const express = require("express");
const bodyParser = require("body-parser");
const fs = require("fs");
const jwt = require("jsonwebtoken");
const privateKey = fs.readFileSync("callback_private.pem");
const cosignerPubKey = fs.readFileSync("cosigner_public.pem");
const app = express();

app.use(
  express.urlencoded({
    extended: true
  })
);
app.use(express.json());

app.use(function (req) {
  req.rawBody = "";
  req.setEncoding("utf8");
  req.on("data", function(chunk) {
    req.rawBody += chunk;
  });
  req.on("end", function () {
   req.next();
  });
});

app.post("/v2/tx_sign_request", async (req, res) => {
  let verified;
  try {
  const tx = jwt.decode(req.rawBody);
  const { requestId } = tx;
  verified = jwt.verify(req.rawBody, cosignerPubKey);
  if (verified) {
    let action = "REJECT";
    let rejectionReason = "Logic returned false";
    const signedRes = jwt.sign(
      {
        action,
        requestId,
        rejectionReason
      },
      privateKey,
      { algorithm: "RS256" }
    );
    res.send(signedRes);
  }
  } catch (e) {
    res.sendStatus(401);
  }
});
app.listen(3000);

from pathlib import Path
from wsgiref.simple_server import make_server
import falcon
import jwt
callback_handler_prikey = None
cosigner_pubkey = None

# Load keys.
f1 = Path("callback_private.pem")
if f1.is_file(): callback_handler_prikey = f1.read_bytes()
f2 = Path("cosigner_public.pem")
if f2.is_file(): cosigner_pubkey = f2.read_bytes()

class JWTTransferRequest(object):
    def on_post(self, req, resp):
        raw_req = req.bounded_stream.read()
        req = jwt.decode(raw_req, cosigner_pubkey, algorithms=["RS256"])
        resp.body = jwt.encode({'action': 'APPROVE', 'requestId': req['requestId']}, callback_handler_prikey, algorithm="RS256")
        resp.status = falcon.HTTP_200

# Create falcon app
app = falcon.App()
app.add_route('/v2/tx_sign_request', JWTTransferRequest())
app.add_route('/v2/config_change_sign_request', JWTTransferRequest())
if __name__ == '__main__':
    with make_server('', 80, app) as httpd:
        print('Serving on port 80...')
        # Serve until process is killed
        httpd.serve_forever()
JWTTransferRequest()