Sign any message with the user’s private key and verify the signature on Ethereum

Question

I'm trying to explore Ethereum and creating a app which let user sign message and validate the message. I'm using web3swift framework for this and what I have tried so far is as follows -

    let web3Rinkeby = Web3.InfuraRinkebyWeb3()
    let msgStr = "This is my first Ethereum App";
    let data = msgStr.data(using: .utf8)
    let signMsg = web3Rinkeby.wallet.signPersonalMessage(data!, account: address);

    print(signMsg);

but I'm not sure if this is right and how to validate any message as well. Please help.

Answer 1

Seems, that you didn't specify exact address. Here is an example:

let web3Rinkeby = Web3.InfuraRinkebyWeb3()

/// 
    let keystore = try! EthereumKeystoreV3(password: "")
    let keystoreManager = KeystoreManager([keystore!])
    web3Rinkeby.addKeystoreManager(keystoreManager)
    let address = keystoreManager.addresses![0]
///

let msgStr = "This is my first Ethereum App";
let data = msgStr.data(using: .utf8)
let signMsg = web3Rinkeby.wallet.signPersonalMessage(data!, account: address);

print(signMsg);

Here is an example, how to sign transactions in the tests of the project :