DESCryptoServiceProvider Class

Definition

Namespace:

System.Security.Cryptography

Assembly:

System.Security.Cryptography.dll

Source:

DESCryptoServiceProvider.Unix.cs

Caution

Derived cryptographic types are obsolete. Use the Create method on the base type instead.

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.Obsolete("Derived cryptographic types are obsolete. Use the Create method on the base type instead.", DiagnosticId="SYSLIB0021", UrlFormat="https://aka.ms/dotnet-warnings/{0}")]
public sealed class DESCryptoServiceProvider : System.Security.Cryptography.DES

[<System.Obsolete("Derived cryptographic types are obsolete. Use the Create method on the base type instead.", DiagnosticId="SYSLIB0021", UrlFormat="https://aka.ms/dotnet-warnings/{0}")>]
type DESCryptoServiceProvider = class
    inherit DES

Public NotInheritable Class DESCryptoServiceProvider
Inherits DES

Inheritance

Object

SymmetricAlgorithm

DES

DESCryptoServiceProvider

Attributes

ObsoleteAttribute

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.

Important

A newer symmetric encryption algorithm, Advanced Encryption Standard (AES), is available. Consider using the Aes class instead of the DES class. Use DES only for compatibility with legacy applications and data.

Constructors

DESCryptoServiceProvider()

Initializes a new instance of the DESCryptoServiceProvider class.

Fields

BlockSizeValue	Represents the block size, in bits, of the cryptographic operation. (Inherited from SymmetricAlgorithm)
FeedbackSizeValue	Represents the feedback size, in bits, of the cryptographic operation. (Inherited from SymmetricAlgorithm)
IVValue	Represents the initialization vector (IV) for the symmetric algorithm. (Inherited from SymmetricAlgorithm)
KeySizeValue	Represents the size, in bits, of the secret key used by the symmetric algorithm. (Inherited from SymmetricAlgorithm)
KeyValue	Represents the secret key for the symmetric algorithm. (Inherited from SymmetricAlgorithm)
LegalBlockSizesValue	Specifies the block sizes, in bits, that are supported by the symmetric algorithm. (Inherited from SymmetricAlgorithm)
LegalKeySizesValue	Specifies the key sizes, in bits, that are supported by the symmetric algorithm. (Inherited from SymmetricAlgorithm)
ModeValue	Represents the cipher mode used in the symmetric algorithm. (Inherited from SymmetricAlgorithm)
PaddingValue	Represents the padding mode used in the symmetric algorithm. (Inherited from SymmetricAlgorithm)

Properties

BlockSize	Gets or sets the block size, in bits, of the cryptographic operation. (Inherited from SymmetricAlgorithm)
FeedbackSize	Gets or sets the feedback size, in bits, of the cryptographic operation for the Cipher Feedback (CFB) and Output Feedback (OFB) cipher modes. (Inherited from SymmetricAlgorithm)
IV	Gets or sets the initialization vector (IV) for the symmetric algorithm. (Inherited from SymmetricAlgorithm)
Key	Gets or sets the secret key for the Data Encryption Standard (DES) algorithm. (Inherited from DES)
KeySize	Gets or sets the size, in bits, of the secret key used by the symmetric algorithm. (Inherited from SymmetricAlgorithm)
LegalBlockSizes	Gets the block sizes, in bits, that are supported by the symmetric algorithm. (Inherited from SymmetricAlgorithm)
LegalKeySizes	Gets the key sizes, in bits, that are supported by the symmetric algorithm. (Inherited from SymmetricAlgorithm)
Mode	Gets or sets the mode for operation of the symmetric algorithm. (Inherited from SymmetricAlgorithm)
Padding	Gets or sets the padding mode used in the symmetric algorithm. (Inherited from SymmetricAlgorithm)

Methods

Clear()	Releases all resources used by the SymmetricAlgorithm class. (Inherited from SymmetricAlgorithm)
CreateDecryptor()	Creates a symmetric decryptor object with the current Key property and initialization vector (IV).
CreateDecryptor(Byte[], Byte[])	Creates a symmetric Data Encryption Standard (DES) decryptor object with the specified key (Key) and initialization vector (IV).
CreateEncryptor()	Creates a symmetric encryptor object with the current Key property and initialization vector (IV).
CreateEncryptor(Byte[], Byte[])	Creates a symmetric Data Encryption Standard (DES) encryptor object with the specified key (Key) and initialization vector (IV).
DecryptCbc(Byte[], Byte[], PaddingMode)	Decrypts data using CBC mode with the specified padding mode. (Inherited from SymmetricAlgorithm)
DecryptCbc(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, PaddingMode)	Decrypts data using CBC mode with the specified padding mode. (Inherited from SymmetricAlgorithm)
DecryptCbc(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, PaddingMode)	Decrypts data into the specified buffer, using CBC mode with the specified padding mode. (Inherited from SymmetricAlgorithm)
DecryptCfb(Byte[], Byte[], PaddingMode, Int32)	Decrypts data using CFB mode with the specified padding mode and feedback size. (Inherited from SymmetricAlgorithm)
DecryptCfb(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, PaddingMode, Int32)	Decrypts data using CFB mode with the specified padding mode and feedback size. (Inherited from SymmetricAlgorithm)
DecryptCfb(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, PaddingMode, Int32)	Decrypts data into the specified buffer, using CFB mode with the specified padding mode and feedback size. (Inherited from SymmetricAlgorithm)
DecryptEcb(Byte[], PaddingMode)	Decrypts data using ECB mode with the specified padding mode. (Inherited from SymmetricAlgorithm)
DecryptEcb(ReadOnlySpan<Byte>, PaddingMode)	Decrypts data using ECB mode with the specified padding mode. (Inherited from SymmetricAlgorithm)
DecryptEcb(ReadOnlySpan<Byte>, Span<Byte>, PaddingMode)	Decrypts data into the specified buffer, using ECB mode with the specified padding mode. (Inherited from SymmetricAlgorithm)
Dispose()	Releases all resources used by the current instance of the SymmetricAlgorithm class. (Inherited from SymmetricAlgorithm)
Dispose(Boolean)	Releases the unmanaged resources used by the SymmetricAlgorithm and optionally releases the managed resources. (Inherited from SymmetricAlgorithm)
EncryptCbc(Byte[], Byte[], PaddingMode)	Encrypts data using CBC mode with the specified padding mode. (Inherited from SymmetricAlgorithm)
EncryptCbc(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, PaddingMode)	Encrypts data using CBC mode with the specified padding mode. (Inherited from SymmetricAlgorithm)
EncryptCbc(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, PaddingMode)	Encrypts data into the specified buffer, using CBC mode with the specified padding mode. (Inherited from SymmetricAlgorithm)
EncryptCfb(Byte[], Byte[], PaddingMode, Int32)	Encrypts data using CFB mode with the specified padding mode and feedback size. (Inherited from SymmetricAlgorithm)
EncryptCfb(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, PaddingMode, Int32)	Encrypts data using CFB mode with the specified padding mode and feedback size. (Inherited from SymmetricAlgorithm)
EncryptCfb(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, PaddingMode, Int32)	Encrypts data into the specified buffer, using CFB mode with the specified padding mode and feedback size. (Inherited from SymmetricAlgorithm)
EncryptEcb(Byte[], PaddingMode)	Encrypts data using ECB mode with the specified padding mode. (Inherited from SymmetricAlgorithm)
EncryptEcb(ReadOnlySpan<Byte>, PaddingMode)	Encrypts data using ECB mode with the specified padding mode. (Inherited from SymmetricAlgorithm)
EncryptEcb(ReadOnlySpan<Byte>, Span<Byte>, PaddingMode)	Encrypts data into the specified buffer, using ECB mode with the specified padding mode. (Inherited from SymmetricAlgorithm)
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GenerateIV()	Generates a random initialization vector (IV) to use for the algorithm.
GenerateKey()	Generates a random key (Key) to be used for the algorithm.
GetCiphertextLengthCbc(Int32, PaddingMode)	Gets the length of a ciphertext with a given padding mode and plaintext length in CBC mode. (Inherited from SymmetricAlgorithm)
GetCiphertextLengthCfb(Int32, PaddingMode, Int32)	Gets the length of a ciphertext with a given padding mode and plaintext length in CFB mode. (Inherited from SymmetricAlgorithm)
GetCiphertextLengthEcb(Int32, PaddingMode)	Gets the length of a ciphertext with a given padding mode and plaintext length in ECB mode. (Inherited from SymmetricAlgorithm)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string that represents the current object. (Inherited from Object)
TryDecryptCbc(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, Int32, PaddingMode)	Attempts to decrypt data into the specified buffer, using CBC mode with the specified padding mode. (Inherited from SymmetricAlgorithm)
TryDecryptCbcCore(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, PaddingMode, Int32)	When overridden in a derived class, attempts to decrypt data into the specified buffer, using CBC mode with the specified padding mode. (Inherited from SymmetricAlgorithm)
TryDecryptCfb(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, Int32, PaddingMode, Int32)	Attempts to decrypt data into the specified buffer, using CFB mode with the specified padding mode and feedback size. (Inherited from SymmetricAlgorithm)
TryDecryptCfbCore(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, PaddingMode, Int32, Int32)	When overridden in a derived class, attempts to decrypt data into the specified buffer, using CFB mode with the specified padding mode and feedback size. (Inherited from SymmetricAlgorithm)
TryDecryptEcb(ReadOnlySpan<Byte>, Span<Byte>, PaddingMode, Int32)	Attempts to decrypt data into the specified buffer, using ECB mode with the specified padding mode. (Inherited from SymmetricAlgorithm)
TryDecryptEcbCore(ReadOnlySpan<Byte>, Span<Byte>, PaddingMode, Int32)	When overridden in a derived class, attempts to decrypt data into the specified buffer, using ECB mode with the specified padding mode. (Inherited from SymmetricAlgorithm)
TryEncryptCbc(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, Int32, PaddingMode)	Attempts to encrypt data into the specified buffer, using CBC mode with the specified padding mode. (Inherited from SymmetricAlgorithm)
TryEncryptCbcCore(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, PaddingMode, Int32)	When overridden in a derived class, attempts to encrypt data into the specified buffer, using CBC mode with the specified padding mode. (Inherited from SymmetricAlgorithm)
TryEncryptCfb(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, Int32, PaddingMode, Int32)	Attempts to encrypt data into the specified buffer, using CFB mode with the specified padding mode and feedback size. (Inherited from SymmetricAlgorithm)
TryEncryptCfbCore(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, PaddingMode, Int32, Int32)	When overridden in a derived class, attempts to encrypt data into the specified buffer, using CFB mode with the specified padding mode and feedback size. (Inherited from SymmetricAlgorithm)
TryEncryptEcb(ReadOnlySpan<Byte>, Span<Byte>, PaddingMode, Int32)	Attempts to encrypt data into the specified buffer, using ECB mode with the specified padding mode. (Inherited from SymmetricAlgorithm)
TryEncryptEcbCore(ReadOnlySpan<Byte>, Span<Byte>, PaddingMode, Int32)	When overridden in a derived class, attempts to encrypt data into the specified buffer, using ECB mode with the specified padding mode. (Inherited from SymmetricAlgorithm)
ValidKeySize(Int32)	Determines whether the specified key size is valid for the current algorithm. (Inherited from SymmetricAlgorithm)

See also

• Cryptographic Services