Error: "invalid sender" from web3.eth.sendSignedTransaction()

Question

I have a client running a private blockchain. It was started with the following command:

geth --datadir private-chain --mine --miner.threads 4 --http --http.addr 127.0.0.1 --http.port 8545 --http.api eth,net,web3,personal --networkid 3456 console 2> private-chain/private-chain.log

My transaction is created in the following function which is supposed to send one ether. It is part of a nodejs application I wrote to interact with the private blockchain. It uses the ethereumjs-tx package. The two account parameters are passed in as strings (which include the 0x). The accounts were created in the genesis block when I initialized the blockchain. The nonce is the number returned by web3.eth.getTransactionCount for the from_account.

function send_one_ether (from_account, nonce, private_key, to_account)
{
    var transaction_data =
    {
        "from": from_account,
        "to": to_account,
        "value": 1000000000000000000,
        "nonce": nonce
    };

    var transaction = new Transaction (transaction_data);

    var bytes = [];
    var private_key_bytes = private_key.substr (2); // remove the 0x
    for (var b = 0; b < private_key_bytes.length; b += 2)
    {
        var hex_byte = private_key_bytes.substr (b, 2);
        var int_byte = parseInt (hex_byte, 16);
        bytes.push (int_byte);
    }

    transaction.sign (Buffer.from (bytes));

    var verified = transaction.verifySignature (); // returns true
    var valid = transaction.validate (); // returns false

    var serialized_transaction = transaction.serialize ();
    web3.eth.sendSignedTransaction ("0x" + serialized_transaction.toString ("hex")).on ("receipt", console.log);
}

The private_key variable passed into the above function comes from the account's keystore file under the datadir, and it was decrypted using the following code.

var json_data = JSON.parse (fs.readFileSync (file_path));
const decrypted_account = web3.eth.accounts.decrypt (json_data, pw);

The transaction object's validate function returns false, and the error message I receive from web3.eth.sendSignedTransaction says invalid sender. Does anyone have any idea what could be wrong or how to get this to work?

Answer 1

According to this issue, private blockchains are not supported by ethereumjs-tx. You have to use ethereumjs-common. So I think the problem was that, since my call to the Transaction constructor did not include a second parameter (an object specifying a chain), it probably defaulted to mainnet. But since the accounts I am working with are all on a private blockchain, they do not exist on the mainnet. Hence, the "invalid sender" error message.

In order to send the signed transaction to my private blockchain, I did the following.

const ethereumjs_common = require ('ethereumjs-common').default;

Then I had to change the way I was creating my Transaction object. (I think the first parameter to forCustomChain might simply be ignored in this case.)

var common = ethereumjs_common.forCustomChain ('ropsten', { networkId: 1994, chainId: 1994, name: 'geth' }, 'muirGlacier');
var transaction = new Transaction (transaction_data, { "common": common });

Finally, I had to add some gas to my transaction_data object.

var transaction_data =
{
    "from": from_account,
    "to": to_account,
    "value": 1000000000000000000,
    "gas": 60000,
    "nonce": nonce
};

After that, I got the receipt I was hoping to get.

Answer 2

Change the below

      const Tx = require('ethereumjs-tx').Transaction;

      var transaction_data = {
        "from": myAddress,
        "gasPrice": web3js.utils.toHex(20 * 1e9),
        "gasLimit": web3js.utils.toHex(210000),
        "to": contractAddress,
        "value": "0x0",
        "data": contract.methods.safeTransferFrom(myAddress, toAddress, tokenId).encodeABI(),
      }

        var privateKey = Buffer.from('abcde', 'hex')

        var transaction = new Tx(transaction_data,{ chain: 'ropsten' , hardfork: 'petersburg' });

        transaction.sign(privateKey);

        web3js.eth.sendSignedTransaction('0x' + transaction.serialize().toString('hex'))
            .on('transactionHash', console.log);

to the below

      const Tx = require('ethereumjs-tx').Transaction;

      var transaction_data = {
        "from": myAddress,
        "gasPrice": web3js.utils.toHex(20 * 1e9),
        "gasLimit": web3js.utils.toHex(210000),
        "to": contractAddress,
        "value": "0x0",
        "data": contract.methods.safeTransferFrom(myAddress, toAddress, tokenId).encodeABI(),
      }

        var privateKey ='abcde'

        web3js.eth.accounts.signTransaction(transaction_data, privateKey)
        .then(function(value){
            web3js.eth.sendSignedTransaction(value.transaction_data)
            .then(function(response){
              console.log("response:" + JSON.stringify(response, null, ' '));
            })
          })

web3js.eth.accounts.signTransaction will take the burden of including the correct chainId and nonce . Reference: https://github.com/ChainSafe/web3.js/issues/1040