feat(Modhex): Introduce basic Modhex conversion

Signed-off-by: İlteriş Yağıztegin Eroğlu <ilteris@asenkron.com.tr>

src/core/config/Categories.json

@@ -74,7 +74,9 @@
             "CBOR Decode",
             "Caret/M-decode",
             "Rison Encode",
-            "Rison Decode"
+            "Rison Decode",
+            "To Modhex",
+            "From Modhex"
         ]
     },
     {

src/core/lib/Modhex.mjs

@@ -0,0 +1,165 @@
+/**
+ * @author linuxgemini [ilteris@asenkron.com.tr]
+ * @copyright Crown Copyright 2024
+ * @license Apache-2.0
+ */
+
+import Utils from "../Utils.mjs";
+import OperationError from "../errors/OperationError.mjs";
+import { fromHex, toHex } from "./Hex.mjs";
+
+/**
+ * Modhex alphabet.
+ */
+const MODHEX_ALPHABET = "cbdefghijklnrtuv";
+
+
+/**
+ * Modhex alphabet map.
+ */
+const MODHEX_ALPHABET_MAP = MODHEX_ALPHABET.split("");
+
+
+/**
+ * Hex alphabet to substitute Modhex.
+ */
+const HEX_ALPHABET = "0123456789abcdef";
+
+
+/**
+ * Hex alphabet map to substitute Modhex.
+ */
+const HEX_ALPHABET_MAP = HEX_ALPHABET.split("");
+
+
+/**
+ * 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], ":");
+ */
+export function toModhex(data, delim=" ", padding=2, extraDelim="", lineSize=0) {
+    if (!data) return "";
+    if (data instanceof ArrayBuffer) data = new Uint8Array(data);
+
+    const regularHexString = toHex(data, "", padding, "", 0);
+
+    let modhexString = "";
+    for (const letter of regularHexString.split("")) {
+        modhexString += MODHEX_ALPHABET_MAP[HEX_ALPHABET_MAP.indexOf(letter)];
+    }
+
+    let output = "";
+    const groupingRegexp = new RegExp(`.{1,${padding}}`, "g");
+    const groupedModhex = modhexString.match(groupingRegexp);
+
+    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;
+    }
+}
+
+
+/**
+ * Convert a byte array into a modhex string as efficiently as possible with no options.
+ *
+ * @param {byteArray|Uint8Array|ArrayBuffer} data
+ * @returns {string}
+ *
+ * @example
+ * // returns "clbfbu"
+ * toModhexFast([10,20,30]);
+ */
+export function toModhexFast(data) {
+    if (!data) return "";
+    if (data instanceof ArrayBuffer) data = new Uint8Array(data);
+
+    const output = [];
+
+    for (let i = 0; i < data.length; i++) {
+        output.push(MODHEX_ALPHABET_MAP[(data[i] >> 4) & 0xf]);
+        output.push(MODHEX_ALPHABET_MAP[data[i] & 0xf]);
+    }
+    return output.join("");
+}
+
+
+/**
+ * Convert a modhex 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");
+ */
+export function fromModhex(data, delim="Auto", byteLen=2) {
+    if (byteLen < 1 || Math.round(byteLen) !== byteLen)
+        throw new OperationError("Byte length must be a positive integer");
+
+    // The `.replace(/\s/g, "")` an interesting workaround: Hex "multiline" tests aren't actually
+    // multiline. Tests for Modhex fixes that, thus exposing the issue.
+    data = data.toLowerCase().replace(/\s/g, "");
+
+    if (delim !== "None") {
+        const delimRegex = delim === "Auto" ? /[^cbdefghijklnrtuv]/gi : Utils.regexRep(delim);
+        data = data.split(delimRegex);
+    } else {
+        data = [data];
+    }
+
+    let regularHexString = "";
+    for (let i = 0; i < data.length; i++) {
+        for (const letter of data[i].split("")) {
+            regularHexString += HEX_ALPHABET_MAP[MODHEX_ALPHABET_MAP.indexOf(letter)];
+        }
+    }
+
+    const output = fromHex(regularHexString, "None", byteLen);
+    return output;
+}
+
+
+/**
+ * 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 +1,84 @@
+/**
+ * @author linuxgemini [ilteris@asenkron.com.tr]
+ * @copyright Crown Copyright 2024
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation.mjs";
+import { FROM_MODHEX_DELIM_OPTIONS, fromModhex } from "../lib/Modhex.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"]
+            }
+        ];
+    }
+
+    /**
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {byteArray}
+     */
+    run(input, args) {
+        const delim = args[0] || "Auto";
+        return fromModhex(input, delim, 2);
+    }
+}
+
+export default FromModhex;

src/core/operations/ToModhex.mjs

@@ -0,0 +1,55 @@
+/**
+ * @author linuxgemini [ilteris@asenkron.com.tr]
+ * @copyright Crown Copyright 2024
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation.mjs";
+import { TO_MODHEX_DELIM_OPTIONS, toModhex } from "../lib/Modhex.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
+            }
+        ];
+    }
+
+    /**
+     * @param {ArrayBuffer} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    run(input, args) {
+        const delim = Utils.charRep(args[0]);
+        const lineSize = args[1];
+
+        return toModhex(new Uint8Array(input), delim, 2, "", lineSize);
+    }
+}
+
+export default ToModhex;