Ethereum web3 sendSignedTransaction: Insufficient funds. The account ... does not have enough funds. Required 750000000000000 and got: 0

Question

I am sending a signed transaction and getting errors:

Insufficient funds. The account you tried to send transaction from does not have enough funds. Required 750000000000000 and got: 0.

The thing is my account has enough funds, you can check it here 0x002D189c25958c60736aE21C966ff3131C2AC849 And if I set gasLimit: web3.utils.toHex(20000), then I get another error:

Transaction gas is too low. There is not enough gas to cover minimal cost of the transaction (minimal: 21464, got: 20000). Try increasing supplied gas.

Here is my node / web3 code:

const Web3 = require('web3')

// connect to Infura node
const web3 = new Web3(new Web3.providers.HttpProvider('https://kovan.infura.io/api_key'))

// the addresses & private key 
const addressFrom = '0x002D189c25958c60736aE21C966ff3131C2AC849';
const contractAddress = '0x36075430619b21Fff798454e2D5C81E9C18DEe81';
const privKey = '240462d...';

//ABI objects
var contractABI = new web3.eth.Contract(
    [ ...abi... ],
    contractAddress);
const contractFunction = contractABI.methods.changeBox(5);
const functionABI = contractFunction.encodeABI();

// construct the Tx data
const rawTx = {
    //gasPrice: '0x09184e72a000',
    gasLimit: web3.utils.toHex(25000),
    to: contractAddress,
    from: addressFrom,
    data: functionABI
    };

//sign & send Tx
web3.eth.accounts.signTransaction(rawTx, privKey)
    .then(RLPencodedTx => {
        web3.eth.sendSignedTransaction(RLPencodedTx['rawTransaction'])
            .on('receipt', console.log);
    });

Does anybody know why web3 is throwing these wrong errors?

Answer 1

I have created the account via Parity and also exported the account as json file, which contains ciphertext, which is the private key

cipthertext is an encrypted version of the private key. This Q&A includes some deeper background, if you're curious.

To get your private key, you will need the keyfile, and the password used to encrypt it. Then you can use web3.eth.accounts.decrypt() from web3.js v1 (beta) to extract the key, like so:

web3.eth.accounts.decrypt({
    version: 3,
    id: '04e9bcbb-96fa-497b-94d1-14df4cd20af6',
    address: '2c7536e3605d9c16a7a3d7b1898e529396a65c23',
    crypto: {
        ciphertext: 'a1c25da3ecde4e6a24f3697251dd15d6208520efc84ad97397e906e6df24d251',
        cipherparams: { iv: '2885df2b63f7ef247d753c82fa20038a' },
        cipher: 'aes-128-ctr',
        kdf: 'scrypt',
        kdfparams: {
            dklen: 32,
            salt: '4531b3c174cc3ff32a6a7a85d6761b410db674807b2d216d022318ceee50be10',
            n: 262144,
            r: 8,
            p: 1
        },
        mac: 'b8b010fff37f9ae5559a352a185e86f9b9c1d7f7a9f1bd4e82a5dd35468fc7f6'
    }
}, 'test!'); // <-- your password for the account goes in place of 'test!'
> {
    address: "0x2c7536E3605D9C16a7a3D7b1898e529396a65c23",
    privateKey: "0x4c0883a69102937d6231471b5dbb6204fe5129617082792ae468d01a3f362318",
    signTransaction: function(tx){...},
    sign: function(data){...},
    encrypt: function(password){...}
}