tweetnacl-es6/test/helpers/nacl-util.js

Port of TweetNaCl cryptographic library to JavaScript es6

// Written in 2014-2016 by Dmitry Chestnykh and Devi Mandiri.
// Public domain.
const util = {};
export default util;

function validateBase64(s) {
    if (!(/^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)?$/.test(s))) {
        throw new TypeError('invalid encoding');
    }
}

util.decodeUTF8 = function(s) {
    if (typeof s !== 'string') throw new TypeError('expected string');
    var i, d = unescape(encodeURIComponent(s)), b = new Uint8Array(d.length);
    for (i = 0; i < d.length; i++) b[i] = d.charCodeAt(i);
    return b;
};

util.encodeUTF8 = function(arr) {
    var i, s = [];
    for (i = 0; i < arr.length; i++) s.push(String.fromCharCode(arr[i]));
    return decodeURIComponent(escape(s.join('')));
};

if (typeof atob === 'undefined') {
    // Node.js

    util.encodeBase64 = function (arr) {
        return Buffer.from(arr).toString('base64');
    };

    util.decodeBase64 = function (s) {
        validateBase64(s);
        return new Uint8Array(Array.prototype.slice.call(Buffer.from(s, 'base64'), 0));
    };

} else {
    // Browsers

    util.encodeBase64 = function(arr) {
        var i, s = [], len = arr.length;
        for (i = 0; i < len; i++) s.push(String.fromCharCode(arr[i]));
        return btoa(s.join(''));
    };

    util.decodeBase64 = function(s) {
        validateBase64(s);
        var i, d = atob(s), b = new Uint8Array(d.length);
        for (i = 0; i < d.length; i++) b[i] = d.charCodeAt(i);
        return b;
    };

}