DES-Klasse
Stellt die Basisklasse für den DES (Data Encryption Standard)-Algorithmus dar, von der alle DES-Implementierungen abgeleitet werden müssen.
Namespace: System.Security.Cryptography
Assembly: mscorlib (in mscorlib.dll)
Syntax
'Declaration
<ComVisibleAttribute(True)> _
Public MustInherit Class DES
Inherits SymmetricAlgorithm
'Usage
Dim instance As DES
[ComVisibleAttribute(true)]
public abstract class DES : SymmetricAlgorithm
[ComVisibleAttribute(true)]
public ref class DES abstract : public SymmetricAlgorithm
/** @attribute ComVisibleAttribute(true) */
public abstract class DES extends SymmetricAlgorithm
ComVisibleAttribute(true)
public abstract class DES extends SymmetricAlgorithm
Hinweise
Dieser Algorithmus unterstützt eine Schlüssellänge von 64 Bits.
Beispiel
In der Methode des folgenden Codebeispiels wird DESCryptoServiceProvider (eine Implementierung von DES) mit dem angegebenen Schlüssel (Key) und dem angegebenen Initialisierungsvektor (IV) verwendet, um die von inName angegebene Datei zu verschlüsseln. Anschließend wird das verschlüsselte Ergebnis in die durch outName angegebene Datei ausgegeben.
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
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();
}
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, ubyte desKey[], ubyte 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.
ubyte bin[] = new ubyte[100]; // This is intermediate
// storage for the encryption.
long rdlen = 0; // This is the total
// number of bytes written.
long totlen = fin.get_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",
System.Convert.ToString(rdlen));
}
encStream.Close();
fout.Close();
fin.Close();
} //EncryptData
Die Entschlüsselung erfolgt ähnlich. Verwenden Sie dafür jedoch nicht CreateEncryptor, sondern CreateDecryptor. Beim Entschlüsseln der Datei müssen derselbe Schlüssel (Key) und derselbe Initialisierungsvektor (IV) verwendet werden wie beim Verschlüsseln.
Vererbungshierarchie
System.Object
System.Security.Cryptography.SymmetricAlgorithm
System.Security.Cryptography.DES
System.Security.Cryptography.DESCryptoServiceProvider
Threadsicherheit
Alle öffentlichen statischen (Shared in Visual Basic) Member dieses Typs sind threadsicher. Bei Instanzmembern ist die Threadsicherheit nicht gewährleistet.
Plattformen
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile für Pocket PC, Windows Mobile für Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.
Versionsinformationen
.NET Framework
Unterstützt in: 2.0, 1.1, 1.0
.NET Compact Framework
Unterstützt in: 2.0
Siehe auch
Referenz
DES-Member
System.Security.Cryptography-Namespace