DESCryptoServiceProvider DESCryptoServiceProvider DESCryptoServiceProvider DESCryptoServiceProvider Class

Definition

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

public ref class DESCryptoServiceProvider sealed : System::Security::Cryptography::DES
[System.Runtime.InteropServices.ComVisible(true)]
public sealed class DESCryptoServiceProvider : System.Security.Cryptography.DES
type DESCryptoServiceProvider = class
    inherit DES
Public NotInheritable Class DESCryptoServiceProvider
Inherits DES
Inheritance
DESCryptoServiceProviderDESCryptoServiceProviderDESCryptoServiceProviderDESCryptoServiceProvider
Attributes

Examples

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();
}

private static void EncryptData(String inName, String outName, byte[] desKey, byte[] desIV)
 {    
     //Create the file streams to handle the input and output files.
     FileStream fin = new FileStream(inName, FileMode.Open, FileAccess.Read);
     FileStream fout = new FileStream(outName, FileMode.OpenOrCreate, FileAccess.Write);
     fout.SetLength(0);
       
     //Create variables to help with read and write.
     byte[] bin = new byte[100]; //This is intermediate storage for the encryption.
     long rdlen = 0;              //This is the total number of bytes written.
     long totlen = 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 = new DESCryptoServiceProvider();          
     CryptoStream encStream = new 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();                   
 }
Private Shared Sub EncryptData(inName As String, outName As String, _
desKey() As Byte, desIV() As Byte)

    'Create the file streams to handle the input and output files.
    Dim fin As New FileStream(inName, FileMode.Open, FileAccess.Read)
    Dim fout As New FileStream(outName, FileMode.OpenOrCreate, _
       FileAccess.Write)
    fout.SetLength(0)
    
    'Create variables to help with read and write.
    Dim bin(4096) As Byte 'This is intermediate storage for the encryption.
    Dim rdlen As Long = 0 'This is the total number of bytes written.
    Dim totlen As Long = fin.Length 'Total length of the input file.
    Dim len As Integer 'This is the number of bytes to be written at a time.
    Dim des As New DESCryptoServiceProvider()
    Dim encStream As New 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, 4096)
        encStream.Write(bin, 0, len)
        rdlen = Convert.ToInt32(rdlen + len / des.BlockSize * des.BlockSize)
        Console.WriteLine("Processed {0} bytes, {1} bytes total", len, _
           rdlen)
    End While
    
    encStream.Close()
End Sub

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.

Remarks

This algorithm supports a key length of 64 bits.

Constructors

DESCryptoServiceProvider() DESCryptoServiceProvider() DESCryptoServiceProvider() DESCryptoServiceProvider()

Initializes a new instance of the DESCryptoServiceProvider class.

Methods

Clear() Clear() Clear() Clear()

Releases all resources used by the SymmetricAlgorithm class.

(Inherited from SymmetricAlgorithm)
CreateDecryptor() CreateDecryptor() CreateDecryptor() CreateDecryptor()
CreateDecryptor(Byte[], Byte[]) CreateDecryptor(Byte[], Byte[]) CreateDecryptor(Byte[], Byte[]) CreateDecryptor(Byte[], Byte[])

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

CreateEncryptor() CreateEncryptor() CreateEncryptor() CreateEncryptor()
CreateEncryptor(Byte[], Byte[]) CreateEncryptor(Byte[], Byte[]) CreateEncryptor(Byte[], Byte[]) CreateEncryptor(Byte[], Byte[])

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

Dispose() Dispose() Dispose() Dispose()

Releases all resources used by the current instance of the SymmetricAlgorithm class.

(Inherited from SymmetricAlgorithm)
Dispose(Boolean) Dispose(Boolean) Dispose(Boolean) Dispose(Boolean)

Releases the unmanaged resources used by the SymmetricAlgorithm and optionally releases the managed resources.

(Inherited from SymmetricAlgorithm)
Equals(Object) Equals(Object) Equals(Object) Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
GenerateIV() GenerateIV() GenerateIV() GenerateIV()

Generates a random initialization vector (IV) to use for the algorithm.

GenerateKey() GenerateKey() GenerateKey() GenerateKey()

Generates a random key (Key) to be used for the algorithm.

GetHashCode() GetHashCode() GetHashCode() GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetType() GetType() GetType() GetType()

Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
ToString() ToString() ToString() ToString()

Returns a string that represents the current object.

(Inherited from Object)
ValidKeySize(Int32) ValidKeySize(Int32) ValidKeySize(Int32) ValidKeySize(Int32)

Determines whether the specified key size is valid for the current algorithm.

(Inherited from SymmetricAlgorithm)

Properties

BlockSize BlockSize BlockSize BlockSize

Gets or sets the block size, in bits, of the cryptographic operation.

(Inherited from SymmetricAlgorithm)
FeedbackSize FeedbackSize FeedbackSize FeedbackSize

Gets or sets the feedback size, in bits, of the cryptographic operation.

(Inherited from SymmetricAlgorithm)
IV IV IV IV

Gets or sets the initialization vector (IV) for the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
Key Key Key Key

Gets or sets the secret key for the Data Encryption Standard (DES) algorithm.

(Inherited from DES)
KeySize KeySize KeySize KeySize

Gets or sets the size, in bits, of the secret key used by the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
LegalBlockSizes LegalBlockSizes LegalBlockSizes LegalBlockSizes

Gets the block sizes, in bits, that are supported by the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
LegalKeySizes LegalKeySizes LegalKeySizes LegalKeySizes

Gets the key sizes, in bits, that are supported by the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
Mode Mode Mode Mode

Gets or sets the mode for operation of the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
Padding Padding Padding Padding

Gets or sets the padding mode used in the symmetric algorithm.

(Inherited from SymmetricAlgorithm)

Fields

BlockSizeValue BlockSizeValue BlockSizeValue BlockSizeValue

Represents the block size, in bits, of the cryptographic operation.

(Inherited from SymmetricAlgorithm)
FeedbackSizeValue FeedbackSizeValue FeedbackSizeValue FeedbackSizeValue

Represents the feedback size, in bits, of the cryptographic operation.

(Inherited from SymmetricAlgorithm)
IVValue IVValue IVValue IVValue

Represents the initialization vector (IV) for the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
KeySizeValue KeySizeValue KeySizeValue KeySizeValue

Represents the size, in bits, of the secret key used by the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
KeyValue KeyValue KeyValue KeyValue

Represents the secret key for the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
LegalBlockSizesValue LegalBlockSizesValue LegalBlockSizesValue LegalBlockSizesValue

Specifies the block sizes, in bits, that are supported by the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
LegalKeySizesValue LegalKeySizesValue LegalKeySizesValue LegalKeySizesValue

Specifies the key sizes, in bits, that are supported by the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
ModeValue ModeValue ModeValue ModeValue

Represents the cipher mode used in the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
PaddingValue PaddingValue PaddingValue PaddingValue

Represents the padding mode used in the symmetric algorithm.

(Inherited from SymmetricAlgorithm)

Explicit Interface Implementations

IDisposable.Dispose() IDisposable.Dispose() IDisposable.Dispose() IDisposable.Dispose() Inherited from SymmetricAlgorithm

Applies to