Merge branch 'tlv' of https://github.com/GCHQ77703/CyberChef into GCHQ77703-tlv

This commit is contained in:
n1474335 2018-08-31 15:12:54 +00:00
commit a15af602e0
5 changed files with 211 additions and 1 deletions

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@ -53,7 +53,8 @@
"To MessagePack",
"From MessagePack",
"To Braille",
"From Braille"
"From Braille",
"LV Decode"
]
},
{

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@ -0,0 +1,71 @@
/**
* @author gchq77703 []
* @copyright Crown Copyright 2018
* @license Apache-2.0
*/
const defaults = {
location: 0,
bytesInLength: 1,
basicEncodingRules: false
};
/**
* Length Value library
*/
export default class LengthValue {
/**
* LengthValue constructor
*/
constructor(input, options) {
this.input = input;
Object.assign(this, defaults, options);
}
/**
* @returns {Number}
*/
getLength() {
if (this.basicEncodingRules) {
const bit = this.input[this.location];
if (bit & 0x80) {
this.bytesInLength = bit & ~0x80;
} else {
this.location++;
return bit & ~0x80;
}
}
let length = 0;
for (let i = 0; i < this.bytesInLength; i++) {
length += this.input[this.location] * Math.pow(Math.pow(2, 8), i);
this.location++;
}
return length;
}
/**
* @param {Number} length
* @returns {Number[]}
*/
getValue(length) {
const value = [];
for (let i = 0; i < length; i++) {
value.push(this.input[this.location]);
this.location++;
}
return value;
}
/**
* @returns {Boolean}
*/
atEnd() {
return this.input.length <= this.location;
}
}

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@ -0,0 +1,81 @@
/**
* @author gchq77703 []
* @copyright Crown Copyright 2018
* @license Apache-2.0
*/
import Operation from "../Operation";
import LengthValue from "../lib/LengthValue";
/**
* From LV Decode operation
*/
class LVDecode extends Operation {
/**
* LVDecode constructor
*/
constructor() {
super();
this.name = "LV Decode";
this.module = "Default";
this.description = "Converts a Length-Value (LV) encoded string into a JSON object. Can optionally include a <code>Key</code> / <code>Type</code> entry.";
this.infoURL = "https://wikipedia.org/wiki/KLV";
this.inputType = "byteArray";
this.outputType = "JSON";
this.args = [
{
name: "Bytes in Key Value",
type: "option",
value: [
"0 Bytes (No Key)",
"1 Byte",
"2 Bytes",
"4 Bytes"
]
},
{
name: "Bytes in Length Value",
type: "option",
value: [
"1 Byte",
"2 Bytes",
"4 Bytes"
]
},
{
name: "Use Basic Encoding Rules",
type: "boolean"
}
];
}
/**
* @param {byteArray} input
* @param {Object[]} args
* @returns {string}
*/
run(input, args) {
const bytesInKey = parseInt(args[0].split(" ")[0], 10);
const bytesInLength = parseInt(args[1].split(" ")[0], 10);
const basicEncodingRules = args[2];
const lv = new LengthValue(input, { bytesInLength, basicEncodingRules });
const data = [];
while (!lv.atEnd()) {
const key = bytesInKey ? lv.getValue(bytesInKey) : undefined;
const length = lv.getLength();
const value = lv.getValue(length);
data.push({ key, length, value });
}
return data;
}
}
export default LVDecode;

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@ -71,6 +71,7 @@ import "./tests/operations/SymmetricDifference";
import "./tests/operations/ToGeohash.mjs";
import "./tests/operations/TranslateDateTimeFormat";
import "./tests/operations/Magic";
import "./tests/operations/LVDecode";
let allTestsPassing = true;
const testStatusCounts = {

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@ -0,0 +1,56 @@
/**
* LV Decoder tests.
*
* @author gchq77703 []
* @copyright Crown Copyright 2018
* @license Apache-2.0
*/
import TestRegister from "../../TestRegister";
TestRegister.addTests([
{
name: "LVDecode: LengthValue",
input: "\x05\x48\x6f\x75\x73\x65\x04\x72\x6f\x6f\x6d\x04\x64\x6f\x6f\x72",
expectedOutput: JSON.stringify([{"length": 5, "value": [72, 111, 117, 115, 101]}, {"length": 4, "value": [114, 111, 111, 109]}, {"length": 4, "value": [100, 111, 111, 114]}]),
recipeConfig: [
{
"op": "LV Decode",
"args": ["0 Bytes (No Key)", "1 Byte", false]
}
]
},
{
name: "LVDecode: LengthValue with BER",
input: "\x05\x48\x6f\x75\x73\x65\x04\x72\x6f\x6f\x6d\x04\x64\x6f\x6f\x72",
expectedOutput: JSON.stringify([{"length": 5, "value": [72, 111, 117, 115, 101]}, {"length": 4, "value": [114, 111, 111, 109]}, {"length": 4, "value": [100, 111, 111, 114]}]),
recipeConfig: [
{
"op": "LV Decode",
"args": ["0 Bytes (No Key)", "4 Bytes", false] // length value is patently wrong, should be ignored by BER.
}
]
},
{
name: "LVDecode: KeyLengthValue",
input: "\x04\x05\x48\x6f\x75\x73\x65\x05\x04\x72\x6f\x6f\x6d\x42\x04\x64\x6f\x6f\x72",
expectedOutput: JSON.stringify([{"key":[4],"length":5,"value":[72,111,117,115,101]},{"key":[5],"length":4,"value":[114,111,111,109]},{"key":[66],"length":4,"value":[100,111,111,114]}]),
recipeConfig: [
{
"op": "LV Decode",
"args": ["1 Byte", "1 Byte", false]
}
]
},
{
name: "LVDecode: KeyLengthValue with BER",
input: "\x04\x05\x48\x6f\x75\x73\x65\x05\x04\x72\x6f\x6f\x6d\x42\x04\x64\x6f\x6f\x72",
expectedOutput: JSON.stringify([{"key":[4],"length":5,"value":[72,111,117,115,101]},{"key":[5],"length":4,"value":[114,111,111,109]},{"key":[66],"length":4,"value":[100,111,111,114]}]),
recipeConfig: [
{
"op": "LV Decode",
"args": ["1 Byte", "4 Byte", true] // length value is patently wrong, should be ignored by BER.
}
]
}
]);