The sodium crypto library compiled to WebAssembly and pure JavaScript using Emscripten, with automatically generated wrappers to make it easy to use in web applications.
The complete library weighs 188 KB (minified, gzipped, includes pure JS + WebAssembly versions) and can run in a web browser as well as server-side.
Supported browsers/JS engines:
This is comparable to the WebCrypto API, which is compatible with a similar number of browsers.
Signatures and other Edwards25519-based operations are compatible with WasmCrypto.
The dist directory contains pre-built scripts. Copy the files from one of its subdirectories to your application:
libsodium-wrappers is the module your application should load, which
will in turn automatically load libsodium as a dependency.The modules are also available on npm:
Load the libsodium-wrappers module. The returned object contains a .ready
property: a promise that must be resolve before the sodium functions
can be used.
Example:
import _sodium from 'libsodium-wrappers';
await (async() => {
await _sodium.ready;
const sodium = _sodium;
let key = sodium.crypto_secretstream_xchacha20poly1305_keygen();
let res = sodium.crypto_secretstream_xchacha20poly1305_init_push(key);
let [state_out, header] = [res.state, res.header];
let c1 = sodium.crypto_secretstream_xchacha20poly1305_push(state_out,
sodium.from_string('message 1'), null,
sodium.crypto_secretstream_xchacha20poly1305_TAG_MESSAGE);
let c2 = sodium.crypto_secretstream_xchacha20poly1305_push(state_out,
sodium.from_string('message 2'), null,
sodium.crypto_secretstream_xchacha20poly1305_TAG_FINAL);
let state_in = sodium.crypto_secretstream_xchacha20poly1305_init_pull(header, key);
let r1 = sodium.crypto_secretstream_xchacha20poly1305_pull(state_in, c1);
let [m1, tag1] = [sodium.to_string(r1.message), r1.tag];
let r2 = sodium.crypto_secretstream_xchacha20poly1305_pull(state_in, c2);
let [m2, tag2] = [sodium.to_string(r2.message), r2.tag];
console.log(m1);
console.log(m2);
})();The sodium.js file includes both the core libsodium functions, as
well as the higher-level JavaScript wrappers. It can be loaded
asynchronusly.
A sodium object should be defined in the global namespace, with the
following property:
onload: the function to call after the wrapper is initialized.Example:
<script>
window.sodium = {
onload: function (sodium) {
let h = sodium.crypto_generichash(64, sodium.from_string('test'));
console.log(sodium.to_hex(h));
}
};
</script>
<script src="https://github.com/jedisct1/libsodium.js/raw/master/sodium.js" async></script>from_base64(), to_base64() with an optional second parameter
whose value is one of: base64_variants.ORIGINAL, base64_variants.ORIGINAL_NO_PADDING,
base64_variants.URLSAFE or base64_variants.URLSAFE_NO_PADDING. Default is base64_variants.URLSAFE_NO_PADDING.from_hex(), to_hex()from_string(), to_string()pad(<buffer>, <block size>), unpad(<buffer>, <block size>)memcmp() (constant-time check for equality, returns true or false)compare() (constant-time comparison. Values must have the same
size. Returns -1, 0 or 1)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)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.
Example (secretbox):
let key = sodium.from_hex('724b092810ec86d7e35c9d067702b31ef90bc43a7b598626749914d6a3e033ed');
function encrypt_and_prepend_nonce(message) {
let nonce = sodium.randombytes_buf(sodium.crypto_secretbox_NONCEBYTES);
return nonce.concat(sodium.crypto_secretbox_easy(message, nonce, key));
}
function decrypt_after_extracting_nonce(nonce_and_ciphertext) {
if (nonce_and_ciphertext.length < sodium.crypto_secretbox_NONCEBYTES + sodium.crypto_secretbox_MACBYTES) {
throw "Short message";
}
let nonce = nonce_and_ciphertext.slice(0, sodium.crypto_secretbox_NONCEBYTES),
ciphertext = nonce_and_ciphertext.slice(sodium.crypto_secretbox_NONCEBYTES);
return sodium.crypto_secretbox_open_easy(ciphertext, nonce, key);
}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) }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 only included in the sumo version.
The sumo version is slightly larger than the standard version, reserves more memory, and should be used only if you really need the extra symbols it provides.
If you want to compile the files yourself, the following dependencies need to be installed on your system:
Running make will install the dev dependencies, clone libsodium,
build it, test it, build the wrapper, and create the modules and
minified distribution files.
Built by Ahmad Ben Mrad, Frank Denis and Ryan Lester.
This wrapper is distributed under the ISC License.