将字段打包到单个字节参数中(&Q；)

问题描述

我正在试验AAVE的FlashLiqudidationAdapter.sol，它需要一个包含address,address,address,uint256,bool的params字段，但每当我编码和提交事务时，它都会在_decodeParameters返回，这是一个函数，它将params解包到智能合同中。我不确定我做错了什么。以下是我的纯(非编码)参数：

"0xb7c325266ec274feb1354021d27fa3e3379d840d,0xff682ff79feb2c057ec3ff1e083efdc66f9b37fb,0x1ea0B089673720e210552c624aFff9d67F8b1535,-1,0"

以下是已编码的参数)：

b"000000000000000000000000b7c325266ec274feb1354021d27fa3e3379d840d000000000000000000000000ff682ff79feb2c057ec3ff1e083efdc66f9b37fb0000000000000000000000001ea0b089673720e210552c624afff9d67f8b1535ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff0000000000000000000000000000000000000000000000000000000000000001"

这是整个交易：

tx = flash_loan.requestFlashLoan(["0xb7c325266ec274feb1354021d27fa3e3379d840d"], [(2.8134148508367174 / 2) * 1e18], [0], b"000000000000000000000000b7c325266ec274feb1354021d27fa3e3379d840d000000000000000000000000ff682ff79feb2c057ec3ff1e083efdc66f9b37fb0000000000000000000000001ea0b089673720e210552c624afff9d67f8b1535ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff0000000000000000000000000000000000000000000000000000000000000001", {"gas_limit": "200000", "gas_price": Wei('4 gwei'), "from": account1, "allow_revert": True, "nonce": 46})

最后，这里是引用的_decodeParams函数，如前所述，其中正在进行还原

 /**
   * @dev Decodes the information encoded in the flash loan params
   * @param params Additional variadic field to include extra params. Expected parameters:
   *   address collateralAsset The collateral asset to claim
   *   address borrowedAsset The asset that must be covered and will be exchanged to pay the flash loan premium
   *   address user The user address with a Health Factor below 1
   *   uint256 debtToCover The amount of debt to cover
   *   bool useEthPath Use WETH as connector path between the collateralAsset and borrowedAsset at Uniswap
   * @return LiquidationParams struct containing decoded params
   */
  function _decodeParams(bytes memory params) internal pure returns (LiquidationParams memory) {
    (
      address collateralAsset,
      address borrowedAsset,
      address user,
      uint256 debtToCover,
      bool useEthPath
    ) = abi.decode(params, (address, address, address, uint256, bool));

    return LiquidationParams(collateralAsset, borrowedAsset, user, debtToCover, useEthPath);
  }
}

https://github.com/aave/protocol-v2/blob/master/contracts/adapters/FlashLiquidationAdapter.sol#L173-L184

注意，我使用的是固态编译器版本^0.6.12。

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解决方案

Solidity要求类型BYTE以0x开头，因此作为params传递的正确字节字符串应如下所示：

b"0x000000000000000000000000b7c325266ec274feb1354021d27fa3e3379d840d000000000000000000000000ff682ff79feb2c057ec3ff1e083efdc66f9b37fb0000000000000000000000001ea0b089673720e210552c624afff9d67f8b1535ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff0000000000000000000000000000000000000000000000000000000000000001"