openpgp

What is openpgp?

The openpgp npm package is a JavaScript implementation of the OpenPGP standard, which allows for encryption, decryption, signing, and verification of messages and files. It is widely used for secure communication and data protection.

What are openpgp's main functionalities?

Encrypting a message

This feature allows you to encrypt a message using a public key. The code sample demonstrates how to read a public key, create a message, and then encrypt it.

const openpgp = require('openpgp');
(async () => {
  const publicKeyArmored = '-----BEGIN PGP PUBLIC KEY BLOCK ... END PGP PUBLIC KEY BLOCK-----';
  const message = 'Hello, world!';
  const publicKey = await openpgp.readKey({ armoredKey: publicKeyArmored });
  const encrypted = await openpgp.encrypt({ message: await openpgp.createMessage({ text: message }), encryptionKeys: publicKey });
  console.log(encrypted);
})();

Decrypting a message

This feature allows you to decrypt a message using a private key and passphrase. The code sample demonstrates how to read a private key, decrypt it with a passphrase, read an encrypted message, and then decrypt it.

const openpgp = require('openpgp');
(async () => {
  const privateKeyArmored = '-----BEGIN PGP PRIVATE KEY BLOCK ... END PGP PRIVATE KEY BLOCK-----';
  const passphrase = 'yourPassphrase';
  const encryptedMessage = '-----BEGIN PGP MESSAGE ... END PGP MESSAGE-----';
  const privateKey = await openpgp.decryptKey({ privateKey: await openpgp.readPrivateKey({ armoredKey: privateKeyArmored }), passphrase });
  const message = await openpgp.readMessage({ armoredMessage: encryptedMessage });
  const { data: decrypted } = await openpgp.decrypt({ message, decryptionKeys: privateKey });
  console.log(decrypted);
})();

Signing a message

This feature allows you to sign a message using a private key and passphrase. The code sample demonstrates how to read a private key, decrypt it with a passphrase, create a message, and then sign it.

const openpgp = require('openpgp');
(async () => {
  const privateKeyArmored = '-----BEGIN PGP PRIVATE KEY BLOCK ... END PGP PRIVATE KEY BLOCK-----';
  const passphrase = 'yourPassphrase';
  const message = 'Hello, world!';
  const privateKey = await openpgp.decryptKey({ privateKey: await openpgp.readPrivateKey({ armoredKey: privateKeyArmored }), passphrase });
  const signedMessage = await openpgp.sign({ message: await openpgp.createMessage({ text: message }), signingKeys: privateKey });
  console.log(signedMessage);
})();

Verifying a signed message

This feature allows you to verify a signed message using a public key. The code sample demonstrates how to read a public key, read a signed message, and then verify the signature.

const openpgp = require('openpgp');
(async () => {
  const publicKeyArmored = '-----BEGIN PGP PUBLIC KEY BLOCK ... END PGP PUBLIC KEY BLOCK-----';
  const signedMessage = '-----BEGIN PGP SIGNED MESSAGE ... END PGP SIGNED MESSAGE-----';
  const publicKey = await openpgp.readKey({ armoredKey: publicKeyArmored });
  const message = await openpgp.readMessage({ armoredMessage: signedMessage });
  const verificationResult = await openpgp.verify({ message, verificationKeys: publicKey });
  const { verified } = verificationResult.signatures[0];
  try {
    await verified;
    console.log('Signature is valid');
  } catch (e) {
    console.log('Signature is invalid');
  }
})();

Other packages similar to openpgp

node-forge

node-forge is a JavaScript library that provides a set of cryptographic utilities, including support for RSA, AES, and other encryption algorithms. It is more general-purpose compared to openpgp, which is specifically focused on the OpenPGP standard.

crypto

The crypto module is a built-in Node.js module that provides cryptographic functionality, including a set of wrappers for OpenSSL's hash, HMAC, cipher, decipher, sign, and verify functions. It is more low-level compared to openpgp, which provides higher-level abstractions for OpenPGP operations.

kbpgp

kbpgp is a JavaScript library for OpenPGP encryption and decryption, similar to openpgp. It is designed to be compatible with the Keybase platform and provides a simpler API for common OpenPGP operations.

README

OpenPGP.js

OpenPGP.js is a Javascript implementation of the OpenPGP protocol. This is defined in RFC 4880.

Node support

For server side use, install via npm:

npm install openpgp

Browser support

For use in browser, install via bower:

bower install --save openpgp

Or Fetch a minified build under releases.

The library can be loaded via AMD/require.js or accessed globally via window.openpgp.

Dependencies

OpenPGP.js only supports browsers that implement window.crypto.getRandomValues. Also, if the browsers support native WebCrypto via the window.crypto.subtle api, this will be used. Though this can be deactivated by setting config.useWebCrypto = false. In this case the library will fall back to Web Worker operations if the initWorker(workerPath) is set.

OpenPGP.js uses ES6 promises which are available in most modern browsers. If you need to support browsers that do not support Promises, fear not! There is a polyfill, which is included in the build step. So no action required on the developer's part for promises!

Examples

Encryption

var openpgp = require('openpgp');
var key = '-----BEGIN PGP PUBLIC KEY BLOCK ... END PGP PUBLIC KEY BLOCK-----';
var publicKey = openpgp.key.readArmored(key);
openpgp.encryptMessage(publicKey.keys, 'Hello, World!').then(function(pgpMessage) {
    // success
}).catch(function(error) {
    // failure
});

Decryption

var openpgp = require('openpgp');
var key = '-----BEGIN PGP PRIVATE KEY BLOCK ... END PGP PRIVATE KEY BLOCK-----';
var privateKey = openpgp.key.readArmored(key).keys[0];
privateKey.decrypt('passphrase');
var pgpMessage = '-----BEGIN PGP MESSAGE ... END PGP MESSAGE-----';
pgpMessage = openpgp.message.readArmored(pgpMessage);
openpgp.decryptMessage(privateKey, pgpMessage).then(function(plaintext) {
    // success
}).catch(function(error) {
    // failure
});

Security recommendations

It should be noted that js crypto apps deployed via regular web hosting (a.k.a. host-based security) provide users with less security than installable apps with auditable static versions. Installable apps can be deployed as a Firefox or Chrome packaged app. These apps are basically signed zip files and their runtimes typically enforce a strict Content Security Policy (CSP) to protect users against XSS. This blogpost explains the trust model of the web quite well.

It is also recommended to set a strong passphrase that protects the user's private key on disk.

Development

To create your own build of the library, just run the following command after cloning the git repo. This will download all dependencies, run the tests and create a minifed bundle under dist/openpgp.min.js to use in your project:

npm install && npm test

Documentation

A jsdoc build of our code comments is available at doc/index.html. Public calls should generally be made through the OpenPGP object doc/openpgp.html.

Mailing List

You can sign up for our mailing list and ask for help there. We've recently worked on getting our archive up and running.

How do I get involved?

You want to help, great! Go ahead and fork our repo, make your changes and send us a pull request.

License

GNU Lesser General Public License (3.0 or any later version). Please take a look at the LICENSE file for more information.

Resources

Below is a collection of resources, many of these were projects that were in someway a precursor to the current OpenPGP.js project. If you'd like to add your link here, please do so in a pull request or email to the list.

• http://www.hanewin.net/encrypt/
• https://github.com/seancolyer/gmail-crypt
• https://github.com/mete0r/openpgp-js
• http://fitblip.github.com/JSPGP-Stuffs/
• http://qooxdoo.org/contrib/project/crypto
• https://github.com/GPGTools/Mobile/wiki/Introduction
• http://gpg4browsers.recurity.com/