CyberChef/src/core/operations/RandomizeColourPalette.mjs

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2019-08-29 17:17:07 +02:00
/**
* @author Ge0rg3 [georgeomnet+cyberchef@gmail.com]
* @copyright Crown Copyright 2019
* @license Apache-2.0
*/
import Operation from "../Operation.mjs";
import OperationError from "../errors/OperationError.mjs";
import Utils from "../Utils";
import PseudoRandomNumberGenerator from "./PseudoRandomNumberGenerator.mjs";
import { isImage } from "../lib/FileType";
import { runHash } from "../lib/Hash.mjs";
import { toBase64 } from "../lib/Base64";
import jimp from "jimp";
/**
* Randomize Colour Palette operation
*/
class RandomizeColourPalette extends Operation {
/**
* RandomizeColourPalette constructor
*/
constructor() {
super();
this.name = "Randomize Colour Palette";
this.module = "Image";
this.description = "Randomize's each colour in an image's colour palette. This can often reveal text or symbols that were previously a very similar colour to their surroundings.";
this.infoURL = "https://en.wikipedia.org/wiki/Indexed_color";
this.inputType = "byteArray";
this.outputType = "byteArray";
this.presentType = "html";
this.args = [
{
name: "Seed",
type: "string",
value: ""
}
];
}
/**
* @param {byteArray} input
* @param {Object[]} args
* @returns {byteArray}
*/
async run(input, args) {
if (!isImage(input)) throw new OperationError("Please enter a valid image file.");
const seed = args[0] || (new PseudoRandomNumberGenerator()).run("", [5, "Hex"]),
parsedImage = await jimp.read(Buffer.from(input)),
width = parsedImage.bitmap.width,
height = parsedImage.bitmap.height;
let rgbString, rgbHash, rgbHex;
parsedImage.scan(0, 0, width, height, function(x, y, idx) {
rgbString = this.bitmap.data.slice(idx, idx+3).join(".");
rgbHash = runHash("md5", Utils.strToArrayBuffer(seed + rgbString));
rgbHex = rgbHash.substr(0, 6) + "ff";
parsedImage.setPixelColor(parseInt(rgbHex, 16), x, y);
});
const imageBuffer = await parsedImage.getBufferAsync(jimp.AUTO);
return Array.from(imageBuffer);
}
/**
* Displays the extracted data as an image for web apps.
* @param {byteArray} data
* @returns {html}
*/
present(data) {
if (!data.length) return "";
const type = isImage(data);
return `<img src="data:${type};base64,${toBase64(data)}">`;
}
}
export default RandomizeColourPalette;