86 lines
2.3 KiB
JavaScript
86 lines
2.3 KiB
JavaScript
import {
|
|
AudioMimeType,
|
|
DetectAudioExt,
|
|
GetArrayBuffer,
|
|
GetFileInfo,
|
|
GetMetaCoverURL,
|
|
IsBytesEqual
|
|
} from "./util";
|
|
|
|
const musicMetadata = require("music-metadata-browser");
|
|
const MagicHeader = [
|
|
0x79, 0x65, 0x65, 0x6C, 0x69, 0x6F, 0x6E, 0x2D,
|
|
0x6B, 0x75, 0x77, 0x6F, 0x2D, 0x74, 0x6D, 0x65,
|
|
]
|
|
const PreDefinedKey = "MoOtOiTvINGwd2E6n0E1i7L5t2IoOoNk"
|
|
|
|
export async function Decrypt(file, raw_filename, raw_ext) {
|
|
const oriData = new Uint8Array(await GetArrayBuffer(file));
|
|
if (!IsBytesEqual(MagicHeader, oriData.slice(0, 0x10)))
|
|
return {status: false, message: "Not a valid kwm file!"}
|
|
|
|
let fileKey = oriData.slice(0x18, 0x20)
|
|
let mask = createMaskFromKey(fileKey)
|
|
|
|
function Uint8ArrayToString(fileData) {
|
|
var dataString = "";
|
|
for (var i = 0; i < fileData.length; i++) {
|
|
dataString += String.fromCharCode(fileData[i]);
|
|
}
|
|
|
|
return dataString
|
|
}
|
|
|
|
console.log(Uint8ArrayToString(oriData.slice(0x30, 0x38)))
|
|
|
|
let audioData = oriData.slice(0x400);
|
|
let lenAudioData = audioData.length;
|
|
for (let cur = 0; cur < lenAudioData; ++cur)
|
|
audioData[cur] ^= mask[cur % 0x20];
|
|
|
|
|
|
const ext = DetectAudioExt(audioData, "mp3");
|
|
const mime = AudioMimeType[ext];
|
|
let musicBlob = new Blob([audioData], {type: mime});
|
|
|
|
const musicMeta = await musicMetadata.parseBlob(musicBlob);
|
|
const info = GetFileInfo(musicMeta.common.artist, musicMeta.common.title, raw_filename);
|
|
|
|
const imgUrl = GetMetaCoverURL(musicMeta);
|
|
|
|
return {
|
|
status: true,
|
|
title: info.title,
|
|
artist: info.artist,
|
|
ext: ext,
|
|
album: musicMeta.common.album,
|
|
picture: imgUrl,
|
|
file: URL.createObjectURL(musicBlob),
|
|
mime: mime
|
|
}
|
|
}
|
|
|
|
|
|
function createMaskFromKey(keyBytes) {
|
|
let keyView = new DataView(keyBytes.buffer)
|
|
let keyStr = keyView.getBigUint64(0, true).toString()
|
|
let keyStrTrim = trimKey(keyStr)
|
|
let key = new Uint8Array(32)
|
|
for (let i = 0; i < 32; i++) {
|
|
key[i] = PreDefinedKey[i].charCodeAt() ^ keyStrTrim[i].charCodeAt()
|
|
}
|
|
return key
|
|
}
|
|
|
|
|
|
function trimKey(keyRaw) {
|
|
let lenRaw = keyRaw.length;
|
|
let out = keyRaw;
|
|
if (lenRaw > 32) {
|
|
out = keyRaw.slice(0, 32)
|
|
} else if (lenRaw < 32) {
|
|
out = keyRaw.padEnd(32, keyRaw)
|
|
}
|
|
return out
|
|
}
|