mirror of https://github.com/gchq/CyberChef.git
105 lines
3.0 KiB
JavaScript
105 lines
3.0 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 {INFLATE_BUFFER_TYPE} from "../lib/Zlib.mjs";
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import rawinflate from "zlibjs/bin/rawinflate.min.js";
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import OperationError from "../errors/OperationError.mjs";
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const Zlib = rawinflate.Zlib;
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const RAW_BUFFER_TYPE_LOOKUP = {
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"Adaptive": Zlib.RawInflate.BufferType.ADAPTIVE,
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"Block": Zlib.RawInflate.BufferType.BLOCK,
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};
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/**
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* Raw Inflate operation
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*/
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class RawInflate extends Operation {
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/**
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* RawInflate constructor
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*/
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constructor() {
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super();
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this.name = "Raw Inflate";
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this.module = "Compression";
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this.description = "Decompresses data which has been compressed using the deflate algorithm with no headers.";
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this.infoURL = "https://wikipedia.org/wiki/DEFLATE";
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this.inputType = "ArrayBuffer";
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this.outputType = "ArrayBuffer";
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this.args = [
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{
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name: "Start index",
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type: "number",
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value: 0
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},
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{
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name: "Initial output buffer size",
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type: "number",
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value: 0
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},
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{
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name: "Buffer expansion type",
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type: "option",
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value: INFLATE_BUFFER_TYPE
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},
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{
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name: "Resize buffer after decompression",
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type: "boolean",
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value: false
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},
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{
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name: "Verify result",
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type: "boolean",
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value: false
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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 {ArrayBuffer}
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*/
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run(input, args) {
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const inflate = new Zlib.RawInflate(new Uint8Array(input), {
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index: args[0],
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bufferSize: args[1],
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bufferType: RAW_BUFFER_TYPE_LOOKUP[args[2]],
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resize: args[3],
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verify: args[4]
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}),
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result = new Uint8Array(inflate.decompress());
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// Raw Inflate sometimes messes up and returns nonsense like this:
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// ]....]....]....]....]....]....]....]....]....]....]....]....]....]...
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// e.g. Input data of [8b, 1d, dc, 44]
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// Look for the first two square brackets:
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if (result.length > 158 && result[0] === 93 && result[5] === 93) {
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// If the first two square brackets are there, check that the others
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// are also there. If they are, throw an error. If not, continue.
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let valid = false;
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for (let i = 0; i < 155; i += 5) {
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if (result[i] !== 93) {
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valid = true;
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}
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}
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if (!valid) {
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throw new OperationError("Error: Unable to inflate data");
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}
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}
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// This seems to be the easiest way...
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return result.buffer;
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}
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}
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export default RawInflate;
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