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 137 Kb (minified, gzipped) and can run in a web browser as well as server-side.

Installation

Ready-to-use files based on libsodium 1.0.3 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.

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 npm. The npm package is called libsodium-wrappers and includes a dependency on the raw libsodium module.

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 (SHA256, SHA512, and the default crypto_auth with SHA512/256)
• crypto_box
• crypto_box_seal
• crypto_generichash (Blake2b)
• crypto_hash (SHA512/256)
• crypto_pwhash (scrypt)
• crypto_scalarmult (Curve25519)
• crypto_secretbox
• crypto_shorthash (SipHash)
• crypto_sign (Ed25519)
• Ed25519->Curve25519 conversion
• randombytes

Additional helpers

• from_base64(), to_base64()
• from_hex(), to_hex()
• memcmp() (constant-time comparison, returns true or false)
• memzero() (applies to Uint8Array objects)

API

The API exposed by the wrappers is identical to the one of the C library, except that buffer lengths never need to be explicitely 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', 'hex' and 'base64'.

Example:

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

In addition, the from_base64, to_base64, from_hex and to_hex functions are available to explicitly convert base64 and hexadecimal 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) }

Compilation

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

• autoconf
• automake
• emscripten
• git
• io.js or nodejs
• libtool
• make
• mocha (npm install -g mocha)
• zopfli

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

Authors

Built by Ahmad Ben Mrad and Frank Denis.

License

This wrapper is distributed under the ISC License.