Added Dahua Hashing

Added the Dahua Hashing selection to the hashing menu

src/core/config/Categories.json

@@ -344,6 +344,7 @@
             "CTPH",
             "Compare SSDEEP hashes",
             "Compare CTPH hashes",
+            "Dahua",
             "HMAC",
             "Bcrypt",
             "Bcrypt compare",

src/core/operations/Dahua.mjs

@@ -0,0 +1,78 @@
+/**
+ * @author Oscar Molnar [tymscar@gmail.com]
+ * @copyright Crown Copyright 2016
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation.mjs";
+import crypto from 'crypto';
+
+/**
+ * Dahua operation
+ */
+class Dahua extends Operation {
+
+    /**
+     * Dahua constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "Dahua";
+        this.module = "Crypto";
+        this.description = "Dahua is a hashing standard used on many DVRs and network cameras.";
+        this.inputType = "string";
+        this.outputType = "string";
+        this.args = [];
+    }
+
+    /**
+     * Compresses the input into the final ascii array
+     * 
+     * @param {Number[]} input
+     * @returns {String[]}
+     */
+    compressor(input) {
+        let j=0, i =0
+        let output = Array(8).fill('')
+        while (i<input.length){
+            output[j] = (input[i] + input[i+1]) % 62
+            if(output[j] < 10){
+                output[j] += 48
+            } else if(output[j] < 36){
+                output[j] += 55
+            } else {
+                output[j] += 61
+            }
+            i+=2
+            j+=1
+        }
+        return output
+    }
+    
+    /**
+     * Calculate the Dahua hash of an input
+     * 
+     * @param {string} input
+     * @returns {string}
+     */
+    dhash(input){
+        const md5Hash = crypto.createHash('md5').update(input)
+        const crypt = [...md5Hash.digest()]
+        const compressed = this.compressor(crypt)
+        const answer = compressed.map((character)=>String.fromCharCode(character))
+        return answer.join('')
+    }
+
+    /**
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    run(input, args) {
+        return this.dhash(input);
+    }
+
+}
+
+export default Dahua;