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] } }