How can I get the same return value as solidity abi encodePacked in Golang

Question

How can i run abi.encodePacked in golang? In solidity i use keccak256(abi.encodePacked(a, b)) to calc the signature of the params.

here is my contract.

pragma solidity ^0.4.24;

import "openzeppelin-solidity/contracts/ECRecovery.sol";


contract MyContract {
    using ECRecovery for bytes32;
    address permittedSinger;

    function doSomething(
    bytes32 id, uint256 amount, bytes sig
    ) {
        bytes32 hash = getHash(msg.sender, id, amount);
        address msgSigner = hash.recover(sig);
        require(msgSigner == permittedSinger);
    }

    function getMsgSigner(bytes32 proveHash, bytes sig) public pure returns (address) {
        return proveHash.recover(sig);
    }

    function getHash(
    address receiver, bytes32 id, uint256 amount
    ) pure returns (bytes32) {
        return keccak256(abi.encodePacked(receiver, id, amount));
    }
}

Answer 1

This is what I used: 

package main

import (
    "math/big"
    "github.com/ethereum/go-ethereum/common/hexutil"
    "github.com/ethereum/go-ethereum/accounts/abi"
    "log"
    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/crypto/sha3"
)

func main() {
    uint256Ty, _ := abi.NewType("uint256")
    bytes32Ty, _ := abi.NewType("bytes32")
    addressTy, _ := abi.NewType("address")

    arguments := abi.Arguments{
        {
            Type: addressTy,
        },
        {
            Type: bytes32Ty,
        },
        {
            Type: uint256Ty,
        },
    }

    bytes, _ := arguments.Pack(
        common.HexToAddress("0x0000000000000000000000000000000000000000"),
        [32]byte{'I','D','1'},
        big.NewInt(42),
    )

    var buf []byte
    hash := sha3.NewKeccak256()
    hash.Write(bytes)
    buf = hash.Sum(buf)

    log.Println(hexutil.Encode(buf))
    // output:
    // 0x1f214438d7c061ad56f98540db9a082d372df1ba9a3c96367f0103aa16c2fe9a
}