update minitool3

minitool1.sln

@@ -7,6 +7,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "minitool1", "minitool1\mini
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "minitool2", "minitool2\minitool2.csproj", "{0FE5458A-A3A9-4D0B-A540-BF4A7CD3F7EA}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "minitool3", "minitool3\minitool3.csproj", "{F6B38C11-304C-4FF8-BB74-D4CA0E515189}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -21,6 +23,10 @@ Global
 		{0FE5458A-A3A9-4D0B-A540-BF4A7CD3F7EA}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{0FE5458A-A3A9-4D0B-A540-BF4A7CD3F7EA}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{0FE5458A-A3A9-4D0B-A540-BF4A7CD3F7EA}.Release|Any CPU.Build.0 = Release|Any CPU
+		{F6B38C11-304C-4FF8-BB74-D4CA0E515189}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{F6B38C11-304C-4FF8-BB74-D4CA0E515189}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{F6B38C11-304C-4FF8-BB74-D4CA0E515189}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{F6B38C11-304C-4FF8-BB74-D4CA0E515189}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

minitool3/Program.cs

@@ -0,0 +1,103 @@
+using System.Security.Cryptography;
+using System.Text;
+
+namespace minitool3
+{
+    internal class Program
+    {
+        private const string DefaultSecretKey = "dB3aqcLtAmBd";
+        private const string DefaultKeyBase = "RWd3NusabzRc";
+
+        static void Main(string[] args)
+        {
+            if (args.Length == 0)
+            {
+                Console.WriteLine("Please drag and drop one or more files onto this program.");
+                Console.ReadKey();
+                return;
+            }
+
+            Byte[] SHA256Byte = GenerateSHA256Byte(DefaultKeyBase, Encoding.UTF8.GetBytes(DefaultSecretKey));
+
+            foreach (var filePath in args)
+            {
+                if (File.Exists(filePath))
+                {
+                    Console.WriteLine($"Processing file: {filePath}");
+                    try
+                    {
+                        byte[] fileData = File.ReadAllBytes(filePath);
+
+                        if (fileData.Length < 20) // 4 bytes (size) + 16 bytes (IV)
+                        {
+                            Console.WriteLine("The file does not contain enough data for size and IV.");
+                            continue;
+                        }
+
+                        // Read the encrypted data & iv size (4 bytes)
+                        int encryptedSize = BitConverter.ToInt32(fileData, 0);
+
+                        if (encryptedSize <= 0 || encryptedSize > fileData.Length - 4)
+                        {
+                            Console.WriteLine("Invalid encrypted data size.");
+                            continue;
+                        }
+
+                        encryptedSize -= 16;
+
+                        // Read the IV (16 bytes)
+                        byte[] iv = new byte[16];
+                        Array.Copy(fileData, 4, iv, 0, 16);
+
+                        // Read the ciphertext based on the size
+                        byte[] cipherText = new byte[encryptedSize];
+                        Array.Copy(fileData, 20, cipherText, 0, encryptedSize);
+
+                        byte[] decryptedData = Decrypt(cipherText, SHA256Byte, iv);
+
+                        string outputDir = Path.Combine(Path.GetDirectoryName(filePath)!, "dec");
+                        Directory.CreateDirectory(outputDir); // Ensure the directory exists
+                        string outputFilePath = Path.Combine(outputDir, Path.GetFileNameWithoutExtension(filePath) + ".assets");
+                        File.WriteAllBytes(outputFilePath, decryptedData);
+
+                    }
+                    catch (Exception ex)
+                    {
+                        Console.WriteLine($"An error occurred: {ex.Message}");
+                    }
+                }
+                else
+                {
+                    Console.WriteLine($"File not found: {filePath}");
+                }
+            }
+
+            Console.WriteLine("Processing complete. Press any key to exit.");
+            Console.ReadKey();
+        }
+
+        public static byte[] GenerateSHA256Byte(string data, byte[] key)
+        {
+            using var hmac = new HMACSHA256(key);
+            return hmac.ComputeHash(Encoding.UTF8.GetBytes(data));
+        }
+
+        public static byte[] Decrypt(byte[] cipherText, byte[] sha256Key, byte[] iv)
+        {
+            using var aes = Aes.Create();
+            aes.Key = sha256Key;
+            aes.IV = iv;
+            aes.Mode = CipherMode.CBC;
+            aes.Padding = PaddingMode.PKCS7;
+
+            using var decryptor = aes.CreateDecryptor();
+            using var memoryStream = new MemoryStream(cipherText);
+            using var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read);
+
+            byte[] decryptedData = new byte[cipherText.Length];
+            int bytesRead = cryptoStream.Read(decryptedData, 0, decryptedData.Length);
+
+            return [.. decryptedData];
+        }
+    }
+}

minitool3/Properties/launchSettings.json

@@ -0,0 +1,8 @@
+{
+  "profiles": {
+    "minitool3": {
+      "commandName": "Project",
+      "commandLineArgs": "\"G:\\source\\minitool1\\minitool3\\bin\\Debug\\net8.0\\bg_avg_003.jp.encrypted\""
+    }
+  }
+}

minitool3/encrypted文件结构.txt

@@ -0,0 +1,13 @@
+*.encrypted文件结构
+(D)
+4B: enc data + iv size
+16B: iv
+{data size}B: enc data(AES256 encryption)
+
+
+SecretKey = "dB3aqcLtAmBd"
+KeyBase = "RWd3NusabzRc"
+
+hmac = new HMACSHA256(Encoding.UTF8.GetBytes(SecretKey))
+AESKey = hmac.ComputeHash(Encoding.UTF8.GetBytes(KeyBase))
+iv = 看顶上

minitool3/minitool3.csproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>