188 lines
No EOL
7.1 KiB
JavaScript
188 lines
No EOL
7.1 KiB
JavaScript
/* global require HKReadTextArea */
|
|
/*
|
|
Parts of the code thanks to bloodorca https://github.com/bloodorca/hollow (base64.js, functions.js) with slight modifications.
|
|
The steps used there for decryption were taken from KayDeeTee https://github.com/KayDeeTee/Hollow-Knight-SaveManager
|
|
Without these two people the existence of this tool wouldn't be possible :)
|
|
*/
|
|
|
|
// ---------------- Constants ----------------- //
|
|
|
|
// AES JS for file decryption
|
|
const aesjs = require("./aes-js.js");
|
|
|
|
const CSHARP_HEADER = [0, 1, 0, 0, 0, 255, 255, 255, 255, 1, 0, 0, 0, 0, 0, 0, 0, 6, 1, 0, 0, 0]; // 22 bytes
|
|
|
|
const BASE64_ARRAY = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=".split("").map(c => c.charCodeAt(0));
|
|
const BASE64_DECODE_TABLE = new Map(BASE64_ARRAY.map((ord, i) => [ord, i]));
|
|
|
|
const AES_KEY = new TextEncoder().encode('UKu52ePUBwetZ9wNX88o54dnfKRu0T1l'); // encodes a string to Uint8Array (prepare for AES JS)
|
|
const ECB_STREAM_CIPHER = new aesjs.ModeOfOperation.ecb(AES_KEY); // create a new AES stream cipher object using the encoded key
|
|
|
|
// ---------------- Variables ----------------- //
|
|
|
|
let benchLSFBegin, benchLSFEnd, benchTotal;
|
|
|
|
// ---------------- Functions ----------------- //
|
|
|
|
/**
|
|
* Main input tag file function. Selects the first file, reads it as an Array Buffer, starts the processing of the file when loaded.
|
|
* Starts benchmarking.
|
|
* @param {FileList} input FileList object containing a list of File objects. The FileList behaves like an array, so you can check its length property to get the number of selected files.
|
|
*/
|
|
// eslint-disable-next-line no-unused-vars
|
|
function LoadSaveFile(input, startTime = new Date()) {
|
|
|
|
// console.info("Input length: " + input.files.length)
|
|
// Cease further processing if user canceled the file input dialog
|
|
if (input.files.length < 1) return false;
|
|
|
|
// start benchmark
|
|
benchLSFBegin = startTime;
|
|
|
|
// Prepares a File object from the first file of the input files for reading as an Array Buffer
|
|
let inputFileObject = input.files[0];
|
|
|
|
// Cleans the file list to avoid problems after subsequent use
|
|
// document.getElementById("save-area-file").value = "";
|
|
|
|
// 1. read file
|
|
// The ArrayBuffer object is used to represent a generic, fixed-length raw binary data buffer.
|
|
// It is an array of bytes, often referred to in other languages as a "byte array".
|
|
|
|
// new FileReader()
|
|
let inputReader = new FileReader();
|
|
// readAsArrayBuffer(file)
|
|
inputReader.readAsArrayBuffer(inputFileObject);
|
|
// addEventListener("load", function) - to decode the file when loaded
|
|
inputReader.addEventListener("load", ProcessFileObject);
|
|
}
|
|
|
|
/**
|
|
* Reads the File object as an Array Buffer and does all other operations (decoding, decryption, conversion to string, pasting to text area).
|
|
* Launches the HKReadTextArea() function automatically after pasting the string to text area
|
|
*/
|
|
function ProcessFileObject() {
|
|
let inputArrayBuffer = this.result;
|
|
let decodedString;
|
|
|
|
// 2. Decode file
|
|
|
|
try {
|
|
// Uint8Array(ArrayBuffer) uint8_t equivalent in C
|
|
inputArrayBuffer = new Uint8Array(inputArrayBuffer);
|
|
|
|
// ArrayBuffer.slice()
|
|
// The slice() method copies up to, but not including, the byte indicated by the end parameter.
|
|
inputArrayBuffer.slice();
|
|
|
|
// remove C# header and LengthPrefixedString header (ArrayBuffer)
|
|
inputArrayBuffer = RemoveHeaders(inputArrayBuffer);
|
|
|
|
// base64 Decoding (ArrayBuffer)
|
|
inputArrayBuffer = Base64Decode(inputArrayBuffer);
|
|
|
|
// AES decryption (ECB) removes pkcs7 padding (ArrayBuffer)
|
|
inputArrayBuffer = AESDecryption(inputArrayBuffer);
|
|
|
|
// Convert ArrayBuffer to string/text TextDecoder().decode(ArrayBuffer)
|
|
decodedString = new TextDecoder().decode(inputArrayBuffer);
|
|
|
|
// 4. Paste decoded string file to text area
|
|
|
|
document.getElementById("save-area").value = "";
|
|
document.getElementById("save-area").value = decodedString;
|
|
|
|
// finish and show benchmark
|
|
benchLSFEnd = new Date();
|
|
console.info("LoadSaveFile() time (ms) =", benchLSFEnd - benchLSFBegin);
|
|
|
|
// after pasting the decoded string, launch the main analyzing function immediately
|
|
HKReadTextArea("save-area");
|
|
|
|
// finish total and show benchmark
|
|
benchTotal = new Date();
|
|
console.info("Total time (ms) =", benchTotal - benchLSFBegin);
|
|
|
|
// alert(`Decoded String: ${decodedString}`);
|
|
// alert(`Array Buffer: ${inputArrayBuffer}`);
|
|
} catch (error) {
|
|
alert(`The file cannot be decoded. ${error}`);
|
|
console.info(`The file cannot be decoded. ${error}`);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Removes C# header, LengthPrefixedString header and byte 11 at the end of the Uint8 Array Buffer
|
|
* @param {Uint8Array} buffer Uint8Array buffer for removing the header from
|
|
* @param {Uint8Array} csHeader Uint8Array for the C# header length calculation
|
|
* @returns {Uint8Array}
|
|
*/
|
|
function RemoveHeaders(buffer, csHeader = CSHARP_HEADER) {
|
|
// Remove the fixed C# header and byte 11 at the end.
|
|
buffer = buffer.subarray(csHeader.length, buffer.length - 1);
|
|
|
|
// Remove LengthPrefixedString header
|
|
let lengthCount = 0;
|
|
for (let i = 0; i < 5; i++) {
|
|
lengthCount++;
|
|
if ((buffer[i] & 0x80) == 0) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
return buffer.subarray(lengthCount);
|
|
}
|
|
|
|
/**
|
|
* Decodes an Array Buffer using a Base64 decode table
|
|
* @param {Uint8Array} buffer Uint8Array Buffer to decode
|
|
* @returns {Uint8Array}
|
|
*/
|
|
function Base64Decode(buffer) {
|
|
buffer = new Uint8Array(buffer).slice();
|
|
buffer = buffer.map(v => BASE64_DECODE_TABLE.get(v));
|
|
|
|
// The indexOf() method returns the first index at which a given element can be found in the array, or -1 if it is not present.
|
|
let p = buffer.indexOf(64);
|
|
let end;
|
|
|
|
if (p != -1) {
|
|
end = p;
|
|
} else {
|
|
end = buffer.length;
|
|
}
|
|
|
|
buffer = buffer.subarray(0, end);
|
|
|
|
let output = new Uint8Array(3 * buffer.length / 4);
|
|
let continuous = Math.floor(buffer.length / 4) * 4;
|
|
|
|
for (let i = 0; i < continuous; i += 4) {
|
|
let k = 3 * i / 4;
|
|
output[k] = buffer[i] << 2 | buffer[i + 1] >> 4;
|
|
output[k + 1] = (buffer[i + 1] & 0x0F) << 4 | buffer[i + 2] >> 2;
|
|
output[k + 2] = (buffer[i + 2] & 0x03) << 6 | buffer[i + 3];
|
|
}
|
|
if (buffer[continuous] != undefined) {
|
|
let k = 3 * continuous / 4;
|
|
output[k] = buffer[continuous] << 2 | buffer[continuous + 1] >> 4;
|
|
if (buffer[continuous + 2] != undefined) {
|
|
output[k + 1] = (buffer[continuous + 1] & 0x0F) << 4 | buffer[continuous + 2] >> 2;
|
|
}
|
|
}
|
|
|
|
return output;
|
|
}
|
|
|
|
/**
|
|
* Decrypt an Uint8Array Buffer using aesjs (ECB) and a predefined AES key + remove pkcs7 padding
|
|
* @param {Uint8Array} buffer Uint8Array buffer to decrypt
|
|
* @returns {Uint8Array}
|
|
*/
|
|
function AESDecryption(buffer, cipherObject = ECB_STREAM_CIPHER) {
|
|
let output = cipherObject.decrypt(buffer);
|
|
return output.subarray(0, -output[output.length - 1]);
|
|
}
|
|
|
|
// Make functions global so they can be used on click and change events (for Webpack)
|
|
window.LoadSaveFile = LoadSaveFile; |