Fix STag Filtering

src/QmcWasm/qmc.hpp

@@ -131,6 +131,10 @@ public:
     int PreDecode(std::string ext) {
         cipherType = checkType(ext);
         size_t tailSize = 0;
+        if (cipherType == "invalid" || cipherType == "STag") {
+            error = "file is invalid or not supported (Please downgrade your app).";
+            return -1;
+        }
         if (cipherType == "QTag") {
             tailSize = 8;
         }
@@ -156,10 +160,6 @@ public:
             }
             rawKeyBuf = tmp;
         }
-        if (cipherType == "invalid") {
-            error = "file is invalid or not supported(Please downgrade your app.)";
-            return -1;
-        }
         return keySize + tailSize;
     }
 

src/decrypt/qmc.ts

@@ -130,7 +130,9 @@ export class QmcDecoder {
   private searchKey() {
     const last4Byte = this.file.slice(-4);
     const textEnc = new TextDecoder();
-    if (textEnc.decode(last4Byte) === 'QTag') {
+    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);