mirror of https://github.com/gchq/CyberChef.git
112 lines
3.0 KiB
JavaScript
112 lines
3.0 KiB
JavaScript
/**
|
|
* @author n1474335 [n1474335@gmail.com]
|
|
* @copyright Crown Copyright 2016
|
|
* @license Apache-2.0
|
|
*/
|
|
|
|
import Operation from "../Operation";
|
|
import Utils from "../Utils";
|
|
import OperationError from "../errors/OperationError";
|
|
|
|
/**
|
|
* Frequency distribution operation
|
|
*/
|
|
class FrequencyDistribution extends Operation {
|
|
|
|
/**
|
|
* FrequencyDistribution constructor
|
|
*/
|
|
constructor() {
|
|
super();
|
|
|
|
this.name = "Frequency distribution";
|
|
this.module = "Default";
|
|
this.description = "Displays the distribution of bytes in the data as a graph.";
|
|
this.infoURL = "https://wikipedia.org/wiki/Frequency_distribution";
|
|
this.inputType = "ArrayBuffer";
|
|
this.outputType = "json";
|
|
this.presentType = "html";
|
|
this.args = [
|
|
{
|
|
"name": "Show 0%s",
|
|
"type": "boolean",
|
|
"value": "Entropy.FREQ_ZEROS"
|
|
}
|
|
];
|
|
}
|
|
|
|
/**
|
|
* @param {ArrayBuffer} input
|
|
* @param {Object[]} args
|
|
* @returns {json}
|
|
*/
|
|
run(input, args) {
|
|
const data = new Uint8Array(input);
|
|
if (!data.length) throw new OperationError("No data");
|
|
|
|
const distrib = new Array(256).fill(0),
|
|
percentages = new Array(256),
|
|
len = data.length;
|
|
let i;
|
|
|
|
// Count bytes
|
|
for (i = 0; i < len; i++) {
|
|
distrib[data[i]]++;
|
|
}
|
|
|
|
// Calculate percentages
|
|
let repr = 0;
|
|
for (i = 0; i < 256; i++) {
|
|
if (distrib[i] > 0) repr++;
|
|
percentages[i] = distrib[i] / len * 100;
|
|
}
|
|
|
|
return {
|
|
"dataLength": len,
|
|
"percentages": percentages,
|
|
"distribution": distrib,
|
|
"bytesRepresented": repr
|
|
};
|
|
}
|
|
|
|
/**
|
|
* Displays the frequency distribution as a bar chart for web apps.
|
|
*
|
|
* @param {json} freq
|
|
* @returns {html}
|
|
*/
|
|
present(freq, args) {
|
|
const showZeroes = args[0];
|
|
// Print
|
|
let output = `<canvas id='chart-area'></canvas><br>
|
|
Total data length: ${freq.dataLength}
|
|
Number of bytes represented: ${freq.bytesRepresented}
|
|
Number of bytes not represented: ${256 - freq.bytesRepresented}
|
|
|
|
Byte Percentage
|
|
<script>
|
|
var canvas = document.getElementById("chart-area"),
|
|
parentRect = canvas.parentNode.getBoundingClientRect(),
|
|
scores = ${JSON.stringify(freq.percentages)};
|
|
|
|
canvas.width = parentRect.width * 0.95;
|
|
canvas.height = parentRect.height * 0.9;
|
|
|
|
CanvasComponents.drawBarChart(canvas, scores, "Byte", "Frequency %", 16, 6);
|
|
</script>`;
|
|
|
|
for (let i = 0; i < 256; i++) {
|
|
if (freq.distribution[i] || showZeroes) {
|
|
output += " " + Utils.hex(i, 2) + " (" +
|
|
(freq.percentages[i].toFixed(2).replace(".00", "") + "%)").padEnd(8, " ") +
|
|
Array(Math.ceil(freq.percentages[i])+1).join("|") + "\n";
|
|
}
|
|
}
|
|
|
|
return output;
|
|
}
|
|
|
|
}
|
|
|
|
export default FrequencyDistribution;
|