I need help to verify that jwt is valid or otherwise create a new one and if the token sent is not correct return an error in nestjs middleware

2
votes

I have already implemented the jwt and it works correctly but when creating a middleware that verifies that the token is still active and that it is valid, if the token has already expired, you must create a new one in case you can not create a new one, return a 404 error with a message, So far I have only been able to obtain the token and decode it, I need to be able to verify it and return an error response or let it continue.

this is my middleware code code:

import { JwtService } from '@nestjs/jwt';
import { Injectable, NestMiddleware } from '@nestjs/common';

@Injectable()
export class JwtMiddleware implements NestMiddleware {
    valid = null;
    decode = null;
    cleanToken = null;

    constructor(private readonly jwtServ: JwtService) {}

    use(req: Request, res: Response, next: Function) {
        const token = req.headers['authorization'];
        try {
            this.cleanToken = token.replace('Bearer','').trim();
            this.decode = this.jwtServ.decode(this.cleanToken);            
        } catch (error) {
            // console.log(error);
        }

        try {
            this.valid = this.jwtServ.verify(this.cleanToken);
        } catch (error) {
            console.log(error.name);
            console.log(error.message);
            console.log(error.expiredAt);
        }

        next();
    }
}

up to here I could only print in console the error of verifying jwt but it is not the correct way to do it besides that I can not return a valid answer to the client

console print:

  • TokenExpiredError
  • jwt expired
  • 2019-03-27T00:18:56.000Z

I searched the jwt documentation to see how to validate the token and found it: https://github.com/auth0/node-jsonwebtoken

// verify a token symmetric
jwt.verify(token, 'shhhhh', function(err, decoded) {
  console.log(decoded.foo) // bar
});

but in nestjs it does not work that way. The function "function (err, decoded)" can not be implemented like this, so it marks me errors so I had to put it in a trycatch

I also tried this:

this.jwtServ.verify(token,(err, decoded) => {
        if (err) {
            return res.status(401).json({
                ok: false,
                message: 'Invalid Token',
                errors: err
            });
        }

        req.user = decoded.user;

        next();
    });

in the nestjs documentation he says:

The Nest middleware, by default, are equal to express middleware. Here's a great list of the middleware capabilities copied from the official express documentation

https://docs.nestjs.com/middleware

I've already tried this and it does not work

return res.status(401).json({
                ok: false,
                message: 'Invalid Token',
                errors: err
            });

Any help is welcome, thanks!

1
jwtnestjs

1 Answers

0
votes

try this.. use 'jsonwebtoken' package

import * as jwt from 'jsonwebtoken';
jwt.verify(token, 'shhhhh', function(err, decoded){
 console.log(decoded.foo) // bar
});