libsodium

What is libsodium?

libsodium is a modern, easy-to-use software library for encryption, decryption, signatures, password hashing, and more. It is designed to be a portable, cross-compilable, installable, and packageable fork of NaCl, with a compatible API.

What are libsodium's main functionalities?

Public Key Cryptography

This feature allows you to perform public key cryptography operations such as encryption and decryption. The code sample demonstrates generating a key pair, encrypting a message, and logging the ciphertext and nonce.

const sodium = require('libsodium-wrappers');
(async() => {
  await sodium.ready;
  const keyPair = sodium.crypto_box_keypair();
  const message = 'Hello, World!';
  const nonce = sodium.randombytes_buf(sodium.crypto_box_NONCEBYTES);
  const cipherText = sodium.crypto_box_easy(message, nonce, keyPair.publicKey, keyPair.privateKey);
  console.log({ cipherText, nonce });
})();

Secret Key Cryptography

This feature allows you to perform secret key cryptography operations such as encryption and decryption. The code sample demonstrates generating a key, encrypting a message, and logging the ciphertext and nonce.

const sodium = require('libsodium-wrappers');
(async() => {
  await sodium.ready;
  const key = sodium.randombytes_buf(sodium.crypto_secretbox_KEYBYTES);
  const nonce = sodium.randombytes_buf(sodium.crypto_secretbox_NONCEBYTES);
  const message = 'Hello, World!';
  const cipherText = sodium.crypto_secretbox_easy(message, nonce, key);
  console.log({ cipherText, nonce });
})();

Password Hashing

This feature allows you to hash passwords securely. The code sample demonstrates hashing a password and logging the hashed password.

const sodium = require('libsodium-wrappers');
(async() => {
  await sodium.ready;
  const password = 'mysecretpassword';
  const hashedPassword = sodium.crypto_pwhash_str(password, sodium.crypto_pwhash_OPSLIMIT_INTERACTIVE, sodium.crypto_pwhash_MEMLIMIT_INTERACTIVE);
  console.log({ hashedPassword });
})();

Digital Signatures

This feature allows you to create and verify digital signatures. The code sample demonstrates generating a key pair, signing a message, and logging the signed message.

const sodium = require('libsodium-wrappers');
(async() => {
  await sodium.ready;
  const keyPair = sodium.crypto_sign_keypair();
  const message = 'Hello, World!';
  const signedMessage = sodium.crypto_sign(message, keyPair.privateKey);
  console.log({ signedMessage });
})();

Other packages similar to libsodium

crypto

The 'crypto' module in Node.js provides cryptographic functionality that includes a set of wrappers for OpenSSL's hash, HMAC, cipher, decipher, sign, and verify functions. It is built into Node.js and does not require additional installation. While it offers a wide range of cryptographic operations, it may not be as user-friendly or modern as libsodium.

tweetnacl

TweetNaCl is a cryptographic library that is a port of the Networking and Cryptography library (NaCl) to JavaScript. It is designed to be small, fast, and easy to use. While it offers similar functionalities to libsodium, it may lack some of the advanced features and optimizations found in libsodium.

bcrypt

bcrypt is a password hashing function designed for secure password storage. It is widely used and well-tested, but it is specialized for password hashing and does not offer the broader range of cryptographic functionalities that libsodium provides.

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

Installation

Ready-to-use files based on libsodium 1.0.2 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 AMD or RequireJS

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_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.