Secure our website using JWT (JSON Web Token) in nodeJS or expressJS

#javascript #react #node #devops

here we are using JWT to secure our application or website from unauthenticated user they try to access our data.

In npmjs a library named is

jsonwebtoken

npm i jsonwebtoken

if we only check user isAuthenticated or not we simply pass the middleware in between request and response

auth.js

`export default function getTokenFromUser(req: Request) {
  const authorization = req.headers.token;
  var decoded = jwt.verify(authorization, 'secret');
  if (!decoded) {
    throw new TokenError("No Authorization Header");
  }
  try {
    const token = decoded?.split("User data ")[1];
    return token;
  } catch {
    throw new TokenError("Invalid Token Format");
  }
}`

we simple pass this auth of in between req,res

app.post('/api/post',auth,(req,res)=>{
//if some operation on code we use middleware
const token=jwt.sign({
  data: 'your data to store as token'
}, 'secret', { expiresIn: '1h' });

res.header('token',token).send("success")
});

we ensure that you can save your secret key in your config file.