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TripleDES::Create Method (String)

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

Namespace:  System.Security.Cryptography
Assembly:  mscorlib (in mscorlib.dll)

public:
static TripleDES^ Create(
	String^ str
)

Parameters

str
Type: System::String

The name of the specific implementation of TripleDES to use.

Return Value

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

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 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 error occurred: {0}", e->Message );
      return nullptr;
   }

}

int main()
{
   try
   {

      // Create a new TripleDES object to generate a key  
      // and initialization vector (IV).  Specify one  
      // of the recognized simple names for this  
      // algorithm.
      TripleDES^ TripleDESalg = TripleDES::Create( "TripleDES" );

      // 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 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).  Specify one  
      // of the recognized simple names for this  
      // algorithm.
      TripleDES^ TripleDESalg = TripleDES::Create( "TripleDES" );

      // 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, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

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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