Sign Message

Sign and verify challenges for off-chain authentication
For dApps relying on signMessage for off-chain authentication, Blocto follows EIP-1654. To verify the signature, you need to call a method on the wallet contract to check if the signature came from a rightful owner of the wallet contract.
Dapper Labs has built the tools to carry out this verification:
​Go implementation​
​JavaScript implementation​
Use it in your dApps:
Go
JavaScript
Go
package main
​
import (
	"log"
	"net/http"
​
	"github.com/ethereum/go-ethereum/ethclient"
	"github.com/dapperlabs/dappauth"
)
​
// AuthenticationHandler ..
type AuthenticationHandler struct {
	client *ethclient.Client
}
​
// NewAuthenticationHandler ..
func NewAuthenticationHandler(rawurl string) (*AuthenticationHandler, error) {
	client, err := ethclient.Dial(rawurl)
	if err != nil {
		return nil, err
	}
	return &AuthenticationHandler{client: client}, nil
}
​
// ServeHTTP serves just a single route for authentication as an example
func (a *AuthenticationHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
​
	challenge := r.PostFormValue("challenge")
	signature := r.PostFormValue("signature")
	addrHex := r.PostFormValue("addrHex")
​
	authenticator := dappauth.NewAuthenticator(r.Context(), a.client)
	isAuthorizedSigner, err := authenticator.IsAuthorizedSigner(challenge, signature, addrHex)
	if err != nil {
		// return a 5XX status code
	}
	if !isAuthorizedSigner{
		// return a 4XX status code
	}
​
	// create an authenticated session for address
	// return a 2XX status code
}
​
func main() {
	handler, err := NewAuthenticationHandler("https://mainnet.infura.io")
	if err != nil {
		log.Fatal(err)
	}
​
	log.Fatal(http.ListenAndServe(":8080", handler))
}
JavaScript
const Web3 = require('web3');
const DappAuth = require('@dapperlabs/dappauth');
​
const dappAuth = new DappAuth(new Web3.providers.HttpProvider('http://localhost:8545'));
​
async function debug() {
  const challenge = 'foo';
  const signature =
    '0x33838c6f4e621982c2009f9b93ecb854a4b122538159623abc87d2e4c5bd6d2e33591f443b419b3bd2790e455ba6d625f2ca14b822c5cef824ef7e9021443bed1c';
  const address = '0x86aa354fc865925f945b803ceae0b3f9d856b269';
​
  try {
    const isAuthorizedSigner = await dappAuth.isAuthorizedSigner(
      challenge,
      signature,
      address,
    );
​
    console.log(isAuthorizedSigner); // true
  } catch (e) {
    console.log(e);
  }
}
Blocto - Previous
Web3.js Integration (Ethereum/BSC/Tron)
Batch Transaction
Last updated 2 months ago