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TripleDES.Create Method

Creates an instance of a cryptographic object to perform the TripleDES algorithm.

Namespace:  System.Security.Cryptography
Assembly:  mscorlib (in mscorlib.dll)
public static TripleDES Create()

Return Value

Type: System.Security.Cryptography.TripleDES
An instance of a cryptographic object.

Creates a new instance of the TripleDES class.

The following code example shows how to create and use a TripleDES object to encrypt and decrypt data in a file.

using System;
using System.Security.Cryptography;
using System.Text;
using System.IO;

class TripleDESSample
{

    static void Main()
    {
        try
        {
            // Create a new TripleDES object to generate a key 
            // and an initialization vector (IV). 
            using (TripleDES TripleDESalg = TripleDES.Create())
            {
                // Create a string to encrypt. 
                string sData = "Here is some data to encrypt.";
                string FileName = "CText.enc";

                // Encrypt text to a file using the file name, key, and IV.
                EncryptTextToFile(sData, FileName, TripleDESalg.Key, TripleDESalg.IV);

                // Decrypt the text from a file using the file name, key, and IV. 
                string Final = DecryptTextFromFile(FileName, TripleDESalg.Key, TripleDESalg.IV);

                // Display the decrypted string to the console.
                Console.WriteLine(Final);
            }
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }

    }

    public static void EncryptTextToFile(String Data, String FileName, byte[] Key, byte[] IV)
    {
        try
        {
            // Create or open the specified file. 
            using (FileStream fStream = File.Open(FileName, FileMode.OpenOrCreate))
            {

                // Create a new TripleDES object. 
                using (TripleDES tripleDESalg = TripleDES.Create())
                {

                    // Create a CryptoStream using the FileStream  
                    // and the passed key and initialization vector (IV). 
                    using (CryptoStream cStream = new CryptoStream(fStream,
                        tripleDESalg.CreateEncryptor(Key, IV),
                        CryptoStreamMode.Write))
                    {

                        // Create a StreamWriter using the CryptoStream. 
                        using (StreamWriter sWriter = new StreamWriter(cStream))
                        {

                            // Write the data to the stream  
                            // to encrypt it.
                            sWriter.WriteLine(Data);
                        }
                    }
                }
            }

        }
        catch (CryptographicException e)
        {
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
        }
        catch (UnauthorizedAccessException e)
        {
            Console.WriteLine("A file access error occurred: {0}", e.Message);
        }

    }

    public static string DecryptTextFromFile(String FileName, byte[] Key, byte[] IV)
    {
        try
        {
            string retVal = "";
            // Create or open the specified file.  
            using (FileStream fStream = File.Open(FileName, FileMode.OpenOrCreate))
            {

                // Create a new TripleDES object. 
                using (TripleDES tripleDESalg = TripleDES.Create())
                {

                    // Create a CryptoStream using the FileStream  
                    // and the passed key and initialization vector (IV). 
                    using (CryptoStream cStream = new CryptoStream(fStream,
                        tripleDESalg.CreateDecryptor(Key, IV),
                        CryptoStreamMode.Read))
                    {

                        // Create a StreamReader using the CryptoStream. 
                        using (StreamReader sReader = new StreamReader(cStream))
                        {

                            // Read the data from the stream  
                            // to decrypt it.
                            retVal = sReader.ReadLine();
                        }
                    }
                }

            }
            // Return the string.  
            return retVal;
        }
        catch (CryptographicException e)
        {
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
            return null;
        }
        catch (UnauthorizedAccessException e)
        {
            Console.WriteLine("A file access error occurred: {0}", e.Message);
            return null;
        }
    }
}

The following code example shows how to create and use a TripleDES object to encrypt and decrypt data in memory.

#using <System.dll>

using namespace System;
using namespace System::Security::Cryptography;
using namespace System::Text;
using namespace System::IO;
array<Byte>^ EncryptTextToMemory( String^ Data, array<Byte>^Key, array<Byte>^IV )
{
   try
   {

      // Create a MemoryStream.
      MemoryStream^ mStream = gcnew MemoryStream;

      // Create a new TripleDES object.
      TripleDES^ tripleDESalg = TripleDES::Create();

      // Create a CryptoStream using the MemoryStream  
      // and the passed key and initialization vector (IV).
      CryptoStream^ cStream = gcnew CryptoStream( mStream,tripleDESalg->CreateEncryptor( Key, IV ),CryptoStreamMode::Write );

      // Convert the passed string to a byte array. 
      array<Byte>^toEncrypt = (gcnew ASCIIEncoding)->GetBytes( Data );

      // Write the byte array to the crypto stream and flush it.
      cStream->Write( toEncrypt, 0, toEncrypt->Length );
      cStream->FlushFinalBlock();

      // Get an array of bytes from the  
      // MemoryStream that holds the  
      // encrypted data. 
      array<Byte>^ret = mStream->ToArray();

      // Close the streams.
      cStream->Close();
      mStream->Close();

      // Return the encrypted buffer. 
      return ret;
   }
   catch ( CryptographicException^ e ) 
   {
      Console::WriteLine( "A Cryptographic error occurred: {0}", e->Message );
      return nullptr;
   }

}

String^ DecryptTextFromMemory( array<Byte>^Data, array<Byte>^Key, array<Byte>^IV )
{
   try
   {

      // Create a new MemoryStream using the passed  
      // array of encrypted data.
      MemoryStream^ msDecrypt = gcnew MemoryStream( Data );

      // Create a new TripleDES object.
      TripleDES^ tripleDESalg = TripleDES::Create();

      // Create a CryptoStream using the MemoryStream  
      // and the passed key and initialization vector (IV).
      CryptoStream^ csDecrypt = gcnew CryptoStream( msDecrypt,tripleDESalg->CreateDecryptor( Key, IV ),CryptoStreamMode::Read );

      // Create buffer to hold the decrypted data. 
      array<Byte>^fromEncrypt = gcnew array<Byte>(Data->Length);

      // Read the decrypted data out of the crypto stream 
      // and place it into the temporary buffer.
      csDecrypt->Read( fromEncrypt, 0, fromEncrypt->Length );

      //Convert the buffer into a string and return it. 
      return (gcnew ASCIIEncoding)->GetString( fromEncrypt );
   }
   catch ( CryptographicException^ e ) 
   {
      Console::WriteLine( "A Cryptographic error occurred: {0}", e->Message );
      return nullptr;
   }

}

int main()
{
   try
   {

      // Create a new TripleDES object to generate a key 
      // and initialization vector (IV).
      TripleDES^ TripleDESalg = TripleDES::Create();

      // Create a string to encrypt.
      String^ sData = "Here is some data to encrypt.";

      // Encrypt the string to an in-memory buffer. 
      array<Byte>^Data = EncryptTextToMemory( sData, TripleDESalg->Key, TripleDESalg->IV );

      // Decrypt the buffer back to a string.
      String^ Final = DecryptTextFromMemory( Data, TripleDESalg->Key, TripleDESalg->IV );

      // Display the decrypted string to the console.
      Console::WriteLine( Final );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( e->Message );
   }

}

.NET Framework

Supported in: 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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