encrypt and decrypt using symmetric key with `node-jose`

node-jose-example.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {
    "deletable": true,
    "editable": true
   },
   "source": [
    "# JOSE encryption and decryption with `node-jose`\n",
    "\n",
    "`node-jose` is `Promise` based."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {
    "collapsed": false,
    "deletable": true,
    "editable": true
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{\"JWA\":{},\"JWE\":{},\"JWK\":{\"MODE_SIGN\":\"sign\",\"MODE_VERIFY\":\"verify\",\"MODE_ENCRYPT\":\"encrypt\",\"MODE_DECRYPT\":\"decrypt\",\"MODE_WRAP\":\"wrap\",\"MODE_UNWRAP\":\"unwrap\"},\"JWS\":{},\"util\":{\"base64url\":{},\"utf8\":{}}}"
      ]
     },
     "execution_count": 3,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "jose = require('node-jose')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Though key is 256bit binary but we use text of 32 characters for this (though it is insecure, just for test)."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {
    "collapsed": false,
    "deletable": true,
    "editable": true
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[Promise] {}"
      ]
     },
     "execution_count": 5,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "keyPromise = jose.JWK.asKey({kty:'oct', k: jose.util.base64url.encode('1234567890abcdef1234567890abcdef')})"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Here is JWK of key created above."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {
    "collapsed": false,
    "deletable": true,
    "editable": true
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[Promise] {}"
      ]
     },
     "execution_count": 7,
     "metadata": {},
     "output_type": "execute_result"
    },
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "{\"kty\":\"oct\",\"kid\":\"9payyFW0LtFts92D19URBI-ylw9Lhveb5tRJbI1S_ow\",\"k\":\"MTIzNDU2Nzg5MGFiY2RlZjEyMzQ1Njc4OTBhYmNkZWY\"}\n"
     ]
    }
   ],
   "source": [
    "keyPromise.then(key => console.log(key.toJSON(true)))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "We are going to encrypt a plaintext `hello!` with JWE and decrypt it."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 22,
   "metadata": {
    "collapsed": false,
    "deletable": true,
    "editable": true,
    "scrolled": false
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[Promise] {}"
      ]
     },
     "execution_count": 22,
     "metadata": {},
     "output_type": "execute_result"
    },
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "eyJhbGciOiJBMjU2S1ciLCJraWQiOiI5cGF5eUZXMEx0RnRzOTJEMTlVUkJJLXlsdzlMaHZlYjV0UkpiSTFTX293IiwiZW5jIjoiQTEyOENCQy1IUzI1NiJ9.7dYNSGo0OPsGAzAfkoD1zTJyIvOFaI6D66dr5Hqgw1u0kdXczQuDkQ.TNOfavBvleb2SQtCFcQU4Q.41Z5hFgYM9cpzBy8RDk3pg.yPMnWxHeTpkyL-f5i5dxxw\n",
      ".......\n",
      "{\n",
      "  \"key\": {\n",
      "    \"kty\": \"oct\",\n",
      "    \"kid\": \"9payyFW0LtFts92D19URBI-ylw9Lhveb5tRJbI1S_ow\"\n",
      "  },\n",
      "  \"header\": {\n",
      "    \"alg\": \"A256KW\",\n",
      "    \"kid\": \"9payyFW0LtFts92D19URBI-ylw9Lhveb5tRJbI1S_ow\",\n",
      "    \"enc\": \"A128CBC-HS256\"\n",
      "  },\n",
      "  \"protected\": [\n",
      "    \"alg\",\n",
      "    \"kid\",\n",
      "    \"enc\"\n",
      "  ],\n",
      "  \"plaintext\": {\n",
      "    \"type\": \"Buffer\",\n",
      "    \"data\": [\n",
      "      104,\n",
      "      101,\n",
      "      108,\n",
      "      108,\n",
      "      111,\n",
      "      33\n",
      "    ]\n",
      "  },\n",
      "  \"payload\": {\n",
      "    \"type\": \"Buffer\",\n",
      "    \"data\": [\n",
      "      104,\n",
      "      101,\n",
      "      108,\n",
      "      108,\n",
      "      111,\n",
      "      33\n",
      "    ]\n",
      "  }\n",
      "}\n",
      ".......\n",
      "hello!\n"
     ]
    }
   ],
   "source": [
    "payload = 'hello!'\n",
    "keyPromise.then(key => {\n",
    "    const encryptedPromise = jose.JWE.createEncrypt({format:'compact'},key).update(payload).final()\n",
    "    \n",
    "    encryptedPromise.then(encrypted => {\n",
    "        console.log(encrypted)\n",
    "        console.log('.......')\n",
    "        jose.JWE.createDecrypt(key).decrypt(encrypted).then(result => {\n",
    "            console.log(JSON.stringify(result, null, 2))\n",
    "            console.log('.......')\n",
    "            console.log(result.payload.toString())\n",
    "        })\n",
    "    })\n",
    "    \n",
    "})"
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "NodeJS",
   "language": "javascript",
   "name": "nodejs"
  },
  "language_info": {
   "codemirror_mode": "javascript",
   "file_extension": ".js",
   "mimetype": "text/javascript",
   "name": "nodejs",
   "pygments_lexer": "javascript",
   "version": "0.10"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 2
}

👍