mirror of https://github.com/gchq/CyberChef.git
133 lines
3.8 KiB
JavaScript
133 lines
3.8 KiB
JavaScript
/**
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* @author n1474335 [n1474335@gmail.com]
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* @copyright Crown Copyright 2016
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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 Utils from "../Utils.mjs";
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import OperationError from "../errors/OperationError.mjs";
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/**
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* Frequency distribution operation
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*/
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class FrequencyDistribution extends Operation {
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/**
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* FrequencyDistribution constructor
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*/
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constructor() {
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super();
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this.name = "Frequency distribution";
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this.module = "Default";
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this.description = "Displays the distribution of bytes in the data as a graph.";
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this.infoURL = "https://wikipedia.org/wiki/Frequency_distribution";
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this.inputType = "ArrayBuffer";
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this.outputType = "json";
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this.presentType = "html";
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this.args = [
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{
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"name": "Show 0%s",
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"type": "boolean",
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"value": true
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},
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{
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"name": "Show ASCII",
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"type": "boolean",
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"value": true
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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 {json}
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*/
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run(input, args) {
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const data = new Uint8Array(input);
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if (!data.length) throw new OperationError("No data");
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const distrib = new Array(256).fill(0),
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percentages = new Array(256),
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len = data.length;
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let i;
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// Count bytes
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for (i = 0; i < len; i++) {
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distrib[data[i]]++;
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}
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// Calculate percentages
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let repr = 0;
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for (i = 0; i < 256; i++) {
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if (distrib[i] > 0) repr++;
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percentages[i] = distrib[i] / len * 100;
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}
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return {
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"dataLength": len,
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"percentages": percentages,
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"distribution": distrib,
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"bytesRepresented": repr
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};
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}
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/**
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* Displays the frequency distribution as a bar chart for web apps.
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*
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* @param {json} freq
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* @returns {html}
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*/
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present(freq, args) {
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const [showZeroes, showAscii] = args;
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// Print
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let output = `<canvas id='chart-area'></canvas><br>
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Total data length: ${freq.dataLength}
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Number of bytes represented: ${freq.bytesRepresented}
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Number of bytes not represented: ${256 - freq.bytesRepresented}
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<script>
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var canvas = document.getElementById("chart-area"),
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parentRect = canvas.closest(".cm-scroller").getBoundingClientRect(),
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scores = ${JSON.stringify(freq.percentages)};
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canvas.width = parentRect.width * 0.95;
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canvas.height = parentRect.height * 0.9;
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CanvasComponents.drawBarChart(canvas, scores, "Byte", "Frequency %", 16, 6);
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</script>
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<table class="table table-hover table-sm">
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<tr><th>Byte</th>${showAscii ? "<th>ASCII</th>" : ""}<th>Percentage</th><th></th></tr>`;
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for (let i = 0; i < 256; i++) {
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if (freq.distribution[i] || showZeroes) {
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let c = "";
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if (showAscii) {
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if (i <= 32) {
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c = String.fromCharCode(0x2400 + i);
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} else if (i === 127) {
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c = String.fromCharCode(0x2421);
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} else {
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c = String.fromCharCode(i);
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}
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}
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const bite = `<td>${Utils.hex(i, 2)}</td>`,
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ascii = showAscii ? `<td>${c}</td>` : "",
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percentage = `<td>${(freq.percentages[i].toFixed(2).replace(".00", "") + "%").padEnd(8, " ")}</td>`,
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bars = `<td>${Array(Math.ceil(freq.percentages[i])+1).join("|")}</td>`;
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output += `<tr>${bite}${ascii}${percentage}${bars}</tr>`;
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}
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}
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output += "</table>";
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return output;
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}
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}
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export default FrequencyDistribution;
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