0

I'm using Infura as my web3 provider, and have MetaMask installed to connect to the blockchain. I'm trying to send a transaction, but have learned that Infura is read-only, and doesn't support the eth_sendTransaction method. I found this thread talking about it.

I'm trying to figure out how to sign a transaction locally then send it. This is my code that deals with signing and sending a transaction

...
let encodedData = await this.props.users.methods.registerUser(this.state.signUpUserName).encodeABI()

let signedData = await this.web3.eth.accounts.sign(encodedData, this.state.userAccount)

await this.web3.eth.sendSignedTransaction("0x" + signedData,function(err, result) {
    if(!err){
        console.log(result)
    }
})
...

I'm getting an error when I try to send the transaction, I think it's due to signedData not being RLP encoded, but I don't know much about it.

invalid argument 0: json: cannot unmarshal hex string of odd length into Go value of type hexutil.Bytes

signedData is an object containing the following data:

Object { message: "0x704f1b94000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000064a61726574680000000000000000000000000000000000000000000000000000", 
messageHash: "0x61f631cd8d21c0c03ca6548c35ec63b00aa41f53c4f3a89f1ef20ccc90b333e7", 
v: "0x1b", 
r: "0x5ed963bd343bdb044faf9a8f4074c074db6055cc72dd9d3e1032851e8d709dd2", 
s: "0x6fb58f55543c473e61dba4556021115c5aff041195453307a579eac5fa313685", 
signature: "0x5ed963bd343bdb044faf9a8f4074c074db6055cc72dd9d3e1032851e8d709dd26fb58f55543c473e61dba4556021115c5aff041195453307a579eac5fa3136851b" }

I was reading up on the ethereumjs-tx library, but that requires a private key to sign data, and as far as I know, you can't get the private key from metamask. Do I need to hardcode my private key from MetaMask into my code? How would one sign data locally and then proceed to send a transaction?

  • Is this in the browser? If so, why aren't you just using MetaMask? – smarx Jan 18 at 5:05
  • How would I do that? When I call web3.eth.sendTransaction or user .send after a contract function call I get the error, Returned error: The method eth_sendTransaction does not exist/is not available – JarethRader Jan 18 at 7:36
  • What web3 provider are you using? If you're using MetaMask's injected web3 provider, web3.eth.sendTransaction should work and pop up the MetaMask UI to have the user authorize the transaction. – smarx Jan 18 at 7:38
  • I'm using Infura as my web3 provider. I'll try using MetaMask instead. – JarethRader Jan 18 at 8:17
  • I switched to using MetaMask as my web3 provider and it works the way you said it would! – JarethRader Jan 23 at 8:26

Your Answer

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Browse other questions tagged or ask your own question.