Sign Function of web3.js for Authenticating users via MetaMask

Question

I am trying to follow the example found at this site in order to authenticate users using the MetaMask functionality. Furthermore, the web3.js documentation at the following site, specifies this sign function:

 web3.eth.personal.sign(dataToSign, address, password [, callback])

I have no issue in passing the dataToSign and address values to this function, however, how can I pass it the password?

Otherwise, is this the proper function to use in order to sign a nonce used for authenticating a user? Perhaps I need to use another function? This is my promise calling the function (with different possible alternative function):

 return new Promise((resolve, reject) =>
   // NOt sure which function among the ones below to use:
   this.web3.eth.personal.sign(this.web3.fromUtf8(nonce), account, (err, signature) => { // Or         
   this.web3.eth.sign(nonce, account, (err, signature) => { // Or
   this.web3.eth.accounts.sign(nonce, account, (err, signature) => { // Or
   this.web3.eth.personal.sign(nonce, account, password, (err, signature) => {
       if (err) return reject(err)
       return resolve([account, signature])
     })
   )

I did not have much success with any of them.

Thank you. J

Answer 1

The article you linked to is more than two years old!! It made references to web3 previous version v0.20.

With web3 v1.2, there were several changes. For signing, you can choose between:

• web3.eth.sign(dataToSign, address [, callback]) leverages account management on web3 provider, for example MetaMask.
• web3.eth.accounts.sign(data, privateKey) in case you have account private key.
• web3.eth.personal.sign(dataToSign, address, password [, callback]) for web3 providers that allow unlocking accounts programmatically, for example geth.

This answer has an example with the correct syntax for web3 v1.2 for the first two cases: https://ethereum.stackexchange.com/a/76578