95 lines
3.2 KiB
JavaScript
95 lines
3.2 KiB
JavaScript
/*
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Copyright (c) 2011, Daniel Guerrero
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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DISCLAIMED. IN NO EVENT SHALL DANIEL GUERRERO BE LIABLE FOR ANY
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DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/**
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* Uses the new array typed in javascript to binary base64 encode/decode
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* at the moment just decodes a binary base64 encoded
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* into either an ArrayBuffer (decodeArrayBuffer)
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* or into an Uint8Array (decode)
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*
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* References:
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* https://developer.mozilla.org/en/JavaScript_typed_arrays/ArrayBuffer
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* https://developer.mozilla.org/en/JavaScript_typed_arrays/Uint8Array
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*/
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var Base64Binary = {
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_keyStr : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
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/* will return a Uint8Array type */
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decodeArrayBuffer: function(input) {
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var bytes = (input.length/4) * 3;
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var ab = new ArrayBuffer(bytes);
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this.decode(input, ab);
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return ab;
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},
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removePaddingChars: function(input){
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var lkey = this._keyStr.indexOf(input.charAt(input.length - 1));
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if(lkey == 64){
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return input.substring(0,input.length - 1);
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}
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return input;
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},
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decode: function (input, arrayBuffer) {
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//get last chars to see if are valid
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input = this.removePaddingChars(input);
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input = this.removePaddingChars(input);
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var bytes = parseInt((input.length / 4) * 3, 10);
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var uarray;
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var chr1, chr2, chr3;
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var enc1, enc2, enc3, enc4;
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var i = 0;
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var j = 0;
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if (arrayBuffer)
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uarray = new Uint8Array(arrayBuffer);
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else
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uarray = new Uint8Array(bytes);
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input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
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for (i=0; i<bytes; i+=3) {
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//get the 3 octects in 4 ascii chars
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enc1 = this._keyStr.indexOf(input.charAt(j++));
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enc2 = this._keyStr.indexOf(input.charAt(j++));
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enc3 = this._keyStr.indexOf(input.charAt(j++));
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enc4 = this._keyStr.indexOf(input.charAt(j++));
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chr1 = (enc1 << 2) | (enc2 >> 4);
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chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
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chr3 = ((enc3 & 3) << 6) | enc4;
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uarray[i] = chr1;
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if (enc3 != 64) uarray[i+1] = chr2;
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if (enc4 != 64) uarray[i+2] = chr3;
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}
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return uarray;
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}
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}
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