OpenPGP.js

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

Table of Contents

OpenPGP.js

Platform Support

The dist/openpgp.min.js bundle works well with recent versions of Chrome, Firefox, Safari and Edge. It also works in Node.js 8+.
The dist/compat/openpgp.min.js bundle also works with Internet Explorer 11 and old versions of Safari. Please note that this bundle overwrites the global Promise with a polyfill version even in some cases where it already exists, which may cause issues. It also adds some built-in prototype functions if they don’t exist, such as Array.prototype.includes.
If you wish, you could even load one or the other depending on which browser the user is using. However, if you’re using the Web Worker, keep in mind that you also need to pass { path: 'compat/openpgp.worker.min.js' } to initWorker whenever you load compat/openpgp.min.js.
Currently, Chrome, Safari and Edge have partial implementations of the Streams specification, and Firefox has a partial implementation behind feature flags. Chrome is the only browser that implements TransformStreams, which we need, so we include a polyfill for all other browsers. Please note that in those browsers, the global ReadableStream property gets overwritten with the polyfill version if it exists. In some edge cases, you might need to use the native ReadableStream (for example when using it to create a Response object), in which case you should store a reference to it before loading OpenPGP.js. There is also the web-streams-adapter library to convert back and forth between them.

Performance

Version 3.0.0 of the library introduces support for public-key cryptography using elliptic curves. We use native implementations on browsers and Node.js when available or Elliptic otherwise. Elliptic curve cryptography provides stronger security per bits of key, which allows for much faster operations. Currently the following curves are supported (* = when available):

Curve	Encryption	Signature	Elliptic	NodeCrypto	WebCrypto
p256	ECDH	ECDSA	Yes	Yes*	Yes*
p384	ECDH	ECDSA	Yes	Yes*	Yes*
p521	ECDH	ECDSA	Yes	Yes*	Yes*
secp256k1	ECDH	ECDSA	Yes	Yes*	No
brainpoolP256r1	ECDH	ECDSA	Yes	Yes*	No
brainpoolP384r1	ECDH	ECDSA	Yes	Yes*	No
brainpoolP512r1	ECDH	ECDSA	Yes	Yes*	No
curve25519	ECDH	N/A	Yes	No	No
ed25519	N/A	EdDSA	Yes	No	No

Version 2.x of the library has been built from the ground up with Uint8Arrays. This allows for much better performance and memory usage than strings.
If the user’s browser supports native WebCrypto via the window.crypto.subtle API, this will be used. Under Node.js the native crypto module is used. This can be deactivated by setting openpgp.config.use_native = false.
The library implements the IETF proposal for authenticated encryption using native AES-EAX, OCB, or GCM. This makes symmetric encryption up to 30x faster on supported platforms. Since the specification has not been finalized and other OpenPGP implementations haven’t adopted it yet, the feature is currently behind a flag. Note: activating this setting can break compatibility with other OpenPGP implementations, and also with future versions of OpenPGP.js. Don’t use it with messages you want to store on disk or in a database. You can enable it by setting openpgp.config.aead_protect = true.

You can change the AEAD mode by setting one of the following options:
```
openpgp.config.aead_mode = openpgp.enums.aead.eax // Default, native
openpgp.config.aead_mode = openpgp.enums.aead.ocb // Non-native
openpgp.config.aead_mode = openpgp.enums.aead.experimental_gcm // **Non-standard**, fastest
```
For environments that don’t provide native crypto, the library falls back to asm.js implementations of AES, SHA-1, and SHA-256. We use Rusha and asmCrypto Lite (a minimal subset of asmCrypto.js built specifically for OpenPGP.js).

Getting started

Npm

npm install --save openpgp

Bower

bower install --save openpgp

Or just fetch a minified build under dist.

Examples

Here are some examples of how to use the v2.x+ API. For more elaborate examples and working code, please check out the public API unit tests. If you’re upgrading from v1.x it might help to check out the documentation.

Set up

Node.js

const openpgp = require('openpgp');

Browser

Copy dist/openpgp.min.js or dist/compat/openpgp.min.js (depending on the browser support you need, see Platform Support) to your project folder, and load it in a script tag:

<script src="openpgp.min.js"></script>

If you want to use the built-in Web Worker, to offload cryptographic operations off the main thread:

await openpgp.initWorker({ path: 'openpgp.worker.js' }); // set the relative web worker path

On logout, be sure to destroy the worker again, to clear private keys from memory:

await openpgp.destroyWorker();

Alternatively, you can also implement a Web Worker in your application and load OpenPGP.js from there. This can be more performant if you store or fetch keys and messages directly inside the Worker, so that they don’t have to be postMessaged there.

If you want to use the lightweight build (which is smaller, and lazily loads non-default curves on demand), copy dist/lightweight/openpgp.min.js and dist/lightweight/elliptic.min.js, load the former in a script tag, and point openpgp.config.indutny_elliptic_path to the latter:

<script src="lightweight/openpgp.min.js"></script>
<script>
openpgp.config.indutny_elliptic_path = 'lightweight/elliptic.min.js';
</script>

To test whether the lazy loading works, try:

await openpgp.generateKey({ curve: 'brainpoolP512r1',  userIds: [{ name: 'Test', email: 'test@test.com' }] });

For more examples of how to generate a key, see Generate new key pair. It is recommended to use curve25519 instead of brainpoolP512r1 by default.

Encrypt and decrypt Uint8Array data with a password

Encryption will use the algorithm specified in config.encryption_cipher (defaults to aes256), and decryption will use the algorithm used for encryption.

(async () => {
    const { message } = await openpgp.encrypt({
        message: openpgp.message.fromBinary(new Uint8Array([0x01, 0x01, 0x01])), // input as Message object
        passwords: ['secret stuff'],                                             // multiple passwords possible
        armor: false                                                             // don't ASCII armor (for Uint8Array output)
    });
    const encrypted = message.packets.write(); // get raw encrypted packets as Uint8Array

    const { data: decrypted } = await openpgp.decrypt({
        message: await openpgp.message.read(encrypted), // parse encrypted bytes
        passwords: ['secret stuff'],                    // decrypt with password
        format: 'binary'                                // output as Uint8Array
    });
    console.log(decrypted); // Uint8Array([0x01, 0x01, 0x01])
})();

Encrypt and decrypt String data with PGP keys

Encryption will use the algorithm preferred by the public key (defaults to aes256 for keys generated in OpenPGP.js), and decryption will use the algorithm used for encryption.

const openpgp = require('openpgp'); // use as CommonJS, AMD, ES6 module or via window.openpgp

(async () => {
    await openpgp.initWorker({ path: 'openpgp.worker.js' }); // set the relative web worker path

    // put keys in backtick (``) to avoid errors caused by spaces or tabs
    const publicKeyArmored = `-----BEGIN PGP PUBLIC KEY BLOCK-----
...
-----END PGP PUBLIC KEY BLOCK-----`;
    const privateKeyArmored = `-----BEGIN PGP PRIVATE KEY BLOCK-----
...
-----END PGP PRIVATE KEY BLOCK-----`; // encrypted private key
    const passphrase = `yourPassphrase`; // what the private key is encrypted with

    const { keys: [privateKey] } = await openpgp.key.readArmored(privateKeyArmored);
    await privateKey.decrypt(passphrase);

    const { data: encrypted } = await openpgp.encrypt({
        message: openpgp.message.fromText('Hello, World!'),                 // input as Message object
        publicKeys: (await openpgp.key.readArmored(publicKeyArmored)).keys, // for encryption
        privateKeys: [privateKey]                                           // for signing (optional)
    });
    console.log(encrypted); // '-----BEGIN PGP MESSAGE ... END PGP MESSAGE-----'
    const { data: decrypted } = await openpgp.decrypt({
        message: await openpgp.message.readArmored(encrypted),              // parse armored message
        publicKeys: (await openpgp.key.readArmored(publicKeyArmored)).keys, // for verification (optional)
        privateKeys: [privateKey]                                           // for decryption
    });
    console.log(decrypted); // 'Hello, World!'
})();

Encrypt with multiple public keys:

(async () => {
    const publicKeysArmored = [
        `-----BEGIN PGP PUBLIC KEY BLOCK-----
...
-----END PGP PUBLIC KEY BLOCK-----`,
        `-----BEGIN PGP PUBLIC KEY BLOCK-----
...
-----END PGP PUBLIC KEY BLOCK-----`
    ];
    const privateKeyArmored = `-----BEGIN PGP PRIVATE KEY BLOCK-----
...
-----END PGP PRIVATE KEY BLOCK-----`;    // encrypted private key
    const passphrase = `yourPassphrase`; // what the private key is encrypted with
    const message = 'Hello, World!';

    const { keys: [privateKey] } = await openpgp.key.readArmored(privateKeyArmored);
    await privateKey.decrypt(passphrase)

    const publicKeys = await Promise.all(publicKeysArmored.map(async (key) => {
        return (await openpgp.key.readArmored(key)).keys[0];
    }));

    const { data: encrypted } = await openpgp.encrypt({
        message: openpgp.message.fromText(message),   // input as Message object
        publicKeys,                                   // for encryption
        privateKeys: [privateKey]                     // for signing (optional)
    });
    console.log(encrypted); // '-----BEGIN PGP MESSAGE ... END PGP MESSAGE-----'
})();

Encrypt with compression

By default, encrypt will not use any compression. It’s possible to override that behavior in two ways:

Either set the compression parameter in the options object when calling encrypt.

(async () => {
    const encrypted = await openpgp.encrypt({
        message: openpgp.message.fromBinary(new Uint8Array([0x01, 0x02, 0x03])), // or .fromText('string')
        passwords: ['secret stuff'],                                             // multiple passwords possible
        compression: openpgp.enums.compression.zip                               // compress the data with zip
    });
})();

Or, override the config to enable compression:

openpgp.config.compression = openpgp.enums.compression.zlib;

Where the value can be any of:

openpgp.enums.compression.zip
openpgp.enums.compression.zlib

Streaming encrypt Uint8Array data with a password

(async () => {
    const readableStream = new ReadableStream({
        start(controller) {
            controller.enqueue(new Uint8Array([0x01, 0x02, 0x03]));
            controller.close();
        }
    });

    const { message } = await openpgp.encrypt({
        message: openpgp.message.fromBinary(readableStream), // input as Message object
        passwords: ['secret stuff'],                         // multiple passwords possible
        armor: false                                         // don't ASCII armor (for Uint8Array output)
    });
    const encrypted = message.packets.write(); // get raw encrypted packets as ReadableStream<Uint8Array>

    // Either pipe the above stream somewhere, pass it to another function,
    // or read it manually as follows:
    const reader = openpgp.stream.getReader(encrypted);
    while (true) {
        const { done, value } = await reader.read();
        if (done) break;
        console.log('new chunk:', value); // Uint8Array
    }

    // Or, in Node.js, you can pipe the above stream as follows:
    const nodeStream = openpgp.stream.webToNode(encrypted);
    nodeStream.pipe(nodeWritableStream);
})();

For more information on creating ReadableStreams, see the MDN Documentation on new ReadableStream(). For more information on reading streams using openpgp.stream, see the documentation of the web-stream-tools dependency, particularly its Reader class.

Streaming encrypt and decrypt String data with PGP keys

(async () => {
    const publicKeyArmored = `-----BEGIN PGP PUBLIC KEY BLOCK-----
...
-----END PGP PUBLIC KEY BLOCK-----`; // Public key
    const [privateKeyArmored] = `-----BEGIN PGP PRIVATE KEY BLOCK-----
...
-----END PGP PRIVATE KEY BLOCK-----`; // Encrypted private key
    const passphrase = `yourPassphrase`; // Password that private key is encrypted with

    const privateKey = (await openpgp.key.readArmored([privateKeyArmored])).keys[0];
    await privateKey.decrypt(passphrase);

    const readableStream = new ReadableStream({
        start(controller) {
            controller.enqueue('Hello, world!');
            controller.close();
        }
    });

    const encrypted = await openpgp.encrypt({
        message: openpgp.message.fromText(readableStream),                  // input as Message object
        publicKeys: (await openpgp.key.readArmored(publicKeyArmored)).keys, // for encryption
        privateKeys: [privateKey]                                           // for signing (optional)
    });
    const ciphertext = encrypted.data; // ReadableStream containing '-----BEGIN PGP MESSAGE ... END PGP MESSAGE-----'

    const decrypted = await openpgp.decrypt({
        message: await openpgp.message.readArmored(ciphertext),             // parse armored message
        publicKeys: (await openpgp.key.readArmored(publicKeyArmored)).keys, // for verification (optional)
        privateKeys: [privateKey]                                           // for decryption
    });
    const plaintext = await openpgp.stream.readToEnd(decrypted.data); // 'Hello, World!'
})();

Generate new key pair

ECC keys:

Possible values for curve are: curve25519, ed25519, p256, p384, p521, secp256k1, brainpoolP256r1, brainpoolP384r1, or brainpoolP512r1. Note that both the curve25519 and ed25519 options generate a primary key for signing using Ed25519 and a subkey for encryption using Curve25519.

(async () => {
    const { privateKeyArmored, publicKeyArmored, revocationCertificate } = await openpgp.generateKey({
        userIds: [{ name: 'Jon Smith', email: 'jon@example.com' }], // you can pass multiple user IDs
        curve: 'ed25519',                                           // ECC curve name
        passphrase: 'super long and hard to guess secret'           // protects the private key
    });

    console.log(privateKeyArmored);     // '-----BEGIN PGP PRIVATE KEY BLOCK ... '
    console.log(publicKeyArmored);      // '-----BEGIN PGP PUBLIC KEY BLOCK ... '
    console.log(revocationCertificate); // '-----BEGIN PGP PUBLIC KEY BLOCK ... '
})();

RSA keys:

(async () => {
    const key = await openpgp.generateKey({
        userIds: [{ name: 'Jon Smith', email: 'jon@example.com' }], // you can pass multiple user IDs
        rsaBits: 4096,                                              // RSA key size
        passphrase: 'super long and hard to guess secret'           // protects the private key
    });
})();

Revoke a key

Using a revocation certificate:

(async () => {
    const { publicKeyArmored: revokedKeyArmored } = await openpgp.revokeKey({
        key: (await openpgp.key.readArmored(publicKeyArmored)).keys[0],
        revocationCertificate
    });
    console.log(revokedKeyArmored); // '-----BEGIN PGP PUBLIC KEY BLOCK ... '
})();

Using the private key:

(async () => {
    const { publicKeyArmored, publicKey } = await openpgp.revokeKey({
        key: (await openpgp.key.readArmored(privateKeyArmored)).keys[0]
    });
})();

Lookup public key on HKP server

(async () => {
    var hkp = new openpgp.HKP(); // Defaults to https://keyserver.ubuntu.com, or pass another keyserver URL as a string

    let publicKeyArmored = await hkp.lookup({
        query: 'alice@example.com'
    });
    var { keys: [publicKey] } = await openpgp.key.readArmored(publicKeyArmored);
})();

Upload public key to HKP server

(async () => {
    var hkp = new openpgp.HKP('https://pgp.mit.edu');

    var publicKeyArmored = `-----BEGIN PGP PUBLIC KEY BLOCK-----
...
-----END PGP PUBLIC KEY BLOCK-----`;

    await hkp.upload(publicKeyArmored);
})();

Sign and verify cleartext messages

(async () => {
    const publicKeyArmored = `-----BEGIN PGP PUBLIC KEY BLOCK-----
...
-----END PGP PUBLIC KEY BLOCK-----`;
    const privateKeyArmored = `-----BEGIN PGP PRIVATE KEY BLOCK-----
...
-----END PGP PRIVATE KEY BLOCK-----`; // encrypted private key
    const passphrase = `yourPassphrase`; // what the private key is encrypted with

    const { keys: [privateKey] } = await openpgp.key.readArmored(privateKeyArmored);
    await privateKey.decrypt(passphrase);

    const { data: cleartext } = await openpgp.sign({
        message: openpgp.cleartext.fromText('Hello, World!'), // CleartextMessage or Message object
        privateKeys: [privateKey]                             // for signing
    });
    console.log(cleartext); // '-----BEGIN PGP SIGNED MESSAGE ... END PGP SIGNATURE-----'

    const verified = await openpgp.verify({
        message: await openpgp.cleartext.readArmored(cleartext),           // parse armored message
        publicKeys: (await openpgp.key.readArmored(publicKeyArmored)).keys // for verification
    });
    const { valid } = verified.signatures[0];
    if (valid) {
        console.log('signed by key id ' + verified.signatures[0].keyid.toHex());
    } else {
        throw new Error('signature could not be verified');
    }
})();

Create and verify detached signatures

(async () => {
    const publicKeyArmored = `-----BEGIN PGP PUBLIC KEY BLOCK-----
...
-----END PGP PUBLIC KEY BLOCK-----`;
    const privateKeyArmored = `-----BEGIN PGP PRIVATE KEY BLOCK-----
...
-----END PGP PRIVATE KEY BLOCK-----`; // encrypted private key
    const passphrase = `yourPassphrase`; // what the private key is encrypted with

    const { keys: [privateKey] } = await openpgp.key.readArmored(privateKeyArmored);
    await privateKey.decrypt(passphrase);

    const { signature: detachedSignature } = await openpgp.sign({
        message: openpgp.cleartext.fromText('Hello, World!'), // CleartextMessage or Message object
        privateKeys: [privateKey],                            // for signing
        detached: true
    });
    console.log(detachedSignature);

    const verified = await openpgp.verify({
        message: openpgp.cleartext.fromText('Hello, World!'),              // CleartextMessage or Message object
        signature: await openpgp.signature.readArmored(detachedSignature), // parse detached signature
        publicKeys: (await openpgp.key.readArmored(publicKeyArmored)).keys // for verification
    });
    const { valid } = verified.signatures[0];
    if (valid) {
        console.log('signed by key id ' + verified.signatures[0].keyid.toHex());
    } else {
        throw new Error('signature could not be verified');
    }
})();

Streaming sign and verify Uint8Array data

(async () => {
    var readableStream = new ReadableStream({
        start(controller) {
            controller.enqueue(new Uint8Array([0x01, 0x02, 0x03]));
            controller.close();
        }
    });

    const publicKeyArmored = `-----BEGIN PGP PUBLIC KEY BLOCK-----
...
-----END PGP PUBLIC KEY BLOCK-----`;
    const privateKeyArmored = `-----BEGIN PGP PRIVATE KEY BLOCK-----
...
-----END PGP PRIVATE KEY BLOCK-----`; // encrypted private key
    const passphrase = `yourPassphrase`; // what the private key is encrypted with

    const { keys: [privateKey] } = await openpgp.key.readArmored(privateKeyArmored);
    await privateKey.decrypt(passphrase);

    const { data: signatureArmored } = await openpgp.sign({
        message: openpgp.message.fromBinary(readableStream),  // or .fromText(readableStream: ReadableStream<String>)
        privateKeys: [privateKey]                             // for signing
    });
    console.log(signatureArmored); // ReadableStream containing '-----BEGIN PGP MESSAGE ... END PGP MESSAGE-----'

    const verified = await openpgp.verify({
        message: await openpgp.message.readArmored(signatureArmored),       // parse armored signature
        publicKeys: (await openpgp.key.readArmored(publicKeyArmored)).keys  // for verification
    });

    await openpgp.stream.readToEnd(verified.data);
    // Note: you *have* to read `verified.data` in some way or other,
    // even if you don't need it, as that is what triggers the
    // verification of the data.

    const { valid } = verified.signatures[0];
    if (valid) {
        console.log('signed by key id ' + verified.signatures[0].keyid.toHex());
    } else {
        throw new Error('signature could not be verified');
    }
})();

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.

For the documentation of openpgp.stream, see the documentation of the web-stream-tools dependency.

Security Audit

To date the OpenPGP.js code base has undergone two complete security audits from Cure53. The first audit’s report has been published here.

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 minified bundle under dist/openpgp.min.js to use in your project:

npm install && npm test

For debugging browser errors, you can open test/unittests.html in a browser or, after running the following command, open http://localhost:3000/test/unittests.html:

grunt browsertest

How do I get involved?

You want to help, great! It’s probably best to send us a message on Gitter before you start your undertaking, to make sure nobody else is working on it, and so we can discuss the best course of action. Other than that, just 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.