CryptoProvider.BlockSize Propiedad

Definición

Obtiene el tamaño del bloque cifrado, en bytes.Gets the cipher block size, in bytes.

public:
 property int BlockSize { int get(); };
public int BlockSize { get; }
member this.BlockSize : int
Public ReadOnly Property BlockSize As Integer

Valor de propiedad

Int32

Tamaño del bloque cifrado, en bytes.The cipher block size, in bytes. El tamaño de bloque predeterminado para Estándar de cifrado avanzado (AES) es 8.The default block size for Advanced Encryption Standard (AES) is 8.

Ejemplos

En el ejemplo siguiente se muestra cómo utilizar la BlockSize propiedad en la conversión de datos sin cifrar en datos de texto cifrado.The following example shows how to use the BlockSize property in converting clear-text data to encrypted-text data.

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.")

Comentarios

Los clearText cipherText búferes y pasados a Encrypt y Decrypt deben tener n * BlockSize bytes de longitud, donde ' n ' es un entero mayor o igual que 1.The clearText and cipherText buffers passed to Encrypt and Decrypt must be n*BlockSize bytes in length, where 'n' is an integer greater than or equal to 1.

Si CanMergeBlocks es false , los búferes pasados a Encrypt deben tener la misma longitud que los búferes pasados a Decrypt .If CanMergeBlocks is false, buffers passed to Encrypt must be the same length as the buffers passed to Decrypt.

Si CanMergeBlocks es true , los búferes pasados a Encrypt pueden tener una longitud diferente de los búferes pasados a Decrypt (todos los tamaños de búfer deben seguir siendo siempre un múltiplo de BlockSize bytes de longitud).If CanMergeBlocks is true, buffers passed to Encrypt can be a different length from the buffers passed to Decrypt (all buffer sizes must still always be a multiple of BlockSize bytes in length).

Un BlockSize de 1 indica que el cifrado es un cifrado de flujo; un BlockSize de 2 o mayor indica un cifrado de bloques.A BlockSize of 1 indicates that the cipher is a stream cipher; a BlockSize of 2 or greater indicates a block cipher.

Se aplica a