Getting access token from Github

Question

I'm trying to get an access token from Github using a NodeJS client.

const axios = require("axios");
var jwt = require("jsonwebtoken");

exports.openedPOST = function openedPOST(req, res) {

// generate jwt
const now = Math.round(Date.now() / 1000);
const payload = {
    // issued at time
    iat: now,
    // expires in 10min
    exp: now + 600,
    // Github app id
    iss: 6700
};

const token = jwt.sign(payload, cert, { algorithm: "RS256" });
console.log(token)

// auth to github
axios({
  method: "get",
  url: "https://api.github.com/app",
  headers: {
    Accept: "application/vnd.github.machine-man-preview+json",
    Authorization: `Bearer ${token}`
  }
})
.then(function(response) {
  console.log(response.data);
})
.catch(function(error) {
  console.warn("Unable to authenticate");
  // The request was made and the server responded with a status code
  // that falls out of the range of 2xx
  if (error.response) {
    console.warn(`Status ${error.response.status}`);
    console.warn(`${error.response.data.message}`);
  }
});

res.status(200).end();

But this just produces: { "message": "A JSON web token could not be decoded", "documentation_url": "https://developer.github.com/v3" }

I have verified the token at https://jwt.io and the payload is as expected.

Answer 1

I got this working. It's largely based on what you have but there are a few tweaks:

const axios = require("axios");
var fs = require('fs');
var jwt = require("jsonwebtoken");


exports.openedPOST = function openedPOST(req, res) {

  // Private key contents
  var private_key = fs.readFileSync("/path/to/pemfile.pem");
  console.log("private_key: ", private_key);

  // generate jwt
  const now = Math.round(Date.now() / 1000);
  const payload = {
    // issued at time
    iat : now,
    // expires in 10min
    exp : now + (10 * 60),
    // Github app id
    iss : 7233
  };
  console.log("payload: ", payload);

  const token = jwt.sign(payload, private_key, { algorithm: 'RS256' })
  console.log("Token: ", token)

  // auth to github
  var instance = axios({
    method: "get",
    url: "https://api.github.com/app",
    headers: {
      "Accept" : "application/vnd.github.machine-man-preview+json",
      "Authorization" : `Bearer ${token}`
    }
  })
  .then(function(response) {
    console.log("Response: ",response.data);
  })
  .catch(function(error) {
    console.warn("Unable to authenticate");
    // The request was made and the server responded with a status code
    // that falls out of the range of 2xx
    if (error.response) {
      console.warn(`Status ${error.response.status}`);
      console.warn(`${error.response.data.message}`);
    }
  });
};
exports.openedPOST();

The main issue for me was with the private_key variable got generated. Alos, I changed 600 to (10 * 60) as I had got a different error at one stage of my investigation but that turned out to not be the problem. It doesn't really matter what you have there so I left it.

The other change I made was to assign axios to a variable. I'm relatively new to node.js so not really sure why this had to be done but suspect its something to do with the synchronous/asynchronous aspect of node.js.