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Lachain ERC20 handler
Contract
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// pragma solidity 0.6.4;
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pragma experimental ABIEncoderV2;
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import "../interfaces/IDepositExecute.sol";
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import "../interfaces/IERC20.sol";
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import "./HandlerHelpers.sol";
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import "../ERC20Safe.sol";
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import "../ExampleToken.sol";
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import "../utils/UpgradableOwnable.sol";
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/**
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@title Handles ERC20 deposits and deposit executions.
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@notice This contract is intended to be used with the Bridge contract.
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*/
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contract ERC20Handler is
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IDepositExecute,
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HandlerHelpers,
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UpgradableOwnable,
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ERC20Safe
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{
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struct DepositRecord {
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address _tokenAddress;
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bytes8 _destinationChainID;
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bytes32 _resourceID;
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address _destinationRecipientAddress;
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address _depositer;
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uint256 _amount;
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}
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// depositNonce => Deposit Record
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mapping(bytes8 => mapping(uint64 => DepositRecord)) public _depositRecords;
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/**
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@param bridgeAddress Contract address of previously deployed Bridge.
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*/
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function initialize(address bridgeAddress) public {
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_bridgeAddress = bridgeAddress;
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ownableInit(msg.sender);
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}
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function adminChangeBridgeAddress(address newBridgeAddress)
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external
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onlyOwner
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isInitisalised
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{
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_bridgeAddress = newBridgeAddress;
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}
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/**
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@param depositNonce This ID will have been generated by the Bridge contract.
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@param destId ID of chain deposit will be bridged to.
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@return DepositRecord which consists of:
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- _tokenAddress Address used when {deposit} was executed.
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- _destinationChainID ChainID deposited tokens are intended to end up on.
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- _resourceID ResourceID used when {deposit} was executed.
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- _destinationRecipientAddress Address tokens are intended to be deposited to on desitnation chain.
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- _depositer Address that initially called {deposit} in the Bridge contract.
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- _amount Amount of tokens that were deposited.
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*/
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function getDepositRecord(uint64 depositNonce, bytes8 destId)
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external
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view
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isInitisalised
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returns (DepositRecord memory)
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{
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return _depositRecords[destId][depositNonce];
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}
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/**
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@notice A deposit is initiatied by making a deposit in the Bridge contract.
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@param destinationChainID Chain ID of chain tokens are expected to be bridged to.
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@param depositNonce This value is generated as an ID by the Bridge contract.
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@param depositer Address of account making the deposit in the Bridge contract.
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@notice Data passed into the function should be constructed as follows:
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amount uint256 bytes 0 - 32
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recipientAddress length uint256 bytes 32 - 64
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recipientAddress bytes bytes 64 - END
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@dev Depending if the corresponding {tokenAddress} for the parsed {resourceID} is
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marked true in {_burnList}, deposited tokens will be burned, if not, they will be locked.
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*/
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function deposit(
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bytes32 resourceID,
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bytes8 destinationChainID,
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uint64 depositNonce,
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address depositer,
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address recipientAddress,
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uint256 amount,
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bytes calldata params
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) external override onlyBridge isInitisalised returns (address) {
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// bytes memory recipientAddress;
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// uint256 amount;
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// uint256 lenRecipientAddress;
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// assembly {
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// amount := calldataload(0xC4)
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// recipientAddress := mload(0x40)
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// lenRecipientAddress := calldataload(0xE4)
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// mstore(0x40, add(0x20, add(recipientAddress, lenRecipientAddress)))
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// calldatacopy(
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// recipientAddress, // copy to destinationRecipientAddress
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// 0xE4, // copy from calldata @ 0x104
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// sub(calldatasize(), 0xE) // copy size (calldatasize - 0x104)
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// )
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// }
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address tokenAddress = _resourceIDToTokenContractAddress[resourceID];
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require(
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_contractWhitelist[tokenAddress],
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"provided tokenAddress is not whitelisted"
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);
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if (_burnList[tokenAddress]) {
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burnERC20(tokenAddress, depositer, amount);
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} else {
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lockERC20(tokenAddress, depositer, address(this), amount);
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}
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_depositRecords[destinationChainID][depositNonce] = DepositRecord(
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tokenAddress,
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destinationChainID,
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resourceID,
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recipientAddress,
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depositer,
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amount
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);
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return (tokenAddress);
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}
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/**
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@notice Proposal execution should be initiated when a proposal is finalized in the Bridge contract.
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by a relayer on the deposit's destination chain.
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@notice Data passed into the function should be constructed as follows:
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amount uint256 bytes 0 - 32
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destinationRecipientAddress length uint256 bytes 32 - 64
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destinationRecipientAddress bytes bytes 64 - END
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*/
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function executeProposal(
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bytes32 resourceID,
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address recipientAddress,
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uint256 amount,
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bytes calldata params
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) external override onlyBridge isInitisalised {
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// uint256 amount;
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// bytes memory destinationRecipientAddress;
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// assembly {
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// amount := calldataload(0x64)
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// destinationRecipientAddress := mload(0x40)
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// let lenDestinationRecipientAddress := calldataload(0x84)
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// mstore(
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// 0x40,
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// add(
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// 0x20,
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// add(
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// destinationRecipientAddress,
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// lenDestinationRecipientAddress
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// )
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// )
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// )
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// // in the calldata the destinationRecipientAddress is stored at 0xC4 after accounting for the function signature and length declaration
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// calldatacopy(
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// destinationRecipientAddress, // copy to destinationRecipientAddress
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// 0x84, // copy from calldata @ 0x84
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// sub(calldatasize(), 0x84) // copy size to the end of calldata
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// )
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// }
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// bytes20 recipientAddress;
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address tokenAddress = _resourceIDToTokenContractAddress[resourceID];
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// assembly {
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// recipientAddress := mload(add(destinationRecipientAddress, 0x20))
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// }
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require(
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_contractWhitelist[tokenAddress],
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"provided tokenAddress is not whitelisted"
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);
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if (_burnList[tokenAddress]) {
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mintERC20(tokenAddress, recipientAddress, amount);
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} else {
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releaseERC20(tokenAddress, recipientAddress, amount);
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}
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}
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/**
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@notice Used to manually release ERC20 tokens from ERC20Safe.
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@param tokenAddress Address of token contract to release.
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@param recipient Address to release tokens to.
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@param amount The amount of ERC20 tokens to release.
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*/
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function withdraw(
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address tokenAddress,
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address recipient,
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uint256 amount
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) external override onlyBridge isInitisalised {
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releaseERC20(tokenAddress, recipient, amount);
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}
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function getAddressFromResourceId(bytes32 resourceID)
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external
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view
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override
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returns (address)
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{
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return _resourceIDToTokenContractAddress[resourceID];
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}
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/**
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@notice Used to approve spending tokens.
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@param resourceID ResourceID to be used for approval.
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@param spender Spender address.
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@param amount Amount to approve.
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*/
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function approve(
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bytes32 resourceID,
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address spender,
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uint256 amount
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) external override onlyBridge isInitisalised {
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address tokenAddress = _resourceIDToTokenContractAddress[resourceID];
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require(
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_contractWhitelist[tokenAddress],
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"provided tokenAddress is not whitelisted"
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);
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approveERC20(tokenAddress, spender, amount);
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}
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}
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