DESCryptoServiceProvider Class

Defines a wrapper object to access the cryptographic service provider (CSP) version of the Data Encryption Standard (DES) algorithm. This class cannot be inherited.

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

[ComVisibleAttribute(true)]
public ref class DESCryptoServiceProvider sealed : public DES

The DESCryptoServiceProvider type exposes the following members.

  NameDescription
Public methodDESCryptoServiceProviderInitializes a new instance of the DESCryptoServiceProvider class.
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  NameDescription
Public propertyBlockSizeGets or sets the block size, in bits, of the cryptographic operation. (Inherited from SymmetricAlgorithm.)
Public propertyFeedbackSizeGets or sets the feedback size, in bits, of the cryptographic operation. (Inherited from SymmetricAlgorithm.)
Public propertyIVGets or sets the initialization vector (IV) for the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Public propertyKeyGets or sets the secret key for the Data Encryption Standard (DES) algorithm. (Inherited from DES.)
Public propertyKeySizeGets or sets the size, in bits, of the secret key used by the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Public propertyLegalBlockSizesGets the block sizes, in bits, that are supported by the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Public propertyLegalKeySizesGets the key sizes, in bits, that are supported by the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Public propertyModeGets or sets the mode for operation of the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Public propertyPaddingGets or sets the padding mode used in the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
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  NameDescription
Public methodClearReleases all resources used by the SymmetricAlgorithm class. (Inherited from SymmetricAlgorithm.)
Public methodCreateDecryptor()Creates a symmetric decryptor object with the current Key property and initialization vector (IV). (Inherited from SymmetricAlgorithm.)
Public methodCreateDecryptor(array<Byte>, array<Byte>)Creates a symmetric Data Encryption Standard (DES) decryptor object with the specified key (Key) and initialization vector (IV). (Overrides SymmetricAlgorithm::CreateDecryptor(array<Byte>, array<Byte>).)
Public methodCreateEncryptor()Creates a symmetric encryptor object with the current Key property and initialization vector (IV). (Inherited from SymmetricAlgorithm.)
Public methodCreateEncryptor(array<Byte>, array<Byte>)Creates a symmetric Data Encryption Standard (DES) encryptor object with the specified key (Key) and initialization vector (IV). (Overrides SymmetricAlgorithm::CreateEncryptor(array<Byte>, array<Byte>).)
Public methodDispose()Releases all resources used by the current instance of the SymmetricAlgorithm class. (Inherited from SymmetricAlgorithm.)
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Public methodGenerateIVGenerates a random initialization vector (IV) to use for the algorithm. (Overrides SymmetricAlgorithm::GenerateIV().)
Public methodGenerateKeyGenerates a random key (Key) to be used for the algorithm. (Overrides SymmetricAlgorithm::GenerateKey().)
Public methodGetHashCodeServes as the default hash function. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
Public methodValidKeySizeDetermines whether the specified key size is valid for the current algorithm. (Inherited from SymmetricAlgorithm.)
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This algorithm supports a key length of 64 bits.

The following code example uses DESCryptoServiceProvider (an implementation of DES) with the specified key (Key) and initialization vector (IV) to encrypt a file specified by inName. It then outputs the encrypted result to the file specified by outName.

void EncryptData( String^ inName, String^ outName, array<Byte>^desKey, array<Byte>^desIV )
{

   //Create the file streams to handle the input and output files.
   FileStream^ fin = gcnew FileStream( inName,FileMode::Open,FileAccess::Read );
   FileStream^ fout = gcnew FileStream( outName,FileMode::OpenOrCreate,FileAccess::Write );
   fout->SetLength( 0 );

   //Create variables to help with read and write. 
   array<Byte>^bin = gcnew array<Byte>(100);
   long rdlen = 0; //This is the total number of bytes written. 

   long totlen = (long)fin->Length; //This is the total length of the input file. 

   int len; //This is the number of bytes to be written at a time.

   DES^ des = gcnew DESCryptoServiceProvider;
   CryptoStream^ encStream = gcnew CryptoStream( fout,des->CreateEncryptor( desKey, desIV ),CryptoStreamMode::Write );
   Console::WriteLine( "Encrypting..." );

   //Read from the input file, then encrypt and write to the output file. 
   while ( rdlen < totlen )
   {
      len = fin->Read( bin, 0, 100 );
      encStream->Write( bin, 0, len );
      rdlen = rdlen + len;
      Console::WriteLine( "{0} bytes processed", rdlen );
   }

   encStream->Close();
   fout->Close();
   fin->Close();
}

Decryption can be handled in the same way; use CreateDecryptor instead of CreateEncryptor. The same key (Key) and initialization vector (IV) used to encrypt the file must be used to decrypt it.

.NET Framework

Supported in: 4.5.2, 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 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.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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