Sign a Message

import { useSignMessage } from '@wankmi/wankmi'
 
export function SignMessage() {
  const { signMessage, isPending, isSuccess, isError, data: signature } =
    useSignMessage()
 
  function handleSign() {
    const message = new TextEncoder().encode(
      `Sign in to MyApp\nTimestamp: ${Date.now()}`
    )
    signMessage(message)
  }
 
  return (
    <div>
      <button onClick={handleSign} disabled={isPending}>
        {isPending ? 'Waiting for signature...' : 'Sign In with Solana'}
      </button>
 
      {isSuccess && signature && (
        <p>
          ✅ Signed! Signature:{' '}
          <code>{Buffer.from(signature).toString('hex').slice(0, 16)}...</code>
        </p>
      )}
 
      {isError && <p>❌ Signing rejected.</p>}
    </div>
  )
}

import nacl from 'tweetnacl'
import { PublicKey } from '@solana/web3.js'
import bs58 from 'bs58'
 
function verifySignature(
  message: string,
  signature: Uint8Array,
  publicKeyBase58: string
): boolean {
  const messageBytes = new TextEncoder().encode(message)
  const publicKeyBytes = new PublicKey(publicKeyBase58).toBytes()
  return nacl.sign.detached.verify(messageBytes, signature, publicKeyBytes)
}

npm install tweetnacl bs58