feat: added support for QMCv2 (#11)

src/decrypt-worker/crypto/qmc/qmc_v2.key.ts

@@ -0,0 +1,3 @@
+export const SEED = 106;
+export const ENC_V2_KEY_1 = '386ZJY!@#*$%^&)(';
+export const ENC_V2_KEY_2 = '**#!(#$%&^a1cZ,T';

src/decrypt-worker/crypto/qmc/qmc_v2.ts

@@ -0,0 +1,17 @@
+import { transformBlob } from '~/decrypt-worker/util/transformBlob';
+import type { CryptoBase } from '../CryptoBase';
+import { SEED, ENC_V2_KEY_1, ENC_V2_KEY_2 } from './qmc_v2.key.ts';
+
+export class QMC2Crypto implements CryptoBase {
+  hasSignature(): boolean {
+    return false;
+  }
+
+  async isSupported(): Promise<boolean> {
+    return true;
+  }
+
+  async decrypt(blob: Blob): Promise<Blob> {
+    return transformBlob(blob, (p) => p.make.QMCv2(p.make.QMCv2FooterParser(SEED, ENC_V2_KEY_1, ENC_V2_KEY_2)));
+  }
+}

src/decrypt-worker/worker.ts

@@ -2,9 +2,11 @@ import { WorkerServerBus } from '~/util/WorkerEventBus';
 import { DECRYPTION_WORKER_ACTION_NAME } from './constants';
 
 import type { CryptoFactory } from './crypto/CryptoBase';
+import { fetchParakeet } from '@jixun/libparakeet';
+
 import { XiamiCrypto } from './crypto/xiami/xiami';
 import { QMC1Crypto } from './crypto/qmc/qmc_v1';
-import { fetchParakeet } from '@jixun/libparakeet';
+import { QMC2Crypto } from './crypto/qmc/qmc_v2';
 
 const bus = new WorkerServerBus();
 onmessage = bus.onmessage;
@@ -15,6 +17,9 @@ const decryptorFactories: CryptoFactory[] = [
 
   // QMCv1 (*.qmcflac)
   () => new QMC1Crypto(),
+
+  // QMCv2 (*.mflac)
+  () => new QMC2Crypto(),
 ];
 
 // Use first 4MiB of the file to perform check.
@@ -27,17 +32,22 @@ bus.addEventHandler(DECRYPTION_WORKER_ACTION_NAME.DECRYPT, async (blobURI) => {
   for (const factory of decryptorFactories) {
     const decryptor = factory();
     if (await decryptor.isSupported(blob)) {
-      const decryptedBlob = await decryptor.decrypt(blob);
+      try {
+        const decryptedBlob = await decryptor.decrypt(blob);
 
-      // Check if we had a successful decryption
-      const header = await decryptedBlob.slice(0, TEST_FILE_HEADER_LEN).arrayBuffer();
-      const audioExt = parakeet.detectAudioExtension(header);
-      if (!decryptor.hasSignature() && audioExt === 'bin') {
-        // skip this decryptor result
+        // Check if we had a successful decryption
+        const header = await decryptedBlob.slice(0, TEST_FILE_HEADER_LEN).arrayBuffer();
+        const audioExt = parakeet.detectAudioExtension(header);
+        if (!decryptor.hasSignature() && audioExt === 'bin') {
+          // skip this decryptor result
+          continue;
+        }
+
+        return { decrypted: URL.createObjectURL(decryptedBlob), ext: audioExt };
+      } catch (error) {
+        console.error('decrypt failed: ', error);
         continue;
       }
-
-      return { decrypted: URL.createObjectURL(decryptedBlob), ext: audioExt };
     }
   }