TripleDES::Create Method ()

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

      // Create or open the specified file.
      FileStream^ fStream = File::Open( FileName, FileMode::OpenOrCreate );

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

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

      // Create a StreamWriter using the CryptoStream.
      StreamWriter^ sWriter = gcnew StreamWriter( cStream );

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

      // Close the streams and
      // close the file.
      sWriter->Close();
      cStream->Close();
      fStream->Close();
   }
   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 );
   }

}

String^ DecryptTextFromFile( String^ FileName, array<Byte>^Key, array<Byte>^IV )
{
   try
   {

      // Create or open the specified file. 
      FileStream^ fStream = File::Open( FileName, FileMode::OpenOrCreate );

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

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

      // Create a StreamReader using the CryptoStream.
      StreamReader^ sReader = gcnew StreamReader( cStream );

      // Read the data from the stream 
      // to decrypt it.
      String^ val = sReader->ReadLine();

      // Close the streams and
      // close the file.
      sReader->Close();
      cStream->Close();
      fStream->Close();

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

}

int main()
{
   try
   {

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

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

      // 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 );
   }

}

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
Available since 1.1
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