github.com/klaytn/klaytn@v1.12.1/contracts/validatesender/validate_sender.sol (about)

     1  // Copyright 2019 The klaytn Authors
     2  // This file is part of the klaytn library.
     3  //
     4  // The klaytn library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The klaytn library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the klaytn library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  pragma solidity ^0.4.24;
    18  
    19  contract ValidateSenderContract {
    20  
    21      function ValidateSender(address sender, bytes32 msgHash, bytes sigs) public returns (bool) {
    22          require(sigs.length % 65 == 0);
    23          bytes memory data = new bytes(20+32+sigs.length);
    24          uint idx = 0;
    25          uint i;
    26          for( i = 0; i < 20; i++) {
    27              data[idx++] = (bytes20)(sender)[i];
    28          }
    29          for( i = 0; i < 32; i++ ) {
    30              data[idx++] = msgHash[i];
    31          }
    32          for( i = 0; i < sigs.length; i++) {
    33              data[idx++] = sigs[i];
    34          }
    35          assembly {
    36              // skip length header.
    37              let ptr := add(data, 0x20)
    38              if iszero(call(gas, 0x0b, 0, ptr, idx, 31, 1)) {
    39                invalid()
    40              }
    41              return(0, 32)
    42          }
    43  
    44      }
    45  }