Added yara rule support

src/core/operations/YaraRules.mjs

@@ -0,0 +1,68 @@
+/**
+ * @author Matt C [matt@artemisbot.uk]
+ * @copyright Crown Copyright 2019
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation";
+import OperationError from "../errors/OperationError";
+import Yara from "libyara-wasm";
+
+/**
+ * Yara Rules operation
+ */
+class YaraRules extends Operation {
+
+    /**
+     * YaraRules constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "Yara Rules";
+        this.module = "Yara";
+        this.description = "Yara support";
+        this.infoURL = "https://en.wikipedia.org/wiki/YARA";
+        this.inputType = "string";
+        this.outputType = "string";
+        this.args = [{
+            name: "Rules",
+            type: "string",
+            value: ""
+        }];
+    }
+
+    /**
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    run(input, args) {
+        return new Promise((resolve, reject) => {
+            Yara().then(yara => {
+                const resp = yara.run(input, args[0]);
+                if (resp.compileErrors.size() > 0) {
+                    for (let i = 0; i < resp.compileErrors.size(); i++) {
+                        const compileError = resp.compileErrors.get(i);
+                        reject(new OperationError(`Error on line ${compileError.lineNumber}: ${compileError.message}`));
+                    }
+                }
+                const matchedRules = resp.matchedRules;
+                let matchString = "";
+                for (let i = 0; i < matchedRules.keys().size(); i++) {
+                    const ruleMatches = matchedRules.get(matchedRules.keys().get(i));
+                    matchString += `Rule "${matchedRules.keys().get(i)}" matches:\n`;
+
+                    for (let j = 0; j < ruleMatches.size(); j++) {
+                        const match = ruleMatches.get(j);
+                        matchString += `Position ${match.location}, length ${match.matchLength}, data: ${match.data}\n`;
+                    }
+                }
+                resolve(matchString);
+            });
+        });
+    }
+
+}
+
+export default YaraRules;