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path: root/packages/migrations/artifacts/2.0.0/MixinSignatureValidator.json
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{
    "schemaVersion": "2.0.0",
    "contractName": "MixinSignatureValidator",
    "compilerOutput": {
        "abi": [
            {
                "constant": false,
                "inputs": [
                    {
                        "name": "hash",
                        "type": "bytes32"
                    },
                    {
                        "name": "signer",
                        "type": "address"
                    },
                    {
                        "name": "signature",
                        "type": "bytes"
                    }
                ],
                "name": "preSign",
                "outputs": [],
                "payable": false,
                "stateMutability": "nonpayable",
                "type": "function"
            },
            {
                "constant": false,
                "inputs": [
                    {
                        "name": "validator",
                        "type": "address"
                    },
                    {
                        "name": "approval",
                        "type": "bool"
                    }
                ],
                "name": "setSignatureValidatorApproval",
                "outputs": [],
                "payable": false,
                "stateMutability": "nonpayable",
                "type": "function"
            },
            {
                "constant": true,
                "inputs": [
                    {
                        "name": "",
                        "type": "address"
                    },
                    {
                        "name": "",
                        "type": "address"
                    }
                ],
                "name": "allowedValidators",
                "outputs": [
                    {
                        "name": "",
                        "type": "bool"
                    }
                ],
                "payable": false,
                "stateMutability": "view",
                "type": "function"
            },
            {
                "constant": true,
                "inputs": [
                    {
                        "name": "",
                        "type": "bytes32"
                    },
                    {
                        "name": "",
                        "type": "address"
                    }
                ],
                "name": "preSigned",
                "outputs": [
                    {
                        "name": "",
                        "type": "bool"
                    }
                ],
                "payable": false,
                "stateMutability": "view",
                "type": "function"
            },
            {
                "constant": true,
                "inputs": [
                    {
                        "name": "hash",
                        "type": "bytes32"
                    },
                    {
                        "name": "signer",
                        "type": "address"
                    },
                    {
                        "name": "signature",
                        "type": "bytes"
                    }
                ],
                "name": "isValidSignature",
                "outputs": [
                    {
                        "name": "isValid",
                        "type": "bool"
                    }
                ],
                "payable": false,
                "stateMutability": "view",
                "type": "function"
            },
            {
                "constant": false,
                "inputs": [
                    {
                        "name": "salt",
                        "type": "uint256"
                    },
                    {
                        "name": "signer",
                        "type": "address"
                    },
                    {
                        "name": "data",
                        "type": "bytes"
                    },
                    {
                        "name": "signature",
                        "type": "bytes"
                    }
                ],
                "name": "executeTransaction",
                "outputs": [],
                "payable": false,
                "stateMutability": "nonpayable",
                "type": "function"
            }
        ],
        "evm": {
            "bytecode": {
                "linkReferences": {},
                "object": "0x",
                "opcodes": "",
                "sourceMap": ""
            },
            "deployedBytecode": {
                "linkReferences": {},
                "object": "0x",
                "opcodes": "",
                "sourceMap": ""
            }
        }
    },
    "sources": {
        "current/protocol/Exchange/MixinSignatureValidator.sol": {
            "id": 0
        },
        "current/protocol/Exchange/interfaces/ISignatureValidator.sol": {
            "id": 1
        },
        "current/protocol/Exchange/interfaces/ITransactions.sol": {
            "id": 2
        },
        "current/protocol/Exchange/interfaces/IValidator.sol": {
            "id": 3
        },
        "current/protocol/Exchange/interfaces/IWallet.sol": {
            "id": 4
        },
        "current/protocol/Exchange/libs/LibExchangeErrors.sol": {
            "id": 5
        },
        "current/protocol/Exchange/mixins/MTransactions.sol": {
            "id": 6
        },
        "current/utils/LibBytes/LibBytes.sol": {
            "id": 7
        },
        "current/utils/LibMem/LibMem.sol": {
            "id": 8
        }
    },
    "sourceCodes": {
        "current/protocol/Exchange/MixinSignatureValidator.sol": "/*\n\n  Copyright 2018 ZeroEx Intl.\n\n  Licensed under the Apache License, Version 2.0 (the \"License\");\n  you may not use this file except in compliance with the License.\n  You may obtain a copy of the License at\n\n    http://www.apache.org/licenses/LICENSE-2.0\n\n  Unless required by applicable law or agreed to in writing, software\n  distributed under the License is distributed on an \"AS IS\" BASIS,\n  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n  See the License for the specific language governing permissions and\n  limitations under the License.\n\n*/\n\npragma solidity ^0.4.24;\n\nimport \"../../utils/LibBytes/LibBytes.sol\";\nimport \"./libs/LibExchangeErrors.sol\";\nimport \"./interfaces/ISignatureValidator.sol\";\nimport \"./mixins/MTransactions.sol\";\nimport \"./interfaces/IWallet.sol\";\nimport \"./interfaces/IValidator.sol\";\n\ncontract MixinSignatureValidator is\n    LibBytes,\n    LibExchangeErrors,\n    ISignatureValidator,\n    MTransactions\n{\n    // Personal message headers\n    string constant ETH_PERSONAL_MESSAGE = \"\\x19Ethereum Signed Message:\\n32\";\n    string constant TREZOR_PERSONAL_MESSAGE = \"\\x19Ethereum Signed Message:\\n\\x41\";\n\n    // Allowed signature types.\n    enum SignatureType {\n        Illegal,    // 0x00, default value\n        Invalid,    // 0x01\n        EIP712,     // 0x02\n        EthSign,    // 0x03\n        Caller,     // 0x04\n        Wallet,     // 0x05\n        Validator,  // 0x06\n        PreSigned,  // 0x07\n        Trezor      // 0x08\n    }\n\n    // Mapping of hash => signer => signed\n    mapping (bytes32 => mapping (address => bool)) public preSigned;\n\n    // Mapping of signer => validator => approved\n    mapping (address => mapping (address => bool)) public allowedValidators;\n\n    /// @dev Approves a hash on-chain using any valid signature type.\n    ///      After presigning a hash, the preSign signature type will become valid for that hash and signer.\n    /// @param signer Address that should have signed the given hash.\n    /// @param signature Proof that the hash has been signed by signer.\n    function preSign(\n        bytes32 hash,\n        address signer,\n        bytes signature\n    )\n        external\n    {\n        require(\n            isValidSignature(hash, signer, signature),\n            INVALID_SIGNATURE\n        );\n        preSigned[hash][signer] = true;\n    }\n\n    /// @dev Approves/unnapproves a Validator contract to verify signatures on signer's behalf.\n    /// @param validator Address of Validator contract.\n    /// @param approval Approval or disapproval of  Validator contract.\n    function setSignatureValidatorApproval(\n        address validator,\n        bool approval\n    )\n        external\n    {\n        address signer = getCurrentContextAddress();\n        allowedValidators[signer][validator] = approval;\n    }\n\n    /// @dev Verifies that a hash has been signed by the given signer.\n    /// @param hash Any 32 byte hash.\n    /// @param signer Address that should have signed the given hash.\n    /// @param signature Proof that the hash has been signed by signer.\n    /// @return True if the address recovered from the provided signature matches the input signer address.\n    function isValidSignature(\n        bytes32 hash,\n        address signer,\n        bytes memory signature\n    )\n        public\n        view\n        returns (bool isValid)\n    {\n        // TODO: Domain separation: make hash depend on role. (Taker sig should not be valid as maker sig, etc.)\n        require(\n            signature.length > 0,\n            LENGTH_GREATER_THAN_0_REQUIRED\n        );\n\n        // Pop last byte off of signature byte array.\n        SignatureType signatureType = SignatureType(uint8(popLastByte(signature)));\n\n        // Variables are not scoped in Solidity.\n        uint8 v;\n        bytes32 r;\n        bytes32 s;\n        address recovered;\n\n        // Always illegal signature.\n        // This is always an implicit option since a signer can create a\n        // signature array with invalid type or length. We may as well make\n        // it an explicit option. This aids testing and analysis. It is\n        // also the initialization value for the enum type.\n        if (signatureType == SignatureType.Illegal) {\n            revert(SIGNATURE_ILLEGAL);\n\n        // Always invalid signature.\n        // Like Illegal, this is always implicitly available and therefore\n        // offered explicitly. It can be implicitly created by providing\n        // a correctly formatted but incorrect signature.\n        } else if (signatureType == SignatureType.Invalid) {\n            require(\n                signature.length == 0,\n                LENGTH_0_REQUIRED\n            );\n            isValid = false;\n            return isValid;\n\n        // Signature using EIP712\n        } else if (signatureType == SignatureType.EIP712) {\n            require(\n                signature.length == 65,\n                LENGTH_65_REQUIRED\n            );\n            v = uint8(signature[0]);\n            r = readBytes32(signature, 1);\n            s = readBytes32(signature, 33);\n            recovered = ecrecover(hash, v, r, s);\n            isValid = signer == recovered;\n            return isValid;\n\n        // Signed using web3.eth_sign\n        } else if (signatureType == SignatureType.EthSign) {\n            require(\n                signature.length == 65,\n                LENGTH_65_REQUIRED\n            );\n            v = uint8(signature[0]);\n            r = readBytes32(signature, 1);\n            s = readBytes32(signature, 33);\n            recovered = ecrecover(\n                keccak256(abi.encodePacked(ETH_PERSONAL_MESSAGE, hash)),\n                v,\n                r,\n                s\n            );\n            isValid = signer == recovered;\n            return isValid;\n\n        // Implicitly signed by caller.\n        // The signer has initiated the call. In the case of non-contract\n        // accounts it means the transaction itself was signed.\n        // Example: let's say for a particular operation three signatures\n        // A, B and C are required. To submit the transaction, A and B can\n        // give a signature to C, who can then submit the transaction using\n        // `Caller` for his own signature. Or A and C can sign and B can\n        // submit using `Caller`. Having `Caller` allows this flexibility.\n        } else if (signatureType == SignatureType.Caller) {\n            require(\n                signature.length == 0,\n                LENGTH_0_REQUIRED\n            );\n            isValid = signer == msg.sender;\n            return isValid;\n\n        // Signature verified by wallet contract.\n        // If used with an order, the maker of the order is the wallet contract.\n        } else if (signatureType == SignatureType.Wallet) {\n            isValid = IWallet(signer).isValidSignature(hash, signature);\n            return isValid;\n\n        // Signature verified by validator contract.\n        // If used with an order, the maker of the order can still be an EOA.\n        // A signature using this type should be encoded as:\n        // | Offset   | Length | Contents                        |\n        // | 0x00     | x      | Signature to validate           |\n        // | 0x00 + x | 20     | Address of validator contract   |\n        // | 0x14 + x | 1      | Signature type is always \"\\x06\" |\n        } else if (signatureType == SignatureType.Validator) {\n            // Pop last 20 bytes off of signature byte array.\n            address validator = popLast20Bytes(signature);\n            // Ensure signer has approved validator.\n            if (!allowedValidators[signer][validator]) {\n                return false;\n            }\n            isValid = IValidator(validator).isValidSignature(\n                hash,\n                signer,\n                signature\n            );\n            return isValid;\n\n        // Signer signed hash previously using the preSign function.\n        } else if (signatureType == SignatureType.PreSigned) {\n            isValid = preSigned[hash][signer];\n            return isValid;\n\n        // Signature from Trezor hardware wallet.\n        // It differs from web3.eth_sign in the encoding of message length\n        // (Bitcoin varint encoding vs ascii-decimal, the latter is not\n        // self-terminating which leads to ambiguities).\n        // See also:\n        // https://en.bitcoin.it/wiki/Protocol_documentation#Variable_length_integer\n        // https://github.com/trezor/trezor-mcu/blob/master/firmware/ethereum.c#L602\n        // https://github.com/trezor/trezor-mcu/blob/master/firmware/crypto.c#L36\n        } else if (signatureType == SignatureType.Trezor) {\n            require(\n                signature.length == 65,\n                LENGTH_65_REQUIRED\n            );\n            v = uint8(signature[0]);\n            r = readBytes32(signature, 1);\n            s = readBytes32(signature, 33);\n            recovered = ecrecover(\n                keccak256(abi.encodePacked(TREZOR_PERSONAL_MESSAGE, hash)),\n                v,\n                r,\n                s\n            );\n            isValid = signer == recovered;\n            return isValid;\n\n        // Signer signed hash previously using the preSign function\n        } else if (signatureType == SignatureType.PreSigned) {\n            isValid = preSigned[hash][signer];\n            return isValid;\n        }\n\n        // Anything else is illegal (We do not return false because\n        // the signature may actually be valid, just not in a format\n        // that we currently support. In this case returning false\n        // may lead the caller to incorrectly believe that the\n        // signature was invalid.)\n        revert(SIGNATURE_UNSUPPORTED);\n    }\n}\n",
        "current/protocol/Exchange/interfaces/ISignatureValidator.sol": "/*\n\n  Copyright 2018 ZeroEx Intl.\n\n  Licensed under the Apache License, Version 2.0 (the \"License\");\n  you may not use this file except in compliance with the License.\n  You may obtain a copy of the License at\n\n    http://www.apache.org/licenses/LICENSE-2.0\n\n  Unless required by applicable law or agreed to in writing, software\n  distributed under the License is distributed on an \"AS IS\" BASIS,\n  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n  See the License for the specific language governing permissions and\n  limitations under the License.\n\n*/\n\npragma solidity ^0.4.24;\n\ncontract ISignatureValidator {\n\n    /// @dev Approves a hash on-chain using any valid signature type.\n    ///      After presigning a hash, the preSign signature type will become valid for that hash and signer.\n    /// @param signer Address that should have signed the given hash.\n    /// @param signature Proof that the hash has been signed by signer.\n    function preSign(\n        bytes32 hash,\n        address signer,\n        bytes signature\n    )\n        external;\n    \n    /// @dev Approves/unnapproves a Validator contract to verify signatures on signer's behalf.\n    /// @param validator Address of Validator contract.\n    /// @param approval Approval or disapproval of  Validator contract.\n    function setSignatureValidatorApproval(\n        address validator,\n        bool approval\n    )\n        external;\n\n    /// @dev Verifies that a signature is valid.\n    /// @param hash Message hash that is signed.\n    /// @param signer Address of signer.\n    /// @param signature Proof of signing.\n    /// @return Validity of order signature.\n    function isValidSignature(\n        bytes32 hash,\n        address signer,\n        bytes memory signature\n    )\n        public\n        view\n        returns (bool isValid);\n}\n",
        "current/protocol/Exchange/interfaces/ITransactions.sol": "/*\n\n  Copyright 2018 ZeroEx Intl.\n\n  Licensed under the Apache License, Version 2.0 (the \"License\");\n  you may not use this file except in compliance with the License.\n  You may obtain a copy of the License at\n\n    http://www.apache.org/licenses/LICENSE-2.0\n\n  Unless required by applicable law or agreed to in writing, software\n  distributed under the License is distributed on an \"AS IS\" BASIS,\n  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n  See the License for the specific language governing permissions and\n  limitations under the License.\n\n*/\npragma solidity ^0.4.24;\n\ncontract ITransactions {\n\n    /// @dev Executes an exchange method call in the context of signer.\n    /// @param salt Arbitrary number to ensure uniqueness of transaction hash.\n    /// @param signer Address of transaction signer.\n    /// @param data AbiV2 encoded calldata.\n    /// @param signature Proof of signer transaction by signer.\n    function executeTransaction(\n        uint256 salt,\n        address signer,\n        bytes data,\n        bytes signature\n    )\n        external;\n}\n",
        "current/protocol/Exchange/interfaces/IValidator.sol": "/*\n\n  Copyright 2018 ZeroEx Intl.\n\n  Licensed under the Apache License, Version 2.0 (the \"License\");\n  you may not use this file except in compliance with the License.\n  You may obtain a copy of the License at\n\n    http://www.apache.org/licenses/LICENSE-2.0\n\n  Unless required by applicable law or agreed to in writing, software\n  distributed under the License is distributed on an \"AS IS\" BASIS,\n  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n  See the License for the specific language governing permissions and\n  limitations under the License.\n\n*/\n\npragma solidity ^0.4.23;\n\ncontract IValidator {\n\n    /// @dev Verifies that a signature is valid.\n    /// @param hash Message hash that is signed.\n    /// @param signer Address that should have signed the given hash.\n    /// @param signature Proof of signing.\n    /// @return Validity of order signature.\n    function isValidSignature(\n        bytes32 hash,\n        address signer,\n        bytes signature\n    )\n        external\n        view\n        returns (bool isValid);\n}\n",
        "current/protocol/Exchange/interfaces/IWallet.sol": "/*\n\n  Copyright 2018 ZeroEx Intl.\n\n  Licensed under the Apache License, Version 2.0 (the \"License\");\n  you may not use this file except in compliance with the License.\n  You may obtain a copy of the License at\n\n    http://www.apache.org/licenses/LICENSE-2.0\n\n  Unless required by applicable law or agreed to in writing, software\n  distributed under the License is distributed on an \"AS IS\" BASIS,\n  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n  See the License for the specific language governing permissions and\n  limitations under the License.\n\n*/\n\npragma solidity ^0.4.24;\n\ncontract IWallet {\n\n    /// @dev Verifies that a signature is valid.\n    /// @param hash Message hash that is signed.\n    /// @param signature Proof of signing.\n    /// @return Validity of order signature.\n    function isValidSignature(\n        bytes32 hash,\n        bytes signature\n    )\n        external\n        view\n        returns (bool isValid);\n}\n",
        "current/protocol/Exchange/libs/LibExchangeErrors.sol": "/*\n\n  Copyright 2018 ZeroEx Intl.\n\n  Licensed under the Apache License, Version 2.0 (the \"License\");\n  you may not use this file except in compliance with the License.\n  You may obtain a copy of the License at\n\n    http://www.apache.org/licenses/LICENSE-2.0\n\n  Unless required by applicable law or agreed to in writing, software\n  distributed under the License is distributed on an \"AS IS\" BASIS,\n  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n  See the License for the specific language governing permissions and\n  limitations under the License.\n\n*/\n\npragma solidity ^0.4.24;\n\ncontract LibExchangeErrors {\n    /// Order validation errors ///\n    string constant ORDER_UNFILLABLE = \"ORDER_UNFILLABLE\";                  // Order cannot be filled.\n    string constant INVALID_MAKER = \"INVALID_MAKER\";                        // Invalid makerAddress.\n    string constant INVALID_TAKER = \"INVALID_TAKER\";                        // Invalid takerAddress.\n    string constant INVALID_SENDER = \"INVALID_SENDER\";                      // Invalid `msg.sender`.\n    string constant INVALID_ORDER_SIGNATURE = \"INVALID_ORDER_SIGNATURE\";    // Signature validation failed. \n    \n    /// fillOrder validation errors ///\n    string constant INVALID_TAKER_AMOUNT = \"INVALID_TAKER_AMOUNT\";          // takerAssetFillAmount cannot equal 0.\n    string constant ROUNDING_ERROR = \"ROUNDING_ERROR\";                      // Rounding error greater than 0.1% of takerAssetFillAmount. \n    \n    /// Signature validation errors ///\n    string constant INVALID_SIGNATURE = \"INVALID_SIGNATURE\";                // Signature validation failed. \n    string constant SIGNATURE_ILLEGAL = \"SIGNATURE_ILLEGAL\";                // Signature type is illegal.\n    string constant SIGNATURE_UNSUPPORTED = \"SIGNATURE_UNSUPPORTED\";        // Signature type unsupported.\n    \n    /// cancelOrdersUptTo errors ///\n    string constant INVALID_NEW_MAKER_EPOCH = \"INVALID_NEW_MAKER_EPOCH\";    // Specified salt must be greater than or equal to existing makerEpoch.\n\n    /// fillOrKillOrder errors ///\n    string constant COMPLETE_FILL_FAILED = \"COMPLETE_FILL_FAILED\";          // Desired takerAssetFillAmount could not be completely filled. \n\n    /// matchOrders errors ///\n    string constant NEGATIVE_SPREAD_REQUIRED = \"NEGATIVE_SPREAD_REQUIRED\";  // Matched orders must have a negative spread.\n\n    /// Transaction errors ///\n    string constant REENTRANCY_ILLEGAL = \"REENTRANCY_ILLEGAL\";              // Recursive reentrancy is not allowed. \n    string constant INVALID_TX_HASH = \"INVALID_TX_HASH\";                    // Transaction has already been executed. \n    string constant INVALID_TX_SIGNATURE = \"INVALID_TX_SIGNATURE\";          // Signature validation failed. \n    string constant FAILED_EXECUTION = \"FAILED_EXECUTION\";                  // Transaction execution failed. \n    \n    /// registerAssetProxy errors ///\n    string constant ASSET_PROXY_MISMATCH = \"ASSET_PROXY_MISMATCH\";          // oldAssetProxy proxy does not match currentAssetProxy. \n    string constant ASSET_PROXY_ID_MISMATCH = \"ASSET_PROXY_ID_MISMATCH\";    // newAssetProxyId does not match given assetProxyId.\n\n    /// Length validation errors ///\n    string constant LENGTH_GREATER_THAN_0_REQUIRED = \"LENGTH_GREATER_THAN_0_REQUIRED\"; // Byte array must have a length greater than 0.\n    string constant LENGTH_0_REQUIRED = \"LENGTH_1_REQUIRED\";                // Byte array must have a length of 1.\n    string constant LENGTH_65_REQUIRED = \"LENGTH_66_REQUIRED\";              // Byte array must have a length of 66.\n}\n",
        "current/protocol/Exchange/mixins/MTransactions.sol": "/*\n\n  Copyright 2018 ZeroEx Intl.\n\n  Licensed under the Apache License, Version 2.0 (the \"License\");\n  you may not use this file except in compliance with the License.\n  You may obtain a copy of the License at\n\n    http://www.apache.org/licenses/LICENSE-2.0\n\n  Unless required by applicable law or agreed to in writing, software\n  distributed under the License is distributed on an \"AS IS\" BASIS,\n  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n  See the License for the specific language governing permissions and\n  limitations under the License.\n\n*/\npragma solidity ^0.4.24;\n\nimport \"../interfaces/ITransactions.sol\";\n\ncontract MTransactions is\n    ITransactions\n{\n\n    /// @dev The current function will be called in the context of this address (either 0x transaction signer or `msg.sender`).\n    ///      If calling a fill function, this address will represent the taker.\n    ///      If calling a cancel function, this address will represent the maker.\n    /// @return Signer of 0x transaction if entry point is `executeTransaction`.\n    ///         `msg.sender` if entry point is any other function.\n    function getCurrentContextAddress()\n        internal\n        view\n        returns (address);\n}\n",
        "current/utils/LibBytes/LibBytes.sol": "/*\n\n  Copyright 2018 ZeroEx Intl.\n\n  Licensed under the Apache License, Version 2.0 (the \"License\");\n  you may not use this file except in compliance with the License.\n  You may obtain a copy of the License at\n\n    http://www.apache.org/licenses/LICENSE-2.0\n\n  Unless required by applicable law or agreed to in writing, software\n  distributed under the License is distributed on an \"AS IS\" BASIS,\n  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n  See the License for the specific language governing permissions and\n  limitations under the License.\n\n*/\n\npragma solidity ^0.4.24;\n\nimport \"../LibMem/LibMem.sol\";\n\ncontract LibBytes is\n    LibMem\n{\n\n    // Revert reasons\n    string constant GREATER_THAN_ZERO_LENGTH_REQUIRED = \"GREATER_THAN_ZERO_LENGTH_REQUIRED\";\n    string constant GREATER_OR_EQUAL_TO_4_LENGTH_REQUIRED = \"GREATER_OR_EQUAL_TO_4_LENGTH_REQUIRED\";\n    string constant GREATER_OR_EQUAL_TO_20_LENGTH_REQUIRED = \"GREATER_OR_EQUAL_TO_20_LENGTH_REQUIRED\";\n    string constant GREATER_OR_EQUAL_TO_32_LENGTH_REQUIRED = \"GREATER_OR_EQUAL_TO_32_LENGTH_REQUIRED\";\n    string constant GREATER_OR_EQUAL_TO_NESTED_BYTES_LENGTH_REQUIRED = \"GREATER_OR_EQUAL_TO_NESTED_BYTES_LENGTH_REQUIRED\";\n    string constant GREATER_OR_EQUAL_TO_SOURCE_BYTES_LENGTH_REQUIRED = \"GREATER_OR_EQUAL_TO_SOURCE_BYTES_LENGTH_REQUIRED\";\n\n    /// @dev Pops the last byte off of a byte array by modifying its length.\n    /// @param b Byte array that will be modified.\n    /// @return The byte that was popped off.\n    function popLastByte(bytes memory b)\n        internal\n        pure\n        returns (bytes1 result)\n    {\n        require(\n            b.length > 0,\n            GREATER_THAN_ZERO_LENGTH_REQUIRED\n        );\n\n        // Store last byte.\n        result = b[b.length - 1];\n\n        assembly {\n            // Decrement length of byte array.\n            let newLen := sub(mload(b), 1)\n            mstore(b, newLen)\n        }\n        return result;\n    }\n\n    /// @dev Pops the last 20 bytes off of a byte array by modifying its length.\n    /// @param b Byte array that will be modified.\n    /// @return The 20 byte address that was popped off.\n    function popLast20Bytes(bytes memory b)\n        internal\n        pure\n        returns (address result)\n    {\n        require(\n            b.length >= 20,\n            GREATER_OR_EQUAL_TO_20_LENGTH_REQUIRED\n        );\n\n        // Store last 20 bytes.\n        result = readAddress(b, b.length - 20);\n\n        assembly {\n            // Subtract 20 from byte array length.\n            let newLen := sub(mload(b), 20)\n            mstore(b, newLen)\n        }\n        return result;\n    }\n\n    /// @dev Reads an address from a position in a byte array.\n    /// @param b Byte array containing an address.\n    /// @param index Index in byte array of address.\n    /// @return address from byte array.\n    function readAddress(\n        bytes memory b,\n        uint256 index\n    )\n        internal\n        pure\n        returns (address result)\n    {\n        require(\n            b.length >= index + 20,  // 20 is length of address\n            GREATER_OR_EQUAL_TO_20_LENGTH_REQUIRED\n        );\n\n        // Add offset to index:\n        // 1. Arrays are prefixed by 32-byte length parameter (add 32 to index)\n        // 2. Account for size difference between address length and 32-byte storage word (subtract 12 from index)\n        index += 20;\n\n        // Read address from array memory\n        assembly {\n            // 1. Add index to address of bytes array\n            // 2. Load 32-byte word from memory\n            // 3. Apply 20-byte mask to obtain address\n            result := and(mload(add(b, index)), 0xffffffffffffffffffffffffffffffffffffffff)\n        }\n        return result;\n    }\n\n    /// @dev Writes an address into a specific position in a byte array.\n    /// @param b Byte array to insert address into.\n    /// @param index Index in byte array of address.\n    /// @param input Address to put into byte array.\n    function writeAddress(\n        bytes memory b,\n        uint256 index,\n        address input\n    )\n        internal\n        pure\n    {\n        require(\n            b.length >= index + 20,  // 20 is length of address\n            GREATER_OR_EQUAL_TO_20_LENGTH_REQUIRED\n        );\n\n        // Add offset to index:\n        // 1. Arrays are prefixed by 32-byte length parameter (add 32 to index)\n        // 2. Account for size difference between address length and 32-byte storage word (subtract 12 from index)\n        index += 20;\n\n        // Store address into array memory\n        assembly {\n            // The address occupies 20 bytes and mstore stores 32 bytes.\n            // First fetch the 32-byte word where we'll be storing the address, then\n            // apply a mask so we have only the bytes in the word that the address will not occupy.\n            // Then combine these bytes with the address and store the 32 bytes back to memory with mstore.\n\n            // 1. Add index to address of bytes array\n            // 2. Load 32-byte word from memory\n            // 3. Apply 12-byte mask to obtain extra bytes occupying word of memory where we'll store the address\n            let neighbors := and(mload(add(b, index)), 0xffffffffffffffffffffffff0000000000000000000000000000000000000000)\n\n            // Store the neighbors and address into memory\n            mstore(add(b, index), xor(input, neighbors))\n        }\n    }\n\n    /// @dev Reads a bytes32 value from a position in a byte array.\n    /// @param b Byte array containing a bytes32 value.\n    /// @param index Index in byte array of bytes32 value.\n    /// @return bytes32 value from byte array.\n    function readBytes32(\n        bytes memory b,\n        uint256 index\n    )\n        internal\n        pure\n        returns (bytes32 result)\n    {\n        require(\n            b.length >= index + 32,\n            GREATER_OR_EQUAL_TO_32_LENGTH_REQUIRED\n        );\n\n        // Arrays are prefixed by a 256 bit length parameter\n        index += 32;\n\n        // Read the bytes32 from array memory\n        assembly {\n            result := mload(add(b, index))\n        }\n        return result;\n    }\n\n    /// @dev Writes a bytes32 into a specific position in a byte array.\n    /// @param b Byte array to insert <input> into.\n    /// @param index Index in byte array of <input>.\n    /// @param input bytes32 to put into byte array.\n    function writeBytes32(\n        bytes memory b,\n        uint256 index,\n        bytes32 input\n    )\n        internal\n        pure\n    {\n        require(\n            b.length >= index + 32,\n            GREATER_OR_EQUAL_TO_32_LENGTH_REQUIRED\n        );\n\n        // Arrays are prefixed by a 256 bit length parameter\n        index += 32;\n\n        // Read the bytes32 from array memory\n        assembly {\n            mstore(add(b, index), input)\n        }\n    }\n\n    /// @dev Reads a uint256 value from a position in a byte array.\n    /// @param b Byte array containing a uint256 value.\n    /// @param index Index in byte array of uint256 value.\n    /// @return uint256 value from byte array.\n    function readUint256(\n        bytes memory b,\n        uint256 index\n    )\n        internal\n        pure\n        returns (uint256 result)\n    {\n        return uint256(readBytes32(b, index));\n    }\n\n    /// @dev Writes a uint256 into a specific position in a byte array.\n    /// @param b Byte array to insert <input> into.\n    /// @param index Index in byte array of <input>.\n    /// @param input uint256 to put into byte array.\n    function writeUint256(\n        bytes memory b,\n        uint256 index,\n        uint256 input\n    )\n        internal\n        pure\n    {\n        writeBytes32(b, index, bytes32(input));\n    }\n\n    /// @dev Reads the first 4 bytes from a byte array of arbitrary length.\n    /// @param b Byte array to read first 4 bytes from.\n    /// @return First 4 bytes of data.\n    function readFirst4(bytes memory b)\n        internal\n        pure\n        returns (bytes4 result)\n    {\n        require(\n            b.length >= 4,\n            GREATER_OR_EQUAL_TO_4_LENGTH_REQUIRED\n        );\n        assembly {\n            result := mload(add(b, 32))\n        }\n        return result;\n    }\n\n    /// @dev Reads nested bytes from a specific position.\n    /// @param b Byte array containing nested bytes.\n    /// @param index Index of nested bytes.\n    /// @return result Nested bytes.\n    function readBytes(\n        bytes memory b,\n        uint256 index\n    )\n        internal\n        pure\n        returns (bytes memory result)\n    {\n        // Read length of nested bytes\n        uint256 nestedBytesLength = readUint256(b, index);\n        index += 32;\n\n        // Assert length of <b> is valid, given\n        // length of nested bytes\n        require(\n            b.length >= index + nestedBytesLength,\n            GREATER_OR_EQUAL_TO_NESTED_BYTES_LENGTH_REQUIRED\n        );\n\n        // Allocate memory and copy value to result\n        result = new bytes(nestedBytesLength);\n        memCopy(\n            getMemAddress(result) + 32, // +32 skips array length\n            getMemAddress(b) + index + 32,\n            nestedBytesLength\n        );\n\n        return result;\n    }\n\n    /// @dev Inserts bytes at a specific position in a byte array.\n    /// @param b Byte array to insert <input> into.\n    /// @param index Index in byte array of <input>.\n    /// @param input bytes to insert.\n    function writeBytes(\n        bytes memory b,\n        uint256 index,\n        bytes memory input\n    )\n        internal\n        pure\n    {\n        // Assert length of <b> is valid, given\n        // length of input\n        require(\n            b.length >= index + 32 /* 32 bytes to store length */ + input.length,\n            GREATER_OR_EQUAL_TO_NESTED_BYTES_LENGTH_REQUIRED\n        );\n\n        // Copy <input> into <b>\n        memCopy(\n            getMemAddress(b) + 32 + index,  // +32 to skip length of <b>\n            getMemAddress(input),           // includes length of <input>\n            input.length + 32               // +32 bytes to store <input> length\n        );\n    }\n\n    /// @dev Tests equality of two byte arrays.\n    /// @param lhs First byte array to compare.\n    /// @param rhs Second byte array to compare.\n    /// @return True if arrays are the same. False otherwise.\n    function areBytesEqual(\n        bytes memory lhs,\n        bytes memory rhs\n    )\n        internal\n        pure\n        returns (bool equal)\n    {\n        assembly {\n            // Get the number of words occupied by <lhs>\n            let lenFullWords := div(add(mload(lhs), 0x1F), 0x20)\n\n            // Add 1 to the number of words, to account for the length field\n            lenFullWords := add(lenFullWords, 0x1)\n\n            // Test equality word-by-word.\n            // Terminates early if there is a mismatch.\n            for {let i := 0} lt(i, lenFullWords) {i := add(i, 1)} {\n                let lhsWord := mload(add(lhs, mul(i, 0x20)))\n                let rhsWord := mload(add(rhs, mul(i, 0x20)))\n                equal := eq(lhsWord, rhsWord)\n                if eq(equal, 0) {\n                    // Break\n                    i := lenFullWords\n                }\n            }\n       }\n\n       return equal;\n    }\n\n    /// @dev Performs a deep copy of a byte array onto another byte array of greater than or equal length.\n    /// @param dest Byte array that will be overwritten with source bytes.\n    /// @param source Byte array to copy onto dest bytes.\n    function deepCopyBytes(\n        bytes memory dest,\n        bytes memory source\n    )\n        internal\n        pure\n    {\n        uint256 sourceLen = source.length;\n        // Dest length must be >= source length, or some bytes would not be copied.\n        require(\n            dest.length >= sourceLen,\n            GREATER_OR_EQUAL_TO_SOURCE_BYTES_LENGTH_REQUIRED\n        );\n        memCopy(\n            getMemAddress(dest) + 32,    // +32 to skip length of <dest>\n            getMemAddress(source) + 32,  // +32 to skip length of <source>\n            sourceLen\n        );\n    }\n}\n",
        "current/utils/LibMem/LibMem.sol": "/*\n\n  Copyright 2018 ZeroEx Intl.\n\n  Licensed under the Apache License, Version 2.0 (the \"License\");\n  you may not use this file except in compliance with the License.\n  You may obtain a copy of the License at\n\n    http://www.apache.org/licenses/LICENSE-2.0\n\n  Unless required by applicable law or agreed to in writing, software\n  distributed under the License is distributed on an \"AS IS\" BASIS,\n  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n  See the License for the specific language governing permissions and\n  limitations under the License.\n\n*/\n\npragma solidity ^0.4.24;\n\ncontract LibMem\n{\n\n    /// @dev Gets the memory address for a byte array.\n    /// @param input Byte array to lookup.\n    /// @return memoryAddress Memory address of byte array.\n    function getMemAddress(bytes memory input)\n        internal\n        pure\n        returns (uint256 memoryAddress)\n    {\n        assembly {\n            memoryAddress := input\n        }\n        return memoryAddress;\n    }\n\n    /// @dev Copies `length` bytes from memory location `source` to `dest`.\n    /// @param dest memory address to copy bytes to.\n    /// @param source memory address to copy bytes from.\n    /// @param length number of bytes to copy.\n    function memCopy(\n        uint256 dest,\n        uint256 source,\n        uint256 length\n    )\n        internal\n        pure\n    {\n        if (length < 32) {\n            // Handle a partial word by reading destination and masking\n            // off the bits we are interested in.\n            // This correctly handles overlap, zero lengths and source == dest\n            assembly {\n                let mask := sub(exp(256, sub(32, length)), 1)\n                let s := and(mload(source), not(mask))\n                let d := and(mload(dest), mask)\n                mstore(dest, or(s, d))\n            }\n        } else {\n            // Skip the O(length) loop when source == dest.\n            if (source == dest) {\n                return;\n            }\n\n            // For large copies we copy whole words at a time. The final\n            // word is aligned to the end of the range (instead of after the\n            // previous) to handle partial words. So a copy will look like this:\n            //\n            //  ####\n            //      ####\n            //          ####\n            //            ####\n            //\n            // We handle overlap in the source and destination range by\n            // changing the copying direction. This prevents us from\n            // overwriting parts of source that we still need to copy.\n            //\n            // This correctly handles source == dest\n            //\n            if (source > dest) {\n                assembly {\n                    // Record the total number of full words to copy\n                    let nWords := div(length, 32)\n\n                    // We subtract 32 from `sEnd` and `dEnd` because it\n                    // is easier to compare with in the loop, and these\n                    // are also the addresses we need for copying the\n                    // last bytes.\n                    length := sub(length, 32)\n                    let sEnd := add(source, length)\n                    let dEnd := add(dest, length)\n\n                    // Remember the last 32 bytes of source\n                    // This needs to be done here and not after the loop\n                    // because we may have overwritten the last bytes in\n                    // source already due to overlap.\n                    let last := mload(sEnd)\n\n                    // Copy whole words front to back\n                    for {let i := 0} lt(i, nWords) {i := add(i, 1)} {\n                        mstore(dest, mload(source))\n                        source := add(source, 32)\n                        dest := add(dest, 32)\n                    }\n\n                    // Write the last 32 bytes\n                    mstore(dEnd, last)\n                }\n            } else {\n                assembly {\n                    // Record the total number of full words to copy\n                    let nWords := div(length, 32)\n\n                    // We subtract 32 from `sEnd` and `dEnd` because those\n                    // are the starting points when copying a word at the end.\n                    length := sub(length, 32)\n                    let sEnd := add(source, length)\n                    let dEnd := add(dest, length)\n\n                    // Remember the first 32 bytes of source\n                    // This needs to be done here and not after the loop\n                    // because we may have overwritten the first bytes in\n                    // source already due to overlap.\n                    let first := mload(source)\n\n                    // Copy whole words back to front\n                    for {let i := 0} lt(i, nWords) {i := add(i, 1)} {\n                        mstore(dEnd, mload(sEnd))\n                        sEnd := sub(sEnd, 32)\n                        dEnd := sub(dEnd, 32)\n                    }\n\n                    // Write the first 32 bytes\n                    mstore(dest, first)\n                }\n            }\n        }\n    }\n}\n"
    },
    "sourceTreeHashHex": "0x27d8cf9ba24d5435c87f0770658d8623c87b8a0a601d5b3d483b2aab5d7824a8",
    "compiler": {
        "name": "solc",
        "version": "soljson-v0.4.24+commit.e67f0147.js",
        "settings": {
            "optimizer": {
                "enabled": true,
                "runs": 200
            },
            "outputSelection": {
                "*": {
                    "*": [
                        "abi",
                        "evm.bytecode.object",
                        "evm.bytecode.sourceMap",
                        "evm.deployedBytecode.object",
                        "evm.deployedBytecode.sourceMap"
                    ]
                }
            }
        }
    },
    "networks": {}
}