Sign a message

Usage

Prove ownership of a wallet to a centralised backend. For eg - https://www.tensor.trade/rewards

Ref - https://github.com/anza-xyz/wallet-adapter/blob/3761cd8cc867da39da7c0b070bbf8779402cff36/packages/starter/example/src/components/SignMessage.tsx#L9

How to sign messages

• Install @noble/curves

npm install @noble/curves

• Coding the SignMessage component

import { ed25519 } from '@noble/curves/ed25519';
import { useWallet } from '@solana/wallet-adapter-react';
import bs58 from 'bs58';
import React from 'react';

export function SignMessage() {
    const { publicKey, signMessage } = useWallet();

    async function onClick() {
        if (!publicKey) throw new Error('Wallet not connected!');
        if (!signMessage) throw new Error('Wallet does not support message signing!');

        const message = document.getElementById("message").value;
        const encodedMessage = new TextEncoder().encode(message);
        const signature = await signMessage(encodedMessage);

        if (!ed25519.verify(signature, encodedMessage, publicKey.toBytes())) throw new Error('Message signature invalid!');
        alert('success', `Message signature: ${bs58.encode(signature)}`);
    };

    return (
        <div>
            <input id="message" type="text" placeholder="Message" />
            <button onClick={onClick}>
                Sign Message
            </button>
        </div>
    );
};