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MaskGenerationMethod Class
Visual Studio 2008
Represents the abstract class from which all mask generator algorithms must derive.
Assembly: mscorlib (in mscorlib.dll)
The following code example demonstrates how to derive from the MaskGenerationMethod class.
Imports System Imports System.Security.Cryptography Public Class MaskGenerator Inherits System.Security.Cryptography.MaskGenerationMethod Private HashNameValue As String ' Initialize a mask to encrypt using the SHA1 algorithm. Public Sub New() HashNameValue = "SHA1" End Sub ' Create a mask with the specified seed. Public Overrides Function GenerateMask( _ ByVal seed() As Byte, _ ByVal maskLength As Integer) As Byte() Dim hash As HashAlgorithm Dim rgbCounter(4) As Byte Dim targetRgb(maskLength) As Byte Dim counter As Integer For inc As Int16 = 0 To targetRgb.Length ConvertIntToByteArray(counter + 1, rgbCounter) hash = CType( _ CryptoConfig.CreateFromName(HashNameValue), _ HashAlgorithm) Dim temp(4 + seed.Length) As Byte Buffer.BlockCopy(rgbCounter, 0, temp, 0, 4) Buffer.BlockCopy(seed, 0, temp, 4, seed.Length) hash.ComputeHash(temp) If (targetRgb.Length - inc > hash.HashSize / 8) Then Buffer.BlockCopy( _ hash.Hash, 0, targetRgb, inc, hash.Hash.Length) Else Buffer.BlockCopy( _ hash.Hash, 0, targetRgb, inc, targetRgb.Length - inc) End If inc += hash.Hash.Length Next Return targetRgb End Function ' Convert the specified integer to the byte array. Private Sub ConvertIntToByteArray( _ ByVal sourceInt As Integer, _ ByRef targetBytes() As Byte) Dim remainder As Integer Dim inc As Int16 = 0 ' Clear the array prior to filling it. Array.Clear(targetBytes, 0, targetBytes.Length) While (sourceInt > 0) remainder = sourceInt Mod 256 targetBytes(3 - inc) = CType(remainder, Byte) sourceInt = (sourceInt - remainder) / 256 inc = inc + 1 End While End Sub End Class Public Class Form1 Inherits System.Windows.Forms.Form ' Event handler for Run button. Private Sub Button1_Click( _ ByVal sender As System.Object, _ ByVal e As System.EventArgs) Handles Button1.Click tbxOutput.Cursor = Cursors.WaitCursor tbxOutput.Text = "" Dim seed() As Byte = {&H1, &H2, &H3, &H4} Dim length As Int16 = 16 Dim maskGenerator As New MaskGenerator Dim mask() As Byte = maskGenerator.GenerateMask(seed, length) tbxOutput.AppendText("Generated the following mask:") tbxOutput.AppendText(System.Text.Encoding.ASCII.GetString(mask)) ' Align interface and conclude application. tbxOutput.AppendText(vbCrLf + "This sample completed" + _ "successfully; press Exit to continue.") tbxOutput.Cursor = Cursors.Default End Sub ' Event handler for Exit button. Private Sub Button2_Click( _ ByVal sender As System.Object, _ ByVal e As System.EventArgs) Handles Button2.Click Application.Exit() End Sub #Region " Windows Form Designer generated code " Public Sub New() MyBase.New() 'This call is required by the Windows Form Designer. InitializeComponent() 'Add any initialization after the InitializeComponent() call End Sub 'Form overrides dispose to clean up the component list. Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean) If disposing Then If Not (components Is Nothing) Then components.Dispose() End If End If MyBase.Dispose(disposing) End Sub 'Required by the Windows Form Designer Private components As System.ComponentModel.IContainer 'NOTE: The following procedure is required by the Windows Form Designer 'It can be modified using the Windows Form Designer. 'Do not modify it using the code editor. Friend WithEvents Panel2 As System.Windows.Forms.Panel Friend WithEvents Panel1 As System.Windows.Forms.Panel Friend WithEvents Button1 As System.Windows.Forms.Button Friend WithEvents Button2 As System.Windows.Forms.Button Friend WithEvents tbxOutput As System.Windows.Forms.RichTextBox <System.Diagnostics.DebuggerStepThrough()> _ Private Sub InitializeComponent() Me.Panel2 = New System.Windows.Forms.Panel Me.Button1 = New System.Windows.Forms.Button Me.Button2 = New System.Windows.Forms.Button Me.Panel1 = New System.Windows.Forms.Panel Me.tbxOutput = New System.Windows.Forms.RichTextBox Me.Panel2.SuspendLayout() Me.Panel1.SuspendLayout() Me.SuspendLayout() ' 'Panel2 ' Me.Panel2.Controls.Add(Me.Button1) Me.Panel2.Controls.Add(Me.Button2) Me.Panel2.Dock = System.Windows.Forms.DockStyle.Bottom Me.Panel2.DockPadding.All = 20 Me.Panel2.Location = New System.Drawing.Point(0, 320) Me.Panel2.Name = "Panel2" Me.Panel2.Size = New System.Drawing.Size(616, 64) Me.Panel2.TabIndex = 1 ' 'Button1 ' Me.Button1.Dock = System.Windows.Forms.DockStyle.Right Me.Button1.Font = New System.Drawing.Font( _ "Microsoft Sans Serif", _ 9.0!, _ System.Drawing.FontStyle.Regular, _ System.Drawing.GraphicsUnit.Point, _ CType(0, Byte)) Me.Button1.Location = New System.Drawing.Point(446, 20) Me.Button1.Name = "Button1" Me.Button1.Size = New System.Drawing.Size(75, 24) Me.Button1.TabIndex = 2 Me.Button1.Text = "&Run" ' 'Button2 ' Me.Button2.Dock = System.Windows.Forms.DockStyle.Right Me.Button2.Font = New System.Drawing.Font( _ "Microsoft Sans Serif", _ 9.0!, _ System.Drawing.FontStyle.Regular, _ System.Drawing.GraphicsUnit.Point, _ CType(0, Byte)) Me.Button2.Location = New System.Drawing.Point(521, 20) Me.Button2.Name = "Button2" Me.Button2.Size = New System.Drawing.Size(75, 24) Me.Button2.TabIndex = 3 Me.Button2.Text = "E&xit" ' 'Panel1 ' Me.Panel1.Controls.Add(Me.tbxOutput) Me.Panel1.Dock = System.Windows.Forms.DockStyle.Fill Me.Panel1.DockPadding.All = 20 Me.Panel1.Location = New System.Drawing.Point(0, 0) Me.Panel1.Name = "Panel1" Me.Panel1.Size = New System.Drawing.Size(616, 320) Me.Panel1.TabIndex = 2 ' 'tbxOutput ' Me.tbxOutput.AccessibleDescription = _ "Displays output from application." Me.tbxOutput.AccessibleName = "Output textbox." Me.tbxOutput.Dock = System.Windows.Forms.DockStyle.Fill Me.tbxOutput.Location = New System.Drawing.Point(20, 20) Me.tbxOutput.Name = "tbxOutput" Me.tbxOutput.Size = New System.Drawing.Size(576, 280) Me.tbxOutput.TabIndex = 1 Me.tbxOutput.Text = "Click the Run button to run the application." ' 'Form1 ' Me.AutoScaleBaseSize = New System.Drawing.Size(6, 15) Me.ClientSize = New System.Drawing.Size(616, 384) Me.Controls.Add(Me.Panel1) Me.Controls.Add(Me.Panel2) Me.Name = "Form1" Me.Text = "MaskGenerationMethod" Me.Panel2.ResumeLayout(False) Me.Panel1.ResumeLayout(False) Me.ResumeLayout(False) End Sub #End Region End Class ' ' This sample produces the following output: ' ' Generated the following mask:~&*(uj98U(*UD989D ' This sample completedsuccessfully; press Exit to continue.
System.Object
System.Security.Cryptography.MaskGenerationMethod
System.Security.Cryptography.PKCS1MaskGenerationMethod
System.Security.Cryptography.MaskGenerationMethod
System.Security.Cryptography.PKCS1MaskGenerationMethod
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
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