From 6ccc6adf816cc78b76be62fc5cf9a7eb5533102f Mon Sep 17 00:00:00 2001
From: Chenx221 <chenx221@yandex.com>
Date: Wed, 1 Jan 2025 18:30:09 +0800
Subject: [PATCH] update

---
 minitool3/Program.cs                     | 19 +++++++++----------
 minitool3/Properties/launchSettings.json |  2 +-
 minitool3/encrypted文件结构.txt          |  2 +-
 3 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/minitool3/Program.cs b/minitool3/Program.cs
index d3bb367..b97cbba 100644
--- a/minitool3/Program.cs
+++ b/minitool3/Program.cs
@@ -28,30 +28,29 @@ namespace minitool3
                     {
                         byte[] fileData = File.ReadAllBytes(filePath);
 
-                        if (fileData.Length < 20) // 4 bytes (size) + 16 bytes (IV)
+                        if (fileData.Length < 16)
                         {
-                            Console.WriteLine("The file does not contain enough data for size and IV.");
+                            Console.WriteLine("The file does not contain enough data.");
                             continue;
                         }
 
-                        // Read the encrypted data & iv size (4 bytes)
+                        // Read the encrypted data & iv size (4 bytes)*
                         int encryptedSize = BitConverter.ToInt32(fileData, 0);
-
-                        if (encryptedSize <= 0 || encryptedSize > fileData.Length - 4)
+                        int sp = 4;
+                        if (fileData.Length - 4 != encryptedSize) //*某些情况下头部不带长度
                         {
-                            Console.WriteLine("Invalid encrypted data size.");
-                            continue;
+                            sp = 0;
+                            encryptedSize = fileData.Length;
                         }
-
                         encryptedSize -= 16;
 
                         // Read the IV (16 bytes)
                         byte[] iv = new byte[16];
-                        Array.Copy(fileData, 4, iv, 0, 16);
+                        Array.Copy(fileData, sp, iv, 0, 16);
 
                         // Read the ciphertext based on the size
                         byte[] cipherText = new byte[encryptedSize];
-                        Array.Copy(fileData, 20, cipherText, 0, encryptedSize);
+                        Array.Copy(fileData, 16 + sp, cipherText, 0, encryptedSize);
 
                         byte[] decryptedData = Decrypt(cipherText, SHA256Byte, iv);
 
diff --git a/minitool3/Properties/launchSettings.json b/minitool3/Properties/launchSettings.json
index f5f5461..22ff9ea 100644
--- a/minitool3/Properties/launchSettings.json
+++ b/minitool3/Properties/launchSettings.json
@@ -2,7 +2,7 @@
   "profiles": {
     "minitool3": {
       "commandName": "Project",
-      "commandLineArgs": "\"G:\\source\\minitool1\\minitool3\\bin\\Debug\\net8.0\\bg_avg_003.jp.encrypted\""
+      "commandLineArgs": "\"G:\\source\\minitool1\\minitool3\\bin\\Release\\net8.0\\publish\\win-x64\\jp.co.dmm.dmmgames.imys_r\\files\\assetbundles\\characters\\tati\\020g2.encrypted\""
     }
   }
 }
\ No newline at end of file
diff --git a/minitool3/encrypted文件结构.txt b/minitool3/encrypted文件结构.txt
index 97d8006..014dbcc 100644
--- a/minitool3/encrypted文件结构.txt
+++ b/minitool3/encrypted文件结构.txt
@@ -1,6 +1,6 @@
 *.encrypted文件结构
 (D)
-4B: enc data + iv size
+4B: enc data + iv size （这4B可能没有）
 16B: iv
 {data size}B: enc data(AES256 encryption)