Nodejs：按顺序运行承诺

Question

For a job where I need to put in place an oauth client authentication with private_key_jwt on an F5 big-ip. Since the built-in module for oauth doesn't take in charge this kind of authentication, this have to be achieved via their iRuleLX module which is nodejs based.

I have the following code to encrypt the JWT , but on some system, the result of the first promise is not available before the second promise is executed, which leads to an error ofc.

I made some google effort to find a way to process the two promises sequentially, but I was not able to find the correct way to achieve it (process asKey before executing the createEncrypt promise).

To be honest I'm not familiar with Node.js .

var f5 = require("f5-nodejs");
const { JWE, JWK } = require("node-jose");
var ilx = new f5.ILXServer();
var contentAlg = "A128CBC-HS256";
var key = "nok";
var token = "nok";
const skey = {
  kty: "RSA",
  e: "AQAB",
  use: "enc",
  kid: "e1",
  n:
    "vVm75k4dzUw_iuG8NvIvGS8o3dMvlpXwBX44ZcGgBzCnzHKjY37T8newmRcfmFkpvTR0qgYqtPeev5RwOZXXDO9Seg6Zkc_6sZjfSpeiOBebwW1DeZlEiYCTWSg6Ri5H26S3j6R8H_b3BCrtcd3gcmD7OwY280QvJ8eDmbJaj4aAaXf_Ef9RTYz1qJHnehbNRlmRr-OJuuYpsH497Is-c7OvUSLfMkItj9mtRKuk4DQ0LY5c5MYiyx1NidCuQTSK4VZSA3l6zMq-WN1pRb61hjfI74OO7gT256vQZZSq0DrzMPxA0mGeNDBlj6J5cBcdwnTAhF9mojs-ZwcAAvbgQ",
  alg: "RSA-OAEP",
  key_ops: ["encrypt", "wrap", ""]
};

var options = {
  compact: true,
  contentAlg: contentAlg,
  fields: {
    alg: "RSA-OAEP",
    kid: "e1",
    cty: "JWT",
    enc: contentAlg
  }
};

ilx.addMethod("test_jwk", function(req, res) {
  var payload = req.params()[0].toString();

  JWK.asKey(skey)
    .then(function(result) {
      key = result;
    })
    .catch(function(error) {
      key = "nok";
    });

  if (key != "nok") {
    jose.JWE.createEncrypt(options, key)
      .update(payload, "utf8")
      .final()
      .then(function(result) {
        token = result;
      })
      .catch(function(error) {
        token = "nok";
      });
  }

  res.reply(token);
});
ilx.listen();

Answer 1

You could use async/Await.

Try this,

var f5 = require('f5-nodejs');
const { JWE, JWK } = require('node-jose')
var ilx = new f5.ILXServer();
var contentAlg = "A128CBC-HS256";
var key = "nok";
var token = "nok";
const skey =
{
    "kty": "RSA",
    "e": "AQAB",
    "use": "enc",
    "kid": "e1",
    "n": "vVm75k4dzUw_iuG8NvIvGS8o3dMvlpXwBX44ZcGgBzCnzHKjY37T8newmRcfmFkpvTR0qgYqtPeev5RwOZXXDO9Seg6Zkc_6sZjfSpeiOBebwW1DeZlEiYCTWSg6Ri5H26S3j6R8H_b3BCrtcd3gcmD7OwY280QvJ8eDmbJaj4aAaXf_Ef9RTYz1qJHnehbNRlmRr-OJuuYpsH497Is-c7OvUSLfMkItj9mtRKuk4DQ0LY5c5MYiyx1NidCuQTSK4VZSA3l6zMq-WN1pRb61hjfI74OO7gT256vQZZSq0DrzMPxA0mGeNDBlj6J5cBcdwnTAhF9mojs-ZwcAAvbgQ",
    "alg": "RSA-OAEP",
    "key_ops": ["encrypt", "wrap", ""]
};
var options =
{
    compact: true,
    contentAlg: contentAlg,
    fields:
    {
        "alg": "RSA-OAEP",
        "kid": "e1",
        "cty": "JWT",
        "enc": contentAlg
    }
};
ilx.addMethod('test_jwk', async function (req, res) {
    var payload = req.params()[0].toString();
    try {
        key = await JWK.asKey(skey);
    } catch (error) {
        key = "nok";
    }

    if (key != "nok") {
        try {
            token = await jose.JWE.createEncrypt(options, key).update(payload, "utf8").final();
        } catch (error) {
            token = "nok";
        }
    }

    res.reply(token);
});
ilx.listen();

With then chaining .

ilx.addMethod('test_jwk',  function (req, res) {
    var payload = req.params()[0].toString();
        JWK.asKey(skey)
        .then( (result) => {
           return  result;
        })
        .then( key => {
            if(key !== "nok"){
                return jose.JWE.createEncrypt(options, key).update(payload, "utf8").final();
            } else {
                throw "Invalid key";
            }
        })
        .then( resToken => {
            token = resToken;
            res.reply(token);
        })
        .catch( error => {
            res.reply("nok");
        });
});

Answer 2

You can use async await:

ilx.addMethod('test_jwk', function async (req, res) {

var payload = req.params()[0].toString();


try {
      const key = await JWK.asKey(skey);

      const token = await jose.JWE.createEncrypt(options, key).update(payload, "utf8").final();

      res.reply(token); 
   } catch {
      res.reply('nok');
   }

});

You can surround the function body with try catch if you want.