added GootLoader decoder

tests/operations/tests/GootLoaderDecode.mjs

@@ -0,0 +1,44 @@
+/**
+ * @author drole [rodelm@gmail.com]
+ * @copyright Crown Copyright 2016
+ * @license Apache-2.0
+ */
+import Operation from "../Operation.mjs";
+ /**
+  * Gootloader decode operation
+  */
+class GootLoaderDecode extends Operation {
+     /**
+      * GootLoader constructor
+      */
+    constructor() {
+        super();
+        this.name = "GootLoader Decode";
+        this.module = "Code";
+        this.description = "Decodes GootLoader JScript code block obfuscation";
+        this.inputType = "string";
+        this.outputType = "string";
+        this.args = [];
+    }
+
+     /**
+    * @param {string} input
+    * @param {Object[]} args
+    * @returns {string}
+    */
+    run(input, args) {
+        if (!input) return "";
+        let decoded = "";
+        let decodedReversed = "";
+        for (let i = 0; i < input.length; i++) {
+            if (i%2) {
+                decoded += input.charAt(i);
+            } else {
+                decodedReversed += input.charAt(i);
+            }
+        }
+        return decodedReversed.split("").reverse().join("") + decoded;
+    }
+}
+
+export default GootLoaderDecode;