Added 'Generate HOTP' and 'Generate TOTP' operations

src/core/operations/OTP.js

@@ -0,0 +1,55 @@
+import otp from "otp";
+import Base64 from "./Base64.js";
+
+/**
+ * One-Time Password operations.
+ *
+ * @author n1474335 [n1474335@gmail.com]
+ * @copyright Crown Copyright 2017
+ * @license Apache-2.0
+ *
+ * @namespace
+ */
+const OTP = {
+
+    /**
+     * Generate TOTP operation.
+     *
+     * @param {byteArray} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    runTOTP: function(input, args) {
+        const otpObj = otp({
+            name: args[0],
+            keySize: args[1],
+            codeLength: args[2],
+            secret: Base64.runTo32(input, []),
+            epoch: args[3],
+            timeSlice: args[4]
+        });
+        return `URI: ${otpObj.totpURL}\n\nPassword: ${otpObj.totp()}`;
+    },
+
+
+    /**
+     * Generate HOTP operation.
+     *
+     * @param {byteArray} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    runHOTP: function(input, args) {
+        const otpObj = otp({
+            name: args[0],
+            keySize: args[1],
+            codeLength: args[2],
+            secret: Base64.runTo32(input, []),
+        });
+        const counter = args[3];
+        return `URI: ${otpObj.hotpURL}\n\nPassword: ${otpObj.hotp(counter)}`;
+    },
+
+};
+
+export default OTP;