ETH Price: $3,457.11 (-0.86%)

Contract

0xCc268f01A9CFC797304082ee028739d48b8ecFDd
 

Overview

ETH Balance

0 ETH

Eth Value

$0.00

Multichain Info

No addresses found
Transaction Hash
Method
Block
From
To
Send Multi Sig181319202023-09-14 3:44:23468 days ago1694663063IN
0xCc268f01...48b8ecFDd
0 ETH0.0009780411.75196387
Send Multi Sig T...181319172023-09-14 3:43:47468 days ago1694663027IN
0xCc268f01...48b8ecFDd
0 ETH0.0010585411.5889292
Send Multi Sig T...181266132023-09-13 9:52:11469 days ago1694598731IN
0xCc268f01...48b8ecFDd
0 ETH0.0035391131.25296945
Send Multi Sig176258212023-07-05 6:11:59539 days ago1688537519IN
0xCc268f01...48b8ecFDd
0 ETH0.0040295151.53231035
Send Multi Sig T...176178892023-07-04 3:27:47540 days ago1688441267IN
0xCc268f01...48b8ecFDd
0 ETH0.0013800214.3536267
Send Multi Sig T...172776062023-05-17 6:33:11588 days ago1684305191IN
0xCc268f01...48b8ecFDd
0 ETH0.0060081953.05106873
Send Multi Sig172776002023-05-17 6:31:59588 days ago1684305119IN
0xCc268f01...48b8ecFDd
0 ETH0.0039161350.08231683
Send Multi Sig169394142023-03-30 10:16:35636 days ago1680171395IN
0xCc268f01...48b8ecFDd
0 ETH0.0040216951.43223196
Send Multi Sig T...166477422023-02-17 10:07:35677 days ago1676628455IN
0xCc268f01...48b8ecFDd
0 ETH0.0025420122.44784441
Send Multi Sig T...165688832023-02-06 9:35:11688 days ago1675676111IN
0xCc268f01...48b8ecFDd
0 ETH0.0020917118.4713208
Send Multi Sig T...165190472023-01-30 10:29:11695 days ago1675074551IN
0xCc268f01...48b8ecFDd
0 ETH0.001787115.77979425
Send Multi Sig164252982023-01-17 8:23:23708 days ago1673943803IN
0xCc268f01...48b8ecFDd
0 ETH0.0014593418.66602382
Send Multi Sig T...163908492023-01-12 12:53:47713 days ago1673528027IN
0xCc268f01...48b8ecFDd
0 ETH0.0016806517.47683496
Send Multi Sig T...163237052023-01-03 3:55:35722 days ago1672718135IN
0xCc268f01...48b8ecFDd
0 ETH0.0024129221.30336774
Send Multi Sig T...162966302022-12-30 9:15:47726 days ago1672391747IN
0xCc268f01...48b8ecFDd
0 ETH0.0016565517.22765043
Send Multi Sig T...162737712022-12-27 4:43:11729 days ago1672116191IN
0xCc268f01...48b8ecFDd
0 ETH0.0023185220.47209905
Send Multi Sig T...162231602022-12-20 3:16:47736 days ago1671506207IN
0xCc268f01...48b8ecFDd
0 ETH0.0019478914.94182939
Send Multi Sig161971272022-12-16 12:02:11740 days ago1671192131IN
0xCc268f01...48b8ecFDd
0 ETH0.0028266929.03552343
Send Multi Sig161673252022-12-12 8:05:47744 days ago1670832347IN
0xCc268f01...48b8ecFDd
0 ETH0.0013841314.2124005
Send Multi Sig T...161665872022-12-12 5:37:23744 days ago1670823443IN
0xCc268f01...48b8ecFDd
0 ETH0.0021624916.58951611
Send Multi Sig T...161318042022-12-07 8:59:47749 days ago1670403587IN
0xCc268f01...48b8ecFDd
0 ETH0.0018900214.49925719
Send Multi Sig T...161253942022-12-06 11:16:23750 days ago1670325383IN
0xCc268f01...48b8ecFDd
0 ETH0.0016123514.23375607
Send Multi Sig T...161250602022-12-06 10:09:23750 days ago1670321363IN
0xCc268f01...48b8ecFDd
0 ETH0.0017458313.39435654
Transfer160665702022-11-28 6:03:59758 days ago1669615439IN
0xCc268f01...48b8ecFDd
1,825.17 ETH0.001029640
Transfer160665162022-11-28 5:53:11758 days ago1669614791IN
0xCc268f01...48b8ecFDd
0.01 ETH0.000514820
View all transactions

Latest 9 internal transactions

Advanced mode:
Parent Transaction Hash Block
From
To
181319202023-09-14 3:44:23468 days ago1694663063
0xCc268f01...48b8ecFDd
467.65915 ETH
176258212023-07-05 6:11:59539 days ago1688537519
0xCc268f01...48b8ecFDd
300 ETH
172776002023-05-17 6:31:59588 days ago1684305119
0xCc268f01...48b8ecFDd
70.38 ETH
169394142023-03-30 10:16:35636 days ago1680171395
0xCc268f01...48b8ecFDd
60 ETH
164252982023-01-17 8:23:23708 days ago1673943803
0xCc268f01...48b8ecFDd
890 ETH
161971272022-12-16 12:02:11740 days ago1671192131
0xCc268f01...48b8ecFDd
14.23944 ETH
161673252022-12-12 8:05:47744 days ago1670832347
0xCc268f01...48b8ecFDd
22.90141 ETH
160653312022-11-28 1:55:35758 days ago1669600535
0xCc268f01...48b8ecFDd
0.05 ETH
160602842022-11-27 8:59:35759 days ago1669539575  Contract Creation0 ETH
Loading...
Loading

Minimal Proxy Contract for 0xe8e847cf573fc8ed75621660a36affd18c543d7e

Contract Name:
WalletSimple

Compiler Version
v0.7.5+commit.eb77ed08

Optimization Enabled:
No with 200 runs

Other Settings:
default evmVersion, Apache-2.0 license

Contract Source Code (Solidity Multiple files format)

File 1 of 4: WalletSimple.sol
// SPDX-License-Identifier: Apache-2.0
pragma solidity 0.7.5;
import './TransferHelper.sol';
import './Forwarder.sol';
import './ERC20Interface.sol';

/**
 *
 * WalletSimple
 * ============
 *
 * Basic multi-signer wallet designed for use in a co-signing environment where 2 signatures are required to move funds.
 * Typically used in a 2-of-3 signing configuration. Uses ecrecover to allow for 2 signatures in a single transaction.
 *
 * The first signature is created on the operation hash (see Data Formats) and passed to sendMultiSig/sendMultiSigToken
 * The signer is determined by verifyMultiSig().
 *
 * The second signature is created by the submitter of the transaction and determined by msg.signer.
 *
 * Data Formats
 * ============
 *
 * The signature is created with ethereumjs-util.ecsign(operationHash).
 * Like the eth_sign RPC call, it packs the values as a 65-byte array of [r, s, v].
 * Unlike eth_sign, the message is not prefixed.
 *
 * The operationHash the result of keccak256(prefix, toAddress, value, data, expireTime).
 * For ether transactions, `prefix` is "ETHER".
 * For token transaction, `prefix` is "ERC20" and `data` is the tokenContractAddress.
 *
 *
 */
contract WalletSimple {
  // Events
  event Deposited(address from, uint256 value, bytes data);
  event SafeModeActivated(address msgSender);
  event Transacted(
    address msgSender, // Address of the sender of the message initiating the transaction
    address otherSigner, // Address of the signer (second signature) used to initiate the transaction
    bytes32 operation, // Operation hash (see Data Formats)
    address toAddress, // The address the transaction was sent to
    uint256 value, // Amount of Wei sent to the address
    bytes data // Data sent when invoking the transaction
  );

  event BatchTransfer(address sender, address recipient, uint256 value);
  // this event shows the other signer and the operation hash that they signed
  // specific batch transfer events are emitted in Batcher
  event BatchTransacted(
    address msgSender, // Address of the sender of the message initiating the transaction
    address otherSigner, // Address of the signer (second signature) used to initiate the transaction
    bytes32 operation // Operation hash (see Data Formats)
  );

  // Public fields
  mapping(address => bool) public signers; // The addresses that can co-sign transactions on the wallet
  bool public safeMode = false; // When active, wallet may only send to signer addresses
  bool public initialized = false; // True if the contract has been initialized

  // Internal fields
  uint256 private constant MAX_SEQUENCE_ID_INCREASE = 10000;
  uint256 constant SEQUENCE_ID_WINDOW_SIZE = 10;
  uint256[SEQUENCE_ID_WINDOW_SIZE] recentSequenceIds;

  /**
   * Set up a simple multi-sig wallet by specifying the signers allowed to be used on this wallet.
   * 2 signers will be required to send a transaction from this wallet.
   * Note: The sender is NOT automatically added to the list of signers.
   * Signers CANNOT be changed once they are set
   *
   * @param allowedSigners An array of signers on the wallet
   */
  function init(address[] calldata allowedSigners) external onlyUninitialized {
    require(allowedSigners.length == 3, 'Invalid number of signers');

    for (uint8 i = 0; i < allowedSigners.length; i++) {
      require(allowedSigners[i] != address(0), 'Invalid signer');
      signers[allowedSigners[i]] = true;
    }
    initialized = true;
  }

  /**
   * Get the network identifier that signers must sign over
   * This provides protection signatures being replayed on other chains
   * This must be a virtual function because chain-specific contracts will need
   *    to override with their own network ids. It also can't be a field
   *    to allow this contract to be used by proxy with delegatecall, which will
   *    not pick up on state variables
   */
  function getNetworkId() internal virtual pure returns (string memory) {
    return 'ETHER';
  }

  /**
   * Get the network identifier that signers must sign over for token transfers
   * This provides protection signatures being replayed on other chains
   * This must be a virtual function because chain-specific contracts will need
   *    to override with their own network ids. It also can't be a field
   *    to allow this contract to be used by proxy with delegatecall, which will
   *    not pick up on state variables
   */
  function getTokenNetworkId() internal virtual pure returns (string memory) {
    return 'ERC20';
  }

  /**
   * Get the network identifier that signers must sign over for batch transfers
   * This provides protection signatures being replayed on other chains
   * This must be a virtual function because chain-specific contracts will need
   *    to override with their own network ids. It also can't be a field
   *    to allow this contract to be used by proxy with delegatecall, which will
   *    not pick up on state variables
   */
  function getBatchNetworkId() internal virtual pure returns (string memory) {
    return 'ETHER-Batch';
  }

  /**
   * Determine if an address is a signer on this wallet
   * @param signer address to check
   * returns boolean indicating whether address is signer or not
   */
  function isSigner(address signer) public view returns (bool) {
    return signers[signer];
  }

  /**
   * Modifier that will execute internal code block only if the sender is an authorized signer on this wallet
   */
  modifier onlySigner {
    require(isSigner(msg.sender), 'Non-signer in onlySigner method');
    _;
  }

  /**
   * Modifier that will execute internal code block only if the contract has not been initialized yet
   */
  modifier onlyUninitialized {
    require(!initialized, 'Contract already initialized');
    _;
  }

  /**
   * Gets called when a transaction is received with data that does not match any other method
   */
  fallback() external payable {
    if (msg.value > 0) {
      // Fire deposited event if we are receiving funds
      Deposited(msg.sender, msg.value, msg.data);
    }
  }

  /**
   * Gets called when a transaction is received with ether and no data
   */
  receive() external payable {
    if (msg.value > 0) {
      // Fire deposited event if we are receiving funds
      Deposited(msg.sender, msg.value, msg.data);
    }
  }

  /**
   * Execute a multi-signature transaction from this wallet using 2 signers: one from msg.sender and the other from ecrecover.
   * Sequence IDs are numbers starting from 1. They are used to prevent replay attacks and may not be repeated.
   *
   * @param toAddress the destination address to send an outgoing transaction
   * @param value the amount in Wei to be sent
   * @param data the data to send to the toAddress when invoking the transaction
   * @param expireTime the number of seconds since 1970 for which this transaction is valid
   * @param sequenceId the unique sequence id obtainable from getNextSequenceId
   * @param signature see Data Formats
   */
  function sendMultiSig(
    address toAddress,
    uint256 value,
    bytes calldata data,
    uint256 expireTime,
    uint256 sequenceId,
    bytes calldata signature
  ) external onlySigner {
    // Verify the other signer
    bytes32 operationHash = keccak256(
      abi.encodePacked(
        getNetworkId(),
        toAddress,
        value,
        data,
        expireTime,
        sequenceId
      )
    );

    address otherSigner = verifyMultiSig(
      toAddress,
      operationHash,
      signature,
      expireTime,
      sequenceId
    );

    // Success, send the transaction
    (bool success, ) = toAddress.call{ value: value }(data);
    require(success, 'Call execution failed');

    emit Transacted(
      msg.sender,
      otherSigner,
      operationHash,
      toAddress,
      value,
      data
    );
  }

  /**
   * Execute a batched multi-signature transaction from this wallet using 2 signers: one from msg.sender and the other from ecrecover.
   * Sequence IDs are numbers starting from 1. They are used to prevent replay attacks and may not be repeated.
   * The recipients and values to send are encoded in two arrays, where for index i, recipients[i] will be sent values[i].
   *
   * @param recipients The list of recipients to send to
   * @param values The list of values to send to
   * @param expireTime the number of seconds since 1970 for which this transaction is valid
   * @param sequenceId the unique sequence id obtainable from getNextSequenceId
   * @param signature see Data Formats
   */
  function sendMultiSigBatch(
    address[] calldata recipients,
    uint256[] calldata values,
    uint256 expireTime,
    uint256 sequenceId,
    bytes calldata signature
  ) external onlySigner {
    require(recipients.length != 0, 'Not enough recipients');
    require(
      recipients.length == values.length,
      'Unequal recipients and values'
    );
    require(recipients.length < 256, 'Too many recipients, max 255');

    // Verify the other signer
    bytes32 operationHash = keccak256(
      abi.encodePacked(
        getBatchNetworkId(),
        recipients,
        values,
        expireTime,
        sequenceId
      )
    );

    // the first parameter (toAddress) is used to ensure transactions in safe mode only go to a signer
    // if in safe mode, we should use normal sendMultiSig to recover, so this check will always fail if in safe mode
    require(!safeMode, 'Batch in safe mode');
    address otherSigner = verifyMultiSig(
      address(0x0),
      operationHash,
      signature,
      expireTime,
      sequenceId
    );

    batchTransfer(recipients, values);
    emit BatchTransacted(msg.sender, otherSigner, operationHash);
  }

  /**
   * Transfer funds in a batch to each of recipients
   * @param recipients The list of recipients to send to
   * @param values The list of values to send to recipients.
   *  The recipient with index i in recipients array will be sent values[i].
   *  Thus, recipients and values must be the same length
   */
  function batchTransfer(
    address[] calldata recipients,
    uint256[] calldata values
  ) internal {
    for (uint256 i = 0; i < recipients.length; i++) {
      require(address(this).balance >= values[i], 'Insufficient funds');

      (bool success, ) = recipients[i].call{ value: values[i] }('');
      require(success, 'Call failed');

      emit BatchTransfer(msg.sender, recipients[i], values[i]);
    }
  }

  /**
   * Execute a multi-signature token transfer from this wallet using 2 signers: one from msg.sender and the other from ecrecover.
   * Sequence IDs are numbers starting from 1. They are used to prevent replay attacks and may not be repeated.
   *
   * @param toAddress the destination address to send an outgoing transaction
   * @param value the amount in tokens to be sent
   * @param tokenContractAddress the address of the erc20 token contract
   * @param expireTime the number of seconds since 1970 for which this transaction is valid
   * @param sequenceId the unique sequence id obtainable from getNextSequenceId
   * @param signature see Data Formats
   */
  function sendMultiSigToken(
    address toAddress,
    uint256 value,
    address tokenContractAddress,
    uint256 expireTime,
    uint256 sequenceId,
    bytes calldata signature
  ) external onlySigner {
    // Verify the other signer
    bytes32 operationHash = keccak256(
      abi.encodePacked(
        getTokenNetworkId(),
        toAddress,
        value,
        tokenContractAddress,
        expireTime,
        sequenceId
      )
    );

    verifyMultiSig(toAddress, operationHash, signature, expireTime, sequenceId);

    TransferHelper.safeTransfer(tokenContractAddress, toAddress, value);
  }

  /**
   * Execute a token flush from one of the forwarder addresses. This transfer needs only a single signature and can be done by any signer
   *
   * @param forwarderAddress the address of the forwarder address to flush the tokens from
   * @param tokenContractAddress the address of the erc20 token contract
   */
  function flushForwarderTokens(
    address payable forwarderAddress,
    address tokenContractAddress
  ) external onlySigner {
    Forwarder forwarder = Forwarder(forwarderAddress);
    forwarder.flushTokens(tokenContractAddress);
  }

  /**
   * Do common multisig verification for both eth sends and erc20token transfers
   *
   * @param toAddress the destination address to send an outgoing transaction
   * @param operationHash see Data Formats
   * @param signature see Data Formats
   * @param expireTime the number of seconds since 1970 for which this transaction is valid
   * @param sequenceId the unique sequence id obtainable from getNextSequenceId
   * returns address that has created the signature
   */
  function verifyMultiSig(
    address toAddress,
    bytes32 operationHash,
    bytes calldata signature,
    uint256 expireTime,
    uint256 sequenceId
  ) private returns (address) {
    address otherSigner = recoverAddressFromSignature(operationHash, signature);

    // Verify if we are in safe mode. In safe mode, the wallet can only send to signers
    require(!safeMode || isSigner(toAddress), 'External transfer in safe mode');

    // Verify that the transaction has not expired
    require(expireTime >= block.timestamp, 'Transaction expired');

    // Try to insert the sequence ID. Will revert if the sequence id was invalid
    tryInsertSequenceId(sequenceId);

    require(isSigner(otherSigner), 'Invalid signer');

    require(otherSigner != msg.sender, 'Signers cannot be equal');

    return otherSigner;
  }

  /**
   * Irrevocably puts contract into safe mode. When in this mode, transactions may only be sent to signing addresses.
   */
  function activateSafeMode() external onlySigner {
    safeMode = true;
    SafeModeActivated(msg.sender);
  }

  /**
   * Gets signer's address using ecrecover
   * @param operationHash see Data Formats
   * @param signature see Data Formats
   * returns address recovered from the signature
   */
  function recoverAddressFromSignature(
    bytes32 operationHash,
    bytes memory signature
  ) private pure returns (address) {
    require(signature.length == 65, 'Invalid signature - wrong length');

    // We need to unpack the signature, which is given as an array of 65 bytes (like eth.sign)
    bytes32 r;
    bytes32 s;
    uint8 v;

    // solhint-disable-next-line
    assembly {
      r := mload(add(signature, 32))
      s := mload(add(signature, 64))
      v := and(mload(add(signature, 65)), 255)
    }
    if (v < 27) {
      v += 27; // Ethereum versions are 27 or 28 as opposed to 0 or 1 which is submitted by some signing libs
    }

    // protect against signature malleability
    // S value must be in the lower half orader
    // reference: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/051d340171a93a3d401aaaea46b4b62fa81e5d7c/contracts/cryptography/ECDSA.sol#L53
    require(
      uint256(s) <=
        0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0,
      "ECDSA: invalid signature 's' value"
    );

    // note that this returns 0 if the signature is invalid
    // Since 0x0 can never be a signer, when the recovered signer address
    // is checked against our signer list, that 0x0 will cause an invalid signer failure
    return ecrecover(operationHash, v, r, s);
  }

  /**
   * Verify that the sequence id has not been used before and inserts it. Throws if the sequence ID was not accepted.
   * We collect a window of up to 10 recent sequence ids, and allow any sequence id that is not in the window and
   * greater than the minimum element in the window.
   * @param sequenceId to insert into array of stored ids
   */
  function tryInsertSequenceId(uint256 sequenceId) private onlySigner {
    // Keep a pointer to the lowest value element in the window
    uint256 lowestValueIndex = 0;
    // fetch recentSequenceIds into memory for function context to avoid unnecessary sloads
    uint256[SEQUENCE_ID_WINDOW_SIZE] memory _recentSequenceIds = recentSequenceIds;
    for (uint256 i = 0; i < SEQUENCE_ID_WINDOW_SIZE; i++) {
      require(_recentSequenceIds[i] != sequenceId, 'Sequence ID already used');

      if (_recentSequenceIds[i] < _recentSequenceIds[lowestValueIndex]) {
        lowestValueIndex = i;
      }
    }

    // The sequence ID being used is lower than the lowest value in the window
    // so we cannot accept it as it may have been used before
    require(
      sequenceId > _recentSequenceIds[lowestValueIndex],
      'Sequence ID below window'
    );

    // Block sequence IDs which are much higher than the lowest value
    // This prevents people blocking the contract by using very large sequence IDs quickly
    require(
      sequenceId <=
        (_recentSequenceIds[lowestValueIndex] + MAX_SEQUENCE_ID_INCREASE),
      'Sequence ID above maximum'
    );

    recentSequenceIds[lowestValueIndex] = sequenceId;
  }

  /**
   * Gets the next available sequence ID for signing when using executeAndConfirm
   * returns the sequenceId one higher than the highest currently stored
   */
  function getNextSequenceId() public view returns (uint256) {
    uint256 highestSequenceId = 0;
    for (uint256 i = 0; i < SEQUENCE_ID_WINDOW_SIZE; i++) {
      if (recentSequenceIds[i] > highestSequenceId) {
        highestSequenceId = recentSequenceIds[i];
      }
    }
    return highestSequenceId + 1;
  }
}

File 2 of 4: ERC20Interface.sol
// SPDX-License-Identifier: UNLICENSED
pragma solidity 0.7.5;

/**
 * Contract that exposes the needed erc20 token functions
 */

abstract contract ERC20Interface {
  // Send _value amount of tokens to address _to
  function transfer(address _to, uint256 _value)
    public
    virtual
    returns (bool success);

  // Get the account balance of another account with address _owner
  function balanceOf(address _owner)
    public
    virtual
    view
    returns (uint256 balance);
}

File 3 of 4: Forwarder.sol
// SPDX-License-Identifier: Apache-2.0
pragma solidity 0.7.5;
import './TransferHelper.sol';
import './ERC20Interface.sol';

/**
 * Contract that will forward any incoming Ether to the creator of the contract
 *
 */
contract Forwarder {
  // Address to which any funds sent to this contract will be forwarded
  address public parentAddress;
  event ForwarderDeposited(address from, uint256 value, bytes data);

  /**
   * Initialize the contract, and sets the destination address to that of the creator
   */
  function init(address _parentAddress) external onlyUninitialized {
    parentAddress = _parentAddress;
    uint256 value = address(this).balance;

    if (value == 0) {
      return;
    }

    (bool success, ) = parentAddress.call{ value: value }('');
    require(success, 'Flush failed');
    // NOTE: since we are forwarding on initialization,
    // we don't have the context of the original sender.
    // We still emit an event about the forwarding but set
    // the sender to the forwarder itself
    emit ForwarderDeposited(address(this), value, msg.data);
  }

  /**
   * Modifier that will execute internal code block only if the sender is the parent address
   */
  modifier onlyParent {
    require(msg.sender == parentAddress, 'Only Parent');
    _;
  }

  /**
   * Modifier that will execute internal code block only if the contract has not been initialized yet
   */
  modifier onlyUninitialized {
    require(parentAddress == address(0x0), 'Already initialized');
    _;
  }

  /**
   * Default function; Gets called when data is sent but does not match any other function
   */
  fallback() external payable {
    flush();
  }

  /**
   * Default function; Gets called when Ether is deposited with no data, and forwards it to the parent address
   */
  receive() external payable {
    flush();
  }

  /**
   * Execute a token transfer of the full balance from the forwarder token to the parent address
   * @param tokenContractAddress the address of the erc20 token contract
   */
  function flushTokens(address tokenContractAddress) external onlyParent {
    ERC20Interface instance = ERC20Interface(tokenContractAddress);
    address forwarderAddress = address(this);
    uint256 forwarderBalance = instance.balanceOf(forwarderAddress);
    if (forwarderBalance == 0) {
      return;
    }

    TransferHelper.safeTransfer(
      tokenContractAddress,
      parentAddress,
      forwarderBalance
    );
  }

  /**
   * Flush the entire balance of the contract to the parent address.
   */
  function flush() public {
    uint256 value = address(this).balance;

    if (value == 0) {
      return;
    }

    (bool success, ) = parentAddress.call{ value: value }('');
    require(success, 'Flush failed');
    emit ForwarderDeposited(msg.sender, value, msg.data);
  }
}

File 4 of 4: TransferHelper.sol
// SPDX-License-Identifier: Apache-2.0

pragma solidity >=0.7.5;

// helper methods for interacting with ERC20 tokens and sending ETH that do not consistently return true/false
library TransferHelper {
    function safeApprove(
        address token,
        address to,
        uint256 value
    ) internal {
        // bytes4(keccak256(bytes('approve(address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x095ea7b3, to, value));
        require(
            success && (data.length == 0 || abi.decode(data, (bool))),
            'TransferHelper::safeApprove: approve failed'
        );
    }

    function safeTransfer(
        address token,
        address to,
        uint256 value
    ) internal {
        // bytes4(keccak256(bytes('transfer(address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0xa9059cbb, to, value));
        require(
            success && (data.length == 0 || abi.decode(data, (bool))),
            'TransferHelper::safeTransfer: transfer failed'
        );
    }

    function safeTransferFrom(
        address token,
        address from,
        address to,
        uint256 value
    ) internal {
        // bytes4(keccak256(bytes('transferFrom(address,address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x23b872dd, from, to, value));
        require(
            success && (data.length == 0 || abi.decode(data, (bool))),
            'TransferHelper::transferFrom: transferFrom failed'
        );
    }

    function safeTransferETH(address to, uint256 value) internal {
        (bool success, ) = to.call{value: value}(new bytes(0));
        require(success, 'TransferHelper::safeTransferETH: ETH transfer failed');
    }
}

Contract ABI

[{"anonymous":false,"inputs":[{"indexed":false,"internalType":"address","name":"msgSender","type":"address"},{"indexed":false,"internalType":"address","name":"otherSigner","type":"address"},{"indexed":false,"internalType":"bytes32","name":"operation","type":"bytes32"}],"name":"BatchTransacted","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"internalType":"address","name":"sender","type":"address"},{"indexed":false,"internalType":"address","name":"recipient","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"BatchTransfer","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"internalType":"address","name":"from","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"},{"indexed":false,"internalType":"bytes","name":"data","type":"bytes"}],"name":"Deposited","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"internalType":"address","name":"msgSender","type":"address"}],"name":"SafeModeActivated","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"internalType":"address","name":"msgSender","type":"address"},{"indexed":false,"internalType":"address","name":"otherSigner","type":"address"},{"indexed":false,"internalType":"bytes32","name":"operation","type":"bytes32"},{"indexed":false,"internalType":"address","name":"toAddress","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"},{"indexed":false,"internalType":"bytes","name":"data","type":"bytes"}],"name":"Transacted","type":"event"},{"stateMutability":"payable","type":"fallback"},{"inputs":[],"name":"activateSafeMode","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address payable","name":"forwarderAddress","type":"address"},{"internalType":"address","name":"tokenContractAddress","type":"address"}],"name":"flushForwarderTokens","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"getNextSequenceId","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address[]","name":"allowedSigners","type":"address[]"}],"name":"init","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"initialized","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"signer","type":"address"}],"name":"isSigner","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"safeMode","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"toAddress","type":"address"},{"internalType":"uint256","name":"value","type":"uint256"},{"internalType":"bytes","name":"data","type":"bytes"},{"internalType":"uint256","name":"expireTime","type":"uint256"},{"internalType":"uint256","name":"sequenceId","type":"uint256"},{"internalType":"bytes","name":"signature","type":"bytes"}],"name":"sendMultiSig","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address[]","name":"recipients","type":"address[]"},{"internalType":"uint256[]","name":"values","type":"uint256[]"},{"internalType":"uint256","name":"expireTime","type":"uint256"},{"internalType":"uint256","name":"sequenceId","type":"uint256"},{"internalType":"bytes","name":"signature","type":"bytes"}],"name":"sendMultiSigBatch","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"toAddress","type":"address"},{"internalType":"uint256","name":"value","type":"uint256"},{"internalType":"address","name":"tokenContractAddress","type":"address"},{"internalType":"uint256","name":"expireTime","type":"uint256"},{"internalType":"uint256","name":"sequenceId","type":"uint256"},{"internalType":"bytes","name":"signature","type":"bytes"}],"name":"sendMultiSigToken","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"}],"name":"signers","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"stateMutability":"payable","type":"receive"}]

Block Transaction Difficulty Gas Used Reward
View All Blocks Produced

Block Uncle Number Difficulty Gas Used Reward
View All Uncles
Loading...
Loading
Loading...
Loading

Validator Index Block Amount
View All Withdrawals

Transaction Hash Block Value Eth2 PubKey Valid
View All Deposits
Loading...
Loading
[ Download: CSV Export  ]
[ Download: CSV Export  ]

A contract address hosts a smart contract, which is a set of code stored on the blockchain that runs when predetermined conditions are met. Learn more about addresses in our Knowledge Base.