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Merge pull request #1105 from linuxgemini/linuxgemini-patch-modhex
Introduce Yubico's Modhex for Conversion
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Diff for: ‎src/core/config/Categories.json

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

Diff for: ‎src/core/lib/Modhex.mjs

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/**
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* @author linuxgemini [[email protected]]
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* @copyright Crown Copyright 2024
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* @license Apache-2.0
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*/
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import Utils from "../Utils.mjs";
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import OperationError from "../errors/OperationError.mjs";
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import { fromHex, toHex } from "./Hex.mjs";
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/**
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* Modhex alphabet.
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*/
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const MODHEX_ALPHABET = "cbdefghijklnrtuv";
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/**
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* Modhex alphabet map.
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*/
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const MODHEX_ALPHABET_MAP = MODHEX_ALPHABET.split("");
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/**
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* Hex alphabet to substitute Modhex.
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*/
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const HEX_ALPHABET = "0123456789abcdef";
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/**
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* Hex alphabet map to substitute Modhex.
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*/
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const HEX_ALPHABET_MAP = HEX_ALPHABET.split("");
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/**
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* Convert a byte array into a modhex string.
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*
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* @param {byteArray|Uint8Array|ArrayBuffer} data
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* @param {string} [delim=" "]
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* @param {number} [padding=2]
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* @returns {string}
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*
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* @example
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* // returns "cl bf bu"
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* toModhex([10,20,30]);
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*
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* // returns "cl:bf:bu"
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* toModhex([10,20,30], ":");
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*/
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export function toModhex(data, delim=" ", padding=2, extraDelim="", lineSize=0) {
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if (!data) return "";
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if (data instanceof ArrayBuffer) data = new Uint8Array(data);
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const regularHexString = toHex(data, "", padding, "", 0);
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let modhexString = "";
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for (const letter of regularHexString.split("")) {
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modhexString += MODHEX_ALPHABET_MAP[HEX_ALPHABET_MAP.indexOf(letter)];
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}
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let output = "";
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const groupingRegexp = new RegExp(`.{1,${padding}}`, "g");
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const groupedModhex = modhexString.match(groupingRegexp);
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for (let i = 0; i < groupedModhex.length; i++) {
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const group = groupedModhex[i];
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output += group + delim;
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if (extraDelim) {
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output += extraDelim;
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}
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// Add LF after each lineSize amount of bytes but not at the end
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if ((i !== groupedModhex.length - 1) && ((i + 1) % lineSize === 0)) {
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output += "\n";
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}
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}
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// Remove the extraDelim at the end (if there is one)
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// and remove the delim at the end, but if it's prepended there's nothing to remove
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const rTruncLen = extraDelim.length + delim.length;
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if (rTruncLen) {
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// If rTruncLen === 0 then output.slice(0,0) will be returned, which is nothing
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return output.slice(0, -rTruncLen);
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} else {
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return output;
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}
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}
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/**
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* Convert a byte array into a modhex string as efficiently as possible with no options.
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*
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* @param {byteArray|Uint8Array|ArrayBuffer} data
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* @returns {string}
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*
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* @example
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* // returns "clbfbu"
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* toModhexFast([10,20,30]);
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*/
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export function toModhexFast(data) {
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if (!data) return "";
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if (data instanceof ArrayBuffer) data = new Uint8Array(data);
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const output = [];
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for (let i = 0; i < data.length; i++) {
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output.push(MODHEX_ALPHABET_MAP[(data[i] >> 4) & 0xf]);
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output.push(MODHEX_ALPHABET_MAP[data[i] & 0xf]);
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}
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return output.join("");
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}
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/**
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* Convert a modhex string into a byte array.
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*
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* @param {string} data
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* @param {string} [delim]
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* @param {number} [byteLen=2]
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* @returns {byteArray}
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*
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* @example
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* // returns [10,20,30]
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* fromModhex("cl bf bu");
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*
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* // returns [10,20,30]
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* fromModhex("cl:bf:bu", "Colon");
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*/
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export function fromModhex(data, delim="Auto", byteLen=2) {
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if (byteLen < 1 || Math.round(byteLen) !== byteLen)
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throw new OperationError("Byte length must be a positive integer");
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// The `.replace(/\s/g, "")` an interesting workaround: Hex "multiline" tests aren't actually
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// multiline. Tests for Modhex fixes that, thus exposing the issue.
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data = data.toLowerCase().replace(/\s/g, "");
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if (delim !== "None") {
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const delimRegex = delim === "Auto" ? /[^cbdefghijklnrtuv]/gi : Utils.regexRep(delim);
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data = data.split(delimRegex);
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} else {
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data = [data];
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}
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let regularHexString = "";
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for (let i = 0; i < data.length; i++) {
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for (const letter of data[i].split("")) {
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regularHexString += HEX_ALPHABET_MAP[MODHEX_ALPHABET_MAP.indexOf(letter)];
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}
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}
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const output = fromHex(regularHexString, "None", byteLen);
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return output;
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}
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/**
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* To Modhex delimiters.
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*/
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export const TO_MODHEX_DELIM_OPTIONS = ["Space", "Percent", "Comma", "Semi-colon", "Colon", "Line feed", "CRLF", "None"];
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/**
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* From Modhex delimiters.
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*/
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export const FROM_MODHEX_DELIM_OPTIONS = ["Auto"].concat(TO_MODHEX_DELIM_OPTIONS);

Diff for: ‎src/core/operations/FromModhex.mjs

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/**
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* @author linuxgemini [[email protected]]
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* @copyright Crown Copyright 2024
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* @license Apache-2.0
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*/
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import Operation from "../Operation.mjs";
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import { FROM_MODHEX_DELIM_OPTIONS, fromModhex } from "../lib/Modhex.mjs";
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/**
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* From Modhex operation
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*/
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class FromModhex extends Operation {
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/**
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* FromModhex constructor
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*/
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constructor() {
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super();
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this.name = "From Modhex";
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this.module = "Default";
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this.description = "Converts a modhex byte string back into its raw value.";
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this.infoURL = "https://en.wikipedia.org/wiki/YubiKey#ModHex";
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this.inputType = "string";
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this.outputType = "byteArray";
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this.args = [
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{
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name: "Delimiter",
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type: "option",
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value: FROM_MODHEX_DELIM_OPTIONS
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}
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];
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this.checks = [
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{
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pattern: "^(?:[cbdefghijklnrtuv]{2})+$",
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flags: "i",
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args: ["None"]
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},
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{
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pattern: "^[cbdefghijklnrtuv]{2}(?: [cbdefghijklnrtuv]{2})*$",
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flags: "i",
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args: ["Space"]
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},
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{
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pattern: "^[cbdefghijklnrtuv]{2}(?:,[cbdefghijklnrtuv]{2})*$",
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flags: "i",
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args: ["Comma"]
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},
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{
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pattern: "^[cbdefghijklnrtuv]{2}(?:;[cbdefghijklnrtuv]{2})*$",
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flags: "i",
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args: ["Semi-colon"]
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},
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{
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pattern: "^[cbdefghijklnrtuv]{2}(?::[cbdefghijklnrtuv]{2})*$",
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flags: "i",
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args: ["Colon"]
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},
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{
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pattern: "^[cbdefghijklnrtuv]{2}(?:\\n[cbdefghijklnrtuv]{2})*$",
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flags: "i",
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args: ["Line feed"]
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},
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{
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pattern: "^[cbdefghijklnrtuv]{2}(?:\\r\\n[cbdefghijklnrtuv]{2})*$",
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flags: "i",
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args: ["CRLF"]
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}
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];
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}
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/**
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* @param {string} input
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* @param {Object[]} args
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* @returns {byteArray}
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*/
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run(input, args) {
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const delim = args[0] || "Auto";
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return fromModhex(input, delim, 2);
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}
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}
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export default FromModhex;

Diff for: ‎src/core/operations/ToModhex.mjs

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/**
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* @author linuxgemini [[email protected]]
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* @copyright Crown Copyright 2024
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* @license Apache-2.0
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*/
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import Operation from "../Operation.mjs";
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import { TO_MODHEX_DELIM_OPTIONS, toModhex } from "../lib/Modhex.mjs";
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import Utils from "../Utils.mjs";
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/**
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* To Modhex operation
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*/
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class ToModhex extends Operation {
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/**
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* ToModhex constructor
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*/
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constructor() {
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super();
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this.name = "To Modhex";
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this.module = "Default";
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this.description = "Converts the input string to modhex bytes separated by the specified delimiter.";
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this.infoURL = "https://en.wikipedia.org/wiki/YubiKey#ModHex";
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this.inputType = "ArrayBuffer";
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this.outputType = "string";
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this.args = [
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{
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name: "Delimiter",
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type: "option",
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value: TO_MODHEX_DELIM_OPTIONS
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},
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{
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name: "Bytes per line",
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type: "number",
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value: 0
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}
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];
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}
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/**
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* @param {ArrayBuffer} input
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* @param {Object[]} args
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* @returns {string}
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*/
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run(input, args) {
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const delim = Utils.charRep(args[0]);
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const lineSize = args[1];
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return toModhex(new Uint8Array(input), delim, 2, "", lineSize);
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}
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}
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export default ToModhex;

Diff for: ‎tests/operations/index.mjs

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@@ -104,6 +104,7 @@ import "./tests/LZNT1Decompress.mjs";
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import "./tests/LZString.mjs";
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import "./tests/Magic.mjs";
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import "./tests/Media.mjs";
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import "./tests/Modhex.mjs";
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import "./tests/MorseCode.mjs";
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import "./tests/MS.mjs";
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import "./tests/MultipleBombe.mjs";

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