jwt ->authentication

create jwt token -> during login,register (authentication) --> access-token and refresh-token
- jwt.sign({},<secret-key>,{ expiresIn : '2h' })
verify jwt token -> (autherization)
- jwt.verify(<token>,<secret-key>,()=>{})
access-token -> expire is given , -> no one can stole this token and use it
refresh-token -> regenerate access-token if user is valided (so that user dont be forced to be login again and again after 2h )

steps:

login generate -> access-token and refresh-token
with refresh-token we can generate ->new access-token and new refresh-token

frontend:

  const handleSubmit = async (e) => {
    e.preventDefault();
    try {
      const res = await axios.post("/login", { username, password });
      setUser(res.data);
    } catch (err) {
      console.log(err);
    }
  };

  const handleDelete = async (id) => {
    setSuccess(false);
    setError(false);
    try {
      await axiosJWT.delete("/users/" + id, {
        headers: { authorization: "Bearer " + user.accessToken },
      });
      setSuccess(true);
    } catch (err) {
      setError(true);
    }
  };

refresh-token -->

automatically called using axios.interceptors


  const refreshToken = async () => {
    try {
      const res = await axios.post("/refresh", { token: user.refreshToken });
      setUser({
        ...user,
        accessToken: res.data.accessToken,
        refreshToken: res.data.refreshToken,
      });
      return res.data;
    } catch (err) {
      console.log(err);
    }
  };

  const axiosJWT = axios.create()

  axiosJWT.interceptors.request.use(
    async (config) => {
      let currentDate = new Date();
      const decodedToken = jwt_decode(user.accessToken);
      if (decodedToken.exp * 1000 < currentDate.getTime()) {
        const data = await refreshToken();
        config.headers["authorization"] = "Bearer " + data.accessToken;
      }
      return config;
    },
    (error) => {
      return Promise.reject(error);
    }
  );