Rijndael-Konstruktor
Initialisiert eine neue Instanz der Rijndael-Klasse.
Namespace: System.Security.Cryptography
Assembly: mscorlib (in mscorlib.dll)
Syntax
'Declaration
Protected Sub New
'Usage
Dim instance As New Rijndael
protected Rijndael ()
protected:
Rijndael ()
protected Rijndael ()
protected function Rijndael ()
Hinweise
Sie können keine Instanz einer abstrakten Klasse erstellen. Eine neue Instanz einer abgeleiteten Klasse wird vom Anwendungscode erstellt.
Diese Methode initialisiert die geschützten Felder von SymmetricAlgorithm mit den Standardwerten, die in der folgenden Tabelle aufgeführt sind.
Feld |
Standardwert |
|---|---|
256 |
|
128 |
|
128 |
Beispiel
Im folgenden Codebeispiel werden Daten mithilfe der Rijndael-Klasse zunächst verschlüsselt und anschließend entschlüsselt.
Imports System.Security.Cryptography
Imports System.Text
Imports System.IO
Module RijndaelSample
Sub Main()
Try
' Create a new Rijndael object to generate a key
' and initialization vector (IV).
Dim RijndaelAlg As Rijndael = Rijndael.Create
' Create a string to encrypt.
Dim sData As String = "Here is some data to encrypt."
Dim FileName As String = "CText.txt"
' Encrypt text to a file using the file name, key, and IV.
EncryptTextToFile(sData, FileName, RijndaelAlg.Key, RijndaelAlg.IV)
' Decrypt the text from a file using the file name, key, and IV.
Dim Final As String = DecryptTextFromFile(FileName, RijndaelAlg.Key, RijndaelAlg.IV)
' Display the decrypted string to the console.
Console.WriteLine(Final)
Catch e As Exception
Console.WriteLine(e.Message)
End Try
Console.ReadLine()
End Sub
Sub EncryptTextToFile(ByVal Data As String, ByVal FileName As String, ByVal Key() As Byte, ByVal IV() As Byte)
Try
' Create or open the specified file.
Dim fStream As FileStream = File.Open(FileName, FileMode.OpenOrCreate)
' Create a new Rijndael object.
Dim RijndaelAlg As Rijndael = Rijndael.Create
' Create a CryptoStream using the FileStream
' and the passed key and initialization vector (IV).
Dim cStream As New CryptoStream(fStream, _
RijndaelAlg.CreateEncryptor(Key, IV), _
CryptoStreamMode.Write)
' Create a StreamWriter using the CryptoStream.
Dim sWriter As New StreamWriter(cStream)
Try
' Write the data to the stream
' to encrypt it.
sWriter.WriteLine(Data)
Catch e As Exception
Console.WriteLine("An error occurred: {0}", e.Message)
Finally
' Close the streams and
' close the file.
sWriter.Close()
cStream.Close()
fStream.Close()
End Try
Catch e As CryptographicException
Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
Catch e As UnauthorizedAccessException
Console.WriteLine("A file error occurred: {0}", e.Message)
End Try
End Sub
Function DecryptTextFromFile(ByVal FileName As String, ByVal Key() As Byte, ByVal IV() As Byte) As String
Try
' Create or open the specified file.
Dim fStream As FileStream = File.Open(FileName, FileMode.OpenOrCreate)
' Create a new Rijndael object.
Dim RijndaelAlg As Rijndael = Rijndael.Create
' Create a CryptoStream using the FileStream
' and the passed key and initialization vector (IV).
Dim cStream As New CryptoStream(fStream, _
RijndaelAlg.CreateDecryptor(Key, IV), _
CryptoStreamMode.Read)
' Create a StreamReader using the CryptoStream.
Dim sReader As New StreamReader(cStream)
' Read the data from the stream
' to decrypt it.
Dim val As String = Nothing
Try
val = sReader.ReadLine()
Catch e As Exception
Console.WriteLine("An Cerror occurred: {0}", e.Message)
Finally
' Close the streams and
' close the file.
sReader.Close()
cStream.Close()
fStream.Close()
End Try
' Return the string.
Return val
Catch e As CryptographicException
Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
Return Nothing
Catch e As UnauthorizedAccessException
Console.WriteLine("A file error occurred: {0}", e.Message)
Return Nothing
End Try
End Function
End Module
using System;
using System.Security.Cryptography;
using System.Text;
using System.IO;
class RijndaelSample
{
static void Main()
{
try
{
// Create a new Rijndael object to generate a key
// and initialization vector (IV).
Rijndael RijndaelAlg = Rijndael.Create();
// 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, RijndaelAlg.Key, RijndaelAlg.IV);
// Decrypt the text from a file using the file name, key, and IV.
string Final = DecryptTextFromFile(FileName, RijndaelAlg.Key, RijndaelAlg.IV);
// Display the decrypted string to the console.
Console.WriteLine(Final);
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
Console.ReadLine();
}
public static void EncryptTextToFile(String Data, String FileName, byte[] Key, byte[] IV)
{
try
{
// Create or open the specified file.
FileStream fStream = File.Open(FileName, FileMode.OpenOrCreate);
// Create a new Rijndael object.
Rijndael RijndaelAlg = Rijndael.Create();
// Create a CryptoStream using the FileStream
// and the passed key and initialization vector (IV).
CryptoStream cStream = new CryptoStream(fStream,
RijndaelAlg.CreateEncryptor(Key, IV),
CryptoStreamMode.Write);
// Create a StreamWriter using the CryptoStream.
StreamWriter sWriter = new StreamWriter(cStream);
try
{
// Write the data to the stream
// to encrypt it.
sWriter.WriteLine(Data);
}
catch (Exception e)
{
Console.WriteLine("An error occurred: {0}", e.Message);
}
finally
{
// 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);
}
}
public static string DecryptTextFromFile(String FileName, byte[] Key, byte[] IV)
{
try
{
// Create or open the specified file.
FileStream fStream = File.Open(FileName, FileMode.OpenOrCreate);
// Create a new Rijndael object.
Rijndael RijndaelAlg = Rijndael.Create();
// Create a CryptoStream using the FileStream
// and the passed key and initialization vector (IV).
CryptoStream cStream = new CryptoStream(fStream,
RijndaelAlg.CreateDecryptor(Key, IV),
CryptoStreamMode.Read);
// Create a StreamReader using the CryptoStream.
StreamReader sReader = new StreamReader(cStream);
string val = null;
try
{
// Read the data from the stream
// to decrypt it.
val = sReader.ReadLine();
}
catch (Exception e)
{
Console.WriteLine("An error occurred: {0}", e.Message);
}
finally
{
// 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 null;
}
catch (UnauthorizedAccessException e)
{
Console.WriteLine("A file error occurred: {0}", e.Message);
return null;
}
}
}
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
Rijndael-Klasse
Rijndael-Member
System.Security.Cryptography-Namespace