fork-openpgpjs/src/encoding/base64.js

115 lines
2.4 KiB
JavaScript

/* OpenPGP radix-64/base64 string encoding/decoding
* Copyright 2005 Herbert Hanewinkel, www.haneWIN.de
* version 1.0, check www.haneWIN.de for the latest version
*
* This software is provided as-is, without express or implied warranty.
* Permission to use, copy, modify, distribute or sell this software, with or
* without fee, for any purpose and by any individual or organization, is hereby
* granted, provided that the above copyright notice and this paragraph appear
* in all copies. Distribution as a part of an application or binary must
* include the above copyright notice in the documentation and/or other materials
* provided with the application or distribution.
*/
/**
* @module encoding/base64
*/
'use strict';
var b64s = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
/**
* Convert binary array to radix-64
* @param {Uint8Array} t Uint8Array to convert
* @returns {string} radix-64 version of input string
* @static
*/
function s2r(t, o) {
// TODO check btoa alternative
var a, c, n;
var r = o ? o : [],
l = 0,
s = 0;
var tl = t.length;
for (n = 0; n < tl; n++) {
c = t[n];
if (s === 0) {
r.push(b64s.charAt((c >> 2) & 63));
a = (c & 3) << 4;
} else if (s === 1) {
r.push(b64s.charAt((a | (c >> 4) & 15)));
a = (c & 15) << 2;
} else if (s === 2) {
r.push(b64s.charAt(a | ((c >> 6) & 3)));
l += 1;
if ((l % 60) === 0) {
r.push("\n");
}
r.push(b64s.charAt(c & 63));
}
l += 1;
if ((l % 60) === 0) {
r.push("\n");
}
s += 1;
if (s === 3) {
s = 0;
}
}
if (s > 0) {
r.push(b64s.charAt(a));
l += 1;
if ((l % 60) === 0) {
r.push("\n");
}
r.push('=');
l += 1;
}
if (s === 1) {
if ((l % 60) === 0) {
r.push("\n");
}
r.push('=');
}
if (o)
{
return;
}
return r.join('');
}
/**
* Convert radix-64 to binary array
* @param {String} t radix-64 string to convert
* @returns {Uint8Array} binary array version of input string
* @static
*/
function r2s(t) {
// TODO check atob alternative
var c, n;
var r = [],
s = 0,
a = 0;
var tl = t.length;
for (n = 0; n < tl; n++) {
c = b64s.indexOf(t.charAt(n));
if (c >= 0) {
if (s) {
r.push(a | (c >> (6 - s)) & 255);
}
s = (s + 2) & 7;
a = (c << s) & 255;
}
}
return new Uint8Array(r);
}
export default {
encode: s2r,
decode: r2s
};