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Diffstat (limited to 'contracts/examples/contracts/Whitelist/Whitelist.sol')
-rw-r--r-- | contracts/examples/contracts/Whitelist/Whitelist.sol | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/contracts/examples/contracts/Whitelist/Whitelist.sol b/contracts/examples/contracts/Whitelist/Whitelist.sol new file mode 100644 index 000000000..2a3d33738 --- /dev/null +++ b/contracts/examples/contracts/Whitelist/Whitelist.sol @@ -0,0 +1,136 @@ +/* + + Copyright 2018 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 0.4.24; +pragma experimental ABIEncoderV2; + +import "@0x/contracts-interfaces/contracts/protocol/Exchange/IExchange.sol"; +import "@0x/contracts-libs/contracts/libs/LibOrder.sol"; +import "@0x/contracts-utils/contracts/utils/Ownable/Ownable.sol"; + + +contract Whitelist is + Ownable +{ + + // Mapping of address => whitelist status. + mapping (address => bool) public isWhitelisted; + + // Exchange contract. + // solhint-disable var-name-mixedcase + IExchange internal EXCHANGE; + bytes internal TX_ORIGIN_SIGNATURE; + // solhint-enable var-name-mixedcase + + byte constant internal VALIDATOR_SIGNATURE_BYTE = "\x05"; + + constructor (address _exchange) + public + { + EXCHANGE = IExchange(_exchange); + TX_ORIGIN_SIGNATURE = abi.encodePacked(address(this), VALIDATOR_SIGNATURE_BYTE); + } + + /// @dev Adds or removes an address from the whitelist. + /// @param target Address to add or remove from whitelist. + /// @param isApproved Whitelist status to assign to address. + function updateWhitelistStatus( + address target, + bool isApproved + ) + external + onlyOwner + { + isWhitelisted[target] = isApproved; + } + + /// @dev Verifies signer is same as signer of current Ethereum transaction. + /// NOTE: This function can currently be used to validate signatures coming from outside of this contract. + /// Extra safety checks can be added for a production contract. + /// @param signerAddress Address that should have signed the given hash. + /// @param signature Proof of signing. + /// @return Validity of order signature. + // solhint-disable no-unused-vars + function isValidSignature( + bytes32 hash, + address signerAddress, + bytes signature + ) + external + view + returns (bool isValid) + { + // solhint-disable-next-line avoid-tx-origin + return signerAddress == tx.origin; + } + // solhint-enable no-unused-vars + + /// @dev Fills an order using `msg.sender` as the taker. + /// The transaction will revert if both the maker and taker are not whitelisted. + /// Orders should specify this contract as the `senderAddress` in order to gaurantee + /// that both maker and taker have been whitelisted. + /// @param order Order struct containing order specifications. + /// @param takerAssetFillAmount Desired amount of takerAsset to sell. + /// @param salt Arbitrary value to gaurantee uniqueness of 0x transaction hash. + /// @param orderSignature Proof that order has been created by maker. + function fillOrderIfWhitelisted( + LibOrder.Order memory order, + uint256 takerAssetFillAmount, + uint256 salt, + bytes memory orderSignature + ) + public + { + address takerAddress = msg.sender; + + // This contract must be the entry point for the transaction. + require( + // solhint-disable-next-line avoid-tx-origin + takerAddress == tx.origin, + "INVALID_SENDER" + ); + + // Check if maker is on the whitelist. + require( + isWhitelisted[order.makerAddress], + "MAKER_NOT_WHITELISTED" + ); + + // Check if taker is on the whitelist. + require( + isWhitelisted[takerAddress], + "TAKER_NOT_WHITELISTED" + ); + + // Encode arguments into byte array. + bytes memory data = abi.encodeWithSelector( + EXCHANGE.fillOrder.selector, + order, + takerAssetFillAmount, + orderSignature + ); + + // Call `fillOrder` via `executeTransaction`. + EXCHANGE.executeTransaction( + salt, + takerAddress, + data, + TX_ORIGIN_SIGNATURE + ); + } +} |