libsodium-wrappers

What is libsodium-wrappers?

libsodium-wrappers is a JavaScript wrapper for the Sodium cryptographic library, providing a wide range of cryptographic operations including encryption, decryption, hashing, and key generation. It is designed to be easy to use and secure, making it suitable for both beginners and advanced users.

What are libsodium-wrappers's main functionalities?

Encryption and Decryption

This feature allows you to encrypt and decrypt messages using secret-key cryptography. The code sample demonstrates generating a key and nonce, encrypting a message, and then decrypting it back to its original form.

const sodium = require('libsodium-wrappers');
(async() => {
  await sodium.ready;
  const key = sodium.crypto_secretbox_keygen();
  const nonce = sodium.randombytes_buf(sodium.crypto_secretbox_NONCEBYTES);
  const message = 'Hello, World!';
  const ciphertext = sodium.crypto_secretbox_easy(message, nonce, key);
  const decrypted = sodium.crypto_secretbox_open_easy(ciphertext, nonce, key);
  console.log(sodium.to_string(decrypted)); // 'Hello, World!'
})();

Hashing

This feature provides hashing capabilities. The code sample shows how to hash a message using the crypto_generichash function and then convert the hash to a hexadecimal string.

const sodium = require('libsodium-wrappers');
(async() => {
  await sodium.ready;
  const message = 'Hello, World!';
  const hash = sodium.crypto_generichash(32, message);
  console.log(sodium.to_hex(hash));
})();

Key Generation

This feature allows you to generate public and private key pairs. The code sample demonstrates generating a key pair and printing the public and private keys in hexadecimal format.

const sodium = require('libsodium-wrappers');
(async() => {
  await sodium.ready;
  const keyPair = sodium.crypto_box_keypair();
  console.log(sodium.to_hex(keyPair.publicKey));
  console.log(sodium.to_hex(keyPair.privateKey));
})();

Other packages similar to libsodium-wrappers

crypto-js

crypto-js is a widely-used library that provides standard and secure cryptographic algorithms for JavaScript. It offers functionalities like encryption, decryption, hashing, and more. Compared to libsodium-wrappers, crypto-js is more focused on providing a broad range of cryptographic algorithms but may not be as optimized for performance and security.

tweetnacl

tweetnacl is a cryptographic library that provides high-level cryptographic operations, including public-key encryption, secret-key encryption, and hashing. It is designed to be small, fast, and secure. Compared to libsodium-wrappers, tweetnacl is more lightweight but offers fewer features and less flexibility.

node-forge

node-forge is a comprehensive library for implementing various cryptographic operations in JavaScript. It includes support for public-key cryptography, symmetric-key cryptography, and more. Compared to libsodium-wrappers, node-forge offers a broader range of cryptographic functionalities but may be more complex to use.

README

libsodium.js

Overview

The sodium crypto library compiled to pure JavaScript using Emscripten, with automatically generated wrappers to make it easy to use in web applications.

The complete library weights 110 Kb (minified, gzipped) and can run in a web browser as well as server-side.

Compatibility

Supported browsers/JS engines:

• Chrome >= 16
• Edge >= 0.11
• Firefox >= 21
• Internet Explorer >= 11
• Mobile Safari on iOS >= 8.0 (older versions produce incorrect results)
• NodeJS
• Opera >= 15
• Safari >= 6 (older versions produce incorrect results)

Installation

Ready-to-use files based on libsodium 1.0.11 can be directly copied to your project.

Usage with global definitions, for web browsers

Use Bower:

$ bower install libsodium.js

or directly include a copy of the sodium.min.js file.

Alternatively, for better performance and to avoid including a local copy, libsodium.js is available on cdnjs.

Including the sodium.min.js file will add a sodium object to the global namespace.

If a sodium object is already present in the global namespace, and the sodium.onload function is defined, this function will be called right after the library has been loaded and initialized.

<script>
window.sodium = { onload: function(sodium) {
  alert(sodium.to_hex(sodium.crypto_generichash(64, 'test')));
}};
</script>
...
<script src="sodium.js" async defer></script>

As an alternative, use a module loader or Browserify as described below.

Usage with CommonJS/AMD/ES6 import

Copy the .js files for libsodium and libsodium-wrappers to your project and load the libsodium-wrappers module.

Alternatively, use yarn. The Yarn package is called libsodium-wrappers and includes a dependency on the raw libsodium module.

$ yarn add libsodium-wrappers

var sodium = require('libsodium-wrappers');
console.log(sodium.to_hex(sodium.crypto_generichash(64, 'test')));

List of wrapped algorithms and functions:

• crypto_aead (ChaCha20-Poly1305)
• crypto_auth (HMAC-SHA-512-256)
• crypto_box
• crypto_box_seal
• crypto_generichash (Blake2b)
• crypto_hash (SHA-512-256)
• crypto_onetimeauth (Poly1305)
• crypto_pwhash (Argon2)
• crypto_scalarmult (Curve25519)
• crypto_secretbox
• crypto_shorthash (SipHash)
• crypto_sign (Ed25519)
• Ed25519->Curve25519 conversion
• randombytes

Additional helpers

• from_hex(), to_hex()
• from_string(), to_string()
• memcmp() (constant-time check for equality, returns true or false)
• compare() (constant-time comparison. Values must have the same size. Returns -1, 0or1`)
• memzero() (applies to Uint8Array objects)
• increment() (increments an arbitrary-long number stored as a little-endian Uint8Array - typically to increment nonces)
• add() (adds two arbitrary-long numbers stored as little-endian Uint8Array vectors)
• is_zero() (constant-time, checks Uint8Array objects for all zeros)

API

The API exposed by the wrappers is identical to the one of the C library, except that buffer lengths never need to be explicitly given.

Binary input buffers should be Uint8Array objects. However, if a string is given instead, the wrappers will automatically convert the string to an array containing a UTF-8 representation of the string.

Example:

var key = sodium.randombytes_buf(sodium.crypto_shorthash_KEYBYTES),
    hash1 = sodium.crypto_shorthash(new Uint8Array([1, 2, 3, 4]), key),
    hash2 = sodium.crypto_shorthash('test', key);

If the output is a unique binary buffer, it is returned as a Uint8Array object.

However, an extra parameter can be given to all wrapped functions, in order to specify what format the output should be in. Valid options are `uint8array' (default), 'text' and 'hex'.

Example (shorthash):

var key = sodium.randombytes_buf(sodium.crypto_shorthash_KEYBYTES),
    hash_hex = sodium.crypto_shorthash('test', key, 'hex');

Example (secretbox):

// Load your secret key from a safe place and reuse it across multiple
// secretbox calls. (Obviously don't use this example key for anything
// real.)
//
var secret = Buffer.from('724b092810ec86d7e35c9d067702b31ef90bc43a7b598626749914d6a3e033ed', 'hex');

// Given a message as a string, return a Buffer containing the
// nonce (in the first 24 bytes) and the encrypted content.
var encrypt = function(message) {
    // You must use a different nonce for each message you encrypt.
    var nonce = Buffer.from(sodium.randombytes_buf(sodium.crypto_box_NONCEBYTES));
    var buf = Buffer.from(message);
    return Buffer.concat([nonce, Buffer.from(sodium.crypto_secretbox_easy(buf, nonce, secret))]);
},

// Decrypt takes a Buffer and returns the decrypted message as plain text.
var decrypt = function(encryptedBuffer) {
    var nonce = encryptedBuffer.slice(0, sodium.crypto_box_NONCEBYTES);
    var encryptedMessage = encryptedBuffer.slice(sodium.crypto_box_NONCEBYTES);
    return sodium.crypto_secretbox_open_easy(encryptedMessage, nonce, secret, 'text');
}

In addition, the from_hex, to_hex, from_string, and to_string functions are available to explicitly convert hexadecimal, and arbitrary string representations from/to Uint8Array objects.

Functions returning more than one output buffer are returning them as an object. For example, the sodium.crypto_box_keypair() function returns the following object:

{ keyType: 'curve25519', privateKey: (Uint8Array), publicKey: (Uint8Array) }

Standard vs Sumo version

The standard version (in the dist/browsers and dist/modules directories) contains the high-level functions, and is the recommended one for most projects.

Alternatively, the "sumo" version, available in the dist/browsers-sumo and dist/modules-sumo directories contains all the symbols from the original library. This includes undocumented, untested, deprecated, low-level and easy to misuse functions.

The crypto_pwhash_* function set is also only included in the Sumo version. The high amount of heap memory (allocated after loading) required by these functions may not be desirable when they are not being used.

The sumo version is slightly larger than the standard version, and should be used only if you really need the extra symbols it provides.

Compilation

If you want to compile the files yourself, the following dependencies need to be installed on your system:

• autoconf
• automake
• emscripten
• git
• nodejs
• libtool
• make
• zopfli (yarn global add node-zopfli)
• uglifyjs (yarn global add uglify-js)

Running make will clone libsodium, build it, test it, build the wrapper, and create the modules and minified distribution files.

Custom build

The build available in this repository does not contain all the functions available in the original libsodium library.

Providing that you have all the build dependencies installed, here is how you can build libsodium.js to include the functions you need :

git clone https://github.com/jedisct1/libsodium.js
cd ./libsodium.js

# Get the original C version of libsodium and configure it
make libsodium/configure

# Modify the emscripten.sh
# Specifically, add the name of the missing functions and constants in the "EXPORTED_FUNCTIONS" array.
# Ensure that the name begins with an underscore and that it is between double quotes.
nano libsodium/dist-build/emscripten.sh

# Build libsodium, and then libsodium.js with your chosen functions
make

NOTE: for each of the functions/constants you add, make sure that the corresponding symbol files exist in the wrapper/symbols folder and that the constants are listed in the wrapper/constants.json file.

Authors

Built by Ahmad Ben Mrad and Frank Denis.

License

This wrapper is distributed under the ISC License.