base64-ct

Safe, constant-time Base64 encoding and decoding in pure JavaScript, with support for common Base64 variants.

Usage no npm install needed!

<script type="module">
  import base64Ct from 'https://cdn.skypack.dev/base64-ct';
</script>

README

Safe Base64 codecs for JavaScript

A pure JavaScript port of the libsodium base64 codecs.

Features:

Supports traditional and URL-safe variants, with or without padding
Rejects non-canonical padding
Constant-time (best-effort), suitable for encoding/decoding secrets
Characters can be ignored by the decoder

Usage:

Traditional alphabet, padding:

const codec = new Base64(true);
const b64 = codec.encode(data);
const data2 = codec.decode(b64);

Traditional alphabet, no padding:

const codec = new Base64(false);
const b64 = codec.encode(data);
const data2 = codec.decode(b64);

URL-safe, no padding:

const codec = new Base64UrlSafe(false);
const b64 = codec.encode(data);
const data2 = codec.decode(b64);

URL-safe, padding, ignoring spaces and \n:

const codec = new Base64UrlSafe(true, " \n");
const b64 = codec.encode(data);
const data2 = codec.decode(b64);