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>
Alternatively, one can load it as a RequireJS module and use Browserify.
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:
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.