From e80c54fc75b8226edd2f260ee534a3d4914fcef7 Mon Sep 17 00:00:00 2001
From: Danny Yoo <dyoo@cs.wpi.edu>
Date: Thu, 26 Jan 2012 17:04:41 -0500
Subject: [PATCH] base64 encoding stuff

---
 js-assembler/runtime-src/base64.js | 78 ++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 js-assembler/runtime-src/base64.js

diff --git a/js-assembler/runtime-src/base64.js b/js-assembler/runtime-src/base64.js
new file mode 100644
index 0000000..a842fcc
--- /dev/null
+++ b/js-assembler/runtime-src/base64.js
@@ -0,0 +1,78 @@
+/**
+ *
+ *  Originally grabbed from:
+ *  Base64 encode / decode
+ *  http://www.webtoolkit.info/
+ *
+ *  dyoo: modified to work with arrays of bytes rather than assume
+ *  the bytes are strings.
+ **/
+var Base64 = (function() {
+    'use strict';
+
+    // private property
+    var _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
+
+    var Base64 = {        
+        // public method for encoding
+        encode : function (inputBytes) {
+	    var output = [];
+	    var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
+	    var i = 0;
+	    while (i < inputBytes.length) {
+                
+	        chr1 = inputBytes[i++];
+	        chr2 = inputBytes[i++];
+	        chr3 = inputBytes[i++];
+                
+	        enc1 = chr1 >> 2;
+	        enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
+	        enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
+	        enc4 = chr3 & 63;
+                
+	        if (isNaN(chr2)) {
+		    enc3 = enc4 = 64;
+	        } else if (isNaN(chr3)) {
+		    enc4 = 64;
+	        }
+	        output.push(_keyStr.charAt(enc1));
+                output.push(_keyStr.charAt(enc2));
+		output.push(_keyStr.charAt(enc3));
+                output.push(_keyStr.charAt(enc4));
+	    }
+	    return output.join('');
+        },
+        
+        // public method for decoding
+        decode : function (inputString) {
+	    var outputBytes = [];
+	    var chr1, chr2, chr3;
+	    var enc1, enc2, enc3, enc4;
+	    var i = 0;
+            
+	    inputString = inputString.replace(/[^A-Za-z0-9\+\/\=]/g, "");
+            
+	    while (i < inputString.length) {
+	        enc1 = _keyStr.indexOf(inputString.charAt(i++));
+	        enc2 = _keyStr.indexOf(inputString.charAt(i++));
+	        enc3 = _keyStr.indexOf(inputString.charAt(i++));
+	        enc4 = _keyStr.indexOf(inputString.charAt(i++));
+                
+	        chr1 = (enc1 << 2) | (enc2 >> 4);
+	        chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
+	        chr3 = ((enc3 & 3) << 6) | enc4;
+                
+	        outputBytes.push(chr1);
+                
+	        if (enc3 !== 64) {
+		    outputBytes.push(chr2);
+	        }
+	        if (enc4 !== 64) {
+		    outputBytes.push(chr3);
+	        }
+	    }
+	    return outputBytes;            
+        }
+    };
+    return Base64;
+}());
\ No newline at end of file