Synnefo

/*jslint adsafe: false, bitwise: true, browser: true, cap: false, css: false,

  debug: false, devel: true, eqeqeq: true, es5: false, evil: false,

  forin: false, fragment: false, immed: true, laxbreak: false, newcap: true,

  nomen: false, on: false, onevar: true, passfail: false, plusplus: true,

  regexp: false, rhino: true, safe: false, strict: false, sub: false,

  undef: true, white: false, widget: false, windows: false */

/*global jQuery: false, window: false */

"use strict";

/*

 * Original code (c) 2010 Nick Galbreath

 * http://code.google.com/p/stringencoders/source/browse/#svn/trunk/javascript

 *

 * jQuery port (c) 2010 Carlo Zottmann

 * http://github.com/carlo/jquery-base64

 *

 * Permission is hereby granted, free of charge, to any person

 * obtaining a copy of this software and associated documentation

 * files (the "Software"), to deal in the Software without

 * restriction, including without limitation the rights to use,

 * copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the

 * Software is furnished to do so, subject to the following

 * conditions:

 *

 * The above copyright notice and this permission notice shall be

 * included in all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES

 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT

 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,

 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR

 * OTHER DEALINGS IN THE SOFTWARE.

*/

/* base64 encode/decode compatible with window.btoa/atob

 *

 * window.atob/btoa is a Firefox extension to convert binary data (the "b")

 * to base64 (ascii, the "a").

 *

 * It is also found in Safari and Chrome.  It is not available in IE.

 *

 * if (!window.btoa) window.btoa = $.base64.encode

 * if (!window.atob) window.atob = $.base64.decode

 *

 * The original spec's for atob/btoa are a bit lacking

 * https://developer.mozilla.org/en/DOM/window.atob

 * https://developer.mozilla.org/en/DOM/window.btoa

 *

 * window.btoa and $.base64.encode takes a string where charCodeAt is [0,255]

 * If any character is not [0,255], then an exception is thrown.

 *

 * window.atob and $.base64.decode take a base64-encoded string

 * If the input length is not a multiple of 4, or contains invalid characters

 *   then an exception is thrown.

 */

jQuery.base64 = ( function( $ ) {

  var _PADCHAR = "=",

    _ALPHA = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/",

    _VERSION = "1.0";

  function _getbyte64( s, i ) {

    // This is oddly fast, except on Chrome/V8.

    // Minimal or no improvement in performance by using a

    // object with properties mapping chars to value (eg. 'A': 0)

    var idx = _ALPHA.indexOf( s.charAt( i ) );

    if ( idx === -1 ) {

      throw "Cannot decode base64";

    }

    return idx;

  }

  function _decode( s ) {

    var pads = 0,

      i,

      b10,

      imax = s.length,

      x = [];

    s = String( s );

    if ( imax === 0 ) {

      return s;

    }

    if ( imax % 4 !== 0 ) {

      throw "Cannot decode base64";

    }

    if ( s.charAt( imax - 1 ) === _PADCHAR ) {

      pads = 1;

      if ( s.charAt( imax - 2 ) === _PADCHAR ) {

        pads = 2;

      }

      // either way, we want to ignore this last block

      imax -= 4;

    }

    for ( i = 0; i < imax; i += 4 ) {

      b10 = ( _getbyte64( s, i ) << 18 ) | ( _getbyte64( s, i + 1 ) << 12 ) | ( _getbyte64( s, i + 2 ) << 6 ) | _getbyte64( s, i + 3 );

      x.push( String.fromCharCode( b10 >> 16, ( b10 >> 8 ) & 0xff, b10 & 0xff ) );

    }

    switch ( pads ) {

      case 1:

        b10 = ( _getbyte64( s, i ) << 18 ) | ( _getbyte64( s, i + 1 ) << 12 ) | ( _getbyte64( s, i + 2 ) << 6 );

        x.push( String.fromCharCode( b10 >> 16, ( b10 >> 8 ) & 0xff ) );

        break;

      case 2:

        b10 = ( _getbyte64( s, i ) << 18) | ( _getbyte64( s, i + 1 ) << 12 );

        x.push( String.fromCharCode( b10 >> 16 ) );

        break;

    }

    return x.join( "" );

  }

  function _getbyte( s, i ) {

    var x = s.charCodeAt( i );

    if ( x > 255 ) {

      throw "INVALID_CHARACTER_ERR: DOM Exception 5";

    }

    return x;

  }

  function _encode( s ) {

    if ( arguments.length !== 1 ) {

      throw "SyntaxError: exactly one argument required";

    }

    s = String( s );

    var i,

      b10,

      x = [],

      imax = s.length - s.length % 3;

    if ( s.length === 0 ) {

      return s;

    }

    for ( i = 0; i < imax; i += 3 ) {

      b10 = ( _getbyte( s, i ) << 16 ) | ( _getbyte( s, i + 1 ) << 8 ) | _getbyte( s, i + 2 );

      x.push( _ALPHA.charAt( b10 >> 18 ) );

      x.push( _ALPHA.charAt( ( b10 >> 12 ) & 0x3F ) );

      x.push( _ALPHA.charAt( ( b10 >> 6 ) & 0x3f ) );

      x.push( _ALPHA.charAt( b10 & 0x3f ) );

    }

    switch ( s.length - imax ) {

      case 1:

        b10 = _getbyte( s, i ) << 16;

        x.push( _ALPHA.charAt( b10 >> 18 ) + _ALPHA.charAt( ( b10 >> 12 ) & 0x3F ) + _PADCHAR + _PADCHAR );

        break;

      case 2:

        b10 = ( _getbyte( s, i ) << 16 ) | ( _getbyte( s, i + 1 ) << 8 );

        x.push( _ALPHA.charAt( b10 >> 18 ) + _ALPHA.charAt( ( b10 >> 12 ) & 0x3F ) + _ALPHA.charAt( ( b10 >> 6 ) & 0x3f ) + _PADCHAR );

        break;

    }

    return x.join( "" );

  }

  return {

    decode: _decode,

    encode: _encode,

    VERSION: _VERSION

  };

}( jQuery ) );