DESCryptoServiceProvider::CreateEncryptor Method (array<Byte>^, array<Byte>^)

 
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Creates a symmetric Data Encryption Standard (DES) encryptor object with the specified key (Key) and initialization vector (IV).

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

public:
virtual ICryptoTransform^ CreateEncryptor(
	array<unsigned char>^ rgbKey,
	array<unsigned char>^ rgbIV
) override

Parameters

rgbKey
Type: array<System::Byte>^

The secret key to use for the symmetric algorithm.

rgbIV
Type: array<System::Byte>^

The initialization vector to use for the symmetric algorithm.

Return Value

Type: System.Security.Cryptography::ICryptoTransform^

A symmetric DES encryptor object.

Exception Condition
CryptographicException

The value of the Mode property is OFB.

-or-

The value of the Mode property is CFB and the value of the FeedbackSize property is not 8.

-or-

An invalid key size was used.

-or-

The algorithm key size was not available.

Use the CreateDecryptor overload with the same parameters to decrypt the result of this method.

The following code example shows how to create and use a DESCryptoServiceProvider 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 CryptoStream using the FileStream 
      // and the passed key and initialization vector (IV).
      CryptoStream^ cStream = gcnew CryptoStream( fStream,(gcnew DESCryptoServiceProvider)->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 CryptoStream using the FileStream 
      // and the passed key and initialization vector (IV).
      CryptoStream^ cStream = gcnew CryptoStream( fStream,(gcnew DESCryptoServiceProvider)->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 DESCryptoServiceProvider object
      // to generate a key and initialization vector (IV).
      DESCryptoServiceProvider^ DESalg = gcnew DESCryptoServiceProvider;

      // 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, DESalg->Key, DESalg->IV );

      // Decrypt the text from a file using the file name, key, and IV.
      String^ Final = DecryptTextFromFile( FileName, DESalg->Key, DESalg->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 DESCryptoServiceProvider 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 CryptoStream using the MemoryStream 
      // and the passed key and initialization vector (IV).
      CryptoStream^ cStream = gcnew CryptoStream( mStream,(gcnew DESCryptoServiceProvider)->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 CryptoStream using the MemoryStream 
      // and the passed key and initialization vector (IV).
      CryptoStream^ csDecrypt = gcnew CryptoStream( msDecrypt,(gcnew DESCryptoServiceProvider)->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 DESCryptoServiceProvider object
      // to generate a key and initialization vector (IV).
      DESCryptoServiceProvider^ DESalg = gcnew DESCryptoServiceProvider;

      // 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, DESalg->Key, DESalg->IV );

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