TripleDESCryptoServiceProvider.CreateDecryptor Methode

Referenz

Definition

Namespace:: System.Security.Cryptography

Assembly:: System.Security.Cryptography.Csp.dll

Assembly:: System.Security.Cryptography.dll

Assembly:: netstandard.dll

Assembly:: mscorlib.dll

Wichtig

Einige Informationen beziehen sich auf Vorabversionen, die vor dem Release ggf. grundlegend überarbeitet werden. Microsoft übernimmt hinsichtlich der hier bereitgestellten Informationen keine Gewährleistungen, seien sie ausdrücklich oder konkludent.

Überlädt

CreateDecryptor()	Erstellt ein symmetrisches Entschlüsselungsobjekt mit der aktuellen Key-Eigenschaft und dem Initialisierungsvektor (IV).
CreateDecryptor(Byte[], Byte[])	Erstellt ein symmetrisches TripleDES-Entschlüsselungsobjekt mit dem angegebenen Schlüssel (Key) und dem angegebenen Initialisierungsvektor (IV).

CreateDecryptor()

Erstellt ein symmetrisches Entschlüsselungsobjekt mit der aktuellen Key-Eigenschaft und dem Initialisierungsvektor (IV).

public:
 override System::Security::Cryptography::ICryptoTransform ^ CreateDecryptor();

public override System.Security.Cryptography.ICryptoTransform CreateDecryptor ();

override this.CreateDecryptor : unit -> System.Security.Cryptography.ICryptoTransform

Public Overrides Function CreateDecryptor () As ICryptoTransform

Gibt zurück

ICryptoTransform

Ein symmetrisches Entschlüsselungsobjekt.

Hinweise

Diese Methode entschlüsselt eine verschlüsselte Nachricht, die mithilfe der CreateEncryptor Überladung mit derselben Signatur erstellt wurde.

Gilt für

CreateDecryptor(Byte[], Byte[])

Erstellt ein symmetrisches TripleDES-Entschlüsselungsobjekt mit dem angegebenen Schlüssel (Key) und dem angegebenen Initialisierungsvektor (IV).

public:
 override System::Security::Cryptography::ICryptoTransform ^ CreateDecryptor(cli::array <System::Byte> ^ rgbKey, cli::array <System::Byte> ^ rgbIV);

public override System.Security.Cryptography.ICryptoTransform CreateDecryptor (byte[] rgbKey, byte[]? rgbIV);

public override System.Security.Cryptography.ICryptoTransform CreateDecryptor (byte[] rgbKey, byte[] rgbIV);

override this.CreateDecryptor : byte[] * byte[] -> System.Security.Cryptography.ICryptoTransform

Public Overrides Function CreateDecryptor (rgbKey As Byte(), rgbIV As Byte()) As ICryptoTransform

Parameter

rgbKey: Byte[]

Der geheime Schlüssel, der für den symmetrischen Algorithmus verwendet werden soll.

rgbIV: Byte[]

Der Initialisierungsvektor, der für den symmetrischen Algorithmus verwendet werden soll.

Gibt zurück

ICryptoTransform

Ein symmetrisches TripleDES-Entschlüsselungsobjekt.

Ausnahmen

CryptographicException

Der Wert der Mode-Eigenschaft ist OFB.

- oder - Der Wert der Mode-Eigenschaft ist CFB, und der Wert der FeedbackSize-Eigenschaft ist nicht 8.

- oder - Eine ungültige Schlüsselgröße wurde verwendet.

- oder - Die Algorithmusschlüsselgröße war nicht verfügbar.

Beispiele

Im folgenden Codebeispiel wird ein TripleDESCryptoServiceProvider Objekt erstellt und zum Verschlüsseln und Entschlüsseln von Daten in einer Datei verwendet.

using namespace System;
using namespace System::Security::Cryptography;
using namespace System::Text;
using namespace System::IO;
void EncryptTextToFile( String^ Data, String^ FileName, array<Byte>^Key, array<Byte>^IV )
{
   try
   {
      
      // Create or open the specified file.
      FileStream^ fStream = File::Open( FileName, FileMode::OpenOrCreate );
      
      // Create a CryptoStream using the FileStream 
      // and the passed key and initialization vector (IV).
      CryptoStream^ cStream = gcnew CryptoStream( fStream,(gcnew TripleDESCryptoServiceProvider)->CreateEncryptor( Key, IV ),CryptoStreamMode::Write );
      
      // Create a StreamWriter using the CryptoStream.
      StreamWriter^ sWriter = gcnew StreamWriter( cStream );
      
      // Write the data to the stream 
      // to encrypt it.
      sWriter->WriteLine( Data );
      
      // 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 access error occurred: {0}", e->Message );
   }

}

String^ DecryptTextFromFile( String^ FileName, array<Byte>^Key, array<Byte>^IV )
{
   try
   {
      
      // Create or open the specified file. 
      FileStream^ fStream = File::Open( FileName, FileMode::OpenOrCreate );
      
      // Create a CryptoStream using the FileStream 
      // and the passed key and initialization vector (IV).
      CryptoStream^ cStream = gcnew CryptoStream( fStream,(gcnew TripleDESCryptoServiceProvider)->CreateDecryptor( Key, IV ),CryptoStreamMode::Read );
      
      // Create a StreamReader using the CryptoStream.
      StreamReader^ sReader = gcnew StreamReader( cStream );
      
      // Read the data from the stream 
      // to decrypt it.
      String^ val = sReader->ReadLine();
      
      // 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 nullptr;
   }
   catch ( UnauthorizedAccessException^ e ) 
   {
      Console::WriteLine( "A file access error occurred: {0}", e->Message );
      return nullptr;
   }

}

int main()
{
   try
   {
      
      // Create a new TripleDESCryptoServiceProvider object
      // to generate a key and initialization vector (IV).
      TripleDESCryptoServiceProvider^ tDESalg = gcnew TripleDESCryptoServiceProvider;
      
      // 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, tDESalg->Key, tDESalg->IV );
      
      // Decrypt the text from a file using the file name, key, and IV.
      String^ Final = DecryptTextFromFile( FileName, tDESalg->Key, tDESalg->IV );
      
      // Display the decrypted string to the console.
      Console::WriteLine( Final );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( e->Message );
   }

}

using System;
using System.Security.Cryptography;
using System.Text;
using System.IO;

class TrippleDESCSPSample
{

    static void Main()
    {
        try
        {
            // Create a new TripleDESCryptoServiceProvider object
            // to generate a key and initialization vector (IV).
            TripleDESCryptoServiceProvider tDESalg = new TripleDESCryptoServiceProvider();

            // 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, tDESalg.Key, tDESalg.IV);

            // Decrypt the text from a file using the file name, key, and IV.
            string Final = DecryptTextFromFile(FileName, tDESalg.Key, tDESalg.IV);

            // Display the decrypted string to the console.
            Console.WriteLine(Final);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
    }

    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 CryptoStream using the FileStream
            // and the passed key and initialization vector (IV).
            CryptoStream cStream = new CryptoStream(fStream,
                new TripleDESCryptoServiceProvider().CreateEncryptor(Key,IV),
                CryptoStreamMode.Write);

            // Create a StreamWriter using the CryptoStream.
            StreamWriter sWriter = new StreamWriter(cStream);

            // Write the data to the stream
            // to encrypt it.
            sWriter.WriteLine(Data);

            // 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 access 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 CryptoStream using the FileStream
            // and the passed key and initialization vector (IV).
            CryptoStream cStream = new CryptoStream(fStream,
                new TripleDESCryptoServiceProvider().CreateDecryptor(Key,IV),
                CryptoStreamMode.Read);

            // Create a StreamReader using the CryptoStream.
            StreamReader sReader = new StreamReader(cStream);

            // Read the data from the stream
            // to decrypt it.
            string val = sReader.ReadLine();

            // 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 access error occurred: {0}", e.Message);
            return null;
        }
    }
}

Imports System.Security.Cryptography
Imports System.Text
Imports System.IO

Module TrippleDESCSPSample

    Sub Main()
        Try
            ' Create a new TripleDESCryptoServiceProvider object
            ' to generate a key and initialization vector (IV).
            Dim tDESalg As New TripleDESCryptoServiceProvider

            ' 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, tDESalg.Key, tDESalg.IV)

            ' Decrypt the text from a file using the file name, key, and IV.
            Dim Final As String = DecryptTextFromFile(FileName, tDESalg.Key, tDESalg.IV)

            ' Display the decrypted string to the console.
            Console.WriteLine(Final)
        Catch e As Exception
            Console.WriteLine(e.Message)
        End Try
    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 CryptoStream using the FileStream 
            ' and the passed key and initialization vector (IV).
            Dim cStream As New CryptoStream(fStream, _
                                            New TripleDESCryptoServiceProvider().CreateEncryptor(Key, IV), _
                                            CryptoStreamMode.Write)

            ' Create a StreamWriter using the CryptoStream.
            Dim sWriter As New StreamWriter(cStream)

            ' Write the data to the stream 
            ' to encrypt it.
            sWriter.WriteLine(Data)

            ' Close the streams and
            ' close the file.
            sWriter.Close()
            cStream.Close()
            fStream.Close()
        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 CryptoStream using the FileStream 
            ' and the passed key and initialization vector (IV).
            Dim cStream As New CryptoStream(fStream, _
                                            New TripleDESCryptoServiceProvider().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 = sReader.ReadLine()

            ' Close the streams and
            ' close the file.
            sReader.Close()
            cStream.Close()
            fStream.Close()

            ' 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

Im folgenden Codebeispiel wird ein TripleDESCryptoServiceProvider Objekt erstellt und zum Verschlüsseln und Entschlüsseln von Daten im Arbeitsspeicher verwendet.

using namespace System;
using namespace System::Security::Cryptography;
using namespace System::Text;
using namespace System::IO;
array<Byte>^ EncryptTextToMemory( String^ Data, array<Byte>^Key, array<Byte>^IV )
{
   try
   {
      
      // Create a MemoryStream.
      MemoryStream^ mStream = gcnew MemoryStream;
      
      // Create a CryptoStream using the MemoryStream 
      // and the passed key and initialization vector (IV).
      CryptoStream^ cStream = gcnew CryptoStream( mStream,(gcnew TripleDESCryptoServiceProvider)->CreateEncryptor( Key, IV ),CryptoStreamMode::Write );
      
      // Convert the passed string to a byte array.
      array<Byte>^toEncrypt = (gcnew ASCIIEncoding)->GetBytes( Data );
      
      // Write the byte array to the crypto stream and flush it.
      cStream->Write( toEncrypt, 0, toEncrypt->Length );
      cStream->FlushFinalBlock();
      
      // Get an array of bytes from the 
      // MemoryStream that holds the 
      // encrypted data.
      array<Byte>^ret = mStream->ToArray();
      
      // Close the streams.
      cStream->Close();
      mStream->Close();
      
      // Return the encrypted buffer.
      return ret;
   }
   catch ( CryptographicException^ e ) 
   {
      Console::WriteLine( "A Cryptographic error occurred: {0}", e->Message );
      return nullptr;
   }

}

String^ DecryptTextFromMemory( array<Byte>^Data, array<Byte>^Key, array<Byte>^IV )
{
   try
   {
      
      // Create a new MemoryStream using the passed 
      // array of encrypted data.
      MemoryStream^ msDecrypt = gcnew MemoryStream( Data );
      
      // Create a CryptoStream using the MemoryStream 
      // and the passed key and initialization vector (IV).
      CryptoStream^ csDecrypt = gcnew CryptoStream( msDecrypt,(gcnew TripleDESCryptoServiceProvider)->CreateDecryptor( Key, IV ),CryptoStreamMode::Read );
      
      // Create buffer to hold the decrypted data.
      array<Byte>^fromEncrypt = gcnew array<Byte>(Data->Length);
      
      // Read the decrypted data out of the crypto stream
      // and place it into the temporary buffer.
      csDecrypt->Read( fromEncrypt, 0, fromEncrypt->Length );
      
      //Convert the buffer into a string and return it.
      return (gcnew ASCIIEncoding)->GetString( fromEncrypt );
   }
   catch ( CryptographicException^ e ) 
   {
      Console::WriteLine( "A Cryptographic error occurred: {0}", e->Message );
      return nullptr;
   }

}

int main()
{
   try
   {
      
      // Create a new TripleDESCryptoServiceProvider object
      // to generate a key and initialization vector (IV).
      TripleDESCryptoServiceProvider^ tDESalg = gcnew TripleDESCryptoServiceProvider;
      
      // Create a string to encrypt.
      String^ sData = "Here is some data to encrypt.";
      
      // Encrypt the string to an in-memory buffer.
      array<Byte>^Data = EncryptTextToMemory( sData, tDESalg->Key, tDESalg->IV );
      
      // Decrypt the buffer back to a string.
      String^ Final = DecryptTextFromMemory( Data, tDESalg->Key, tDESalg->IV );
      
      // Display the decrypted string to the console.
      Console::WriteLine( Final );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( e->Message );
   }

}

using System;
using System.Security.Cryptography;
using System.Text;
using System.IO;

class TrippleDESCSPSample
{

    static void Main()
    {
        try
        {
            // Create a new TripleDESCryptoServiceProvider object
            // to generate a key and initialization vector (IV).
            TripleDESCryptoServiceProvider tDESalg = new TripleDESCryptoServiceProvider();

            // Create a string to encrypt.
            string sData = "Here is some data to encrypt.";

            // Encrypt the string to an in-memory buffer.
            byte[] Data = EncryptTextToMemory(sData, tDESalg.Key, tDESalg.IV);

            // Decrypt the buffer back to a string.
            string Final = DecryptTextFromMemory(Data, tDESalg.Key, tDESalg.IV);

            // Display the decrypted string to the console.
            Console.WriteLine(Final);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
    }

    public static byte[] EncryptTextToMemory(string Data,  byte[] Key, byte[] IV)
    {
        try
        {
            // Create a MemoryStream.
            MemoryStream mStream = new MemoryStream();

            // Create a CryptoStream using the MemoryStream
            // and the passed key and initialization vector (IV).
            CryptoStream cStream = new CryptoStream(mStream,
                new TripleDESCryptoServiceProvider().CreateEncryptor(Key, IV),
                CryptoStreamMode.Write);

            // Convert the passed string to a byte array.
            byte[] toEncrypt = new ASCIIEncoding().GetBytes(Data);

            // Write the byte array to the crypto stream and flush it.
            cStream.Write(toEncrypt, 0, toEncrypt.Length);
            cStream.FlushFinalBlock();

            // Get an array of bytes from the
            // MemoryStream that holds the
            // encrypted data.
            byte[] ret = mStream.ToArray();

            // Close the streams.
            cStream.Close();
            mStream.Close();

            // Return the encrypted buffer.
            return ret;
        }
        catch(CryptographicException e)
        {
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
            return null;
        }
    }

    public static string DecryptTextFromMemory(byte[] Data,  byte[] Key, byte[] IV)
    {
        try
        {
            // Create a new MemoryStream using the passed
            // array of encrypted data.
            MemoryStream msDecrypt = new MemoryStream(Data);

            // Create a CryptoStream using the MemoryStream
            // and the passed key and initialization vector (IV).
            CryptoStream csDecrypt = new CryptoStream(msDecrypt,
                new TripleDESCryptoServiceProvider().CreateDecryptor(Key, IV),
                CryptoStreamMode.Read);

            // Create buffer to hold the decrypted data.
            byte[] fromEncrypt = new byte[Data.Length];

            // Read the decrypted data out of the crypto stream
            // and place it into the temporary buffer.
            csDecrypt.Read(fromEncrypt, 0, fromEncrypt.Length);

            //Convert the buffer into a string and return it.
            return new ASCIIEncoding().GetString(fromEncrypt);
        }
        catch(CryptographicException e)
        {
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
            return null;
        }
    }
}

Imports System.Security.Cryptography
Imports System.Text
Imports System.IO

Module TrippleDESCSPSample

    Sub Main()
        Try
            ' Create a new TripleDESCryptoServiceProvider object
            ' to generate a key and initialization vector (IV).
            Dim tDESalg As New TripleDESCryptoServiceProvider

            ' Create a string to encrypt.
            Dim sData As String = "Here is some data to encrypt."

            ' Encrypt the string to an in-memory buffer.
            Dim Data As Byte() = EncryptTextToMemory(sData, tDESalg.Key, tDESalg.IV)

            ' Decrypt the buffer back to a string.
            Dim Final As String = DecryptTextFromMemory(Data, tDESalg.Key, tDESalg.IV)

            ' Display the decrypted string to the console.
            Console.WriteLine(Final)
        Catch e As Exception
            Console.WriteLine(e.Message)
        End Try
    End Sub


    Function EncryptTextToMemory(ByVal Data As String, ByVal Key() As Byte, ByVal IV() As Byte) As Byte()
        Try
            ' Create a MemoryStream.
            Dim mStream As New MemoryStream

            ' Create a CryptoStream using the MemoryStream 
            ' and the passed key and initialization vector (IV).
            Dim cStream As New CryptoStream(mStream, _
                                            New TripleDESCryptoServiceProvider().CreateEncryptor(Key, IV), _
                                            CryptoStreamMode.Write)

            ' Convert the passed string to a byte array.
            Dim toEncrypt As Byte() = New ASCIIEncoding().GetBytes(Data)

            ' Write the byte array to the crypto stream and flush it.
            cStream.Write(toEncrypt, 0, toEncrypt.Length)
            cStream.FlushFinalBlock()

            ' Get an array of bytes from the 
            ' MemoryStream that holds the 
            ' encrypted data.
            Dim ret As Byte() = mStream.ToArray()

            ' Close the streams.
            cStream.Close()
            mStream.Close()

            ' Return the encrypted buffer.
            Return ret
        Catch e As CryptographicException
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
            Return Nothing
        End Try
    End Function


    Function DecryptTextFromMemory(ByVal Data() As Byte, ByVal Key() As Byte, ByVal IV() As Byte) As String
        Try
            ' Create a new MemoryStream using the passed 
            ' array of encrypted data.
            Dim msDecrypt As New MemoryStream(Data)

            ' Create a CryptoStream using the MemoryStream 
            ' and the passed key and initialization vector (IV).
            Dim csDecrypt As New CryptoStream(msDecrypt, _
                                              New TripleDESCryptoServiceProvider().CreateDecryptor(Key, IV), _
                                              CryptoStreamMode.Read)

            ' Create buffer to hold the decrypted data.
            Dim fromEncrypt(Data.Length - 1) As Byte

            ' Read the decrypted data out of the crypto stream
            ' and place it into the temporary buffer.
            csDecrypt.Read(fromEncrypt, 0, fromEncrypt.Length)

            'Convert the buffer into a string and return it.
            Return New ASCIIEncoding().GetString(fromEncrypt)
        Catch e As CryptographicException
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
            Return Nothing
        End Try
    End Function
End Module

Hinweise

Diese Methode entschlüsselt eine verschlüsselte Nachricht, die mithilfe der CreateEncryptor Überladung mit denselben Parametern erstellt wurde.

Siehe auch

Kryptografische Dienste

Gilt für

TripleDESCryptoServiceProvider.CreateDecryptor Methode

Definition

Überlädt

CreateDecryptor()

Gibt zurück

Hinweise

Gilt für

CreateDecryptor(Byte[], Byte[])

Parameter

Gibt zurück

Ausnahmen

Beispiele

Hinweise

Siehe auch

Gilt für

Zusätzliche Ressourcen