openpgpjs/src/encoding/base64.js

/* 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.
 */

var b64s = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';

function s2r(t) {
	var a, c, n;
	var r = '', l = 0, s = 0;
	var tl = t.length;

	for (n = 0; n < tl; n++) {
		c = t.charCodeAt(n);
		if (s == 0) {
			r += b64s.charAt((c >> 2) & 63);
			a = (c & 3) << 4;
		} else if (s == 1) {
			r += b64s.charAt((a | (c >> 4) & 15));
			a = (c & 15) << 2;
		} else if (s == 2) {
			r += b64s.charAt(a | ((c >> 6) & 3));
			l += 1;
			if ((l % 60) == 0)
				r += "\n";
			r += b64s.charAt(c & 63);
		}
		l += 1;
		if ((l % 60) == 0)
			r += "\n";

		s += 1;
		if (s == 3)
			s = 0;
	}
	if (s > 0) {
		r += b64s.charAt(a);
		l += 1;
		if ((l % 60) == 0)
			r += "\n";
		r += '=';
		l += 1;
	}
	if (s == 1) {
		if ((l % 60) == 0)
			r += "\n";
		r += '=';
	}
  	if (r.charAt(r.length-1)==="\n")
    		r=r.slice(0,-1);
	return r;
}

function r2s(t) {
	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 += String.fromCharCode(a | (c >> (6 - s)) & 255);
			s = (s + 2) & 7;
			a = (c << s) & 255;
		}
	}
	return r;
}