feature: use online info to correct qmc meta

(cherry picked from commit 7c62f35adb268509f543d67b4a36f49ada3ae206)
This commit is contained in:
MengYX 2021-12-25 14:41:05 +08:00
parent 9edb12b008
commit 2e0b24a6fc

View File

@ -1,6 +1,5 @@
import { QmcMapCipher, QmcRC4Cipher, QmcStaticCipher, QmcStreamCipher } from './qmc_cipher'; import { QmcMapCipher, QmcRC4Cipher, QmcStaticCipher, QmcStreamCipher } from './qmc_cipher';
import { AudioMimeType, GetArrayBuffer, SniffAudioExt } from '@/decrypt/utils'; import { AudioMimeType, GetArrayBuffer, SniffAudioExt } from '@/decrypt/utils';
import { DecryptQMCWasm } from './qmc_wasm';
import { DecryptResult } from '@/decrypt/entity'; import { DecryptResult } from '@/decrypt/entity';
import { QmcDeriveKey } from '@/decrypt/qmc_key'; import { QmcDeriveKey } from '@/decrypt/qmc_key';
@ -42,20 +41,24 @@ export async function Decrypt(file: Blob, raw_filename: string, raw_ext: string)
const fileBuffer = await GetArrayBuffer(file); const fileBuffer = await GetArrayBuffer(file);
let musicDecoded: Uint8Array | undefined; let musicDecoded: Uint8Array | undefined;
let musicID: number | undefined;
// todo: wasm decoder doesn't support extract the song id for .mgg1/.mflac0 currently
// if (version === 2 && globalThis.WebAssembly) {
// console.log('qmc: using wasm decoder');
// const v2Decrypted = await DecryptQMCWasm(fileBuffer);
// // 如果 v2 检测失败,降级到 v1 再尝试一次
// if (v2Decrypted) {
// musicDecoded = v2Decrypted;
// }
// }
if (version === 2 && globalThis.WebAssembly) {
console.log('qmc: using wasm decoder');
const v2Decrypted = await DecryptQMCWasm(fileBuffer);
// 如果 v2 检测失败,降级到 v1 再尝试一次
if (v2Decrypted) {
musicDecoded = v2Decrypted;
}
}
if (!musicDecoded) { if (!musicDecoded) {
// may throw error // may throw error
console.log('qmc: using js decoder'); console.log('qmc: using js decoder');
const d = new QmcDecoder(new Uint8Array(fileBuffer)); const d = new QmcDecoder(new Uint8Array(fileBuffer));
musicDecoded = d.decrypt(); musicDecoded = d.decrypt();
musicID = d.songID;
} }
const ext = SniffAudioExt(musicDecoded, handler.ext); const ext = SniffAudioExt(musicDecoded, handler.ext);
@ -65,6 +68,7 @@ export async function Decrypt(file: Blob, raw_filename: string, raw_ext: string)
new Blob([musicDecoded], { type: mime }), new Blob([musicDecoded], { type: mime }),
raw_filename, raw_filename,
ext, ext,
musicID,
); );
return { return {
@ -81,19 +85,25 @@ export async function Decrypt(file: Blob, raw_filename: string, raw_ext: string)
export class QmcDecoder { export class QmcDecoder {
private static readonly BYTE_COMMA = ','.charCodeAt(0); private static readonly BYTE_COMMA = ','.charCodeAt(0);
file: Uint8Array; private readonly file: Uint8Array;
size: number; private readonly size: number;
decoded: boolean = false; private decoded: boolean = false;
audioSize?: number; private audioSize?: number;
cipher?: QmcStreamCipher; private cipher?: QmcStreamCipher;
constructor(file: Uint8Array) { public constructor(file: Uint8Array) {
this.file = file; this.file = file;
this.size = file.length; this.size = file.length;
this.searchKey(); this.searchKey();
} }
decrypt(): Uint8Array { private _songID?: number;
public get songID() {
return this._songID;
}
public decrypt(): Uint8Array {
if (!this.cipher) { if (!this.cipher) {
throw new Error('no cipher found'); throw new Error('no cipher found');
} }
@ -118,9 +128,20 @@ export class QmcDecoder {
const sizeView = new DataView(sizeBuf.buffer, sizeBuf.byteOffset); const sizeView = new DataView(sizeBuf.buffer, sizeBuf.byteOffset);
const keySize = sizeView.getUint32(0, false); const keySize = sizeView.getUint32(0, false);
this.audioSize = this.size - keySize - 8; this.audioSize = this.size - keySize - 8;
const rawKey = this.file.subarray(this.audioSize, this.size - 8); const rawKey = this.file.subarray(this.audioSize, this.size - 8);
const keyEnd = rawKey.findIndex((v) => v == QmcDecoder.BYTE_COMMA); const keyEnd = rawKey.findIndex((v) => v == QmcDecoder.BYTE_COMMA);
if (keyEnd < 0) {
throw new Error('invalid key: search raw key failed');
}
this.setCipher(rawKey.subarray(0, keyEnd)); this.setCipher(rawKey.subarray(0, keyEnd));
const idBuf = rawKey.subarray(keyEnd + 1);
const idEnd = idBuf.findIndex((v) => v == QmcDecoder.BYTE_COMMA);
if (keyEnd < 0) {
throw new Error('invalid key: search song id failed');
}
this._songID = parseInt(textEnc.decode(idBuf.subarray(0, idEnd)));
} else { } else {
const sizeView = new DataView(last4Byte.buffer, last4Byte.byteOffset); const sizeView = new DataView(last4Byte.buffer, last4Byte.byteOffset);
const keySize = sizeView.getUint32(0, true); const keySize = sizeView.getUint32(0, true);