simple saml decoder

package.json

{
  "name": "saml-decode",
  "version": "1.0.0",
  "description": "",
  "main": "saml-decode.js",
  "scripts": {
    "start": "node saml-decode.js"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "saml-encoder-decoder-js": "^1.0.1",
    "xml2json": "^0.12.0"
  }
}

saml-decode.js

const fs = require('fs/promises')
const SAML = require('saml-encoder-decoder-js')
const xmlParser = require('xml2json')
const payloadFilename = process.env.FILE || 'input.txt'

const decodeSaml = async (token) => (
  new Promise(accept => {
    SAML.decodeSamlPost(token, function(err, xml) {
      if (err) {
        console.error(err)
        throw new Error(err)
      }
      accept(xml)
    })
  })
)

async function decode() {
  const data = await fs.readFile(payloadFilename, { encoding: 'utf8' })
  const xml = await decodeSaml(data).catch(e => process.exit(0))
  const json = xmlParser.toJson(xml, {
    object: true,
    sanitize: true,
    trim: true
  })
  console.log(json["samlp:Response"])
}

(async () => await decode())()