JavaScript library to encrypt/decrypt data in JSON Web Encryption (JWE) format. This library is designed to work in the browser (tested in Chrome 38). It can do RSA-based public/private crypto as well as shared key.

JWE is an encapsulation format which makes it easy to share ciphertext between different platforms: data encrypted in a browser can be decrypted in Go, Java, etc.

The library uses compact representation. There is therefore no support for multiple recipients. It should be easy to add that if needed.

The library partially supports extra headers.

The library uses the Web Crypto API, which is available in recent browsers (http://caniuse.com/#feat=cryptography). As of March 2015, it seems ~68% of users have some form of Web Crypto support.

This code has been tested in Chrome 38 and is compatible with the Golang implementation.

JSON web encryption is currently a set of drafts. This code is based on the following drafts:

• https://tools.ietf.org/html/draft-ietf-jose-json-web-encryption-40
• https://tools.ietf.org/html/draft-ietf-jose-json-web-algorithms-40
• https://tools.ietf.org/html/draft-ietf-jose-json-web-key-41
• https://tools.ietf.org/html/draft-ietf-jose-json-web-signature-41

Disclaimer: This library contains encryption software that is subject to the U.S. Export Administration Regulations. You may not export, re-export, transfer or download this code or any part of it in violation of any United States law, directive or regulation. In particular this software may not be exported or re-exported in any form or on any media to Iran, North Sudan, Syria, Cuba, or North Korea, or to denied persons or entities mentioned on any US maintained blocked list.

<script src="jose-jwe.min.js"></script>
var joseJWE = new JoseJWE();
var rsa_key = JoseJWE.Utils.importRsaPublicKey({
	"n": "c2:4b:af:0f:2d:2b:ad:36:72:a7:91:0f:ee:30:a0:95:d5:3a:46:82:86:96:7e:42:c6:fe:8f:20:97:af:49:f6:48:a3:91:53:ac:2e:e6:ec:9a:9a:e0:0a:fb:1c:db:44:40:5b:8c:fc:d5:1c:cb:b6:9b:60:c0:a8:ac:06:f1:6b:29:5e:2f:7b:09:d9:93:32:da:3f:db:53:9c:2e:ea:3b:41:7f:6b:c9:7b:88:9f:2e:c5:dd:42:1e:7f:8f:04:f6:60:3c:fe:43:6d:32:10:ce:8d:99:cb:76:f7:10:97:05:af:28:1e:39:0f:78:35:50:7b:8e:28:22:a4:7d:11:51:22:d1:0e:ab:6b:6f:96:cb:cf:7d:eb:c6:aa:a2:6a:2e:97:2a:93:af:a5:89:e6:c8:bc:9f:fd:85:2b:0f:b4:c0:e4:ca:b5:a7:9a:01:05:81:93:6b:f5:8d:1c:f7:f3:77:0e:6e:53:34:92:0f:48:21:34:33:44:14:5e:4a:00:41:3a:7d:cb:38:82:c1:65:e0:79:ea:a1:05:84:b2:6e:40:19:77:1a:0e:38:4b:28:1f:34:b5:cb:ac:c5:2f:58:51:d7:ec:a8:08:0e:7c:c0:20:c1:5e:a1:4d:b1:30:17:63:0e:e7:58:8e:7f:6e:9f:a4:77:8b:1e:a2:d2:2e:1b:e9",
    "e": 65537
});
joseJWE.encrypt(rsa_key, "hello world").then(function(result) {
	console.log(result);
}).catch(function(err){
	console.error(err);
});

Key Encryption:

• RSA-OAEP (default)
• RSA-OAEP-256
• A128KW (supported, but not recommended for use)
• A256KW (supported, but not recommended for use)

Content Encryption:

• A256GCM (default)
• A128GCM
• A128CBC-HS256
• A256CBC-HS512

• DIR (could be added if deemed useful, would require little work)
• PBES2-HS256+A128KW (would require implementing PBES2)
• PBES2-HS512+A256KW (would require implementing PBES2)
• RSAES-PKCS1-v_5 was removed in Chrome (https://code.google.com/p/chromium/issues/detail?id=372920)
• PBES2-HS384+A192KW (AES with 192-bit keys isn't supported in Chrome)
• A192KW (AES with 192-bit keys isn't supported in Chrome)
• ECDH-ES (Chrome and IE currently don't support it)
• ECDH-ES+A128KW (Chrome and IE currently don't support it)
• ECDH-ES+A192KW (Chrome and IE currently don't support it)
• ECDH-ES+A256KW (Chrome and IE currently don't support it)
• RSA-PSS, ECDSA (could be added once Chrome supports these)

npm install
grunt

The Web Crypto API is still pretty new and isn't always very well documented. The following resources are useful:

• www.w3.org
• msdn.microsoft.com
• docs.google.com
• developer.mozilla.org

Note: Internet Explorer's Web Crypto API differs from Chrome's (as it was implemented against an earlier version of the ietf draft). We will either need to implement a thin abstraction layer or wait for Microsoft to update things.

• Web Crypto API polyfill (no longer under active development): http://polycrypt.net/
• Netflix' Web Crypto API polyfill: https://github.com/Netflix/NfWebCrypto
• JWT: https://github.com/michaelrhanson/jwt-js
• BigInt, RSA, ECC: http://www-cs-students.stanford.edu/~tjw/jsbn/
• asn1, pem, x509 and more: http://kjur.github.io/jsrsasign/ and https://github.com/michaelrhanson/jwt-js/tree/master/lib/kurushima-jsrsa
• Stanford Javascript Crypto library: https://github.com/bitwiseshiftleft/sjcl
• https://github.com/GlobalSign/ASN1.js
• https://gist.github.com/jo/8619441