fix typecheck

src/lib/aes-decryptor.ts

@@ -139,8 +139,8 @@ export class AESDecryptor {
     const invSubMix2 = invSubMix[2];
     const invSubMix3 = invSubMix[3];
 
-    let prev;
-    let t;
+    let prev: number = 0;
+    let t: number;
 
     for (ksRow = 0; ksRow < ksRows; ksRow++) {
       if (ksRow < keySize) {
@@ -168,6 +168,10 @@ export class AESDecryptor {
         t = keySchedule[ksRow - 4];
       }
 
+      if (t === undefined) {
+        throw new Error('Invalid key schedule');
+      }
+
       if (invKsRow < 4 || ksRow <= 4) {
         invKeySchedule[invKsRow] = t;
       } else {

src/lib/m3u8-downloader.ts

@@ -545,8 +545,10 @@ export class M3U8Downloader {
           if (xhr.status >= 200 && xhr.status < 300) {
             task.aesConf.key = xhr.response;
             // 初始化 AES 解密器
-            task.aesConf.decryption = new AESDecryptor();
-            task.aesConf.decryption.expandKey(task.aesConf.key);
+            if (task.aesConf.key) {
+              task.aesConf.decryption = new AESDecryptor();
+              task.aesConf.decryption.expandKey(task.aesConf.key);
+            }
             resolve();
           } else {
             reject(new Error('获取 AES 密钥失败'));
@@ -562,7 +564,7 @@ export class M3U8Downloader {
    * AES 解密
    */
   private aesDecrypt(task: M3U8DownloadTask, data: ArrayBuffer, index: number): ArrayBuffer {
-    if (!task.aesConf.decryption) {
+    if (!task.aesConf.decryption || !task.aesConf.key) {
       return data;
     }