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