從CryptoStream就到流

Question

我遇到一些麻煩，下面的代碼可以在讀取。我有一個需要加密的臨時位置的文件，這個函數會加密那些存儲在「pathToSave」位置的數據。

在檢查似乎並沒有被正確地處理整個文件 - 有從我的輸出失位，我懷疑它做的，而不是循環在整個流運行。

順便說一句，如果我嘗試和while循環後調用CryptStrm.Close（）我收到一個異常。這意味着如果我試圖解密文件，我得到一個已經在使用中的文件錯誤！

嘗試了所有的常用和伊夫這裏看着在類似的問題，任何幫助將是巨大的。

感謝

public void EncryptFile(String tempPath, String pathToSave) 
    { 
     try 
     { 
      FileStream InputFile = new FileStream(tempPath, FileMode.Open, FileAccess.Read); 
      FileStream OutputFile = new FileStream(pathToSave, FileMode.Create, FileAccess.Write); 

      RijndaelManaged RijCrypto = new RijndaelManaged(); 

      //Key 
      byte[] Key = new byte[32] { ... }; 

      //Initialisation Vector 
      byte[] IV = new byte[32] { ... }; 

      RijCrypto.Padding = PaddingMode.None; 
      RijCrypto.KeySize = 256; 
      RijCrypto.BlockSize = 256; 
      RijCrypto.Key = Key; 
      RijCrypto.IV = IV; 

      ICryptoTransform Encryptor = RijCrypto.CreateEncryptor(Key, IV); 

      CryptoStream CryptStrm = new CryptoStream(OutputFile, Encryptor, CryptoStreamMode.Write); 

      int data; 
      while (-1 != (data = InputFile.ReadByte())) 
      { 
       CryptStrm.WriteByte((byte)data); 
      } 
     } 
     catch (Exception EncEx) 
     { 
      throw new Exception("Encoding Error: " + EncEx.Message); 
     } 
    } 

編輯：

我所做的假設，我的問題是加密。我的解密可能是罪魁禍首

 public String DecryptFile(String encryptedFilePath) 
    { 
     FileStream InputFile = new FileStream(encryptedFilePath, FileMode.Open, FileAccess.Read); 

     RijndaelManaged RijCrypto = new RijndaelManaged(); 

     //Key 
     byte[] Key = new byte[32] { ... }; 

     //Initialisation Vector 
     byte[] IV = new byte[32] { ... }; 

     RijCrypto.Padding = PaddingMode.None; 
     RijCrypto.KeySize = 256; 
     RijCrypto.BlockSize = 256; 
     RijCrypto.Key = Key; 
     RijCrypto.IV = IV; 

     ICryptoTransform Decryptor = RijCrypto.CreateDecryptor(Key, IV); 

     CryptoStream CryptStrm = new CryptoStream(InputFile, Decryptor, CryptoStreamMode.Read); 

     String OutputFilePath = Path.GetTempPath() + "myfile.name"; 
     StreamWriter OutputFile = new StreamWriter(OutputFilePath); 

     OutputFile.Write(new StreamReader(CryptStrm).ReadToEnd()); 

     CryptStrm.Close(); 
     OutputFile.Close(); 

     return OutputFilePath; 
    } 

Answer 1

好吧，這裏有幾件事情出錯了。

1.您設置IV過大的尺寸。如果您的密鑰大小爲256，Rijndael的IV爲16個字節。如果您嘗試使用比該字節更多的字節來設置密鑰，則會發生異常。 IV尺寸應設置爲塊尺寸/ 8 see MSDN，因此您擁有的IV尺寸是正確的。

您有無的填充模式。除非你的數據是正確的塊大小，否則你將會遇到問題。您可能想要選擇填充模式。

當您在加密時寫入密碼流時，通常需要調用FlushFInalBlock以確保將所有數據寫入流中。

我發佈了一些示例代碼，使用內存流來顯示加密和解密。

var tempData = "This is the text to encrypt. It's not much, but it's all there is."; 

using (var rijCrypto = new RijndaelManaged()) 
{ 
    byte[] encryptedData; 
    rijCrypto.Padding = System.Security.Cryptography.PaddingMode.ISO10126; 
    rijCrypto.KeySize = 256; 

    using (var input = new MemoryStream(Encoding.Unicode.GetBytes(tempData))) 
    using (var output = new MemoryStream()) 
    { 
     var encryptor = rijCrypto.CreateEncryptor(); 

     using (var cryptStream = new CryptoStream(output, encryptor, CryptoStreamMode.Write)) 
     { 
      var buffer = new byte[1024]; 
      var read = input.Read(buffer, 0, buffer.Length); 
      while (read > 0) 
      { 
       cryptStream.Write(buffer, 0, read); 
       read = input.Read(buffer, 0, buffer.Length); 
      } 
      cryptStream.FlushFinalBlock(); 
      encryptedData = output.ToArray(); 
     } 
    } 

    using (var input = new MemoryStream(encryptedData)) 
    using (var output = new MemoryStream()) 
    { 
     var decryptor = rijCrypto.CreateDecryptor(); 
     using (var cryptStream = new CryptoStream(input, decryptor, CryptoStreamMode.Read)) 
     { 
      var buffer = new byte[1024]; 
      var read = cryptStream.Read(buffer, 0, buffer.Length); 
      while (read > 0) 
      { 
       output.Write(buffer, 0, read); 
       read = cryptStream.Read(buffer, 0, buffer.Length); 
      } 
      cryptStream.Flush(); 
      var result = Encoding.Unicode.GetString(output.ToArray()); 
     } 
    } 
}