryStorage|LibSpenderRichErrors|LibStorage|LibTokenSpenderStorage|LibTransformERC20RichErrors|LibTransformERC20Storage|LibWalletRichErrors|MetaTransactions|Ownable|PayTakerTransformer|SignatureValidator|SimpleFunctionRegistry|TestCallTarget|TestDelegateCaller|TestFillQuoteTransformerBridge|TestFillQuoteTransformerExchange|TestFillQuoteTransformerHost|TestFullMigration|TestInitialMigration|TestMetaTransactionsTransformERC20Feature|TestMigrator|TestMintTokenERC20Transformer|TestMintableERC20Token|TestSimpleFunctionRegistryFeatureImpl1|TestSimpleFunctionRegistryFeatureImpl2|TestTokenSpender|TestTokenSpenderERC20Token|TestTransformERC20|TestTransformerBase|TestTransformerDeployerTransformer|TestTransformerHost|TestWeth|TestWethTransformerHost|TestZeroExFeature|TokenSpender|TransformERC20|Transformer|TransformerDeployer|WethTransformer|ZeroEx).json"
     },
     "repository": {
         "type": "git",

contracts/zero-ex/src/artifacts.ts

@@ -16,8 +16,10 @@ import * as IOwnable from '../generated-artifacts/IOwnable.json';
 import * as ISimpleFunctionRegistry from '../generated-artifacts/ISimpleFunctionRegistry.json';
 import * as ITokenSpender from '../generated-artifacts/ITokenSpender.json';
 import * as ITransformERC20 from '../generated-artifacts/ITransformERC20.json';
+import * as MetaTransactions from '../generated-artifacts/MetaTransactions.json';
 import * as Ownable from '../generated-artifacts/Ownable.json';
 import * as PayTakerTransformer from '../generated-artifacts/PayTakerTransformer.json';
+import * as SignatureValidator from '../generated-artifacts/SignatureValidator.json';
 import * as SimpleFunctionRegistry from '../generated-artifacts/SimpleFunctionRegistry.json';
 import * as TokenSpender from '../generated-artifacts/TokenSpender.json';
 import * as TransformERC20 from '../generated-artifacts/TransformERC20.json';
@@ -42,4 +44,6 @@ export const artifacts = {
     TransformERC20: TransformERC20 as ContractArtifact,
     TokenSpender: TokenSpender as ContractArtifact,
     AffiliateFeeTransformer: AffiliateFeeTransformer as ContractArtifact,
+    SignatureValidator: SignatureValidator as ContractArtifact,
+    MetaTransactions: MetaTransactions as ContractArtifact,
 };

contracts/zero-ex/src/migration.ts

@@ -1,4 +1,3 @@
-import { BaseContract } from '@0x/base-contract';
 import { SupportedProvider } from '@0x/subproviders';
 import { TxData } from 'ethereum-types';
 import * as _ from 'lodash';
@@ -7,7 +6,9 @@ import { artifacts } from './artifacts';
 import {
     FullMigrationContract,
     InitialMigrationContract,
+    MetaTransactionsContract,
     OwnableContract,
+    SignatureValidatorContract,
     SimpleFunctionRegistryContract,
     TokenSpenderContract,
     TransformERC20Contract,
@@ -16,11 +17,17 @@ import {
 
 // tslint:disable: completed-docs
 
+/**
+ * Addresses of minimum features for a deployment of the Exchange Proxy.
+ */
 export interface BootstrapFeatures {
-    registry: SimpleFunctionRegistryContract;
+    registry: string;
-    ownable: OwnableContract;
+    ownable: string;
 }
 
+/**
+ * Deploy the minimum features of the Exchange Proxy.
+ */
 export async function deployBootstrapFeaturesAsync(
     provider: SupportedProvider,
     txDefaults: Partial<TxData>,
@@ -34,20 +41,23 @@ export async function deployBootstrapFeaturesAsync(
                 provider,
                 txDefaults,
                 artifacts,
-            )),
+            )).address,
         ownable:
             features.ownable ||
-            (await OwnableContract.deployFrom0xArtifactAsync(artifacts.Ownable, provider, txDefaults, artifacts)),
+            (await OwnableContract.deployFrom0xArtifactAsync(artifacts.Ownable, provider, txDefaults, artifacts))
+                .address,
     };
 }
 
+/**
+ * Migrate an instance of the Exchange proxy with minimum viable features.
+ */
 export async function initialMigrateAsync(
     owner: string,
     provider: SupportedProvider,
     txDefaults: Partial<TxData>,
     features: Partial<BootstrapFeatures> = {},
 ): Promise<ZeroExContract> {
-    const _features = await deployBootstrapFeaturesAsync(provider, txDefaults, features);
     const migrator = await InitialMigrationContract.deployFrom0xArtifactAsync(
         artifacts.InitialMigration,
         provider,
@@ -55,24 +65,42 @@ export async function initialMigrateAsync(
         artifacts,
         txDefaults.from as string,
     );
-    const deployCall = migrator.deploy(owner, toFeatureAdddresses(_features));
+    const zeroEx = await ZeroExContract.deployFrom0xArtifactAsync(
-    const zeroEx = new ZeroExContract(await deployCall.callAsync(), provider, {});
+        artifacts.ZeroEx,
-    await deployCall.awaitTransactionSuccessAsync();
+        provider,
+        txDefaults,
+        artifacts,
+        migrator.address,
+    );
+    const _features = await deployBootstrapFeaturesAsync(provider, txDefaults, features);
+    await migrator.initializeZeroEx(owner, zeroEx.address, _features).awaitTransactionSuccessAsync();
     return zeroEx;
 }
 
+/**
+ * Addresses of features for a full deployment of the Exchange Proxy.
+ */
 export interface FullFeatures extends BootstrapFeatures {
-    tokenSpender: TokenSpenderContract;
+    tokenSpender: string;
-    transformERC20: TransformERC20Contract;
+    transformERC20: string;
+    signatureValidator: string;
+    metaTransactions: string;
 }
 
+/**
+ * Extra configuration options for a full migration of the Exchange Proxy.
+ */
 export interface FullMigrationOpts {
     transformerDeployer: string;
 }
 
+/**
+ * Deploy all the features for a full Exchange Proxy.
+ */
 export async function deployFullFeaturesAsync(
     provider: SupportedProvider,
     txDefaults: Partial<TxData>,
+    zeroExAddress: string,
     features: Partial<FullFeatures> = {},
 ): Promise<FullFeatures> {
     return {
@@ -84,7 +112,7 @@ export async function deployFullFeaturesAsync(
                 provider,
                 txDefaults,
                 artifacts,
-            )),
+            )).address,
         transformERC20:
             features.transformERC20 ||
             (await TransformERC20Contract.deployFrom0xArtifactAsync(
@@ -92,10 +120,30 @@ export async function deployFullFeaturesAsync(
                 provider,
                 txDefaults,
                 artifacts,
-            )),
+            )).address,
+        signatureValidator:
+            features.signatureValidator ||
+            (await SignatureValidatorContract.deployFrom0xArtifactAsync(
+                artifacts.SignatureValidator,
+                provider,
+                txDefaults,
+                artifacts,
+            )).address,
+        metaTransactions:
+            features.metaTransactions ||
+            (await MetaTransactionsContract.deployFrom0xArtifactAsync(
+                artifacts.MetaTransactions,
+                provider,
+                txDefaults,
+                artifacts,
+                zeroExAddress,
+            )).address,
     };
 }
 
+/**
+ * Deploy a fully featured instance of the Exchange Proxy.
+ */
 export async function fullMigrateAsync(
     owner: string,
     provider: SupportedProvider,
@@ -103,7 +151,6 @@ export async function fullMigrateAsync(
     features: Partial<FullFeatures> = {},
     opts: Partial<FullMigrationOpts> = {},
 ): Promise<ZeroExContract> {
-    const _features = await deployFullFeaturesAsync(provider, txDefaults, features);
     const migrator = await FullMigrationContract.deployFrom0xArtifactAsync(
         artifacts.FullMigration,
         provider,
@@ -111,20 +158,18 @@ export async function fullMigrateAsync(
         artifacts,
         txDefaults.from as string,
     );
+    const zeroEx = await ZeroExContract.deployFrom0xArtifactAsync(
+        artifacts.ZeroEx,
+        provider,
+        txDefaults,
+        artifacts,
+        await migrator.getBootstrapper().callAsync(),
+    );
+    const _features = await deployFullFeaturesAsync(provider, txDefaults, zeroEx.address, features);
     const _opts = {
         transformerDeployer: txDefaults.from as string,
         ...opts,
     };
-    const deployCall = migrator.deploy(owner, toFeatureAdddresses(_features), _opts);
+    await migrator.initializeZeroEx(owner, zeroEx.address, _features, _opts).awaitTransactionSuccessAsync();
-    const zeroEx = new ZeroExContract(await deployCall.callAsync(), provider, {});
-    await deployCall.awaitTransactionSuccessAsync();
     return zeroEx;
 }
-
-// tslint:disable:space-before-function-parent one-line
-export function toFeatureAdddresses<T extends BootstrapFeatures | FullFeatures | (BootstrapFeatures & FullFeatures)>(
-    features: T,
-): { [name in keyof T]: string } {
-    // TS can't figure this out.
-    return _.mapValues(features, (c: BaseContract) => c.address) as any;
-}

contracts/zero-ex/src/wrappers.ts

@@ -14,8 +14,10 @@ export * from '../generated-wrappers/i_simple_function_registry';
 export * from '../generated-wrappers/i_token_spender';
 export * from '../generated-wrappers/i_transform_erc20';
 export * from '../generated-wrappers/initial_migration';
+export * from '../generated-wrappers/meta_transactions';
 export * from '../generated-wrappers/ownable';
 export * from '../generated-wrappers/pay_taker_transformer';
+export * from '../generated-wrappers/signature_validator';
 export * from '../generated-wrappers/simple_function_registry';
 export * from '../generated-wrappers/token_spender';
 export * from '../generated-wrappers/transform_erc20';

contracts/zero-ex/test/artifacts.ts

@@ -10,6 +10,7 @@ import * as AllowanceTarget from '../test/generated-artifacts/AllowanceTarget.js
 import * as Bootstrap from '../test/generated-artifacts/Bootstrap.json';
 import * as FillQuoteTransformer from '../test/generated-artifacts/FillQuoteTransformer.json';
 import * as FixinCommon from '../test/generated-artifacts/FixinCommon.json';
+import * as FixinEIP712 from '../test/generated-artifacts/FixinEIP712.json';
 import * as FixinGasToken from '../test/generated-artifacts/FixinGasToken.json';
 import * as FlashWallet from '../test/generated-artifacts/FlashWallet.json';
 import * as FullMigration from '../test/generated-artifacts/FullMigration.json';
@@ -21,8 +22,10 @@ import * as IExchange from '../test/generated-artifacts/IExchange.json';
 import * as IFeature from '../test/generated-artifacts/IFeature.json';
 import * as IFlashWallet from '../test/generated-artifacts/IFlashWallet.json';
 import * as IGasToken from '../test/generated-artifacts/IGasToken.json';
+import * as IMetaTransactions from '../test/generated-artifacts/IMetaTransactions.json';
 import * as InitialMigration from '../test/generated-artifacts/InitialMigration.json';
 import * as IOwnable from '../test/generated-artifacts/IOwnable.json';
+import * as ISignatureValidator from '../test/generated-artifacts/ISignatureValidator.json';
 import * as ISimpleFunctionRegistry from '../test/generated-artifacts/ISimpleFunctionRegistry.json';
 import * as ITestSimpleFunctionRegistryFeature from '../test/generated-artifacts/ITestSimpleFunctionRegistryFeature.json';
 import * as ITokenSpender from '../test/generated-artifacts/ITokenSpender.json';
@@ -30,11 +33,14 @@ import * as ITransformERC20 from '../test/generated-artifacts/ITransformERC20.js
 import * as LibBootstrap from '../test/generated-artifacts/LibBootstrap.json';
 import * as LibCommonRichErrors from '../test/generated-artifacts/LibCommonRichErrors.json';
 import * as LibERC20Transformer from '../test/generated-artifacts/LibERC20Transformer.json';
+import * as LibMetaTransactionsRichErrors from '../test/generated-artifacts/LibMetaTransactionsRichErrors.json';
+import * as LibMetaTransactionsStorage from '../test/generated-artifacts/LibMetaTransactionsStorage.json';
 import * as LibMigrate from '../test/generated-artifacts/LibMigrate.json';
 import * as LibOwnableRichErrors from '../test/generated-artifacts/LibOwnableRichErrors.json';
 import * as LibOwnableStorage from '../test/generated-artifacts/LibOwnableStorage.json';
 import * as LibProxyRichErrors from '../test/generated-artifacts/LibProxyRichErrors.json';
 import * as LibProxyStorage from '../test/generated-artifacts/LibProxyStorage.json';
+import * as LibSignatureRichErrors from '../test/generated-artifacts/LibSignatureRichErrors.json';
 import * as LibSimpleFunctionRegistryRichErrors from '../test/generated-artifacts/LibSimpleFunctionRegistryRichErrors.json';
 import * as LibSimpleFunctionRegistryStorage from '../test/generated-artifacts/LibSimpleFunctionRegistryStorage.json';
 import * as LibSpenderRichErrors from '../test/generated-artifacts/LibSpenderRichErrors.json';
@@ -43,8 +49,10 @@ import * as LibTokenSpenderStorage from '../test/generated-artifacts/LibTokenSpe
 import * as LibTransformERC20RichErrors from '../test/generated-artifacts/LibTransformERC20RichErrors.json';
 import * as LibTransformERC20Storage from '../test/generated-artifacts/LibTransformERC20Storage.json';
 import * as LibWalletRichErrors from '../test/generated-artifacts/LibWalletRichErrors.json';
+import * as MetaTransactions from '../test/generated-artifacts/MetaTransactions.json';
 import * as Ownable from '../test/generated-artifacts/Ownable.json';
 import * as PayTakerTransformer from '../test/generated-artifacts/PayTakerTransformer.json';
+import * as SignatureValidator from '../test/generated-artifacts/SignatureValidator.json';
 import * as SimpleFunctionRegistry from '../test/generated-artifacts/SimpleFunctionRegistry.json';
 import * as TestCallTarget from '../test/generated-artifacts/TestCallTarget.json';
 import * as TestDelegateCaller from '../test/generated-artifacts/TestDelegateCaller.json';
@@ -53,6 +61,7 @@ import * as TestFillQuoteTransformerExchange from '../test/generated-artifacts/T
 import * as TestFillQuoteTransformerHost from '../test/generated-artifacts/TestFillQuoteTransformerHost.json';
 import * as TestFullMigration from '../test/generated-artifacts/TestFullMigration.json';
 import * as TestInitialMigration from '../test/generated-artifacts/TestInitialMigration.json';
+import * as TestMetaTransactionsTransformERC20Feature from '../test/generated-artifacts/TestMetaTransactionsTransformERC20Feature.json';
 import * as TestMigrator from '../test/generated-artifacts/TestMigrator.json';
 import * as TestMintableERC20Token from '../test/generated-artifacts/TestMintableERC20Token.json';
 import * as TestMintTokenERC20Transformer from '../test/generated-artifacts/TestMintTokenERC20Transformer.json';
@@ -76,8 +85,10 @@ import * as ZeroEx from '../test/generated-artifacts/ZeroEx.json';
 export const artifacts = {
     ZeroEx: ZeroEx as ContractArtifact,
     LibCommonRichErrors: LibCommonRichErrors as ContractArtifact,
+    LibMetaTransactionsRichErrors: LibMetaTransactionsRichErrors as ContractArtifact,
     LibOwnableRichErrors: LibOwnableRichErrors as ContractArtifact,
     LibProxyRichErrors: LibProxyRichErrors as ContractArtifact,
+    LibSignatureRichErrors: LibSignatureRichErrors as ContractArtifact,
     LibSimpleFunctionRegistryRichErrors: LibSimpleFunctionRegistryRichErrors as ContractArtifact,
     LibSpenderRichErrors: LibSpenderRichErrors as ContractArtifact,
     LibTransformERC20RichErrors: LibTransformERC20RichErrors as ContractArtifact,
@@ -90,20 +101,26 @@ export const artifacts = {
     Bootstrap: Bootstrap as ContractArtifact,
     IBootstrap: IBootstrap as ContractArtifact,
     IFeature: IFeature as ContractArtifact,
+    IMetaTransactions: IMetaTransactions as ContractArtifact,
     IOwnable: IOwnable as ContractArtifact,
+    ISignatureValidator: ISignatureValidator as ContractArtifact,
     ISimpleFunctionRegistry: ISimpleFunctionRegistry as ContractArtifact,
     ITokenSpender: ITokenSpender as ContractArtifact,
     ITransformERC20: ITransformERC20 as ContractArtifact,
+    MetaTransactions: MetaTransactions as ContractArtifact,
     Ownable: Ownable as ContractArtifact,
+    SignatureValidator: SignatureValidator as ContractArtifact,
     SimpleFunctionRegistry: SimpleFunctionRegistry as ContractArtifact,
     TokenSpender: TokenSpender as ContractArtifact,
     TransformERC20: TransformERC20 as ContractArtifact,
     FixinCommon: FixinCommon as ContractArtifact,
+    FixinEIP712: FixinEIP712 as ContractArtifact,
     FixinGasToken: FixinGasToken as ContractArtifact,
     FullMigration: FullMigration as ContractArtifact,
     InitialMigration: InitialMigration as ContractArtifact,
     LibBootstrap: LibBootstrap as ContractArtifact,
     LibMigrate: LibMigrate as ContractArtifact,
+    LibMetaTransactionsStorage: LibMetaTransactionsStorage as ContractArtifact,
     LibOwnableStorage: LibOwnableStorage as ContractArtifact,
     LibProxyStorage: LibProxyStorage as ContractArtifact,
     LibSimpleFunctionRegistryStorage: LibSimpleFunctionRegistryStorage as ContractArtifact,
@@ -128,6 +145,7 @@ export const artifacts = {
     TestFillQuoteTransformerHost: TestFillQuoteTransformerHost as ContractArtifact,
     TestFullMigration: TestFullMigration as ContractArtifact,
     TestInitialMigration: TestInitialMigration as ContractArtifact,
+    TestMetaTransactionsTransformERC20Feature: TestMetaTransactionsTransformERC20Feature as ContractArtifact,
     TestMigrator: TestMigrator as ContractArtifact,
     TestMintTokenERC20Transformer: TestMintTokenERC20Transformer as ContractArtifact,
     TestMintableERC20Token: TestMintableERC20Token as ContractArtifact,

contracts/zero-ex/test/features/meta_transactions_test.ts

@@ -0,0 +1,548 @@
+import {
+    blockchainTests,
+    constants,
+    expect,
+    getRandomInteger,
+    randomAddress,
+    verifyEventsFromLogs,
+} from '@0x/contracts-test-utils';
+import { getExchangeProxyMetaTransactionHash, signatureUtils } from '@0x/order-utils';
+import { ExchangeProxyMetaTransaction } from '@0x/types';
+import { BigNumber, hexUtils, StringRevertError, ZeroExRevertErrors } from '@0x/utils';
+import * as _ from 'lodash';
+
+import { MetaTransactionsContract, ZeroExContract } from '../../src/wrappers';
+import { artifacts } from '../artifacts';
+import { abis } from '../utils/abis';
+import { fullMigrateAsync } from '../utils/migration';
+import {
+    ITokenSpenderContract,
+    TestMetaTransactionsTransformERC20FeatureContract,
+    TestMetaTransactionsTransformERC20FeatureEvents,
+    TestMintableERC20TokenContract,
+} from '../wrappers';
+
+const { NULL_ADDRESS, ZERO_AMOUNT } = constants;
+
+blockchainTests.resets('MetaTransactions feature', env => {
+    let owner: string;
+    let sender: string;
+    let signers: string[];
+    let zeroEx: ZeroExContract;
+    let feature: MetaTransactionsContract;
+    let feeToken: TestMintableERC20TokenContract;
+    let transformERC20Feature: TestMetaTransactionsTransformERC20FeatureContract;
+    let allowanceTarget: string;
+
+    const MAX_FEE_AMOUNT = new BigNumber('1e18');
+
+    before(async () => {
+        [owner, sender, ...signers] = await env.getAccountAddressesAsync();
+        transformERC20Feature = await TestMetaTransactionsTransformERC20FeatureContract.deployFrom0xArtifactAsync(
+            artifacts.TestMetaTransactionsTransformERC20Feature,
+            env.provider,
+            env.txDefaults,
+            {},
+        );
+        zeroEx = await fullMigrateAsync(owner, env.provider, env.txDefaults, {
+            transformERC20: transformERC20Feature.address,
+        });
+        feature = new MetaTransactionsContract(zeroEx.address, env.provider, { ...env.txDefaults, from: sender }, abis);
+        feeToken = await TestMintableERC20TokenContract.deployFrom0xArtifactAsync(
+            artifacts.TestMintableERC20Token,
+            env.provider,
+            env.txDefaults,
+            {},
+        );
+        allowanceTarget = await new ITokenSpenderContract(zeroEx.address, env.provider, env.txDefaults)
+            .getAllowanceTarget()
+            .callAsync();
+        // Fund signers with fee tokens.
+        await Promise.all(
+            signers.map(async signer => {
+                await feeToken.mint(signer, MAX_FEE_AMOUNT).awaitTransactionSuccessAsync();
+                await feeToken.approve(allowanceTarget, MAX_FEE_AMOUNT).awaitTransactionSuccessAsync({ from: signer });
+            }),
+        );
+    });
+
+    function getRandomMetaTransaction(
+        fields: Partial<ExchangeProxyMetaTransaction> = {},
+    ): ExchangeProxyMetaTransaction {
+        return {
+            signer: _.sampleSize(signers)[0],
+            sender,
+            minGasPrice: getRandomInteger('2', '1e9'),
+            maxGasPrice: getRandomInteger('1e9', '100e9'),
+            expirationTimeSeconds: new BigNumber(Math.floor(_.now() / 1000) + 360),
+            salt: new BigNumber(hexUtils.random()),
+            callData: hexUtils.random(4),
+            value: getRandomInteger(1, '1e18'),
+            feeToken: feeToken.address,
+            feeAmount: getRandomInteger(1, MAX_FEE_AMOUNT),
+            domain: {
+                chainId: 1, // Ganache's `chainid` opcode is hardcoded as 1
+                verifyingContract: zeroEx.address,
+            },
+            ...fields,
+        };
+    }
+
+    async function signMetaTransactionAsync(mtx: ExchangeProxyMetaTransaction, signer?: string): Promise<string> {
+        return signatureUtils.ecSignHashAsync(
+            env.provider,
+            getExchangeProxyMetaTransactionHash(mtx),
+            signer || mtx.signer,
+        );
+    }
+
+    describe('getMetaTransactionHash()', () => {
+        it('generates the correct hash', async () => {
+            const mtx = getRandomMetaTransaction();
+            const expected = getExchangeProxyMetaTransactionHash(mtx);
+            const actual = await feature.getMetaTransactionHash(mtx).callAsync();
+            expect(actual).to.eq(expected);
+        });
+    });
+
+    interface TransformERC20Args {
+        inputToken: string;
+        outputToken: string;
+        inputTokenAmount: BigNumber;
+        minOutputTokenAmount: BigNumber;
+        transformations: Array<{ deploymentNonce: BigNumber; data: string }>;
+    }
+
+    function getRandomTransformERC20Args(fields: Partial<TransformERC20Args> = {}): TransformERC20Args {
+        return {
+            inputToken: randomAddress(),
+            outputToken: randomAddress(),
+            inputTokenAmount: getRandomInteger(1, '1e18'),
+            minOutputTokenAmount: getRandomInteger(1, '1e18'),
+            transformations: [{ deploymentNonce: new BigNumber(123), data: hexUtils.random() }],
+            ...fields,
+        };
+    }
+
+    const RAW_SUCCESS_RESULT = hexUtils.leftPad(1337);
+
+    describe('executeMetaTransaction()', () => {
+        it('can call `TransformERC20.transformERC20()`', async () => {
+            const args = getRandomTransformERC20Args();
+            const mtx = getRandomMetaTransaction({
+                callData: transformERC20Feature
+                    .transformERC20(
+                        args.inputToken,
+                        args.outputToken,
+                        args.inputTokenAmount,
+                        args.minOutputTokenAmount,
+                        args.transformations,
+                    )
+                    .getABIEncodedTransactionData(),
+            });
+            const signature = await signMetaTransactionAsync(mtx);
+            const callOpts = {
+                gasPrice: mtx.minGasPrice,
+                value: mtx.value,
+            };
+            const rawResult = await feature.executeMetaTransaction(mtx, signature).callAsync(callOpts);
+            expect(rawResult).to.eq(RAW_SUCCESS_RESULT);
+            const receipt = await feature.executeMetaTransaction(mtx, signature).awaitTransactionSuccessAsync(callOpts);
+            verifyEventsFromLogs(
+                receipt.logs,
+                [
+                    {
+                        inputToken: args.inputToken,
+                        outputToken: args.outputToken,
+                        inputTokenAmount: args.inputTokenAmount,
+                        minOutputTokenAmount: args.minOutputTokenAmount,
+                        transformations: args.transformations,
+                        sender: zeroEx.address,
+                        value: mtx.value,
+                        callDataHash: hexUtils.hash(mtx.callData),
+                        taker: mtx.signer,
+                    },
+                ],
+                TestMetaTransactionsTransformERC20FeatureEvents.TransformERC20Called,
+            );
+        });
+
+        it('can call with any sender if `sender == 0`', async () => {
+            const args = getRandomTransformERC20Args();
+            const mtx = getRandomMetaTransaction({
+                sender: NULL_ADDRESS,
+                callData: transformERC20Feature
+                    .transformERC20(
+                        args.inputToken,
+                        args.outputToken,
+                        args.inputTokenAmount,
+                        args.minOutputTokenAmount,
+                        args.transformations,
+                    )
+                    .getABIEncodedTransactionData(),
+            });
+            const signature = await signMetaTransactionAsync(mtx);
+            const callOpts = {
+                gasPrice: mtx.minGasPrice,
+                value: mtx.value,
+                from: randomAddress(),
+            };
+            const rawResult = await feature.executeMetaTransaction(mtx, signature).callAsync(callOpts);
+            expect(rawResult).to.eq(RAW_SUCCESS_RESULT);
+        });
+
+        it('works without fee', async () => {
+            const args = getRandomTransformERC20Args();
+            const mtx = getRandomMetaTransaction({
+                feeAmount: ZERO_AMOUNT,
+                feeToken: randomAddress(),
+                callData: transformERC20Feature
+                    .transformERC20(
+                        args.inputToken,
+                        args.outputToken,
+                        args.inputTokenAmount,
+                        args.minOutputTokenAmount,
+                        args.transformations,
+                    )
+                    .getABIEncodedTransactionData(),
+            });
+            const signature = await signMetaTransactionAsync(mtx);
+            const callOpts = {
+                gasPrice: mtx.minGasPrice,
+                value: mtx.value,
+            };
+            const rawResult = await feature.executeMetaTransaction(mtx, signature).callAsync(callOpts);
+            expect(rawResult).to.eq(RAW_SUCCESS_RESULT);
+        });
+
+        it('fails if the translated call fails', async () => {
+            const args = getRandomTransformERC20Args();
+            const mtx = getRandomMetaTransaction({
+                value: new BigNumber(666),
+                callData: transformERC20Feature
+                    .transformERC20(
+                        args.inputToken,
+                        args.outputToken,
+                        args.inputTokenAmount,
+                        args.minOutputTokenAmount,
+                        args.transformations,
+                    )
+                    .getABIEncodedTransactionData(),
+            });
+            const mtxHash = getExchangeProxyMetaTransactionHash(mtx);
+            const signature = await signMetaTransactionAsync(mtx);
+            const callOpts = {
+                gasPrice: mtx.minGasPrice,
+                value: mtx.value,
+            };
+            const tx = feature.executeMetaTransaction(mtx, signature).callAsync(callOpts);
+            const actualCallData = transformERC20Feature
+                ._transformERC20(
+                    hexUtils.hash(mtx.callData),
+                    mtx.signer,
+                    args.inputToken,
+                    args.outputToken,
+                    args.inputTokenAmount,
+                    args.minOutputTokenAmount,
+                    args.transformations,
+                )
+                .getABIEncodedTransactionData();
+            return expect(tx).to.revertWith(
+                new ZeroExRevertErrors.MetaTransactions.MetaTransactionCallFailedError(
+                    mtxHash,
+                    actualCallData,
+                    new StringRevertError('FAIL').encode(),
+                ),
+            );
+        });
+
+        it('fails with unsupported function', async () => {
+            const mtx = getRandomMetaTransaction({
+                callData: transformERC20Feature.createTransformWallet().getABIEncodedTransactionData(),
+            });
+            const mtxHash = getExchangeProxyMetaTransactionHash(mtx);
+            const signature = await signMetaTransactionAsync(mtx);
+            const callOpts = {
+                gasPrice: mtx.minGasPrice,
+                value: mtx.value,
+            };
+            const tx = feature.executeMetaTransaction(mtx, signature).awaitTransactionSuccessAsync(callOpts);
+            return expect(tx).to.revertWith(
+                new ZeroExRevertErrors.MetaTransactions.MetaTransactionUnsupportedFunctionError(
+                    mtxHash,
+                    hexUtils.slice(mtx.callData, 0, 4),
+                ),
+            );
+        });
+
+        it('cannot execute the same mtx twice', async () => {
+            const args = getRandomTransformERC20Args();
+            const mtx = getRandomMetaTransaction({
+                callData: transformERC20Feature
+                    .transformERC20(
+                        args.inputToken,
+                        args.outputToken,
+                        args.inputTokenAmount,
+                        args.minOutputTokenAmount,
+                        args.transformations,
+                    )
+                    .getABIEncodedTransactionData(),
+            });
+            const mtxHash = getExchangeProxyMetaTransactionHash(mtx);
+            const signature = await signMetaTransactionAsync(mtx);
+            const callOpts = {
+                gasPrice: mtx.minGasPrice,
+                value: mtx.value,
+            };
+            const receipt = await feature.executeMetaTransaction(mtx, signature).awaitTransactionSuccessAsync(callOpts);
+            const tx = feature.executeMetaTransaction(mtx, signature).awaitTransactionSuccessAsync(callOpts);
+            return expect(tx).to.revertWith(
+                new ZeroExRevertErrors.MetaTransactions.MetaTransactionAlreadyExecutedError(
+                    mtxHash,
+                    receipt.blockNumber,
+                ),
+            );
+        });
+
+        it('fails if not enough ETH provided', async () => {
+            const mtx = getRandomMetaTransaction();
+            const mtxHash = getExchangeProxyMetaTransactionHash(mtx);
+            const signature = await signMetaTransactionAsync(mtx);
+            const callOpts = {
+                gasPrice: mtx.minGasPrice,
+                value: mtx.value.minus(1),
+            };
+            const tx = feature.executeMetaTransaction(mtx, signature).awaitTransactionSuccessAsync(callOpts);
+            return expect(tx).to.revertWith(
+                new ZeroExRevertErrors.MetaTransactions.MetaTransactionInsufficientEthError(
+                    mtxHash,
+                    callOpts.value,
+                    mtx.value,
+                ),
+            );
+        });
+
+        it('fails if gas price too low', async () => {
+            const mtx = getRandomMetaTransaction();
+            const mtxHash = getExchangeProxyMetaTransactionHash(mtx);
+            const signature = await signMetaTransactionAsync(mtx);
+            const callOpts = {
+                gasPrice: mtx.minGasPrice.minus(1),
+                value: mtx.value,
+            };
+            const tx = feature.executeMetaTransaction(mtx, signature).awaitTransactionSuccessAsync(callOpts);
+            return expect(tx).to.revertWith(
+                new ZeroExRevertErrors.MetaTransactions.MetaTransactionGasPriceError(
+                    mtxHash,
+                    callOpts.gasPrice,
+                    mtx.minGasPrice,
+                    mtx.maxGasPrice,
+                ),
+            );
+        });
+
+        it('fails if gas price too high', async () => {
+            const mtx = getRandomMetaTransaction();
+            const mtxHash = getExchangeProxyMetaTransactionHash(mtx);
+            const signature = await signMetaTransactionAsync(mtx);
+            const callOpts = {
+                gasPrice: mtx.maxGasPrice.plus(1),
+                value: mtx.value,
+            };
+            const tx = feature.executeMetaTransaction(mtx, signature).awaitTransactionSuccessAsync(callOpts);
+            return expect(tx).to.revertWith(
+                new ZeroExRevertErrors.MetaTransactions.MetaTransactionGasPriceError(
+                    mtxHash,
+                    callOpts.gasPrice,
+                    mtx.minGasPrice,
+                    mtx.maxGasPrice,
+                ),
+            );
+        });
+
+        it('fails if expired', async () => {
+            const mtx = getRandomMetaTransaction({
+                expirationTimeSeconds: new BigNumber(Math.floor(_.now() / 1000 - 60)),
+            });
+            const mtxHash = getExchangeProxyMetaTransactionHash(mtx);
+            const signature = await signMetaTransactionAsync(mtx);
+            const callOpts = {
+                gasPrice: mtx.maxGasPrice,
+                value: mtx.value,
+            };
+            const tx = feature.executeMetaTransaction(mtx, signature).awaitTransactionSuccessAsync(callOpts);
+            return expect(tx).to.revertWith(
+                new ZeroExRevertErrors.MetaTransactions.MetaTransactionExpiredError(
+                    mtxHash,
+                    undefined,
+                    mtx.expirationTimeSeconds,
+                ),
+            );
+        });
+
+        it('fails if wrong sender', async () => {
+            const requiredSender = randomAddress();
+            const mtx = getRandomMetaTransaction({
+                sender: requiredSender,
+            });
+            const mtxHash = getExchangeProxyMetaTransactionHash(mtx);
+            const signature = await signMetaTransactionAsync(mtx);
+            const callOpts = {
+                gasPrice: mtx.maxGasPrice,
+                value: mtx.value,
+            };
+            const tx = feature.executeMetaTransaction(mtx, signature).awaitTransactionSuccessAsync(callOpts);
+            return expect(tx).to.revertWith(
+                new ZeroExRevertErrors.MetaTransactions.MetaTransactionWrongSenderError(
+                    mtxHash,
+                    sender,
+                    requiredSender,
+                ),
+            );
+        });
+
+        it('fails if signature is wrong', async () => {
+            const mtx = getRandomMetaTransaction({ signer: signers[0] });
+            const mtxHash = getExchangeProxyMetaTransactionHash(mtx);
+            const signature = await signMetaTransactionAsync(mtx, signers[1]);
+            const callOpts = {
+                gasPrice: mtx.maxGasPrice,
+                value: mtx.value,
+            };
+            const tx = feature.executeMetaTransaction(mtx, signature).awaitTransactionSuccessAsync(callOpts);
+            return expect(tx).to.revertWith(
+                new ZeroExRevertErrors.MetaTransactions.MetaTransactionInvalidSignatureError(
+                    mtxHash,
+                    signature,
+                    new ZeroExRevertErrors.SignatureValidator.SignatureValidationError(
+                        ZeroExRevertErrors.SignatureValidator.SignatureValidationErrorCodes.WrongSigner,
+                        mtxHash,
+                        signers[0],
+                        signature,
+                    ).encode(),
+                ),
+            );
+        });
+    });
+
+    describe('batchExecuteMetaTransactions()', () => {
+        it('can execute multiple transactions', async () => {
+            const mtxs = _.times(2, i => {
+                const args = getRandomTransformERC20Args();
+                return getRandomMetaTransaction({
+                    signer: signers[i],
+                    callData: transformERC20Feature
+                        .transformERC20(
+                            args.inputToken,
+                            args.outputToken,
+                            args.inputTokenAmount,
+                            args.minOutputTokenAmount,
+                            args.transformations,
+                        )
+                        .getABIEncodedTransactionData(),
+                });
+            });
+            const signatures = await Promise.all(mtxs.map(async mtx => signMetaTransactionAsync(mtx)));
+            const callOpts = {
+                gasPrice: BigNumber.max(...mtxs.map(mtx => mtx.minGasPrice)),
+                value: BigNumber.sum(...mtxs.map(mtx => mtx.value)),
+            };
+            const rawResults = await feature.batchExecuteMetaTransactions(mtxs, signatures).callAsync(callOpts);
+            expect(rawResults).to.eql(mtxs.map(() => RAW_SUCCESS_RESULT));
+        });
+
+        it('cannot execute the same transaction twice', async () => {
+            const mtx = (() => {
+                const args = getRandomTransformERC20Args();
+                return getRandomMetaTransaction({
+                    signer: _.sampleSize(signers, 1)[0],
+                    callData: transformERC20Feature
+                        .transformERC20(
+                            args.inputToken,
+                            args.outputToken,
+                            args.inputTokenAmount,
+                            args.minOutputTokenAmount,
+                            args.transformations,
+                        )
+                        .getABIEncodedTransactionData(),
+                });
+            })();
+            const mtxHash = getExchangeProxyMetaTransactionHash(mtx);
+            const mtxs = _.times(2, () => mtx);
+            const signatures = await Promise.all(mtxs.map(async m => signMetaTransactionAsync(m)));
+            const callOpts = {
+                gasPrice: BigNumber.max(...mtxs.map(m => m.minGasPrice)),
+                value: BigNumber.sum(...mtxs.map(m => m.value)),
+            };
+            const block = await env.web3Wrapper.getBlockNumberAsync();
+            const tx = feature.batchExecuteMetaTransactions(mtxs, signatures).callAsync(callOpts);
+            return expect(tx).to.revertWith(
+                new ZeroExRevertErrors.MetaTransactions.MetaTransactionAlreadyExecutedError(mtxHash, block),
+            );
+        });
+    });
+
+    describe('getMetaTransactionExecutedBlock()', () => {
+        it('returns zero for an unexecuted mtx', async () => {
+            const mtx = getRandomMetaTransaction();
+            const block = await feature.getMetaTransactionExecutedBlock(mtx).callAsync();
+            expect(block).to.bignumber.eq(0);
+        });
+
+        it('returns the block it was executed in', async () => {
+            const args = getRandomTransformERC20Args();
+            const mtx = getRandomMetaTransaction({
+                callData: transformERC20Feature
+                    .transformERC20(
+                        args.inputToken,
+                        args.outputToken,
+                        args.inputTokenAmount,
+                        args.minOutputTokenAmount,
+                        args.transformations,
+                    )
+                    .getABIEncodedTransactionData(),
+            });
+            const signature = await signMetaTransactionAsync(mtx);
+            const callOpts = {
+                gasPrice: mtx.minGasPrice,
+                value: mtx.value,
+            };
+            const receipt = await feature.executeMetaTransaction(mtx, signature).awaitTransactionSuccessAsync(callOpts);
+            const block = await feature.getMetaTransactionExecutedBlock(mtx).callAsync();
+            expect(block).to.bignumber.eq(receipt.blockNumber);
+        });
+    });
+
+    describe('getMetaTransactionHashExecutedBlock()', () => {
+        it('returns zero for an unexecuted mtx', async () => {
+            const mtx = getRandomMetaTransaction();
+            const mtxHash = getExchangeProxyMetaTransactionHash(mtx);
+            const block = await feature.getMetaTransactionHashExecutedBlock(mtxHash).callAsync();
+            expect(block).to.bignumber.eq(0);
+        });
+
+        it('returns the block it was executed in', async () => {
+            const args = getRandomTransformERC20Args();
+            const mtx = getRandomMetaTransaction({
+                callData: transformERC20Feature
+                    .transformERC20(
+                        args.inputToken,
+                        args.outputToken,
+                        args.inputTokenAmount,
+                        args.minOutputTokenAmount,
+                        args.transformations,
+                    )
+                    .getABIEncodedTransactionData(),
+            });
+            const signature = await signMetaTransactionAsync(mtx);
+            const callOpts = {
+                gasPrice: mtx.minGasPrice,
+                value: mtx.value,
+            };
+            const receipt = await feature.executeMetaTransaction(mtx, signature).awaitTransactionSuccessAsync(callOpts);
+            const mtxHash = getExchangeProxyMetaTransactionHash(mtx);
+            const block = await feature.getMetaTransactionHashExecutedBlock(mtxHash).callAsync();
+            expect(block).to.bignumber.eq(receipt.blockNumber);
+        });
+    });
+});

contracts/zero-ex/test/features/signature_validator_test.ts

@@ -0,0 +1,231 @@
+import { blockchainTests, constants, expect, randomAddress, signingUtils } from '@0x/contracts-test-utils';
+import { signatureUtils } from '@0x/order-utils';
+import { SignatureType } from '@0x/types';
+import { hexUtils, ZeroExRevertErrors } from '@0x/utils';
+import * as ethjs from 'ethereumjs-util';
+import * as _ from 'lodash';
+
+import { SignatureValidatorContract, ZeroExContract } from '../../src/wrappers';
+import { abis } from '../utils/abis';
+import { fullMigrateAsync } from '../utils/migration';
+
+const { NULL_BYTES } = constants;
+
+blockchainTests.resets('SignatureValidator feature', env => {
+    let owner: string;
+    let signers: string[];
+    let zeroEx: ZeroExContract;
+    let feature: SignatureValidatorContract;
+
+    before(async () => {
+        [owner, ...signers] = await env.getAccountAddressesAsync();
+        zeroEx = await fullMigrateAsync(owner, env.provider, env.txDefaults);
+        feature = new SignatureValidatorContract(zeroEx.address, env.provider, env.txDefaults, abis);
+    });
+
+    describe('validateHashSignature()', () => {
+        it('can validate an eth_sign signature', async () => {
+            const hash = hexUtils.random();
+            const signer = _.sampleSize(signers, 1)[0];
+            const signature = await signatureUtils.ecSignHashAsync(env.provider, hash, signer);
+            await feature.validateHashSignature(hash, signer, signature).callAsync();
+        });
+
+        it('rejects a wrong eth_sign signature', async () => {
+            const hash = hexUtils.random();
+            const signer = _.sampleSize(signers, 1)[0];
+            const signature = await signatureUtils.ecSignHashAsync(env.provider, hash, signer);
+            const notSigner = randomAddress();
+            const tx = feature.validateHashSignature(hash, notSigner, signature).callAsync();
+            return expect(tx).to.revertWith(
+                new ZeroExRevertErrors.SignatureValidator.SignatureValidationError(
+                    ZeroExRevertErrors.SignatureValidator.SignatureValidationErrorCodes.WrongSigner,
+                    hash,
+                    notSigner,
+                    signature,
+                ),
+            );
+        });
+
+        it('rejects an eth_sign if ecrecover() fails', async () => {
+            const hash = hexUtils.random();
+            const signer = _.sampleSize(signers, 1)[0];
+            const signature = hexUtils.concat(hexUtils.random(65), SignatureType.EthSign);
+            const tx = feature.validateHashSignature(hash, signer, signature).callAsync();
+            return expect(tx).to.revertWith(
+                new ZeroExRevertErrors.SignatureValidator.SignatureValidationError(
+                    ZeroExRevertErrors.SignatureValidator.SignatureValidationErrorCodes.WrongSigner,
+                    hash,
+                    signer,
+                    signature,
+                ),
+            );
+        });
+
+        it('rejects a too short eth_sign signature', async () => {
+            const hash = hexUtils.random();
+            const signer = _.sampleSize(signers, 1)[0];
+            const signature = hexUtils.slice(await signatureUtils.ecSignHashAsync(env.provider, hash, signer), 1);
+            const tx = feature.validateHashSignature(hash, signer, signature).callAsync();
+            return expect(tx).to.revertWith(
+                new ZeroExRevertErrors.SignatureValidator.SignatureValidationError(
+                    ZeroExRevertErrors.SignatureValidator.SignatureValidationErrorCodes.InvalidLength,
+                    hash,
+                    signer,
+                    signature,
+                ),
+            );
+        });
+
+        it('can validate an eip712 signature', async () => {
+            const privateKey = hexUtils.random();
+            const signer = hexUtils.toHex(ethjs.privateToAddress(ethjs.toBuffer(privateKey)));
+            const hash = hexUtils.random();
+            const signature = hexUtils.toHex(
+                signingUtils.signMessage(ethjs.toBuffer(hash), ethjs.toBuffer(privateKey), SignatureType.EIP712),
+            );
+            await feature.validateHashSignature(hash, signer, signature).callAsync();
+        });
+
+        it('rejects a wrong eip712 signature', async () => {
+            const privateKey = hexUtils.random();
+            const hash = hexUtils.random();
+            const signature = hexUtils.toHex(
+                signingUtils.signMessage(ethjs.toBuffer(hash), ethjs.toBuffer(privateKey), SignatureType.EIP712),
+            );
+            const notSigner = randomAddress();
+            const tx = feature.validateHashSignature(hash, notSigner, signature).callAsync();
+            return expect(tx).to.revertWith(
+                new ZeroExRevertErrors.SignatureValidator.SignatureValidationError(
+                    ZeroExRevertErrors.SignatureValidator.SignatureValidationErrorCodes.WrongSigner,
+                    hash,
+                    notSigner,
+                    signature,
+                ),
+            );
+        });
+
+        it('rejects an eip712 if ecrecover() fails', async () => {
+            const hash = hexUtils.random();
+            const signer = _.sampleSize(signers, 1)[0];
+            const signature = hexUtils.concat(hexUtils.random(65), SignatureType.EIP712);
+            const tx = feature.validateHashSignature(hash, signer, signature).callAsync();
+            return expect(tx).to.revertWith(
+                new ZeroExRevertErrors.SignatureValidator.SignatureValidationError(
+                    ZeroExRevertErrors.SignatureValidator.SignatureValidationErrorCodes.WrongSigner,
+                    hash,
+                    signer,
+                    signature,
+                ),
+            );
+        });
+
+        it('rejects a too short eip712 signature', async () => {
+            const privateKey = hexUtils.random();
+            const signer = hexUtils.toHex(ethjs.privateToAddress(ethjs.toBuffer(privateKey)));
+            const hash = hexUtils.random();
+            const signature = hexUtils.slice(
+                hexUtils.toHex(
+                    signingUtils.signMessage(ethjs.toBuffer(hash), ethjs.toBuffer(privateKey), SignatureType.EIP712),
+                ),
+                1,
+            );
+            const tx = feature.validateHashSignature(hash, signer, signature).callAsync();
+            return expect(tx).to.revertWith(
+                new ZeroExRevertErrors.SignatureValidator.SignatureValidationError(
+                    ZeroExRevertErrors.SignatureValidator.SignatureValidationErrorCodes.InvalidLength,
+                    hash,
+                    signer,
+                    signature,
+                ),
+            );
+        });
+
+        it('rejects an INVALID signature type', async () => {
+            const hash = hexUtils.random();
+            const signer = _.sampleSize(signers, 1)[0];
+            const signature = hexUtils.concat(
+                hexUtils.slice(await signatureUtils.ecSignHashAsync(env.provider, hash, signer), 0, -1),
+                SignatureType.Invalid,
+            );
+            const tx = feature.validateHashSignature(hash, signer, signature).callAsync();
+            return expect(tx).to.revertWith(
+                new ZeroExRevertErrors.SignatureValidator.SignatureValidationError(
+                    ZeroExRevertErrors.SignatureValidator.SignatureValidationErrorCodes.AlwaysInvalid,
+                    hash,
+                    signer,
+                    signature,
+                ),
+            );
+        });
+
+        it('rejects an ILLEGAL signature type', async () => {
+            const hash = hexUtils.random();
+            const signer = _.sampleSize(signers, 1)[0];
+            const signature = hexUtils.concat(
+                hexUtils.slice(await signatureUtils.ecSignHashAsync(env.provider, hash, signer), 0, -1),
+                SignatureType.Illegal,
+            );
+            const tx = feature.validateHashSignature(hash, signer, signature).callAsync();
+            return expect(tx).to.revertWith(
+                new ZeroExRevertErrors.SignatureValidator.SignatureValidationError(
+                    ZeroExRevertErrors.SignatureValidator.SignatureValidationErrorCodes.Illegal,
+                    hash,
+                    signer,
+                    signature,
+                ),
+            );
+        });
+
+        it('rejects an unsupported signature type', async () => {
+            const hash = hexUtils.random();
+            const signer = _.sampleSize(signers, 1)[0];
+            const signature = hexUtils.concat(
+                hexUtils.slice(await signatureUtils.ecSignHashAsync(env.provider, hash, signer), 0, -1),
+                SignatureType.Wallet,
+            );
+            const tx = feature.validateHashSignature(hash, signer, signature).callAsync();
+            return expect(tx).to.revertWith(
+                new ZeroExRevertErrors.SignatureValidator.SignatureValidationError(
+                    ZeroExRevertErrors.SignatureValidator.SignatureValidationErrorCodes.Unsupported,
+                    hash,
+                    signer,
+                    signature,
+                ),
+            );
+        });
+
+        it('rejects an empty signature type', async () => {
+            const hash = hexUtils.random();
+            const signer = _.sampleSize(signers, 1)[0];
+            const signature = NULL_BYTES;
+            const tx = feature.validateHashSignature(hash, signer, signature).callAsync();
+            return expect(tx).to.revertWith(
+                new ZeroExRevertErrors.SignatureValidator.SignatureValidationError(
+                    ZeroExRevertErrors.SignatureValidator.SignatureValidationErrorCodes.InvalidLength,
+                    hash,
+                    signer,
+                    signature,
+                ),
+            );
+        });
+    });
+
+    describe('isValidHashSignature()', () => {
+        it('returns true on valid signature', async () => {
+            const hash = hexUtils.random();
+            const signer = _.sampleSize(signers, 1)[0];
+            const signature = await signatureUtils.ecSignHashAsync(env.provider, hash, signer);
+            const r = await feature.isValidHashSignature(hash, signer, signature).callAsync();
+            expect(r).to.eq(true);
+        });
+
+        it('returns false on invalid signature', async () => {
+            const hash = hexUtils.random();
+            const signer = _.sampleSize(signers, 1)[0];
+            const signature = await signatureUtils.ecSignHashAsync(env.provider, hash, signer);
+            const r = await feature.isValidHashSignature(hash, randomAddress(), signature).callAsync();
+            expect(r).to.eq(false);
+        });
+    });
+});

contracts/zero-ex/test/features/token_spender_test.ts

@@ -22,12 +22,12 @@ blockchainTests.resets('TokenSpender feature', env => {
     before(async () => {
         const [owner] = await env.getAccountAddressesAsync();
         zeroEx = await fullMigrateAsync(owner, env.provider, env.txDefaults, {
-            tokenSpender: await TokenSpenderContract.deployFrom0xArtifactAsync(
+            tokenSpender: (await TokenSpenderContract.deployFrom0xArtifactAsync(
                 artifacts.TestTokenSpender,
                 env.provider,
                 env.txDefaults,
                 artifacts,
-            ),
+            )).address,
         });
         feature = new TokenSpenderContract(zeroEx.address, env.provider, env.txDefaults, abis);
         token = await TestTokenSpenderERC20TokenContract.deployFrom0xArtifactAsync(

contracts/zero-ex/test/features/transform_erc20_test.ts

@@ -40,12 +40,12 @@ blockchainTests.resets('TransformERC20 feature', env => {
             env.provider,
             env.txDefaults,
             {
-                transformERC20: await TransformERC20Contract.deployFrom0xArtifactAsync(
+                transformERC20: (await TransformERC20Contract.deployFrom0xArtifactAsync(
                     artifacts.TestTransformERC20,
                     env.provider,
                     env.txDefaults,
                     artifacts,
-                ),
+                )).address,
             },
             { transformerDeployer },
         );

contracts/zero-ex/test/full_migration_test.ts

@@ -6,10 +6,12 @@ import * as _ from 'lodash';
 
 import { artifacts } from './artifacts';
 import { abis } from './utils/abis';
-import { deployFullFeaturesAsync, FullFeatures, toFeatureAdddresses } from './utils/migration';
+import { deployFullFeaturesAsync, FullFeatures } from './utils/migration';
 import {
     AllowanceTargetContract,
+    IMetaTransactionsContract,
     IOwnableContract,
+    ISignatureValidatorContract,
     ITokenSpenderContract,
     ITransformERC20Contract,
     TestFullMigrationContract,
@@ -27,7 +29,6 @@ blockchainTests.resets('Full migration', env => {
 
     before(async () => {
         [owner] = await env.getAccountAddressesAsync();
-        features = await deployFullFeaturesAsync(env.provider, env.txDefaults);
         migrator = await TestFullMigrationContract.deployFrom0xArtifactAsync(
             artifacts.TestFullMigration,
             env.provider,
@@ -35,9 +36,17 @@ blockchainTests.resets('Full migration', env => {
             artifacts,
             env.txDefaults.from as string,
         );
-        const deployCall = migrator.deploy(owner, toFeatureAdddresses(features), { transformerDeployer });
+        zeroEx = await ZeroExContract.deployFrom0xArtifactAsync(
-        zeroEx = new ZeroExContract(await deployCall.callAsync(), env.provider, env.txDefaults);
+            artifacts.ZeroEx,
-        await deployCall.awaitTransactionSuccessAsync();
+            env.provider,
+            env.txDefaults,
+            artifacts,
+            await migrator.getBootstrapper().callAsync(),
+        );
+        features = await deployFullFeaturesAsync(env.provider, env.txDefaults, zeroEx.address);
+        await migrator
+            .initializeZeroEx(owner, zeroEx.address, features, { transformerDeployer })
+            .awaitTransactionSuccessAsync();
     });
 
     it('ZeroEx has the correct owner', async () => {
@@ -51,10 +60,10 @@ blockchainTests.resets('Full migration', env => {
         expect(dieRecipient).to.eq(owner);
     });
 
-    it('Non-deployer cannot call deploy()', async () => {
+    it('Non-deployer cannot call initializeZeroEx()', async () => {
         const notDeployer = randomAddress();
         const tx = migrator
-            .deploy(owner, toFeatureAdddresses(features), { transformerDeployer })
+            .initializeZeroEx(owner, zeroEx.address, features, { transformerDeployer })
             .callAsync({ from: notDeployer });
         return expect(tx).to.revertWith('FullMigration/INVALID_SENDER');
     });
@@ -74,6 +83,21 @@ blockchainTests.resets('Full migration', env => {
                 'setTransformerDeployer',
             ],
         },
+        SignatureValidator: {
+            contractType: ISignatureValidatorContract,
+            fns: ['isValidHashSignature', 'validateHashSignature'],
+        },
+        MetaTransactions: {
+            contractType: IMetaTransactionsContract,
+            fns: [
+                'executeMetaTransaction',
+                'batchExecuteMetaTransactions',
+                '_executeMetaTransaction',
+                'getMetaTransactionExecutedBlock',
+                'getMetaTransactionHashExecutedBlock',
+                'getMetaTransactionHash',
+            ],
+        },
     };
 
     function createFakeInputs(inputs: DataItem[] | DataItem): any | any[] {

contracts/zero-ex/test/initial_migration_test.ts

@@ -2,7 +2,7 @@ import { blockchainTests, expect, randomAddress } from '@0x/contracts-test-utils
 import { hexUtils, ZeroExRevertErrors } from '@0x/utils';
 
 import { artifacts } from './artifacts';
-import { BootstrapFeatures, deployBootstrapFeaturesAsync, toFeatureAdddresses } from './utils/migration';
+import { BootstrapFeatures, deployBootstrapFeaturesAsync } from './utils/migration';
 import {
     IBootstrapContract,
     InitialMigrationContract,
@@ -35,9 +35,14 @@ blockchainTests.resets('Initial migration', env => {
             env.txDefaults,
             {},
         );
-        const deployCall = migrator.deploy(owner, toFeatureAdddresses(features));
+        zeroEx = await ZeroExContract.deployFrom0xArtifactAsync(
-        zeroEx = new ZeroExContract(await deployCall.callAsync(), env.provider, env.txDefaults);
+            artifacts.ZeroEx,
-        await deployCall.awaitTransactionSuccessAsync();
+            env.provider,
+            env.txDefaults,
+            artifacts,
+            migrator.address,
+        );
+        await migrator.initializeZeroEx(owner, zeroEx.address, features).awaitTransactionSuccessAsync();
     });
 
     it('Self-destructs after deployment', async () => {
@@ -45,9 +50,9 @@ blockchainTests.resets('Initial migration', env => {
         expect(dieRecipient).to.eq(owner);
     });
 
-    it('Non-deployer cannot call deploy()', async () => {
+    it('Non-deployer cannot call initializeZeroEx()', async () => {
         const notDeployer = randomAddress();
-        const tx = migrator.deploy(owner, toFeatureAdddresses(features)).callAsync({ from: notDeployer });
+        const tx = migrator.initializeZeroEx(owner, zeroEx.address, features).callAsync({ from: notDeployer });
         return expect(tx).to.revertWith('InitialMigration/INVALID_SENDER');
     });
 

contracts/zero-ex/test/utils/migration.ts

@@ -4,7 +4,6 @@ export {
     deployFullFeaturesAsync,
     initialMigrateAsync,
     fullMigrateAsync,
-    toFeatureAdddresses,
     FullMigrationOpts,
     FullFeatures,
 } from '../../src/migration';

contracts/zero-ex/test/wrappers.ts

@@ -8,6 +8,7 @@ export * from '../test/generated-wrappers/allowance_target';
 export * from '../test/generated-wrappers/bootstrap';
 export * from '../test/generated-wrappers/fill_quote_transformer';
 export * from '../test/generated-wrappers/fixin_common';
+export * from '../test/generated-wrappers/fixin_e_i_p712';
 export * from '../test/generated-wrappers/fixin_gas_token';
 export * from '../test/generated-wrappers/flash_wallet';
 export * from '../test/generated-wrappers/full_migration';
@@ -19,7 +20,9 @@ export * from '../test/generated-wrappers/i_exchange';
 export * from '../test/generated-wrappers/i_feature';
 export * from '../test/generated-wrappers/i_flash_wallet';
 export * from '../test/generated-wrappers/i_gas_token';
+export * from '../test/generated-wrappers/i_meta_transactions';
 export * from '../test/generated-wrappers/i_ownable';
+export * from '../test/generated-wrappers/i_signature_validator';
 export * from '../test/generated-wrappers/i_simple_function_registry';
 export * from '../test/generated-wrappers/i_test_simple_function_registry_feature';
 export * from '../test/generated-wrappers/i_token_spender';
@@ -28,11 +31,14 @@ export * from '../test/generated-wrappers/initial_migration';
 export * from '../test/generated-wrappers/lib_bootstrap';
 export * from '../test/generated-wrappers/lib_common_rich_errors';
 export * from '../test/generated-wrappers/lib_erc20_transformer';
+export * from '../test/generated-wrappers/lib_meta_transactions_rich_errors';
+export * from '../test/generated-wrappers/lib_meta_transactions_storage';
 export * from '../test/generated-wrappers/lib_migrate';
 export * from '../test/generated-wrappers/lib_ownable_rich_errors';
 export * from '../test/generated-wrappers/lib_ownable_storage';
 export * from '../test/generated-wrappers/lib_proxy_rich_errors';
 export * from '../test/generated-wrappers/lib_proxy_storage';
+export * from '../test/generated-wrappers/lib_signature_rich_errors';
 export * from '../test/generated-wrappers/lib_simple_function_registry_rich_errors';
 export * from '../test/generated-wrappers/lib_simple_function_registry_storage';
 export * from '../test/generated-wrappers/lib_spender_rich_errors';
@@ -41,8 +47,10 @@ export * from '../test/generated-wrappers/lib_token_spender_storage';
 export * from '../test/generated-wrappers/lib_transform_erc20_rich_errors';
 export * from '../test/generated-wrappers/lib_transform_erc20_storage';
 export * from '../test/generated-wrappers/lib_wallet_rich_errors';
+export * from '../test/generated-wrappers/meta_transactions';
 export * from '../test/generated-wrappers/ownable';
 export * from '../test/generated-wrappers/pay_taker_transformer';
+export * from '../test/generated-wrappers/signature_validator';
 export * from '../test/generated-wrappers/simple_function_registry';
 export * from '../test/generated-wrappers/test_call_target';
 export * from '../test/generated-wrappers/test_delegate_caller';
@@ -51,6 +59,7 @@ export * from '../test/generated-wrappers/test_fill_quote_transformer_exchange';
 export * from '../test/generated-wrappers/test_fill_quote_transformer_host';
 export * from '../test/generated-wrappers/test_full_migration';
 export * from '../test/generated-wrappers/test_initial_migration';
+export * from '../test/generated-wrappers/test_meta_transactions_transform_erc20_feature';
 export * from '../test/generated-wrappers/test_migrator';
 export * from '../test/generated-wrappers/test_mint_token_erc20_transformer';
 export * from '../test/generated-wrappers/test_mintable_erc20_token';

contracts/zero-ex/tsconfig.json

@@ -14,8 +14,10 @@
         "generated-artifacts/ITokenSpender.json",
         "generated-artifacts/ITransformERC20.json",
         "generated-artifacts/InitialMigration.json",
+        "generated-artifacts/MetaTransactions.json",
         "generated-artifacts/Ownable.json",
         "generated-artifacts/PayTakerTransformer.json",
+        "generated-artifacts/SignatureValidator.json",
         "generated-artifacts/SimpleFunctionRegistry.json",
         "generated-artifacts/TokenSpender.json",
         "generated-artifacts/TransformERC20.json",
@@ -26,6 +28,7 @@
         "test/generated-artifacts/Bootstrap.json",
         "test/generated-artifacts/FillQuoteTransformer.json",
         "test/generated-artifacts/FixinCommon.json",
+        "test/generated-artifacts/FixinEIP712.json",
         "test/generated-artifacts/FixinGasToken.json",
         "test/generated-artifacts/FlashWallet.json",
         "test/generated-artifacts/FullMigration.json",
@@ -37,7 +40,9 @@
         "test/generated-artifacts/IFeature.json",
         "test/generated-artifacts/IFlashWallet.json",
         "test/generated-artifacts/IGasToken.json",
+        "test/generated-artifacts/IMetaTransactions.json",
         "test/generated-artifacts/IOwnable.json",
+        "test/generated-artifacts/ISignatureValidator.json",
         "test/generated-artifacts/ISimpleFunctionRegistry.json",
         "test/generated-artifacts/ITestSimpleFunctionRegistryFeature.json",
         "test/generated-artifacts/ITokenSpender.json",
@@ -46,11 +51,14 @@
         "test/generated-artifacts/LibBootstrap.json",
         "test/generated-artifacts/LibCommonRichErrors.json",
         "test/generated-artifacts/LibERC20Transformer.json",
+        "test/generated-artifacts/LibMetaTransactionsRichErrors.json",
+        "test/generated-artifacts/LibMetaTransactionsStorage.json",
         "test/generated-artifacts/LibMigrate.json",
         "test/generated-artifacts/LibOwnableRichErrors.json",
         "test/generated-artifacts/LibOwnableStorage.json",
         "test/generated-artifacts/LibProxyRichErrors.json",
         "test/generated-artifacts/LibProxyStorage.json",
+        "test/generated-artifacts/LibSignatureRichErrors.json",
         "test/generated-artifacts/LibSimpleFunctionRegistryRichErrors.json",
         "test/generated-artifacts/LibSimpleFunctionRegistryStorage.json",
         "test/generated-artifacts/LibSpenderRichErrors.json",
@@ -59,8 +67,10 @@
         "test/generated-artifacts/LibTransformERC20RichErrors.json",
         "test/generated-artifacts/LibTransformERC20Storage.json",
         "test/generated-artifacts/LibWalletRichErrors.json",
+        "test/generated-artifacts/MetaTransactions.json",
         "test/generated-artifacts/Ownable.json",
         "test/generated-artifacts/PayTakerTransformer.json",
+        "test/generated-artifacts/SignatureValidator.json",
         "test/generated-artifacts/SimpleFunctionRegistry.json",
         "test/generated-artifacts/TestCallTarget.json",
         "test/generated-artifacts/TestDelegateCaller.json",
@@ -69,6 +79,7 @@
         "test/generated-artifacts/TestFillQuoteTransformerHost.json",
         "test/generated-artifacts/TestFullMigration.json",
         "test/generated-artifacts/TestInitialMigration.json",
+        "test/generated-artifacts/TestMetaTransactionsTransformERC20Feature.json",
         "test/generated-artifacts/TestMigrator.json",
         "test/generated-artifacts/TestMintTokenERC20Transformer.json",
         "test/generated-artifacts/TestMintableERC20Token.json",

packages/0x.js/CHANGELOG.json

@@ -5,6 +5,10 @@
             {
                 "note": "Export `GethCallOverrides` type",
                 "pr": 2620
+            },
+            {
+                "note": "Export `ExchangeProxyMetaTransaction` and `SignedExchangeProxyMetaTransaction`",
+                "pr": 2610
             }
         ]
     },

packages/0x.js/src/index.ts

@@ -82,6 +82,8 @@ export {
     EventCallback,
     IndexedFilterValues,
     DecodedLogEvent,
+    ExchangeProxyMetaTransaction,
+    SignedExchangeProxyMetaTransaction,
 } from '@0x/types';
 
 export {

packages/contract-addresses/CHANGELOG.json

@@ -21,6 +21,10 @@
             {
                 "note": "Redeploy DFB on kovan",
                 "pr": 2628
+            },
+            {
+                "note": "Update ganache snapshot Exchange Proxy addresses for MetaTransactions",
+                "pr": 2610
             }
         ]
     },

packages/contract-addresses/addresses.json

@@ -218,15 +218,15 @@
         "dexForwarderBridge": "0x0000000000000000000000000000000000000000",
         "multiBridge": "0x0000000000000000000000000000000000000000",
         "exchangeProxyGovernor": "0x0000000000000000000000000000000000000000",
-        "exchangeProxy": "0x4b8ce0fa221284de4aaa09be3e7bf6193444b786",
+        "exchangeProxy": "0x2ebb94cc79d7d0f1195300aaf191d118f53292a8",
-        "exchangeProxyAllowanceTarget": "0xd6724bf180441a89d08ea3aeded2c995180b9a04",
+        "exchangeProxyAllowanceTarget": "0x3eab3df72fd584b50184ff7d988a0d8f9328c866",
         "exchangeProxyTransformerDeployer": "0x5409ed021d9299bf6814279a6a1411a7e866a631",
-        "exchangeProxyFlashWallet": "0xdec8629610e2f4087bd9cc441d10ca8be0c6f6c5",
+        "exchangeProxyFlashWallet": "0x8362c3ebd90041b30ec45908332e592721642637",
         "transformers": {
-            "wethTransformer": "0xb125995f5a4766c451cd8c34c4f5cac89b724571",
+            "wethTransformer": "0x7209185959d7227fb77274e1e88151d7c4c368d3",
-            "payTakerTransformer": "0x10a736a7b223f1fe1050264249d1abb975741e75",
+            "payTakerTransformer": "0xc6b0d3c45a6b5092808196cb00df5c357d55e1d5",
-            "fillQuoteTransformer": "0x33def1aa867be09809f3a01ce41d5ec1888846c9",
+            "fillQuoteTransformer": "0xc7124963ab16c33e5bf421d4c0090116622b3074",
-            "affiliateFeeTransformer": "0xc7124963ab16c33e5bf421d4c0090116622b3074"
+            "affiliateFeeTransformer": "0x3f16ca81691dab9184cb4606c361d73c4fd2510a"
         }
     }
 }

packages/contract-wrappers-test/package.json

@@ -15,7 +15,7 @@
         "fix": "tslint --fix --format stylish --project .--exclude **/lib/**/*",
         "test:circleci": "run-s test:coverage",
         "test": "yarn run_mocha",
-        "run_mocha": "mocha --require source-map-support/register --require make-promises-safe lib/test/**/*_test.js lib/test/global_hooks.js --timeout 20000 --bail --exit",
+        "run_mocha": "mocha --require source-map-support/register --require make-promises-safe lib/test/**/*_test.js lib/test/global_hooks.js --timeout 30000 --bail --exit",
         "test:coverage": "nyc npm run test --all && yarn coverage:report:lcov",
         "coverage:report:lcov": "nyc report --reporter=text-lcov > coverage/lcov.info",
         "prettier": "prettier --write **/* --config ../../.prettierrc",

packages/order-utils/CHANGELOG.json

@@ -5,6 +5,10 @@
             {
                 "note": "Add ERC20 Transformer utils and export useful constants.",
                 "pr": 2604
+            },
+            {
+                "note": "Add `getOrderHash()`, `getExchangeTransactionHash()`, `getExchangeProxyTransactionHash()`",
+                "pr": 2610
             }
         ]
     },

packages/order-utils/package.json

@@ -64,6 +64,7 @@
     },
     "dependencies": {
         "@0x/assert": "^3.0.8",
+        "@0x/contract-addresses": "^4.10.0",
         "@0x/contract-wrappers": "^13.7.0",
         "@0x/json-schemas": "^5.0.8",
         "@0x/utils": "^5.5.0",

packages/order-utils/src/constants.ts

@@ -1,3 +1,4 @@
+import { getContractAddressesForChainOrThrow } from '@0x/contract-addresses';
 import { BigNumber, NULL_ADDRESS, NULL_BYTES } from '@0x/utils';
 import { MethodAbi } from 'ethereum-types';
 
@@ -150,6 +151,27 @@ export const constants = {
             { name: 'transactionSignature', type: 'bytes' },
         ],
     },
+    MAINNET_EXCHANGE_PROXY_DOMAIN: {
+        name: 'ZeroEx',
+        version: '1.0.0',
+        chainId: 1,
+        verifyingContract: getContractAddressesForChainOrThrow(1).exchangeProxy,
+    },
+    EXCHANGE_PROXY_MTX_SCEHMA: {
+        name: 'MetaTransactionData',
+        parameters: [
+            { name: 'signer', type: 'address' },
+            { name: 'sender', type: 'address' },
+            { name: 'minGasPrice', type: 'uint256' },
+            { name: 'maxGasPrice', type: 'uint256' },
+            { name: 'expirationTimeSeconds', type: 'uint256' },
+            { name: 'salt', type: 'uint256' },
+            { name: 'callData', type: 'bytes' },
+            { name: 'value', type: 'uint256' },
+            { name: 'feeToken', type: 'address' },
+            { name: 'feeAmount', type: 'uint256' },
+        ],
+    },
     ERC20_METHOD_ABI,
     ERC721_METHOD_ABI,
     MULTI_ASSET_METHOD_ABI,

packages/order-utils/src/eip712_utils.ts

@@ -5,11 +5,12 @@ import {
     EIP712Object,
     EIP712TypedData,
     EIP712Types,
+    ExchangeProxyMetaTransaction,
     Order,
     SignedZeroExTransaction,
     ZeroExTransaction,
 } from '@0x/types';
-import { hexUtils, signTypedDataUtils } from '@0x/utils';
+import { BigNumber, hexUtils, signTypedDataUtils } from '@0x/utils';
 import * as _ from 'lodash';
 
 import { constants } from './constants';
@@ -131,4 +132,21 @@ export const eip712Utils = {
         );
         return typedData;
     },
+    createExchangeProxyMetaTransactionTypedData(mtx: ExchangeProxyMetaTransaction): EIP712TypedData {
+        return eip712Utils.createTypedData(
+            constants.EXCHANGE_PROXY_MTX_SCEHMA.name,
+            {
+                MetaTransactionData: constants.EXCHANGE_PROXY_MTX_SCEHMA.parameters,
+            },
+            _.mapValues(
+                _.omit(mtx, 'domain'),
+                // tslint:disable-next-line: custom-no-magic-numbers
+                v => (BigNumber.isBigNumber(v) ? v.toString(10) : v),
+            ) as EIP712Object,
+            {
+                ...constants.MAINNET_EXCHANGE_PROXY_DOMAIN,
+                ...mtx.domain,
+            },
+        );
+    },
 };

packages/order-utils/src/hash_utils.ts

@@ -0,0 +1,29 @@
+import { ExchangeProxyMetaTransaction, Order, ZeroExTransaction } from '@0x/types';
+import { hexUtils, signTypedDataUtils } from '@0x/utils';
+
+import { eip712Utils } from './eip712_utils';
+import { orderHashUtils } from './order_hash_utils';
+import { transactionHashUtils } from './transaction_hash_utils';
+
+/**
+ * Compute the EIP712 hash of an order.
+ */
+export function getOrderHash(order: Order): string {
+    return orderHashUtils.getOrderHash(order);
+}
+
+/**
+ * Compute the EIP712 hash of an Exchange meta-transaction.
+ */
+export function getExchangeMetaTransactionHash(tx: ZeroExTransaction): string {
+    return transactionHashUtils.getTransactionHash(tx);
+}
+
+/**
+ * Compute the EIP712 hash of an Exchange Proxy meta-transaction.
+ */
+export function getExchangeProxyMetaTransactionHash(mtx: ExchangeProxyMetaTransaction): string {
+    return hexUtils.toHex(
+        signTypedDataUtils.generateTypedDataHash(eip712Utils.createExchangeProxyMetaTransactionTypedData(mtx)),
+    );
+}

packages/order-utils/src/index.ts

@@ -49,6 +49,8 @@ export {
     ZeroExTransaction,
     SignedZeroExTransaction,
     ValidatorSignature,
+    ExchangeProxyMetaTransaction,
+    SignedExchangeProxyMetaTransaction,
 } from '@0x/types';
 
 export {
@@ -77,6 +79,8 @@ export {
     decodeAffiliateFeeTransformerData,
 } from './transformer_data_encoders';
 
+export { getOrderHash, getExchangeMetaTransactionHash, getExchangeProxyMetaTransactionHash } from './hash_utils';
+
 import { constants } from './constants';
 export const NULL_ADDRESS = constants.NULL_ADDRESS;
 export const NULL_BYTES = constants.NULL_BYTES;

packages/order-utils/src/signature_utils.ts

@@ -1,14 +1,16 @@
 import { schemas } from '@0x/json-schemas';
 import {
     ECSignature,
+    ExchangeProxyMetaTransaction,
     Order,
     SignatureType,
+    SignedExchangeProxyMetaTransaction,
     SignedOrder,
     SignedZeroExTransaction,
     ValidatorSignature,
     ZeroExTransaction,
 } from '@0x/types';
-import { providerUtils } from '@0x/utils';
+import { hexUtils, providerUtils } from '@0x/utils';
 import { Web3Wrapper } from '@0x/web3-wrapper';
 import { SupportedProvider } from 'ethereum-types';
 import * as ethUtil from 'ethereumjs-util';
@@ -16,6 +18,7 @@ import * as _ from 'lodash';
 
 import { assert } from './assert';
 import { eip712Utils } from './eip712_utils';
+import { getExchangeProxyMetaTransactionHash } from './hash_utils';
 import { orderHashUtils } from './order_hash_utils';
 import { transactionHashUtils } from './transaction_hash_utils';
 import { TypedDataError } from './types';
@@ -187,6 +190,96 @@ export const signatureUtils = {
             }
         }
     },
+    /**
+     * Signs an Exchange Proxy meta-transaction and returns a SignedExchangeProxyMetaTransaction.
+     * First `eth_signTypedData` is requested then a fallback to `eth_sign` if not
+     * available on the supplied provider.
+     * @param   supportedProvider  Web3 provider to use for all JSON RPC requests
+     * @param   transaction The ExchangeProxyMetaTransaction to sign.
+     * @param   signerAddress The hex encoded Ethereum address you wish to sign it with. This address
+     *          must be available via the supplied Provider.
+     * @return  A SignedExchangeProxyMetaTransaction containing the order and
+     *          elliptic curve signature with Signature Type.
+     */
+    async ecSignExchangeProxyMetaTransactionAsync(
+        supportedProvider: SupportedProvider,
+        transaction: ExchangeProxyMetaTransaction,
+        signerAddress: string,
+    ): Promise<SignedExchangeProxyMetaTransaction> {
+        assert.doesConformToSchema('transaction', transaction, schemas.zeroExTransactionSchema, [schemas.hexSchema]);
+        try {
+            const signedTransaction = await signatureUtils.ecSignTypedDataExchangeProxyMetaTransactionAsync(
+                supportedProvider,
+                transaction,
+                signerAddress,
+            );
+            return signedTransaction;
+        } catch (err) {
+            // HACK: We are unable to handle specific errors thrown since provider is not an object
+            //       under our control. It could be Metamask Web3, Ethers, or any general RPC provider.
+            //       We check for a user denying the signature request in a way that supports Metamask and
+            //       Coinbase Wallet. Unfortunately for signers with a different error message,
+            //       they will receive two signature requests.
+            if (err.message.includes('User denied message signature')) {
+                throw err;
+            }
+            const transactionHash = getExchangeProxyMetaTransactionHash(transaction);
+            const signatureHex = await signatureUtils.ecSignHashAsync(
+                supportedProvider,
+                transactionHash,
+                signerAddress,
+            );
+            const signedTransaction = {
+                ...transaction,
+                signature: signatureHex,
+            };
+            return signedTransaction;
+        }
+    },
+    /**
+     * Signs an Exchange Proxy meta-transaction using `eth_signTypedData` and
+     * returns a SignedZeroExTransaction.
+     * @param   supportedProvider      Web3 provider to use for all JSON RPC requests
+     * @param   transaction            The Exchange Proxy transaction to sign.
+     * @param   signerAddress          The hex encoded Ethereum address you wish
+     *          to sign it with. This address must be available via the supplied Provider.
+     * @return  A SignedExchangeProxyMetaTransaction containing the
+     *          ExchangeProxyMetaTransaction and elliptic curve signature with Signature Type.
+     */
+    async ecSignTypedDataExchangeProxyMetaTransactionAsync(
+        supportedProvider: SupportedProvider,
+        transaction: ExchangeProxyMetaTransaction,
+        signerAddress: string,
+    ): Promise<SignedExchangeProxyMetaTransaction> {
+        const provider = providerUtils.standardizeOrThrow(supportedProvider);
+        assert.isETHAddressHex('signerAddress', signerAddress);
+        assert.doesConformToSchema('transaction', transaction, schemas.zeroExTransactionSchema, [schemas.hexSchema]);
+        const web3Wrapper = new Web3Wrapper(provider);
+        await assert.isSenderAddressAsync('signerAddress', signerAddress, web3Wrapper);
+        const normalizedSignerAddress = signerAddress.toLowerCase();
+        const typedData = eip712Utils.createExchangeProxyMetaTransactionTypedData(transaction);
+        try {
+            const signature = await web3Wrapper.signTypedDataAsync(normalizedSignerAddress, typedData);
+            const ecSignatureRSV = parseSignatureHexAsRSV(signature);
+            const signatureHex = hexUtils.concat(
+                ecSignatureRSV.v,
+                ecSignatureRSV.r,
+                ecSignatureRSV.s,
+                SignatureType.EIP712,
+            );
+            return {
+                ...transaction,
+                signature: signatureHex,
+            };
+        } catch (err) {
+            // Detect if Metamask to transition users to the MetamaskSubprovider
+            if ((provider as any).isMetaMask) {
+                throw new Error(TypedDataError.InvalidMetamaskSigner);
+            } else {
+                throw err;
+            }
+        }
+    },
     /**
      * Signs a hash using `eth_sign` and returns its elliptic curve signature and signature type.
      * @param   supportedProvider      Web3 provider to use for all JSON RPC requests
@@ -245,12 +338,7 @@ export const signatureUtils = {
      * @return Hex encoded string of signature (v,r,s) with Signature Type
      */
     convertECSignatureToSignatureHex(ecSignature: ECSignature): string {
-        const signatureBuffer = Buffer.concat([
+        const signatureHex = hexUtils.concat(ecSignature.v, ecSignature.r, ecSignature.s);
-            ethUtil.toBuffer(ecSignature.v),
-            ethUtil.toBuffer(ecSignature.r),
-            ethUtil.toBuffer(ecSignature.s),
-        ]);
-        const signatureHex = `0x${signatureBuffer.toString('hex')}`;
         const signatureWithType = signatureUtils.convertToSignatureWithType(signatureHex, SignatureType.EthSign);
         return signatureWithType;
     },

packages/types/CHANGELOG.json

@@ -1,4 +1,13 @@
 [
+    {
+        "version": "3.2.0",
+        "changes": [
+            {
+                "note": "Add `ExchangeProxyMetaTransaction` and `SignedExchangeProxyMetaTransaction`",
+                "pr": 2610
+            }
+        ]
+    },
     {
         "timestamp": 1592969527,
         "version": "3.1.3",

packages/types/src/index.ts

@@ -54,6 +54,30 @@ export interface SignedZeroExTransaction extends ZeroExTransaction {
     signature: string;
 }
 
+/**
+ * Exchange Proxy meta transaction struct.
+ */
+export interface ExchangeProxyMetaTransaction {
+    signer: string;
+    sender: string;
+    minGasPrice: BigNumber;
+    maxGasPrice: BigNumber;
+    expirationTimeSeconds: BigNumber;
+    salt: BigNumber;
+    callData: string;
+    value: BigNumber;
+    feeToken: string;
+    feeAmount: BigNumber;
+    domain: EIP712DomainWithDefaultSchema;
+}
+
+/**
+ * `ExchangeProxyMetaTransaction` with `signature` field.
+ */
+export interface SignedExchangeProxyMetaTransaction extends ExchangeProxyMetaTransaction {
+    signature: string;
+}
+
 /**
  * Elliptic Curve signature
  */

packages/utils/CHANGELOG.json

@@ -29,6 +29,10 @@
             {
                 "note": "Update `ZeroExRevertErrors`",
                 "pr": 2597
+            },
+            {
+                "note": "Add more revert errors to `ZeroExRevertErrors`",
+                "pr": 2610
             }
         ],
         "timestamp": 1592969527

packages/utils/src/index.ts

@@ -52,4 +52,6 @@ export const ZeroExRevertErrors = {
     Spender: require('./revert_errors/zero-ex/spender_revert_errors'),
     TransformERC20: require('./revert_errors/zero-ex/transform_erc20_revert_errors'),
     Wallet: require('./revert_errors/zero-ex/wallet_revert_errors'),
+    MetaTransactions: require('./revert_errors/zero-ex/meta_transaction_revert_errors'),
+    SignatureValidator: require('./revert_errors/zero-ex/signature_validator_revert_errors'),
 };

packages/utils/src/revert_errors/zero-ex/meta_transaction_revert_errors.ts

@@ -0,0 +1,144 @@
+import { RevertError } from '../../revert_error';
+import { Numberish } from '../../types';
+
+// tslint:disable:max-classes-per-file
+export class InvalidMetaTransactionsArrayLengthsError extends RevertError {
+    constructor(mtxCount?: Numberish, signatureCount?: Numberish) {
+        super(
+            'InvalidMetaTransactionsArrayLengthsError',
+            'InvalidMetaTransactionsArrayLengthsError(uint256 mtxCount, uint256 signatureCount)',
+            {
+                mtxCount,
+                signatureCount,
+            },
+        );
+    }
+}
+
+export class MetaTransactionAlreadyExecutedError extends RevertError {
+    constructor(mtxHash?: string, executedBlockNumber?: Numberish) {
+        super(
+            'MetaTransactionAlreadyExecutedError',
+            'MetaTransactionAlreadyExecutedError(bytes32 mtxHash, uint256 executedBlockNumber)',
+            {
+                mtxHash,
+                executedBlockNumber,
+            },
+        );
+    }
+}
+
+export class MetaTransactionUnsupportedFunctionError extends RevertError {
+    constructor(mtxHash?: string, selector?: string) {
+        super(
+            'MetaTransactionUnsupportedFunctionError',
+            'MetaTransactionUnsupportedFunctionError(bytes32 mtxHash, bytes4 selector)',
+            {
+                mtxHash,
+                selector,
+            },
+        );
+    }
+}
+
+export class MetaTransactionWrongSenderError extends RevertError {
+    constructor(mtxHash?: string, sender?: string, expectedSender?: string) {
+        super(
+            'MetaTransactionWrongSenderError',
+            'MetaTransactionWrongSenderError(bytes32 mtxHash, address sender, address expectedSender)',
+            {
+                mtxHash,
+                sender,
+                expectedSender,
+            },
+        );
+    }
+}
+
+export class MetaTransactionExpiredError extends RevertError {
+    constructor(mtxHash?: string, time?: Numberish, expirationTime?: Numberish) {
+        super(
+            'MetaTransactionExpiredError',
+            'MetaTransactionExpiredError(bytes32 mtxHash, uint256 time, uint256 expirationTime)',
+            {
+                mtxHash,
+                time,
+                expirationTime,
+            },
+        );
+    }
+}
+
+export class MetaTransactionGasPriceError extends RevertError {
+    constructor(mtxHash?: string, gasPrice?: Numberish, minGasPrice?: Numberish, maxGasPrice?: Numberish) {
+        super(
+            'MetaTransactionGasPriceError',
+            'MetaTransactionGasPriceError(bytes32 mtxHash, uint256 gasPrice, uint256 minGasPrice, uint256 maxGasPrice)',
+            {
+                mtxHash,
+                gasPrice,
+                minGasPrice,
+                maxGasPrice,
+            },
+        );
+    }
+}
+
+export class MetaTransactionInsufficientEthError extends RevertError {
+    constructor(mtxHash?: string, ethBalance?: Numberish, ethRequired?: Numberish) {
+        super(
+            'MetaTransactionInsufficientEthError',
+            'MetaTransactionInsufficientEthError(bytes32 mtxHash, uint256 ethBalance, uint256 ethRequired)',
+            {
+                mtxHash,
+                ethBalance,
+                ethRequired,
+            },
+        );
+    }
+}
+
+export class MetaTransactionInvalidSignatureError extends RevertError {
+    constructor(mtxHash?: string, signature?: string, errData?: string) {
+        super(
+            'MetaTransactionInvalidSignatureError',
+            'MetaTransactionInvalidSignatureError(bytes32 mtxHash, bytes signature, bytes errData)',
+            {
+                mtxHash,
+                signature,
+                errData,
+            },
+        );
+    }
+}
+
+export class MetaTransactionCallFailedError extends RevertError {
+    constructor(mtxHash?: string, callData?: string, returnData?: string) {
+        super(
+            'MetaTransactionCallFailedError',
+            'MetaTransactionCallFailedError(bytes32 mtxHash, bytes callData, bytes returnData)',
+            {
+                mtxHash,
+                callData,
+                returnData,
+            },
+        );
+    }
+}
+
+const types = [
+    InvalidMetaTransactionsArrayLengthsError,
+    MetaTransactionAlreadyExecutedError,
+    MetaTransactionUnsupportedFunctionError,
+    MetaTransactionWrongSenderError,
+    MetaTransactionExpiredError,
+    MetaTransactionGasPriceError,
+    MetaTransactionInsufficientEthError,
+    MetaTransactionInvalidSignatureError,
+    MetaTransactionCallFailedError,
+];
+
+// Register the types we've defined.
+for (const type of types) {
+    RevertError.registerType(type);
+}

packages/utils/src/revert_errors/zero-ex/signature_validator_revert_errors.ts

@@ -0,0 +1,33 @@
+import { RevertError } from '../../revert_error';
+
+// tslint:disable:max-classes-per-file
+
+export enum SignatureValidationErrorCodes {
+    AlwaysInvalid = 0,
+    InvalidLength = 1,
+    Unsupported = 2,
+    Illegal = 3,
+    WrongSigner = 4,
+}
+
+export class SignatureValidationError extends RevertError {
+    constructor(code?: SignatureValidationErrorCodes, hash?: string, signerAddress?: string, signature?: string) {
+        super(
+            'SignatureValidationError',
+            'SignatureValidationError(uint8 code, bytes32 hash, address signerAddress, bytes signature)',
+            {
+                code,
+                hash,
+                signerAddress,
+                signature,
+            },
+        );
+    }
+}
+
+const types = [SignatureValidationError];
+
+// Register the types we've defined.
+for (const type of types) {
+    RevertError.registerType(type);
+}