1
0
forked from um/web
qqmusicunlock/src/plugins/mflac.js
2019-11-23 18:09:33 +08:00

119 lines
3.6 KiB
JavaScript

const musicMetadata = require("music-metadata-browser");
export {Decrypt}
async function Decrypt(file) {
// 获取扩展名
let filename_ext = file.name.substring(file.name.lastIndexOf(".") + 1, file.name.length).toLowerCase();
if (filename_ext !== "mflac") return;
// 读取文件
const fileBuffer = await new Promise(resolve => {
const reader = new FileReader();
reader.onload = (e) => {
resolve(e.target.result);
};
reader.readAsArrayBuffer(file);
});
const audioData = new Uint8Array(fileBuffer.slice(0, -0x170));
const audioDataLen = audioData.length;
// 转换数据
const seed = new Mask();
if (!seed.DetectMask(audioData)) return;
for (let cur = 0; cur < audioDataLen; ++cur) {
audioData[cur] ^= seed.NextMask();
}
// 导出
const musicData = new Blob([audioData], {type: "audio/flac"});
const musicUrl = URL.createObjectURL(musicData);
console.log(musicUrl);
// 读取Meta
let tag = await musicMetadata.parseBlob(musicData);
// 处理无标题歌手
let filename_array = file.name.substring(0, file.name.lastIndexOf(".")).split("-");
let title = tag.common.title;
let artist = tag.common.artist;
if (filename_array.length > 1) {
if (artist === undefined) artist = filename_array[0].trim();
if (title === undefined) title = filename_array[1].trim();
} else if (filename_array.length === 1) {
if (title === undefined) title = filename_array[0].trim();
}
const filename = artist + " - " + title + ".flac";
// 处理无封面
let pic_url = "";
if (tag.common.picture !== undefined && tag.common.picture.length >= 1) {
const picture = tag.common.picture[0];
const blobPic = new Blob([picture.data], {type: picture.format});
pic_url = URL.createObjectURL(blobPic);
}
// 返回*/
return {
filename: filename,
title: title,
artist: artist,
album: tag.common.album,
picture: pic_url,
file: musicUrl,
mime: "audio/flac"
}
}
class Mask {
FLAC_HEADER = [0x66, 0x4C, 0x61, 0x43, 0x00];
constructor() {
this.index = -1;
this.mask_index = -1;
this.mask = Array(128).fill(0x00);
}
DetectMask(data) {
let search_len = data.length - 256, mask;
for (let block_idx = 0; block_idx < search_len; block_idx += 128) {
let flag = true;
mask = data.slice(block_idx, block_idx + 128);
let next_mask = data.slice(block_idx + 128, block_idx + 256);
for (let idx = 0; idx < 128; idx++) {
if (mask[idx] !== next_mask[idx]) {
flag = false;
break;
}
}
if (!flag) continue;
for (let test_idx = 0; test_idx < this.FLAC_HEADER.length; test_idx++) {
let p = data[test_idx] ^ mask[test_idx];
if (p !== this.FLAC_HEADER[test_idx]) {
flag = false;
debugger;
break;
}
}
if (!flag) continue;
this.mask = mask;
console.log(mask);
return true;
}
return false;
}
NextMask() {
this.index++;
this.mask_index++;
if (this.index === 0x8000 || (this.index > 0x8000 && (this.index + 1) % 0x8000 === 0)) {
this.index++;
this.mask_index++;
}
if (this.mask_index >= 128) {
this.mask_index -= 128;
}
return this.mask[this.mask_index]
}
}