Verify public and private key combination

Question

If we have both a wallet address and private key, what is the best way to determine if the private key is indeed corresponding to the wallet address using a NodeJS server. Is the best way to sign a message with private key and verify the signature with public key, or is there a better way?

Answer 1

Using solana-keygen cli tool you can verify by running this,

solana-keygen verify <walletPublickey> path_to_wallet/keypair.json

Yes, we sign a message with a private key and verify the signature with public key.

In NodeJs:-

Solana web3 package has a Keypair class using that one can verify a secret belongs to a publicKey or not.

const { Keypair } = require('@solana/web3.js');

const data = require('path_to_keypair.json'); // this is just an array, need to create a Uint8 array

const secretKey = new Uint8Array(data);
let account = Keypair.fromSecretKey(secretKey);

console.log(account.publicKey.toBase58()); // publicKey