hanewinpgp/src/base64.js

PGP / GnuPG / OpenPGP Message Encryption in JavaScript by Herbert Hanewinkel.

/* 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+='=';
 }

 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;
}