DES 파일 암호화 / 복호화

private string PassWord = "암호(8byte)";

  

public void EncryptFile(string ReadFilename, string WriteFilename)  //파일 암호화

{

    FileStream fsInput = new FileStream(ReadFilename, FileMode.Open, FileAccess.Read,FileShare.None);        

    FileStream fsEncrypted = new FileStream(WriteFilename, FileMode.Create, FileAccess.Write);

 

    DESCryptoServiceProvider DES = new DESCryptoServiceProvider();

    DES.Key = ASCIIEncoding.ASCII.GetBytes(key);

    DES.IV = ASCIIEncoding.ASCII.GetBytes(key);

 

    ICryptoTransform Encrypt = DES.CreateEncryptor();

    CryptoStream cryptostream = new CryptoStream(fsEncrypted, Encrypt, CryptoStreamMode.Write);

 

    byte[] bytearrayinput = new byte[fsInput.Length];

    fsInput.Read(bytearrayinput, 0, bytearrayinput.Length);

 

    cryptostream.Write(bytearrayinput, 0, bytearrayinput.Length);

    fsEncrypted.Flush();

    cryptostream.Close();

    fsInput.Close();

    fsEncrypted.Close();

}

 

public void DecryptFile(string ReadFilename, string WriteFilename)//파일 복호화

{

    DESCryptoServiceProvider DES = new DESCryptoServiceProvider();

 

    DES.Key = ASCIIEncoding.ASCII.GetBytes(key);

    DES.IV = ASCIIEncoding.ASCII.GetBytes(key);

 

    FileStream fsread = new FileStream(ReadFilename, FileMode.Open, FileAccess.ReadWrite,FileShare.ReadWrite);

    ICryptoTransform Decrypt = DES.CreateDecryptor();

    CryptoStream cryptostreamDecr = new CryptoStream(fsread, Decrypt, CryptoStreamMode.Read);

 

    StreamWriter fsDecrypted = new StreamWriter(WriteFilename);

    fsDecrypted.Write(new StreamReader(cryptostreamDecr).ReadToEnd());

    fsDecrypted.Flush();

    fsDecrypted.Close();

}

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