Merge pull request #33 from linuxgemini/linuxgemini-patch-modhex

feat(Modhex): Introduce basic Modhex conversion

src/core/config/Categories.json

@@ -10,6 +10,8 @@
             "From Hexdump",
             "To Hex",
             "From Hex",
+            "To Modhex",
+            "From Modhex",
             "To Charcode",
             "From Charcode",
             "To Decimal",

src/core/lib/Modhex.mjs

@@ -0,0 +1,65 @@
+/**
+ * Modhex helpers.
+ *
+ * @author linuxgemini [[email protected]]
+ * @copyright Crown Copyright 2020
+ * @license Apache-2.0
+ */
+
+
+/**
+ * Modhex to Hex conversion map.
+ */
+export const MODHEX_TO_HEX_CONVERSION_MAP = {
+    "c": "0",
+    "b": "1",
+    "d": "2",
+    "e": "3",
+    "f": "4",
+    "g": "5",
+    "h": "6",
+    "i": "7",
+    "j": "8",
+    "k": "9",
+    "l": "a",
+    "n": "b",
+    "r": "c",
+    "t": "d",
+    "u": "e",
+    "v": "f"
+};
+
+
+/**
+ * Hex to Modhex conversion map.
+ */
+export const HEX_TO_MODHEX_CONVERSION_MAP = {
+    "0": "c",
+    "1": "b",
+    "2": "d",
+    "3": "e",
+    "4": "f",
+    "5": "g",
+    "6": "h",
+    "7": "i",
+    "8": "j",
+    "9": "k",
+    "a": "l",
+    "b": "n",
+    "c": "r",
+    "d": "t",
+    "e": "u",
+    "f": "v"
+};
+
+
+/**
+ * To Modhex delimiters.
+ */
+export const TO_MODHEX_DELIM_OPTIONS = ["Space", "Percent", "Comma", "Semi-colon", "Colon", "Line feed", "CRLF", "None"];
+
+
+/**
+ * From Modhex delimiters.
+ */
+export const FROM_MODHEX_DELIM_OPTIONS = ["Auto"].concat(TO_MODHEX_DELIM_OPTIONS);

src/core/operations/FromModhex.mjs

@@ -0,0 +1,123 @@
+/**
+ * @author linuxgemini [[email protected]]
+ * @copyright Crown Copyright 2020
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation.mjs";
+import { FROM_MODHEX_DELIM_OPTIONS, MODHEX_TO_HEX_CONVERSION_MAP } from "../lib/Modhex.mjs";
+import { fromHex } from "../lib/Hex.mjs";
+import Utils from "../Utils.mjs";
+
+/**
+ * From Modhex operation
+ */
+class FromModhex extends Operation {
+
+    /**
+     * FromModhex constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "From Modhex";
+        this.module = "Default";
+        this.description = "Converts a modhex byte string back into its raw value.";
+        this.infoURL = "https://en.wikipedia.org/wiki/YubiKey#ModHex";
+        this.inputType = "string";
+        this.outputType = "byteArray";
+        this.args = [
+            {
+                name: "Delimiter",
+                type: "option",
+                value: FROM_MODHEX_DELIM_OPTIONS
+            }
+        ];
+        this.checks = [
+            {
+                pattern: "^(?:[cbdefghijklnrtuv]{2})+$",
+                flags: "i",
+                args: ["None"]
+            },
+            {
+                pattern: "^[cbdefghijklnrtuv]{2}(?: [cbdefghijklnrtuv]{2})*$",
+                flags: "i",
+                args: ["Space"]
+            },
+            {
+                pattern: "^[cbdefghijklnrtuv]{2}(?:,[cbdefghijklnrtuv]{2})*$",
+                flags: "i",
+                args: ["Comma"]
+            },
+            {
+                pattern: "^[cbdefghijklnrtuv]{2}(?:;[cbdefghijklnrtuv]{2})*$",
+                flags: "i",
+                args: ["Semi-colon"]
+            },
+            {
+                pattern: "^[cbdefghijklnrtuv]{2}(?::[cbdefghijklnrtuv]{2})*$",
+                flags: "i",
+                args: ["Colon"]
+            },
+            {
+                pattern: "^[cbdefghijklnrtuv]{2}(?:\\n[cbdefghijklnrtuv]{2})*$",
+                flags: "i",
+                args: ["Line feed"]
+            },
+            {
+                pattern: "^[cbdefghijklnrtuv]{2}(?:\\r\\n[cbdefghijklnrtuv]{2})*$",
+                flags: "i",
+                args: ["CRLF"]
+            }
+        ];
+    }
+
+    /**
+     * Convert a hex string into a byte array.
+     *
+     * @param {string} data
+     * @param {string} [delim]
+     * @param {number} [byteLen=2]
+     * @returns {byteArray}
+     *
+     * @example
+     * // returns [10,20,30]
+     * fromModhex("cl bf bu");
+     *
+     * // returns [10,20,30]
+     * fromModhex("cl:bf:bu", "Colon");
+     */
+    fromModhex(data, delim="Auto", byteLen=2) {
+        if (!data || data.length === 0) return [];
+
+        data = data.toLowerCase();
+
+        if (delim !== "None") {
+            const delimRegex = delim === "Auto" ? /[^cbdefghijklnrtuv]/gi : Utils.regexRep(delim);
+            data = data.replace(delimRegex, "");
+        }
+
+        data = data.replace(/\s/g, "");
+
+        let hexconv = "";
+        for (const letter of data.split("")) {
+            hexconv += MODHEX_TO_HEX_CONVERSION_MAP[letter];
+        }
+
+        const output = fromHex(hexconv, "None", byteLen);
+        return output;
+    }
+
+    /**
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {byteArray}
+     */
+    run(input, args) {
+        const delim = args[0] || "Auto";
+        return this.fromModhex(input, delim, 2);
+    }
+
+}
+
+export default FromModhex;

src/core/operations/ToModhex.mjs

@@ -0,0 +1,110 @@
+/**
+ * @author linuxgemini [[email protected]]
+ * @copyright Crown Copyright 2020
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation.mjs";
+import { TO_MODHEX_DELIM_OPTIONS, HEX_TO_MODHEX_CONVERSION_MAP } from "../lib/Modhex.mjs";
+import { toHex } from "../lib/Hex.mjs";
+import Utils from "../Utils.mjs";
+
+/**
+ * To Modhex operation
+ */
+class ToModhex extends Operation {
+
+    /**
+     * ToModhex constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "To Modhex";
+        this.module = "Default";
+        this.description = "Converts the input string to modhex bytes separated by the specified delimiter.";
+        this.infoURL = "https://en.wikipedia.org/wiki/YubiKey#ModHex";
+        this.inputType = "ArrayBuffer";
+        this.outputType = "string";
+        this.args = [
+            {
+                name: "Delimiter",
+                type: "option",
+                value: TO_MODHEX_DELIM_OPTIONS
+            },
+            {
+                name: "Bytes per line",
+                type: "number",
+                value: 0
+            }
+        ];
+    }
+
+    /**
+     * Convert a byte array into a modhex string.
+     *
+     * @param {byteArray|Uint8Array|ArrayBuffer} data
+     * @param {string} [delim=" "]
+     * @param {number} [padding=2]
+     * @returns {string}
+     *
+     * @example
+     * // returns "cl bf bu"
+     * toModhex([10,20,30]);
+     *
+     * // returns "cl:bf:bu"
+     * toModhex([10,20,30], ":");
+     */
+    toModhex(data, delim=" ", padding=2, extraDelim="", lineSize=0) {
+        if (!data || data.length === 0) return "";
+        if (data instanceof ArrayBuffer) data = new Uint8Array(data);
+
+        const hexconv = toHex(data, "", padding, "", 0);
+        let modhexconv = "";
+        let output = "";
+
+        for (const letter of hexconv.split("")) {
+            modhexconv += HEX_TO_MODHEX_CONVERSION_MAP[letter];
+        }
+
+        const groupedModhex = modhexconv.match(/.{1,2}/g);
+
+        for (let i = 0; i < groupedModhex.length; i++) {
+            const group = groupedModhex[i];
+            output += group + delim;
+
+            if (extraDelim) {
+                output += extraDelim;
+            }
+            // Add LF after each lineSize amount of bytes but not at the end
+            if ((i !== groupedModhex.length - 1) && ((i + 1) % lineSize === 0)) {
+                output += "\n";
+            }
+        }
+
+        // Remove the extraDelim at the end (if there is one)
+        // and remove the delim at the end, but if it's prepended there's nothing to remove
+        const rTruncLen = extraDelim.length + delim.length;
+        if (rTruncLen) {
+            // If rTruncLen === 0 then output.slice(0,0) will be returned, which is nothing
+            return output.slice(0, -rTruncLen);
+        } else {
+            return output;
+        }
+    }
+
+    /**
+     * @param {ArrayBuffer} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    run(input, args) {
+        const delim = Utils.charRep(args[0]);
+        const lineSize = args[1];
+
+        return this.toModhex(new Uint8Array(input), delim, 2, "", lineSize);
+    }
+
+}
+
+export default ToModhex;

tests/operations/index.mjs

@@ -66,6 +66,7 @@ import "./tests/JWTSign.mjs";
 import "./tests/JWTVerify.mjs";
 import "./tests/MS.mjs";
 import "./tests/Magic.mjs";
+import "./tests/Modhex.mjs";
 import "./tests/MorseCode.mjs";
 import "./tests/NetBIOS.mjs";
 import "./tests/NormaliseUnicode.mjs";