delete js implementations

src/decrypt/qmc.ts

@@ -1,8 +1,6 @@
-import { QmcMapCipher, QmcRC4Cipher, QmcStaticCipher, QmcStreamCipher } from './qmc_cipher';
 import { AudioMimeType, GetArrayBuffer, SniffAudioExt } from '@/decrypt/utils';
 
 import { DecryptResult } from '@/decrypt/entity';
-import { QmcDeriveKey } from '@/decrypt/qmc_key';
 import { DecryptQmcWasm } from '@/decrypt/qmc_wasm';
 import { extractQQMusicMeta } from '@/utils/qm_meta';
 
@@ -18,7 +16,7 @@ export const HandlerMap: { [key: string]: Handler } = {
   mgg1: { ext: 'ogg', version: 2 },
   mflac: { ext: 'flac', version: 2 },
   mflac0: { ext: 'flac', version: 2 },
-  mmp4: { ext: 'mmp4', version: 2 },
+  mmp4: { ext: 'mp4', version: 2 },
 
   // qmcflac / qmcogg:
   // 有可能是 v2 加密但混用同一个后缀名。
@@ -52,12 +50,10 @@ export async function Decrypt(file: Blob, raw_filename: string, raw_ext: string)
   let { version } = handler;
 
   const fileBuffer = await GetArrayBuffer(file);
-  let musicDecoded: Uint8Array | undefined;
+  let musicDecoded = new Uint8Array();
   let musicID: number | string | undefined;
 
   if (version === 2 && globalThis.WebAssembly) {
-    console.log('qmc: using wasm decoder');
-
     const v2Decrypted = await DecryptQmcWasm(fileBuffer, raw_ext);
     // 若 v2 检测失败，降级到 v1 再尝试一次
     if (v2Decrypted.success) {
@@ -65,18 +61,10 @@ export async function Decrypt(file: Blob, raw_filename: string, raw_ext: string)
       musicID = v2Decrypted.songId;
       console.log('qmc wasm decoder suceeded');
     } else {
-      console.warn('QmcWasm failed with error %s', v2Decrypted.error || '(unknown error)');
+      throw new Error(v2Decrypted.error || '(unknown error)');
     }
   }
 
-  if (!musicDecoded) {
-    // may throw error
-    console.log('qmc: using js decoder');
-    const d = new QmcDecoder(new Uint8Array(fileBuffer));
-    musicDecoded = d.decrypt();
-    musicID = d.songID;
-  }
-
   const ext = SniffAudioExt(musicDecoded, handler.ext);
   const mime = AudioMimeType[ext];
 
@@ -98,88 +86,3 @@ export async function Decrypt(file: Blob, raw_filename: string, raw_ext: string)
     mime: mime,
   };
 }
-
-export class QmcDecoder {
-  private static readonly BYTE_COMMA = ','.charCodeAt(0);
-  private readonly file: Uint8Array;
-  private readonly size: number;
-  private decoded: boolean = false;
-  private audioSize?: number;
-  private cipher?: QmcStreamCipher;
-
-  public constructor(file: Uint8Array) {
-    this.file = file;
-    this.size = file.length;
-    this.searchKey();
-  }
-
-  private _songID?: number;
-
-  public get songID() {
-    return this._songID;
-  }
-
-  public 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(-4);
-    const textEnc = new TextDecoder();
-    if (textEnc.decode(last4Byte) === 'STag') {
-      throw new Error('文件中没有写入密钥，无法解锁，请降级App并重试');
-    } else if (textEnc.decode(last4Byte) === 'QTag') {
-      const sizeBuf = this.file.slice(-8, -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 == QmcDecoder.BYTE_COMMA);
-      if (keyEnd < 0) {
-        throw new Error('invalid key: search raw key failed');
-      }
-      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)), 10);
-    } else {
-      const sizeView = new DataView(last4Byte.buffer, last4Byte.byteOffset);
-      const keySize = sizeView.getUint32(0, true);
-      if (keySize < 0x400) {
-        this.audioSize = this.size - keySize - 4;
-        const rawKey = this.file.subarray(this.audioSize, this.size - 4);
-        this.setCipher(rawKey);
-      } else {
-        this.audioSize = this.size;
-        this.cipher = new QmcStaticCipher();
-      }
-    }
-  }
-
-  private setCipher(keyRaw: Uint8Array) {
-    const keyDec = QmcDeriveKey(keyRaw);
-    if (keyDec.length > 300) {
-      this.cipher = new QmcRC4Cipher(keyDec);
-    } else {
-      this.cipher = new QmcMapCipher(keyDec);
-    }
-  }
-}