import {QmcMapCipher, QmcRC4Cipher, QmcStaticCipher, StreamCipher} from "./qmc_cipher"; import { AudioMimeType, GetArrayBuffer, GetCoverFromFile, GetImageFromURL, GetMetaFromFile, SniffAudioExt, WriteMetaToFlac, WriteMetaToMp3 } from "@/decrypt/utils"; import {parseBlob as metaParseBlob} from "music-metadata-browser"; import {DecryptQMCv2} from "./qmcv2"; import iconv from "iconv-lite"; import {DecryptResult} from "@/decrypt/entity"; import {queryAlbumCover} from "@/utils/api"; import {QmcDecryptKey} from "@/decrypt/qmc_key"; interface Handler { ext: string version: number } export const HandlerMap: { [key: string]: Handler } = { "mgg": {ext: "ogg", version: 2}, "mgg1": {ext: "ogg", version: 2}, "mflac": {ext: "flac", version: 2}, "mflac0": {ext: "flac", version: 2}, // qmcflac / qmcogg: // 有可能是 v2 加密但混用同一个后缀名。 "qmcflac": {ext: "flac", version: 2}, "qmcogg": {ext: "ogg", version: 2}, "qmc0": {ext: "mp3", version: 1}, "qmc2": {ext: "ogg", version: 1}, "qmc3": {ext: "mp3", version: 1}, "bkcmp3": {ext: "mp3", version: 1}, "bkcflac": {ext: "flac", version: 1}, "tkm": {ext: "m4a", version: 1}, "666c6163": {ext: "flac", version: 1}, "6d7033": {ext: "mp3", version: 1}, "6f6767": {ext: "ogg", version: 1}, "6d3461": {ext: "m4a", version: 1}, "776176": {ext: "wav", version: 1} }; export async function Decrypt(file: Blob, raw_filename: string, raw_ext: string): Promise { if (!(raw_ext in HandlerMap)) throw `Qmc cannot handle type: ${raw_ext}`; const handler = HandlerMap[raw_ext]; let {version} = handler; const fileBuffer = await GetArrayBuffer(file); let musicDecoded: Uint8Array | undefined; if (version === 2) { const v2Decrypted = await DecryptQMCv2(fileBuffer); // 如果 v2 检测失败,降级到 v1 再尝试一次 if (v2Decrypted) { musicDecoded = v2Decrypted; } else { version = 1; } } if (version === 1) { const seed = new QmcStaticCipher(); musicDecoded = new Uint8Array(fileBuffer) seed.decrypt(musicDecoded, 0); } else if (!musicDecoded) { throw new Error(`解密失败: ${raw_ext}`); } const ext = SniffAudioExt(musicDecoded, handler.ext); const mime = AudioMimeType[ext]; let musicBlob = new Blob([musicDecoded], {type: mime}); const musicMeta = await metaParseBlob(musicBlob); for (let metaIdx in musicMeta.native) { if (!musicMeta.native.hasOwnProperty(metaIdx)) continue if (musicMeta.native[metaIdx].some(item => item.id === "TCON" && item.value === "(12)")) { console.warn("try using gbk encoding to decode meta") musicMeta.common.artist = iconv.decode(new Buffer(musicMeta.common.artist ?? ""), "gbk"); musicMeta.common.title = iconv.decode(new Buffer(musicMeta.common.title ?? ""), "gbk"); musicMeta.common.album = iconv.decode(new Buffer(musicMeta.common.album ?? ""), "gbk"); } } const info = GetMetaFromFile(raw_filename, musicMeta.common.title, musicMeta.common.artist) let imgUrl = GetCoverFromFile(musicMeta); if (!imgUrl) { imgUrl = await getCoverImage(info.title, info.artist, musicMeta.common.album); if (imgUrl) { const imageInfo = await GetImageFromURL(imgUrl); if (imageInfo) { imgUrl = imageInfo.url try { const newMeta = {picture: imageInfo.buffer, title: info.title, artists: info.artist?.split(" _ ")} if (ext === "mp3") { musicDecoded = WriteMetaToMp3(Buffer.from(musicDecoded), newMeta, musicMeta) musicBlob = new Blob([musicDecoded], {type: mime}); } else if (ext === 'flac') { musicDecoded = WriteMetaToFlac(Buffer.from(musicDecoded), newMeta, musicMeta) musicBlob = new Blob([musicDecoded], {type: mime}); } else { console.info("writing metadata for " + ext + " is not being supported for now") } } catch (e) { console.warn("Error while appending cover image to file " + e) } } } } return { title: info.title, artist: info.artist, ext: ext, album: musicMeta.common.album, picture: imgUrl, file: URL.createObjectURL(musicBlob), blob: musicBlob, mime: mime } } async function getCoverImage(title: string, artist?: string, album?: string): Promise { const song_query_url = "https://stats.ixarea.com/apis" + "/music/qq-cover" try { const data = await queryAlbumCover(title, artist, album) return `${song_query_url}/${data.Type}/${data.Id}` } catch (e) { console.warn(e); } return "" } export class QmcDecoder { file: Uint8Array size: number decoded: boolean = false audioSize?: number cipher?: StreamCipher constructor(file: Uint8Array) { this.file = file this.size = file.length this.searchKey() } decrypt(): Uint8Array { if (!this.cipher) { throw new Error("no cipher found") } if (!this.audioSize || this.audioSize <= 0) { throw new Error("invalid audio size") } const audioBuf = this.file.subarray(0, this.audioSize) if (!this.decoded) { this.cipher.decrypt(audioBuf, 0) this.decoded = true } return audioBuf } private searchKey() { const last4Byte = this.file.slice(this.size - 4); const textEnc = new TextDecoder() if (textEnc.decode(last4Byte) === 'QTag') { const sizeBuf = this.file.slice(this.size - 8, this.size - 4) const sizeView = new DataView(sizeBuf.buffer, sizeBuf.byteOffset) const keySize = sizeView.getUint32(0, false) this.audioSize = this.size - keySize - 8 const rawKey = this.file.subarray(this.audioSize, this.size - 8) const keyEnd = rawKey.findIndex(v => v == ','.charCodeAt(0)) const keyDec = QmcDecryptKey(rawKey.subarray(0, keyEnd)) this.cipher = new QmcRC4Cipher(keyDec) } else { const sizeView = new DataView(last4Byte.buffer, last4Byte.byteOffset); const keySize = sizeView.getUint32(0, true) if (keySize < 0x300) { this.audioSize = this.size - keySize - 4 const rawKey = this.file.subarray(this.audioSize, this.size - 4) const keyDec = QmcDecryptKey(rawKey) this.cipher = new QmcMapCipher(keyDec) } else { this.audioSize = this.size this.cipher = new QmcStaticCipher() } } } }