MaskGenerationMethod クラス

.NET Framework クラス ライブラリ リファレンス

MaskGenerationMethod クラス

すべてのマスク ジェネレータ アルゴリズムの派生元となる抽象クラスを表します。

名前空間: System.Security.Cryptography
アセンブリ: mscorlib (mscorlib.dll 内)
構文

Visual Basic (宣言)

<ComVisibleAttribute(True)> _
Public MustInherit Class
 MaskGenerationMethod

Visual Basic (使用法)

Dim instance As MaskGenerationMethod

C#

[ComVisibleAttribute(true)] 
public abstract class MaskGenerationMethod

C++

[ComVisibleAttribute(true)] 
public ref class MaskGenerationMethod abstract

J#

/** @attribute ComVisibleAttribute(true) */ 
public abstract class MaskGenerationMethod

JScript

ComVisibleAttribute(true) 
public abstract class MaskGenerationMethod

解説

MaskGenerationMethod の派生クラスは、OAEP (Optimal Asymmetric Encryption Padding) などのキー交換アルゴリズムで使用されるマスクを計算します。

このクラスは、マスク生成のためだけに、キー交換アルゴリズムの実装によって使用されます。アプリケーション コードでは、このクラスを直接使用しません。

使用例

MaskGenerationMethod クラスから派生させる方法を次のコード例に示します。

Visual Basic

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.

C#

using System;
using System.Security.Cryptography;

namespace Contoso
{
    class MaskGenerator : System.Security.Cryptography.MaskGenerationMethod
    {
        private String HashNameValue;

        // Initialize a mask to encrypt using the SHA1 algorithm.
        public MaskGenerator() 
        {
            HashNameValue = "SHA1";
        }

        // Create a mask with the specified seed.
        override public byte[] GenerateMask(byte[] seed, int
 maskLength)
        {
            HashAlgorithm hash;
            byte[] rgbCounter = new byte[4];
            byte[] targetRgb = new byte[maskLength];
            uint counter = 0;

            for (int inc = 0; inc < targetRgb.Length;
 )
            {
                ConvertIntToByteArray(counter++, ref rgbCounter);
                hash = (HashAlgorithm)
                    CryptoConfig.CreateFromName(HashNameValue);

                byte[] temp = new byte[4 + seed.Length];
                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)
 
                {
                    Buffer.BlockCopy(
                        hash.Hash,
                        0,
                        targetRgb,
                        inc,
                        hash.Hash.Length);
                }
                else
                {
                    Buffer.BlockCopy(
                        hash.Hash,
                        0,
                        targetRgb,
                        inc,
                        targetRgb.Length - inc);
                }
                inc += hash.Hash.Length;
            }
            return targetRgb;
        }

        // Convert the specified integer to the byte array.
        private void ConvertIntToByteArray(
            uint sourceInt,
            ref byte[] targetBytes)
        {
            uint remainder;
            int inc = 0;

            // Clear the array prior to filling it.
            Array.Clear(targetBytes, 0, targetBytes.Length);

            while (sourceInt > 0) 
            {
                remainder = sourceInt % 256;
                targetBytes[3 - inc] = (byte) remainder;
                sourceInt = (sourceInt - remainder)/256;
                inc++;
            }
        }
    }
// This class demonstrates how to create the MaskGenerator class 
// and call its GenerateMask member.
    class MaskGeneratorImpl
    {
      public static void
 Main(string[] args)
      {
          byte[] seed = new byte[] {0x01, 0x02, 0x03, 0x04};
          int length = 16;
          MaskGenerator maskGenerator = new MaskGenerator();
          byte[] mask = maskGenerator.GenerateMask(seed, length);
          Console.WriteLine("Generated the following mask:");
          Console.WriteLine(System.Text.Encoding.ASCII.GetString(mask));

          Console.WriteLine("This sample completed successfully; " +
                "press Enter to exit.");
          Console.ReadLine();
      }
  }
}
//
// This sample produces the following output:
//
// Generated the following mask:
// ?"TFd(?~OtO?
// This sample completed successfully; press Enter to exit.

C++

#using <System.dll>

using namespace System;
using namespace System::Security::Cryptography;

namespace Contoso
{
    ref class MaskGenerator: MaskGenerationMethod
    {
    private:
        String^ hashNameValue;

    public:
        // Initialize a mask to encrypt using the SHA1 algorithm.
        MaskGenerator()
        {
            hashNameValue = "SHA1";
        }

        // Create a mask with the specified seed.
        virtual array<Byte>^ GenerateMask(array<Byte>^ seed, int
 maskLength) override
        {
            HashAlgorithm^ hash;
            array<Byte>^ rgbCounter = gcnew array<Byte>(4);
            array<Byte>^ targetRgb = gcnew array<Byte>(maskLength);
            UInt32 counter = 0;
            for (int inc = 0; inc < targetRgb->Length;
 )
            {
                ConvertIntToByteArray(counter++, rgbCounter);
                hash = (HashAlgorithm^)CryptoConfig::CreateFromName(
                    hashNameValue);
                array<Byte>^ temp = gcnew array<Byte>(
                    4 + seed->Length);
                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)
                {
                    Buffer::BlockCopy(hash->Hash, 0, targetRgb, inc,
                        hash->Hash->Length);
                }
                else
                {
                    Buffer::BlockCopy(hash->Hash, 0, targetRgb, inc,
                        targetRgb->Length - inc);
                }

                inc += hash->Hash->Length;
            }
            return targetRgb;
        }

    private:
        // Convert the specified integer to the byte array.
        void ConvertIntToByteArray(UInt32 source,
            array<Byte>^ targetBytes)
        {
            UInt32 remainder;
            int inc = 0;

            // Clear the array prior to filling it.
            Array::Clear(targetBytes, 0, targetBytes->Length);
            while (source > 0)
            {
                remainder = source % 256;
                targetBytes[ 3 - inc ] = (Byte)remainder;
                source = (source - remainder) / 256;
                inc++;
            }
        }
    };

    // This class demonstrates how to create the MaskGenerator class
 
    // and call its GenerateMask member.
    ref class MaskGeneratorImpl
    {
    public:
        void static Work()
        {
            array<Byte>^ seed = gcnew array<Byte>(4){
                0x01,0x02,0x03,0x04};
            int length = 16;
            MaskGenerator^ maskGenerator = gcnew MaskGenerator;
            array<Byte>^ mask = maskGenerator->GenerateMask(seed,
                length);
            Console::WriteLine("Generated the following mask:");
            Console::WriteLine(System::Text::Encoding::
                ASCII::get()->GetString(mask));
            Console::WriteLine("This sample completed successfully;"
                " press Enter to exit.");
            Console::ReadLine();
        }
    };
}

void main()
{
    Contoso::MaskGeneratorImpl::Work();
}

//
// This sample produces the following output:
//
// Generated the following mask:
// ?"TFd(?~OtO?
// This sample completed successfully; press Enter to exit.

J#

import System.*;
import System.Security.Cryptography.*;

class MaskGenerator extends System.Security.Cryptography.MaskGenerationMethod
{
    private String hashNameValue;

    // Initialize a mask to encrypt using the SHA1 algorithm.
    public MaskGenerator()
    {
        hashNameValue = "SHA1";
    } //MaskGenerator

    // Create a mask with the specified seed.
    public ubyte[] GenerateMask(ubyte seed[], int
 maskLength)
    {
        HashAlgorithm hash;
        ubyte rgbCounter[] = new ubyte[4];
        ubyte targetRgb[] = new ubyte[maskLength];
        int counter = 0;
        for (int inc = 0; inc < targetRgb.get_Length();
 ) {
            ConvertIntToByteArray(counter++, rgbCounter);
            hash = ((HashAlgorithm)CryptoConfig.CreateFromName(hashNameValue));
            ubyte temp[] = new ubyte[4 + seed.get_Length()];
            Buffer.BlockCopy(rgbCounter, 0, temp, 0, 4);
            Buffer.BlockCopy(seed, 0, temp, 4, seed.get_Length());
            hash.ComputeHash(temp);

            if (targetRgb.get_Length() - inc > hash.get_HashSize()
 / 8) {
                Buffer.BlockCopy(hash.get_Hash(), 0, targetRgb, inc, 
                    hash.get_Hash().get_Length());
            }
            else {
                Buffer.BlockCopy(hash.get_Hash(), 0, targetRgb, inc, 
                    targetRgb.get_Length() - inc);
            }
            inc += hash.get_Hash().get_Length();
        }
        return targetRgb;
    } //GenerateMask

    // Convert the specified integer to the byte array.
    private void ConvertIntToByteArray(int
 sourceInt, ubyte targetBytes[])
    {
        int remainder;
        int inc = 0;
        // Clear the array prior to filling it.
        Array.Clear(targetBytes, 0, targetBytes.get_Length());
        while (sourceInt > 0) {
            remainder = sourceInt % 256;
            targetBytes.set_Item((3 - inc), (Int32)remainder);
            sourceInt = (sourceInt - remainder) / 256;
            inc++;
        }
    } //ConvertIntToByteArray
} //MaskGenerator

// This class demonstrates how to create the MaskGenerator class 
// and call its GenerateMask member.
class MaskGeneratorImpl
{
    public static void main(String[]
 args)
    {
        ubyte seed[] = new ubyte[] { 0x1, 0x2, 0x3, 0x4 };
        int length = 16;
        MaskGenerator maskGenerator = new MaskGenerator();
        ubyte mask[] = maskGenerator.GenerateMask(seed, length);
        Console.WriteLine("Generated the following mask:");
        Console.WriteLine(System.Text.Encoding.get_ASCII().GetString(mask));
        Console.WriteLine("This sample completed successfully; " 
            + "press Enter to exit.");
        Console.ReadLine();
    } //main
} //MaskGeneratorImpl
//
// This sample produces the following output:
//
// Generated the following mask:
// ?"TFd(?~OtO?
// This sample completed successfully; press Enter to exit.

継承階層

System.Object
  System.Security.Cryptography.MaskGenerationMethod
     System.Security.Cryptography.PKCS1MaskGenerationMethod

スレッド セーフ

この型の public static (Visual Basic では Shared) メンバはすべて、スレッド セーフです。インスタンス メンバの場合は、スレッド セーフであるとは限りません。

プラットフォーム

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。

バージョン情報

.NET Framework
サポート対象 : 2.0、1.1、1.0

参照

関連項目
MaskGenerationMethod メンバ
System.Security.Cryptography 名前空間