SymmetricAlgorithm.LegalBlockSizes Property

Gets the block sizes, in bits, that are supported by the symmetric algorithm.

Namespace:  System.Security.Cryptography
Assembly:  mscorlib (in mscorlib.dll)

'Declaration
Public Overridable ReadOnly Property LegalBlockSizes As KeySizes()

Property Value

Type: System.Security.Cryptography.KeySizes()
An array that contains the block sizes supported by the algorithm.

The symmetric algorithm supports only block sizes that match an entry in this array.

The following example shows the value of LegalBlockSizes for the symmetric algorithms.

Imports System
Imports System.Security.Cryptography


Class Program

    Shared Sub Main(ByVal args() As String)
        Dim aes As New AesManaged()
        Console.WriteLine("AesManaged ")
        Dim ks As KeySizes() = aes.LegalKeySizes
        Dim k As KeySizes
        For Each k In ks
            Console.WriteLine(vbTab + "Legal min key size = " + k.MinSize)
            Console.WriteLine(vbTab + "Legal max key size = " + k.MaxSize)
        Next k
        ks = aes.LegalBlockSizes

        For Each k In ks
            Console.WriteLine(vbTab + "Legal min block size = " + k.MinSize)
            Console.WriteLine(vbTab + "Legal max block size = " + k.MaxSize)
        Next k

        Dim des As New DESCryptoServiceProvider()
        Console.WriteLine("DESCryptoServiceProvider ")
        ks = des.LegalKeySizes

        For Each k In ks
            Console.WriteLine(vbTab + "Legal min key size = " + k.MinSize)
            Console.WriteLine(vbTab + "Legal max key size = " + k.MaxSize)
        Next k
        ks = des.LegalBlockSizes

        For Each k In ks
            Console.WriteLine(vbTab + "Legal min block size = " + k.MinSize)
            Console.WriteLine(vbTab + "Legal max block size = " + k.MaxSize)
        Next k

        Dim rc2 As New RC2CryptoServiceProvider()
        Console.WriteLine("RC2CryptoServiceProvider ")
        ks = rc2.LegalKeySizes

        For Each k In ks
            Console.WriteLine(vbTab + "Legal min key size = " + k.MinSize)
            Console.WriteLine(vbTab + "Legal max key size = " + k.MaxSize)
        Next k
        ks = rc2.LegalBlockSizes

        For Each k In ks
            Console.WriteLine(vbTab + "Legal min block size = " + k.MinSize)
            Console.WriteLine(vbTab + "Legal max block size = " + k.MaxSize)
        Next k

        Dim rij As New RijndaelManaged()
        Console.WriteLine("RijndaelManaged ")
        ks = rij.LegalKeySizes

        For Each k In ks
            Console.WriteLine(vbTab + "Legal min key size = " + k.MinSize)
            Console.WriteLine(vbTab + "Legal max key size = " + k.MaxSize)
        Next k
        ks = rij.LegalBlockSizes

        For Each k In ks
            Console.WriteLine(vbTab + "Legal min block size = " + k.MinSize)
            Console.WriteLine(vbTab + "Legal max block size = " + k.MaxSize)
        Next k

        Dim tsp As New TripleDESCryptoServiceProvider()
        Console.WriteLine("TripleDESCryptoServiceProvider ")
        ks = tsp.LegalKeySizes

        For Each k In ks
            Console.WriteLine(vbTab + "Legal min key size = " + k.MinSize)
            Console.WriteLine(vbTab + "Legal max key size = " + k.MaxSize)
        Next k
        ks = tsp.LegalBlockSizes

        For Each k In ks
            Console.WriteLine(vbTab + "Legal min block size = " + k.MinSize)
            Console.WriteLine(vbTab + "Legal max block size = " + k.MaxSize)
        Next k

    End Sub 'Main 
End Class 'Program
'This sample produces the following output: 
'AesManaged 
'        Legal min key size = 128 
'        Legal max key size = 256 
'        Legal min block size = 128 
'        Legal max block size = 128 
'DESCryptoServiceProvider 
'        Legal min key size = 64 
'        Legal max key size = 64 
'        Legal min block size = 64 
'        Legal max block size = 64 
'RC2CryptoServiceProvider 
'        Legal min key size = 40 
'        Legal max key size = 128 
'        Legal min block size = 64 
'        Legal max block size = 64 
'RijndaelManaged 
'        Legal min key size = 128 
'        Legal max key size = 256 
'        Legal min block size = 128 
'        Legal max block size = 256 
'TripleDESCryptoServiceProvider 
'        Legal min key size = 128 
'        Legal max key size = 192 
'        Legal min block size = 64 
'        Legal max block size = 64

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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