CryptoProvider.Encrypt(Byte[]) Methode

  • Referenz

Definition

Namespace:
System.Security.RightsManagement
Assembly:
WindowsBase.dll

Verschlüsselt Klartext in Verschlüsselungstext.

public:
 cli::array <System::Byte> ^ Encrypt(cli::array <System::Byte> ^ clearText);
public byte[] Encrypt (byte[] clearText);
member this.Encrypt : byte[] -> byte[]
Public Function Encrypt (clearText As Byte()) As Byte()

Parameter

clearText
Byte[]

Der zu verschlüsselnde Klartextinhalt.

Gibt zurück

Byte[]

Der verschlüsselte Verschlüsselungstext des angegebenen clearText.

Ausnahmen

ArgumentNullException

clearText ist NULL.

RightsManagementException

Verschlüsselung ist nicht zulässig.

Beispiele

Das folgende Beispiel zeigt, wie Sie die Encrypt -Methode verwenden, um Klartextdaten in Verschlüsselte Textdaten zu konvertieren.

WriteStatus("   Binding the author's UseLicense and");
WriteStatus("       obtaining the CryptoProvider.");
using (CryptoProvider cryptoProvider =
            authorsUseLicense.Bind(_secureEnv))
{
    WriteStatus("   Writing encrypted content.");
    using (Stream clearTextStream =
                File.OpenRead(contentFile) )
    {
        using (Stream cryptoTextStream =
                    File.OpenWrite(encryptedFile))
        {
            // Write the length of the source content file
            // as the first four bytes of the encrypted file.
            cryptoTextStream.Write(
                BitConverter.GetBytes(clearTextStream.Length),
                0, sizeof(Int32));

            // Allocate clearText buffer.
            byte[] clearTextBlock =
                new byte[cryptoProvider.BlockSize];

            // Encrypt clearText to cryptoText block by block.
            for(;;)
            {   // Read clearText block.
                int readCount = ReliableRead(
                                    clearTextStream,
                                    clearTextBlock, 0 ,
                                    cryptoProvider.BlockSize);
                // readCount of zero is end of data.
                if (readCount == 0)  break; // for

                // Encrypt clearText to cryptoText.
                byte[] cryptoTextBlock =
                    cryptoProvider.Encrypt(clearTextBlock);

                // Write cryptoText block.
                cryptoTextStream.Write(cryptoTextBlock, 0,
                                       cryptoTextBlock.Length);
            }
            WriteStatus("   Closing '" + encryptedFilename + "'.");
        }// end:using (Stream cryptoTextStream =
    }// end:using (Stream clearTextStream =
}// end:using (CryptoProvider cryptoProvider =
WriteStatus("   Done - Content encryption complete.");

WriteStatus("   Binding the author's UseLicense and")
WriteStatus("       obtaining the CryptoProvider.")
Using cryptoProvider As CryptoProvider = authorsUseLicense.Bind(_secureEnv)
    WriteStatus("   Writing encrypted content.")
    Using clearTextStream As Stream = File.OpenRead(contentFile)
        Using cryptoTextStream As Stream = File.OpenWrite(encryptedFile)
            ' Write the length of the source content file
            ' as the first four bytes of the encrypted file.
            Dim expression As Int32
            cryptoTextStream.Write(BitConverter.GetBytes(clearTextStream.Length), 0, Len(expression))

            ' Allocate clearText buffer.
            Dim clearTextBlock(cryptoProvider.BlockSize - 1) As Byte

            ' Encrypt clearText to cryptoText block by block.
            Do
                Dim readCount As Integer = ReliableRead(clearTextStream, clearTextBlock, 0, cryptoProvider.BlockSize)
                ' readCount of zero is end of data.
                If readCount = 0 Then ' for
                    Exit Do
                End If

                ' Encrypt clearText to cryptoText.
                Dim cryptoTextBlock() As Byte = cryptoProvider.Encrypt(clearTextBlock)

                ' Write cryptoText block.
                cryptoTextStream.Write(cryptoTextBlock, 0, cryptoTextBlock.Length)
            Loop
            WriteStatus("   Closing '" & encryptedFilename & "'.")
        End Using ' end:using (Stream cryptoTextStream =
    End Using ' end:using (Stream clearTextStream =
End Using ' end:using (CryptoProvider cryptoProvider =
WriteStatus("   Done - Content encryption complete.")

Hinweise

Die Bytelänge des Puffers clearText sollte ein Vielfaches der Verschlüsselungseigenschaft BlockSize sein.

Das Digitale Rechteverwaltungssystem verwendet AES-Blockchiffre. Bei AES werden Blöcke unabhängig voneinander verschlüsselt, sodass zwei Blöcke identischen Klartext identische Chiffretextergebnisse erzeugen. Um potenzielle Entschlüsselungsrisiken durch die unabhängige Blockverschlüsselung zu minimieren, sollten Anwendungen Methoden zum Ändern von Inhalten wie Komprimierung verwenden, um identische Klartextblöcke zu verschlüsseln.

Gilt für:

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