MACTripleDES-Klasse
Berechnet einen MAC (Message Authentication Code) unter Verwendung von TripleDES für den CryptoStream der Eingabedaten.
Namespace: System.Security.Cryptography
Assembly: mscorlib (in mscorlib.dll)
Syntax
'Declaration
<ComVisibleAttribute(True)> _
Public Class MACTripleDES
Inherits KeyedHashAlgorithm
'Usage
Dim instance As MACTripleDES
[ComVisibleAttribute(true)]
public class MACTripleDES : KeyedHashAlgorithm
[ComVisibleAttribute(true)]
public ref class MACTripleDES : public KeyedHashAlgorithm
/** @attribute ComVisibleAttribute(true) */
public class MACTripleDES extends KeyedHashAlgorithm
ComVisibleAttribute(true)
public class MACTripleDES extends KeyedHashAlgorithm
Hinweise
Mit einem MAC kann bestimmt werden, ob eine über einen unsicheren Channel gesendete Nachricht manipuliert wurde, sofern Absender und Empfänger einen gemeinsamen geheimen Schlüssel besitzen. Der Absender berechnet den MAC für die ursprünglichen Daten und sendet beide zusammen in einer einzelnen Nachricht. Der Empfänger führt eine Neuberechnung des MAC der empfangenen Nachricht durch und überprüft, ob der berechnete MAC dem übermittelten MAC entspricht.
Alle Änderungen an den Daten oder dem MAC führen zu einem abweichenden MAC, da zur Erzeugung eines korrekten MAC für die geänderte Nachricht die Kenntnis des geheimen Schlüssels erforderlich ist. Wenn die Codes identisch sind, ist die Nachricht daher authentifiziert.
MACTripleDES verwendet einen Schlüssel in einer Länge von 16 oder 24 Bytes und erzeugt eine Hashsequenz in einer Länge von 8 Bytes.
Beispiel
Der folgende Abschnitt enthält Codebeispiele. Im ersten Beispiel wird unter Verwendung des TripleDES-Hashalgorithmus der MAC für data berechnet und in result gespeichert. Im zweiten Beispiel wird veranschaulicht, wie jeder Member der MACTripleDES-Klasse verwendet wird.
Beispiel 1
In diesem Beispiel wird davon ausgegangen, dass die vordefinierte Konstante DATA_SIZE vorhanden ist.
Dim data(DATA_SIZE) As Byte
Dim key(24) As Byte
Dim mac3des As New MACTripleDES(key)
Dim result As Byte() = mac3des.ComputeHash(data)
byte[] data = new byte[DATA_SIZE];
byte[] key = new byte[24];
MACTripleDES mac3des = new MACTripleDES(key);
byte[] result = mac3des.ComputeHash(data);
array<Byte>^data = gcnew array<Byte>(DATA_SIZE);
array<Byte>^key = gcnew array<Byte>(24);
MACTripleDES^ mac3des = gcnew MACTripleDES( key );
array<Byte>^result = mac3des->ComputeHash( data );
ubyte data[] = new ubyte[dataSize];
ubyte key[] = new ubyte[24];
MACTripleDES mac3des = new MACTripleDES(key);
ubyte result[] = mac3des.ComputeHash(data);
Beispiel 2
Imports System
Imports System.IO
Imports System.Text
Imports System.Security.Cryptography
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 = ""
EncodeNothing()
EncodeMessage()
EncodeStream()
tbxOutput.AppendText(vbCrLf + "This sample completed " + _
"successfully; press Exit to continue.")
tbxOutput.Cursor = Cursors.Default
End Sub
Private Sub EncodeNothing()
Dim macTriple As New MACTripleDES
macTriple.Initialize()
Dim key(23) As Byte
RandomNumberGenerator.Create().GetBytes(key)
macTriple.Key = key
Dim message(1023) As Byte
macTriple.ComputeHash(message)
SummarizeMAC(macTriple, "MACTripleDES after initialization.")
End Sub
' Compute the hash for a MACTripleDES that has transformed a byte array.
Private Sub EncodeMessage()
Dim keyData(23) As Byte
RandomNumberGenerator.Create().GetBytes(keyData)
Dim macTriple As New MACTripleDES(keyData)
Dim message As String = "Encoding is fun!"
Dim encodedMessage() As Byte
encodedMessage = EncodeBytes(Encoding.ASCII.GetBytes(message))
macTriple.ComputeHash(encodedMessage)
SummarizeMAC(macTriple, "MACTripleDES after encoding a message.")
End Sub
' Transform the byte array using MacTripleDES,
' and then summarize its properties.
Private Function EncodeBytes(ByVal sourceBytes() As Byte)
Dim currentPosition As Int16 = 0
Dim targetBytes(1023) As Byte
Dim sourceByteLength As Int16 = sourceBytes.Length
' Create an encryptor with a random key and the TripleDES
' class name.
Dim key(23) As Byte
RandomNumberGenerator.Create().GetBytes(key)
Dim tripleDesName As String = "System.Security.Cryptography.TripleDES"
Dim macTriple As New MACTripleDES(tripleDesName, key)
' Retrieve the block size to read the bytes.
Dim inputBlockSize As Integer = macTriple.InputBlockSize
Try
' Determine if multiple blocks can be transformed.
If (macTriple.CanTransformMultipleBlocks) Then
Dim numBytesRead As Int16 = 0
While (sourceByteLength - currentPosition >= inputBlockSize)
' Transform the bytes from the currentposition in the
' sourceBytes array, writing the bytes to the
' targetBytes array.
numBytesRead = macTriple.TransformBlock( _
sourceBytes, _
currentPosition, _
inputBlockSize, _
targetBytes, _
currentPosition)
' Advance the current position in the sourceBytes array.
currentPosition += numBytesRead
End While
' Transform the final block of bytes.
Dim finalBytes() As Byte = macTriple.TransformFinalBlock( _
sourceBytes, _
currentPosition, _
sourceByteLength - currentPosition)
' Copy the contents of the finalBytes array to the
' targetBytes array.
finalBytes.CopyTo(targetBytes, currentPosition)
End If
Catch ex As Exception
WriteLine("Caught unexpected exception:" + _
ex.ToString())
End Try
' Determine if the current transform can be reused.
If (Not macTriple.CanReuseTransform) Then
' Free up any used resources.
macTriple.Clear()
End If
' Find the length of valid bytes (those without zeros).
Dim iEnum As System.Collections.IEnumerator
iEnum = targetBytes.GetEnumerator()
Dim i As Int16 = 0
While (iEnum.MoveNext())
If (iEnum.Current.ToString().Equals("0")) Then
Exit While
End If
i = i + 1
End While
' Compute the hash based on the valid bytes in the array.
macTriple.ComputeHash(targetBytes, 0, i)
SummarizeMAC(macTriple, "MACTripleDES after computing the hash " + _
"for the specified region of the byte array.")
' Create a new array with the number of valid bytes.
Dim returnedArray(i) As Byte
For j As Int16 = 0 To i - 1 Step 1
returnedArray(j) = targetBytes(j)
Next j
Return returnedArray
End Function
Private Sub EncodeStream()
Dim keyData(23) As Byte
RandomNumberGenerator.Create().GetBytes(keyData)
Dim macTriple As New MACTripleDES(keyData)
Dim filePath As String
filePath = System.IO.Directory.GetCurrentDirectory() + "\members.txt"
Try
Dim fileStream As New FileStream( _
filePath, _
FileMode.Open, _
FileAccess.Read)
macTriple.ComputeHash(fileStream)
SummarizeMAC(macTriple, _
"MACTripleDES after encoding a file stream.")
Catch ex As Exception
WriteLine("Specified path was not found: " + filePath)
End Try
End Sub
Private Sub SummarizeMAC( _
ByVal macTriple As MACTripleDES, _
ByVal description As String)
Dim classDescription As String = macTriple.ToString()
Dim computedHash() As Byte = macTriple.Hash
Dim hashSize As Integer = macTriple.HashSize
Dim outputBlockSize As Integer = macTriple.OutputBlockSize
' Retrieve the key used in the hash algorithm.
Dim key() As Byte = macTriple.Key
WriteLine(vbCrLf + "**********************************")
WriteLine(classDescription)
WriteLine(description)
WriteLine("----------------------------------")
WriteLine("The size of the computed hash : " + hashSize.ToString())
WriteLine("The key used in the hash algorithm : " + _
Encoding.ASCII.GetString(key))
WriteLine("The value of the computed hash : " + _
Encoding.ASCII.GetString(computedHash))
End Sub
' Write the specified message and carriage return to the output textbox.
Private Sub WriteLine(ByVal message As String)
tbxOutput.AppendText(message + vbCrLf)
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 = "MACTripleDES"
Me.Panel2.ResumeLayout(False)
Me.Panel1.ResumeLayout(False)
Me.ResumeLayout(False)
End Sub
#End Region
End Class
using System;
using System.IO;
using System.Text;
using System.Collections;
using System.Security.Cryptography;
namespace csMACTripleDES
{
class Class1
{
[STAThread]
static void Main(string[] args)
{
EncodeNothing();
EncodeMessage();
EncodeStream();
Console.WriteLine("This sample completed successfully; " +
"press Enter to exit.");
Console.ReadLine();
}
// Compute the hash for an empty array; summarize the properties.
private static void EncodeNothing()
{
MACTripleDES macTriple = new MACTripleDES();
macTriple.Initialize();
byte[] key = new byte[24];
RandomNumberGenerator.Create().GetBytes(key);
macTriple.Key = key;
macTriple.ComputeHash(new byte[1024]);
SummarizeMAC(macTriple, "MACTripleDES after initialization.");
}
// Compute the hash for a MACTripleDES that has transformed a
// file stream.
private static void EncodeStream()
{
byte[] keyData = new byte[24];
RandomNumberGenerator.Create().GetBytes(keyData);
MACTripleDES macTriple = new MACTripleDES(keyData);
string filePath = (System.IO.Directory.GetCurrentDirectory() +
"\\members.txt");
try
{
FileStream fileStream =
new FileStream(filePath, FileMode.Open, FileAccess.Read);
macTriple.ComputeHash(fileStream);
SummarizeMAC(macTriple,
"MACTripleDES after encoding a file stream.");
}
catch (FileNotFoundException ex)
{
Console.WriteLine("Specified path was not found: "
+ filePath);
}
}
// Compute the hash for a MACTripleDES that has transformed a
// byte array.
private static void EncodeMessage()
{
byte[] keyData = new byte[24];
RandomNumberGenerator.Create().GetBytes(keyData);
MACTripleDES macTriple = new MACTripleDES(keyData);
string message = "Encoding is fun!";
byte[] encodedMessage =
EncodeBytes(Encoding.ASCII.GetBytes(message));
macTriple.ComputeHash(encodedMessage);
SummarizeMAC(macTriple, "MACTripleDES after encoding a message.");
}
// Transform the byte array using MacTripleDES,
// and then summarize its properties.
private static byte[] EncodeBytes(byte[] sourceBytes)
{
int currentPosition = 0;
byte[] targetBytes = new byte[1024];
int sourceByteLength = sourceBytes.Length;
// Create an encryptor with a random key and the TripleDES
// class name.
byte[] key = new byte[24];
RandomNumberGenerator.Create().GetBytes(key);
string tripleDesName = "System.Security.Cryptography.TripleDES";
MACTripleDES macTriple = new MACTripleDES(tripleDesName, key);
// Retrieve the block size to read the bytes.
int inputBlockSize = macTriple.InputBlockSize;
try
{
// Determine if multiple blocks can be transformed.
if (macTriple.CanTransformMultipleBlocks)
{
int numBytesRead = 0;
while (
sourceByteLength - currentPosition >= inputBlockSize)
{
// Transform the bytes from the currentposition in the
// sourceBytes array, writing the bytes to the
// targetBytes array.
numBytesRead = macTriple.TransformBlock(
sourceBytes,
currentPosition,
inputBlockSize,
targetBytes,
currentPosition);
// Advance the current position in the
// sourceBytes array.
currentPosition += numBytesRead;
}
// Transform the final block of bytes.
byte[] finalBytes = macTriple.TransformFinalBlock(
sourceBytes,
currentPosition,
sourceByteLength - currentPosition);
// Copy the contents of the finalBytes array to the
// targetBytes array.
finalBytes.CopyTo(targetBytes,currentPosition);
}
}
catch(Exception ex)
{
Console.WriteLine("Caught unexpected exception:" +
ex.ToString());
}
// Determine if the current transform can be reused.
if (!macTriple.CanReuseTransform)
{
// Free up any used resources.
macTriple.Clear();
}
// Find the length of valid bytes (those without zeros).
IEnumerator enum1 = targetBytes.GetEnumerator();
int i = 0;
while (enum1.MoveNext())
{
if (enum1.Current.ToString().Equals("0"))
{
break;
}
i++;
}
// Compute the hash based on the valid bytes in the array.
macTriple.ComputeHash(targetBytes,0,i);
SummarizeMAC(macTriple, "MACTripleDES after computing the hash " +
"for the specified region of the byte array.");
// Create a new array with the number of valid bytes.
byte[] returnedArray = new byte[i];
for (int j=0; j<i; j++)
{
returnedArray[j] = targetBytes[j];
}
return returnedArray;
}
// Write a summary of the specified MACTripleDES to the console.
private static void SummarizeMAC(
MACTripleDES macTriple,
string description)
{
string classDescription = macTriple.ToString();
byte[] computedHash = macTriple.Hash;
int hashSize = macTriple.HashSize;
int outputBlockSize = macTriple.OutputBlockSize;
// Retrieve the key used in the hash algorithm.
byte[] key = macTriple.Key;
Console.WriteLine("\n**********************************");
Console.WriteLine(classDescription);
Console.WriteLine(description);
Console.WriteLine("----------------------------------");
Console.WriteLine("The size of the computed hash : " + hashSize);
Console.WriteLine("The key used in the hash algorithm : " +
Encoding.ASCII.GetString(key));
Console.WriteLine("The value of the computed hash : " +
Encoding.ASCII.GetString(computedHash));
}
}
}
using namespace System;
using namespace System::IO;
using namespace System::Text;
using namespace System::Collections;
using namespace System::Security::Cryptography;
namespace CryptographySample
{
ref class DESSample
{
public:
static void TestDES();
private:
static void EncodeNothing();
static void EncodeStream();
static void EncodeMessage();
static array<Byte>^ EncodeBytes(array<Byte>^ sourceBytes);
static void SummarizeMAC(MACTripleDES^ macTriple,
String^ description);
};
void DESSample::TestDES()
{
EncodeNothing();
EncodeMessage();
EncodeStream();
Console::WriteLine("This sample completed successfully; "
"press Enter to exit.");
Console::ReadLine();
}
// Compute the hash for an empty array; summarize the properties.
void DESSample::EncodeNothing()
{
MACTripleDES^ macTriple = gcnew MACTripleDES;
macTriple->Initialize();
array<Byte>^ key = gcnew array<Byte>(24);
RandomNumberGenerator::Create()->GetBytes(key);
macTriple->Key = key;
macTriple->ComputeHash(gcnew array<Byte>(1024));
SummarizeMAC(macTriple, "MACTripleDES after initialization.");
}
// Compute the hash for a MACTripleDES that has transformed a
// file stream.
void DESSample::EncodeStream()
{
array<Byte>^ keyData = gcnew array<Byte>(24);
RandomNumberGenerator::Create()->GetBytes(keyData);
MACTripleDES^ macTriple = gcnew MACTripleDES(keyData);
String^ filePath = (String::Concat(
System::IO::Directory::GetCurrentDirectory(),
"\\members.txt"));
try
{
FileStream fileStream(filePath,
FileMode::Open, FileAccess::Read);
macTriple->ComputeHash(%fileStream);
SummarizeMAC(macTriple,
"MACTripleDES after encoding a file stream.");
}
catch (FileNotFoundException^ ex)
{
Console::WriteLine("Specified path was not found: {0}",
filePath);
__assume(ex);
}
}
// Compute the hash for a MACTripleDES that has transformed a
// byte array.
void DESSample::EncodeMessage()
{
Encoding^ encodingASCII = Encoding::ASCII;
array<Byte>^ keyData = gcnew array<Byte>(24);
RandomNumberGenerator::Create()->GetBytes(keyData);
MACTripleDES^ macTriple = gcnew MACTripleDES(keyData);
String^ message = "Encoding is fun!";
array<Byte>^ encodedMessage = EncodeBytes(
encodingASCII->GetBytes(message));
macTriple->ComputeHash(encodedMessage);
SummarizeMAC(macTriple,
"MACTripleDES after encoding a message.");
}
// Transform the byte array using MacTripleDES,
// and then summarize its properties.
array<Byte>^ DESSample::EncodeBytes(array<Byte>^ sourceBytes)
{
int currentPosition = 0;
array<Byte>^ targetBytes = gcnew array<Byte>(1024);
int sourceByteLength = sourceBytes->Length;
// Create an encryptor with a random key and the TripleDES
// class name.
array<Byte>^ key = gcnew array<Byte>(24);
RandomNumberGenerator::Create()->GetBytes(key);
String^ tripleName = "System.Security.Cryptography.TripleDES";
MACTripleDES^ macTriple = gcnew MACTripleDES(tripleName, key);
// Retrieve the block size to read the bytes.
int inputBlockSize = macTriple->InputBlockSize;
try
{
// Determine if multiple blocks can be transformed.
if (macTriple->CanTransformMultipleBlocks)
{
int bytesRead = 0;
while (sourceByteLength - currentPosition >=
inputBlockSize)
{
// Transform the bytes from the currentposition in
// the sourceBytes array, writing the bytes to the
// targetBytes array.
bytesRead =
macTriple->TransformBlock(sourceBytes,
currentPosition, inputBlockSize, targetBytes,
currentPosition);
// Advance the current position in the
// sourceBytes array.
currentPosition += bytesRead;
}
// Transform the final block of bytes.
array<Byte>^ finalBytes =
macTriple->TransformFinalBlock(sourceBytes,
currentPosition, sourceByteLength -
currentPosition);
// Copy the contents of the finalBytes array to the
// targetBytes array.
finalBytes->CopyTo(targetBytes, currentPosition);
}
}
catch (ArgumentException^ ex)
{
Console::WriteLine("Caught unexpected exception:{0}", ex);
}
// Determine if the current transform can be reused.
if (!macTriple->CanReuseTransform)
{
// Free up any used resources.
macTriple->Clear();
}
// Find the length of valid bytes (those without zeros).
int i = 0;
for each (Byte byte in targetBytes)
{
if (byte == 0)
break;
i++;
}
// Compute the hash based on the valid bytes in the array.
macTriple->ComputeHash(targetBytes, 0, i);
SummarizeMAC(macTriple, "MACTripleDES after computing "
"the hash for the specified region of the byte array.");
// Create a new array with the number of valid bytes.
array<Byte>^ returnedArray = gcnew array<Byte>(i);
Array::Copy(targetBytes, returnedArray, i);
return returnedArray;
}
// Write a summary of the specified MACTripleDES to the console.
void DESSample::SummarizeMAC(MACTripleDES^ macTriple,
String^ description)
{
Encoding^ encASCIIEncoding = Encoding::ASCII;
String^ classDescription = macTriple->ToString();
array<Byte>^ computedHash = macTriple->Hash;
int hashSize = macTriple->HashSize;
int outputBlockSize = macTriple->OutputBlockSize;
// Retrieve the key used in the hash algorithm.
array<Byte>^ key = macTriple->Key;
Console::WriteLine("\n**********************************");
Console::WriteLine(classDescription);
Console::WriteLine(description);
Console::WriteLine("----------------------------------");
Console::WriteLine("The size of the computed hash : {0}",
hashSize);
Console::WriteLine("The key used in the hash algorithm : {0}",
encASCIIEncoding->GetString(key));
Console::WriteLine("The value of the computed hash : {0}",
encASCIIEncoding->GetString(computedHash));
}
}
using namespace CryptographySample;
int main()
{
DESSample::TestDES();
}
//
// This sample produces the following output:
//
// **********************************
// System.Security.Cryptography.MACTripleDES
// MACTripleDES after initialization.
// ----------------------------------
// The size of the computed hash : 64
// The key used in the hash algorithm : +Lnf>j%?4?7?V???K?Jv_AcB
// The value of the computed hash : YH>|*DX;
//
// **********************************
// System.Security.Cryptography.MACTripleDES
// MACTripleDES after computing the hash for the specified region
// of the byte array.
// ----------------------------------
// The size of the computed hash : 64
// The key used in the hash algorithm : >
// -?h?v?tF*r`f%V?t`.jS50
// The value of the computed hash : :?9q1$b?
//
// **********************************
// System.Security.Cryptography.MACTripleDES
// MACTripleDES after encoding a message.
// ----------------------------------
// The size of the computed hash : 64
// The key used in the hash algorithm : ?rK>~6>?xy-R? r7s,_kCP{}
// The value of the computed hash : bG?*UO?S
//
// **********************************
// System.Security.Cryptography.MACTripleDES
// MACTripleDES after encoding a file stream.
// ----------------------------------
// The size of the computed hash : 64
// Yv)???rTY?}?T?/\FOI?D$sh algorithm :
// The value of the computed hash : K??T]QgN
// This sample completed successfully; press Enter to exit.
import System.*;
import System.IO.*;
import System.Text.*;
import System.Collections.*;
import System.Security.Cryptography.*;
class Class1
{
/** @attribute STAThread()
*/
public static void main(String[] args)
{
EncodeNothing();
EncodeMessage();
EncodeStream();
Console.WriteLine("This sample completed successfully; "
+ "press Enter to exit.");
Console.ReadLine();
} //main
// Compute the hash for an empty array; summarize the properties.
private static void EncodeNothing()
{
MACTripleDES macTriple = new MACTripleDES();
macTriple.Initialize();
ubyte key[] = new ubyte[24];
RandomNumberGenerator.Create().GetBytes(key);
macTriple.set_Key(key);
macTriple.ComputeHash(new ubyte[1024]);
SummarizeMAC(macTriple, "MACTripleDES after initialization.");
} //EncodeNothing
// Compute the hash for a MACTripleDES that has transformed a
// file stream.
private static void EncodeStream()
{
ubyte keyData[] = new ubyte[24];
RandomNumberGenerator.Create().GetBytes(keyData);
MACTripleDES macTriple = new MACTripleDES(keyData);
String filePath = System.IO.Directory.GetCurrentDirectory()
+ "\\members.txt";
try {
FileStream fileStream = new FileStream(filePath, FileMode.Open,
FileAccess.Read);
macTriple.ComputeHash(fileStream);
SummarizeMAC(macTriple,
"MACTripleDES after encoding a file stream.");
}
catch (FileNotFoundException ex) {
Console.WriteLine("Specified path was not found: " + filePath);
}
} //EncodeStream
// Compute the hash for a MACTripleDES that has transformed a
// byte array.
private static void EncodeMessage()
{
ubyte keyData[] = new ubyte[24];
RandomNumberGenerator.Create().GetBytes(keyData);
MACTripleDES macTriple = new MACTripleDES(keyData);
String message = "Encoding is fun!";
ubyte encodedMessage[] = EncodeBytes(Encoding.get_ASCII().
GetBytes(message));
macTriple.ComputeHash(encodedMessage);
SummarizeMAC(macTriple, "MACTripleDES after encoding a message.");
} //EncodeMessage
// Transform the byte array using MacTripleDES,
// and then summarize its properties.
private static ubyte[] EncodeBytes(ubyte sourceBytes[])
{
int currentPosition = 0;
ubyte targetBytes[] = new ubyte[1024];
int sourceByteLength = sourceBytes.get_Length();
// Create an encryptor with a random key and the TripleDES
// class name.
ubyte key[] = new ubyte[24];
RandomNumberGenerator.Create().GetBytes(key);
String tripleDesName = "System.Security.Cryptography.TripleDES";
MACTripleDES macTriple = new MACTripleDES(tripleDesName, key);
// Retrieve the block size to read the bytes.
int inputBlockSize = macTriple.get_InputBlockSize();
try {
// Determine if multiple blocks can be transformed.
if (macTriple.get_CanTransformMultipleBlocks()) {
int numBytesRead = 0;
while (sourceByteLength - currentPosition >= inputBlockSize) {
// Transform the bytes from the currentposition in the
// sourceBytes array, writing the bytes to the
// targetBytes array.
numBytesRead = macTriple.TransformBlock(sourceBytes,
currentPosition, inputBlockSize, targetBytes,
currentPosition);
// Advance the current position in the
// sourceBytes array.
currentPosition += numBytesRead;
}
// Transform the final block of bytes.
ubyte finalBytes[] = macTriple.TransformFinalBlock(sourceBytes,
currentPosition, sourceByteLength - currentPosition);
// Copy the contents of the finalBytes array to the
// targetBytes array.
finalBytes.CopyTo(targetBytes, currentPosition);
}
}
catch (System.Exception ex) {
Console.WriteLine("Caught unexpected exception:" + ex.ToString());
}
// Determine if the current transform can be reused.
if (!(macTriple.get_CanReuseTransform())) {
// Free up any used resources.
macTriple.Clear();
}
// Find the length of valid bytes (those without zeros).
IEnumerator enum1 = targetBytes.GetEnumerator();
int i = 0;
while (enum1.MoveNext()) {
if (enum1.get_Current().ToString().Equals("0")) {
break;
}
i++;
}
// Compute the hash based on the valid bytes in the array.
macTriple.ComputeHash(targetBytes, 0, i);
SummarizeMAC(macTriple, "MACTripleDES after computing the hash "
+ "for the specified region of the byte array.");
// Create a new array with the number of valid bytes.
ubyte returnedArray[] = new ubyte[i];
for (int j = 0; j < i; j++) {
returnedArray.set_Item(j, targetBytes.get_Item(j));
}
return returnedArray;
} //EncodeBytes
// Write a summary of the specified MACTripleDES to the console.
private static void SummarizeMAC(MACTripleDES macTriple,
String description)
{
String classDescription = macTriple.ToString();
ubyte computedHash[] = macTriple.get_Hash();
int hashSize = macTriple.get_HashSize();
int outputBlockSize = macTriple.get_OutputBlockSize();
// Retrieve the key used in the hash algorithm.
ubyte key[] = macTriple.get_Key();
Console.WriteLine("\n**********************************");
Console.WriteLine(classDescription);
Console.WriteLine(description);
Console.WriteLine("----------------------------------");
Console.WriteLine("The size of the computed hash : " + hashSize);
Console.WriteLine("The key used in the hash algorithm : "
+ Encoding.get_ASCII().GetString(key));
Console.WriteLine("The value of the computed hash : "
+ Encoding.get_ASCII().GetString(computedHash));
} //SummarizeMAC
} //Class1
Vererbungshierarchie
System.Object
System.Security.Cryptography.HashAlgorithm
System.Security.Cryptography.KeyedHashAlgorithm
System.Security.Cryptography.MACTripleDES
Threadsicherheit
Alle öffentlichen statischen (Shared in Visual Basic) Member dieses Typs sind threadsicher. Bei Instanzmembern ist die Threadsicherheit nicht gewährleistet.
Plattformen
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
.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.
Versionsinformationen
.NET Framework
Unterstützt in: 2.0, 1.1, 1.0