OpenPGP.js
OpenPGP.js is a JavaScript implementation of the OpenPGP protocol. It implements the crypto-refresh (superseding RFC4880 and RFC4880bis).
Table of Contents
Platform Support
-
The dist/openpgp.min.js
(or .mjs
) bundle works with recent versions of Chrome, Firefox, Edge and Safari 13+.
-
The dist/node/openpgp.min.mjs
(or .cjs
) bundle works in Node.js v16+: it is used by default when you import ... from 'openpgp'
(resp. require('openpgp')
).
-
Streaming support: the latest versions of Chrome, Firefox, Edge and Safari implement the
Streams specification, including TransformStream
s.
These are needed if you use the library with streamed inputs.
In previous versions of OpenPGP.js, WebStreams were automatically polyfilled by the library,
but from v6 this task is left up to the library user, due to the more extensive browser support, and the
polyfilling side-effects. If you're working with older browsers versions which do not implement e.g. TransformStreams, you can manually
load WebStream polyfill.
Please note that when you load the polyfills, the global ReadableStream
property (if it exists) gets overwritten with the polyfill version.
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
the polyfills. 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. Elliptic curve cryptography provides stronger security per bits of key, which allows for much faster operations. Currently the following curves are supported:
Curve | Encryption | Signature | NodeCrypto | WebCrypto | Constant-Time |
---|
curve25519 | ECDH | N/A | No | No | Algorithmically** |
ed25519 | N/A | EdDSA | No | No | Algorithmically** |
p256 | ECDH | ECDSA | Yes* | Yes* | If native*** |
p384 | ECDH | ECDSA | Yes* | Yes* | If native*** |
p521 | ECDH | ECDSA | Yes* | Yes* | If native*** |
brainpoolP256r1 | ECDH | ECDSA | Yes* | No | If native*** |
brainpoolP384r1 | ECDH | ECDSA | Yes* | No | If native*** |
brainpoolP512r1 | ECDH | ECDSA | Yes* | No | If native*** |
secp256k1 | ECDH | ECDSA | Yes* | No | If native*** |
* when available
** the curve25519 and ed25519 implementations are algorithmically constant-time, but may not be constant-time after optimizations of the JavaScript compiler
*** these curves are only constant-time if the underlying native implementation is available and constant-time
-
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.
-
The library implements authenticated encryption (AEAD) as per the "crypto refresh" draft standard using AES-OCB, EAX, or GCM. This makes symmetric encryption faster on platforms with native implementations. However, since the specification is very recent and other OpenPGP implementations are in the process of adopting it, the feature is currently behind a flag. Note: activating this setting can break compatibility with other OpenPGP implementations which have yet to implement the feature. You can enable it by setting openpgp.config.aeadProtect = true
.
Note that this setting has a different effect from the one in OpenPGP.js v5, which implemented support for a provisional version of AEAD from RFC4880bis, which was modified in a later draft of the crypto refresh.
You can change the AEAD mode by setting one of the following options:
openpgp.config.preferredAEADAlgorithm = openpgp.enums.aead.ocb; // Default (widest ecosystem support), non-native
openpgp.config.preferredAEADAlgorithm = openpgp.enums.aead.gcm; // Native in WebCrypto and Node.js
openpgp.config.preferredAEADAlgorithm = openpgp.enums.aead.eax; // Native in Node.js
-
For environments that don't provide native crypto, the library falls back to asm.js AES and AEAD implementations.
Getting started
Node.js
Install OpenPGP.js using npm and save it in your dependencies:
npm install --save openpgp
And import it as an ES module, from a .mjs file:
import * as openpgp from 'openpgp';
Or as a CommonJS module:
const openpgp = require('openpgp');
Deno (experimental)
Import as an ES6 module, using /dist/openpgp.mjs.
import * as openpgp from './openpgpjs/dist/openpgp.mjs';
Browser (webpack)
Install OpenPGP.js using npm and save it in your devDependencies:
npm install --save-dev openpgp
And import it as an ES6 module:
import * as openpgp from 'openpgp';
You can also only import the functions you need, as follows:
import { readMessage, decrypt } from 'openpgp';
Or, if you want to use the lightweight build (which is smaller, and lazily loads non-default curves on demand):
import * as openpgp from 'openpgp/lightweight';
To test whether the lazy loading works, try to generate a key with a non-standard curve:
import { generateKey } from 'openpgp/lightweight';
await 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.
Browser (plain files)
Grab openpgp.min.js
from unpkg.com/openpgp/dist, and load it in a script tag:
<script src="openpgp.min.js"></script>
Or, to load OpenPGP.js as an ES6 module, grab openpgp.min.mjs
from unpkg.com/openpgp/dist, and import it as follows:
<script type="module">
import * as openpgp from './openpgp.min.mjs';
</script>
To offload cryptographic operations off the main thread, you can implement a Web Worker in your application and load OpenPGP.js from there. For an example Worker implementation, see test/worker/worker_example.js
.
TypeScript
Since TS is not fully integrated in the library, TS-only dependencies are currently listed as devDependencies
, so to compile the project you’ll need to add @openpgp/web-stream-tools
manually:
npm install --save-dev @openpgp/web-stream-tools
If you notice missing or incorrect type definitions, feel free to open a PR.
Examples
Here are some examples of how to use OpenPGP.js v5. For more elaborate examples and working code, please check out the public API unit tests. If you're upgrading from v4 it might help to check out the changelog and documentation.
Encrypt and decrypt Uint8Array data with a password
Encryption will use the algorithm specified in config.preferredSymmetricAlgorithm (defaults to aes256), and decryption will use the algorithm used for encryption.
(async () => {
const message = await openpgp.createMessage({ binary: new Uint8Array([0x01, 0x01, 0x01]) });
const encrypted = await openpgp.encrypt({
message,
passwords: ['secret stuff'],
format: 'binary'
});
console.log(encrypted);
const encryptedMessage = await openpgp.readMessage({
binaryMessage: encrypted
});
const { data: decrypted } = await openpgp.decrypt({
message: encryptedMessage,
passwords: ['secret stuff'],
format: 'binary'
});
console.log(decrypted);
})();
Encrypt and decrypt String data with PGP keys
Encryption will use the algorithm preferred by the public (encryption) key (defaults to aes256 for keys generated in OpenPGP.js), and decryption will use the algorithm used for encryption.
const openpgp = require('openpgp');
(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-----`;
const passphrase = `yourPassphrase`;
const publicKey = await openpgp.readKey({ armoredKey: publicKeyArmored });
const privateKey = await openpgp.decryptKey({
privateKey: await openpgp.readPrivateKey({ armoredKey: privateKeyArmored }),
passphrase
});
const encrypted = await openpgp.encrypt({
message: await openpgp.createMessage({ text: 'Hello, World!' }),
encryptionKeys: publicKey,
signingKeys: privateKey
});
console.log(encrypted);
const message = await openpgp.readMessage({
armoredMessage: encrypted
});
const { data: decrypted, signatures } = await openpgp.decrypt({
message,
verificationKeys: publicKey,
decryptionKeys: privateKey
});
console.log(decrypted);
try {
await signatures[0].verified;
console.log('Signature is valid');
} catch (e) {
throw new Error('Signature could not be verified: ' + e.message);
}
})();
Encrypt to 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-----`;
const passphrase = `yourPassphrase`;
const plaintext = 'Hello, World!';
const publicKeys = await Promise.all(publicKeysArmored.map(armoredKey => openpgp.readKey({ armoredKey })));
const privateKey = await openpgp.decryptKey({
privateKey: await openpgp.readKey({ armoredKey: privateKeyArmored }),
passphrase
});
const message = await openpgp.createMessage({ text: plaintext });
const encrypted = await openpgp.encrypt({
message,
encryptionKeys: publicKeys,
signingKeys: privateKey
});
console.log(encrypted);
})();
If you expect an encrypted message to be signed with one of the public keys you have, and do not want to trust the decrypted data otherwise, you can pass the decryption option expectSigned = true
, so that the decryption operation will fail if no valid signature is found:
(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-----`;
const passphrase = `yourPassphrase`;
const publicKey = await openpgp.readKey({ armoredKey: publicKeyArmored });
const privateKey = await openpgp.decryptKey({
privateKey: await openpgp.readPrivateKey({ armoredKey: privateKeyArmored }),
passphrase
});
const encryptedAndSignedMessage = `-----BEGIN PGP MESSAGE-----
...
-----END PGP MESSAGE-----`;
const message = await openpgp.readMessage({
armoredMessage: encryptedAndSignedMessage
});
const { data: decrypted, signatures } = await openpgp.decrypt({
message,
decryptionKeys: privateKey,
expectSigned: true,
verificationKeys: publicKey,
});
console.log(decrypted);
})();
Encrypt symmetrically with compression
By default, encrypt
will not use any compression when encrypting symmetrically only (i.e. when no encryptionKeys
are given).
It's possible to change that behaviour by enabling compression through the config, either for the single encryption:
(async () => {
const message = await openpgp.createMessage({ binary: new Uint8Array([0x01, 0x02, 0x03]) });
const encrypted = await openpgp.encrypt({
message,
passwords: ['secret stuff'],
config: { preferredCompressionAlgorithm: openpgp.enums.compression.zlib }
});
})();
or by changing the default global configuration:
openpgp.config.preferredCompressionAlgorithm = openpgp.enums.compression.zlib
Where the value can be any of:
openpgp.enums.compression.zip
openpgp.enums.compression.zlib
openpgp.enums.compression.uncompressed
(default)
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.createMessage({ binary: readableStream });
const encrypted = await openpgp.encrypt({
message,
passwords: ['secret stuff'],
format: 'binary'
});
console.log(encrypted);
for await (const chunk of encrypted) {
console.log('new chunk:', chunk);
}
})();
For more information on using ReadableStreams, see the MDN Documentation on the
Streams API.
You can also pass a Node.js Readable
stream, in
which case OpenPGP.js will return a Node.js Readable
stream as well, which you
can .pipe()
to a Writable
stream, for example.
Streaming encrypt and decrypt String data with PGP keys
(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-----`;
const passphrase = `yourPassphrase`;
const publicKey = await openpgp.readKey({ armoredKey: publicKeyArmored });
const privateKey = await openpgp.decryptKey({
privateKey: await openpgp.readPrivateKey({ armoredKey: privateKeyArmored }),
passphrase
});
const readableStream = new ReadableStream({
start(controller) {
controller.enqueue('Hello, world!');
controller.close();
}
});
const encrypted = await openpgp.encrypt({
message: await openpgp.createMessage({ text: readableStream }),
encryptionKeys: publicKey,
signingKeys: privateKey
});
console.log(encrypted);
const message = await openpgp.readMessage({
armoredMessage: encrypted
});
const decrypted = await openpgp.decrypt({
message,
verificationKeys: publicKey,
decryptionKeys: privateKey
});
const chunks = [];
for await (const chunk of decrypted.data) {
chunks.push(chunk);
}
const plaintext = chunks.join('');
console.log(plaintext);
})();
Generate new key pair
ECC keys (smaller and faster to generate):
Possible values for curve
are: curve25519
, ed25519
, p256
, p384
, p521
,
brainpoolP256r1
, brainpoolP384r1
, brainpoolP512r1
, and secp256k1
.
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 { privateKey, publicKey, revocationCertificate } = await openpgp.generateKey({
type: 'ecc',
curve: 'curve25519',
userIDs: [{ name: 'Jon Smith', email: 'jon@example.com' }],
passphrase: 'super long and hard to guess secret',
format: 'armored'
});
console.log(privateKey);
console.log(publicKey);
console.log(revocationCertificate);
})();
RSA keys (increased compatibility):
(async () => {
const { privateKey, publicKey } = await openpgp.generateKey({
type: 'rsa',
rsaBits: 4096,
userIDs: [{ name: 'Jon Smith', email: 'jon@example.com' }],
passphrase: 'super long and hard to guess secret'
});
})();
Revoke a key
Using a revocation certificate:
(async () => {
const { publicKey: revokedKeyArmored } = await openpgp.revokeKey({
key: await openpgp.readKey({ armoredKey: publicKeyArmored }),
revocationCertificate,
format: 'armored'
});
console.log(revokedKeyArmored);
})();
Using the private key:
(async () => {
const { publicKey: revokedKeyArmored } = await openpgp.revokeKey({
key: await openpgp.readKey({ armoredKey: privateKeyArmored }),
format: 'armored'
});
console.log(revokedKeyArmored);
})();
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-----`;
const passphrase = `yourPassphrase`;
const publicKey = await openpgp.readKey({ armoredKey: publicKeyArmored });
const privateKey = await openpgp.decryptKey({
privateKey: await openpgp.readPrivateKey({ armoredKey: privateKeyArmored }),
passphrase
});
const unsignedMessage = await openpgp.createCleartextMessage({ text: 'Hello, World!' });
const cleartextMessage = await openpgp.sign({
message: unsignedMessage,
signingKeys: privateKey
});
console.log(cleartextMessage);
const signedMessage = await openpgp.readCleartextMessage({
cleartextMessage
});
const verificationResult = await openpgp.verify({
message: signedMessage,
verificationKeys: publicKey
});
const { verified, keyID } = verificationResult.signatures[0];
try {
await verified;
console.log('Signed by key id ' + keyID.toHex());
} catch (e) {
throw new Error('Signature could not be verified: ' + e.message);
}
})();
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-----`;
const passphrase = `yourPassphrase`;
const publicKey = await openpgp.readKey({ armoredKey: publicKeyArmored });
const privateKey = await openpgp.decryptKey({
privateKey: await openpgp.readPrivateKey({ armoredKey: privateKeyArmored }),
passphrase
});
const message = await openpgp.createMessage({ text: 'Hello, World!' });
const detachedSignature = await openpgp.sign({
message,
signingKeys: privateKey,
detached: true
});
console.log(detachedSignature);
const signature = await openpgp.readSignature({
armoredSignature: detachedSignature
});
const verificationResult = await openpgp.verify({
message,
signature,
verificationKeys: publicKey
});
const { verified, keyID } = verificationResult.signatures[0];
try {
await verified;
console.log('Signed by key id ' + keyID.toHex());
} catch (e) {
throw new Error('Signature could not be verified: ' + e.message);
}
})();
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-----`;
const passphrase = `yourPassphrase`;
const privateKey = await openpgp.decryptKey({
privateKey: await openpgp.readPrivateKey({ armoredKey: privateKeyArmored }),
passphrase
});
const message = await openpgp.createMessage({ binary: readableStream });
const signatureArmored = await openpgp.sign({
message,
signingKeys: privateKey
});
console.log(signatureArmored);
const verificationResult = await openpgp.verify({
message: await openpgp.readMessage({ armoredMessage: signatureArmored }),
verificationKeys: await openpgp.readKey({ armoredKey: publicKeyArmored })
});
for await (const chunk of verificationResult.data) {}
try {
await verificationResult.signatures[0].verified;
console.log('Signed by key id ' + verificationResult.signatures[0].keyID.toHex());
} catch (e) {
throw new Error('Signature could not be verified: ' + e.message);
}
})();
Documentation
The full documentation is available at openpgpjs.org.
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 run npm start
and open http://localhost:8080/test/unittests.html
in a browser, or run the following command:
npm run 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.