Base 64 encoding

stevengill · Nov 15, 2009 · 7e2fdbd · 7e2fdbd
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diff --git a/encodings/base64/base64.htm b/encodings/base64/base64.htm
@@ -0,0 +1,76 @@
+<html>
+<head>
+<title>Base64 Tests</title>
+<!-- Combo-handled YUI CSS files: -->
+<link rel="stylesheet" type="text/css" href="http://yui.yahooapis.com/combo?2.7.0/build/logger/assets/logger.css&2.7.0/build/yuitest/assets/testlogger.css">
+<!-- Combo-handled YUI JS files: -->
+<script type="text/javascript" src="http://yui.yahooapis.com/combo?2.7.0/build/yahoo-dom-event/yahoo-dom-event.js&2.7.0/build/logger/logger-min.js&2.7.0/build/yuitest/yuitest-min.js"></script>
+<script type="text/javascript" src="base64.js"></script>
+
+
+</head>
+<body>
+<h1>Doubly Linked List Tests</h1>
+<script type="text/javascript">
+
+YAHOO.namespace("test");
+
+YAHOO.test.Base64 = (function(){
+
+    var assert = YAHOO.util.Assert;
+
+    //-------------------------------------------------------------------------
+    // Base Test Suite
+    //-------------------------------------------------------------------------
+
+    var suite = new YAHOO.tool.TestSuite("Base64 Tests");
+
+    //-------------------------------------------------------------------------
+    // Test Case for adding
+    //-------------------------------------------------------------------------
+
+    suite.add(new YAHOO.tool.TestCase({
+
+        name : "Base 64 Encoding Tests",
+
+        //---------------------------------------------------------------------
+        // Tests
+        //---------------------------------------------------------------------
+
+        testMan: function(){            
+            var result = base64Encode("Man");
+            assert.areEqual("TWFu", result);                   
+        },
+
+        testHelloWorld: function(){            
+            var result = base64Encode("Hello world");
+            assert.areEqual("SGVsbG8gd29ybGQ=", result);                   
+        },
+
+        testPhrase: function(){
+            var expected = "TWFuIGlzIGRpc3Rpbmd1aXNoZWQsIG5vdCBvbmx5IGJ5IGhpcyByZWFzb24sIGJ1dCBieSB0aGlzIHNpbmd1bGFyIHBhc3Npb24gZnJvbSBvdGhlciBhbmltYWxzLCB3aGljaCBpcyBhIGx1c3Qgb2YgdGhlIG1pbmQsIHRoYXQgYnkgYSBwZXJzZXZlcmFuY2Ugb2YgZGVsaWdodCBpbiB0aGUgY29udGludWVkIGFuZCBpbmRlZmF0aWdhYmxlIGdlbmVyYXRpb24gb2Yga25vd2xlZGdlLCBleGNlZWRzIHRoZSBzaG9ydCB2ZWhlbWVuY2Ugb2YgYW55IGNhcm5hbCBwbGVhc3VyZS4=";
+            var result = base64Encode("Man is distinguished, not only by his reason, but by this singular passion from other animals, which is a lust of the mind, that by a perseverance of delight in the continued and indefatigable generation of knowledge, exceeds the short vehemence of any carnal pleasure.");
+            assert.areEqual(expected, result);
+        }
+    }));
+
+
+    //return it
+    return suite;
+
+})();
+
+(function (){
+    //create the logger
+    var logger = new YAHOO.tool.TestLogger();
+
+    //add the tests
+    YAHOO.tool.TestRunner.add(YAHOO.test.Base64);
+    YAHOO.tool.TestRunner.run();
+
+})();
+
+
+</script>
+</body>
+</html>
diff --git a/encodings/base64/base64.js b/encodings/base64/base64.js
@@ -0,0 +1,98 @@
+/*
+ * Base 64 implementation in JavaScript
+ * Copyright (c) 2009 Nicholas C. Zakas. All rights reserved.
+ * 
+ * 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-encodes a string of text.
+ * @param {String} text The text to encode
+ * @return {String} The base64-encoded string.
+ */
+function base64Encode(text){
+
+    //helper function to left-pad an array with zeros
+    function padLeft(bits, length){
+        while (bits.length < length){
+            bits.unshift("0");
+        }        
+        return bits;
+    }
+
+    //helper function to right-pad an array with zeros
+    function padRight(bits, length){
+        while (bits.length < length){
+            bits.push("0");
+        }        
+        return bits;        
+    }
+
+    //local variables
+    var digits = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/",
+        part, index,
+        i=0, j=0,
+        padding="",
+        quantaCount,
+        bits = [],
+        result = [];
+
+    //create an array of binary digits representing the text
+    for (; i < text.length; i++){
+        part = text.charCodeAt(i).toString(2);
+        bits = bits.concat(padLeft(part.split(""), 8));
+    }
+
+    //figure out how many 24-bit quanta are in the array
+    quantaCount = Math.floor(bits.length / 24);
+
+    //encode all bits
+    encodeBits: while(true){
+
+        //must encode one complete quanta at a time
+        for(i=0; i < quantaCount; i++){
+            for (j=0; j < 4; j++){
+                part = bits.splice(0, 6).join("");
+                index = parseInt(part,2);
+                result.push(digits[index]);
+            }
+        }
+
+        //take care of any extra bits
+        switch(bits.length){
+            case 8:
+                padRight(bits, 12);
+                padding = "==";
+                continue encodeBits;
+            case 16:
+                padRight(bits, 18);
+                padding = "=";
+                continue encodeBits;
+            default:
+                break encodeBits;
+        }
+    }
+
+    //add any padding to the result
+    result.push(padding);
+
+    //return a string
+    return result.join("");
+
+}