CryptoAPITransform Class
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Performs a cryptographic transformation of data. This class cannot be inherited.
public ref class CryptoAPITransform sealed : System::Security::Cryptography::ICryptoTransformpublic sealed class CryptoAPITransform : System.Security.Cryptography.ICryptoTransform[System.Runtime.InteropServices.ComVisible(true)]
public sealed class CryptoAPITransform : System.Security.Cryptography.ICryptoTransformtype CryptoAPITransform = class
interface ICryptoTransform
interface IDisposable[<System.Runtime.InteropServices.ComVisible(true)>]
type CryptoAPITransform = class
interface ICryptoTransform
interface IDisposablePublic NotInheritable Class CryptoAPITransform
Implements ICryptoTransform- Inheritance
-
CryptoAPITransform
- Attributes
- Implements
Examples
The following code example demonstrates how to use members of the CryptoAPITransform class.
using namespace System;
using namespace System::Security::Cryptography;
using namespace System::Collections;
using namespace System::Text;
ref class Members
{
private:
// Use a public service provider for encryption and decryption.
static DESCryptoServiceProvider^ des = gcnew DESCryptoServiceProvider;
public:
[STAThread]
static void Main()
{
String^ message = L"012345678901234567890";
array<Byte>^sourceBytes = Encoding::ASCII->GetBytes( message );
Console::WriteLine( L"** Phrase to be encoded: {0}", message );
array<Byte>^encodedBytes = EncodeBytes( sourceBytes );
Console::WriteLine( L"** Phrase after encoding: {0}",
Encoding::ASCII->GetString( encodedBytes ) );
array<Byte>^decodedBytes = DecodeBytes( encodedBytes );
Console::WriteLine( L"** Phrase after decoding: {0}",
Encoding::ASCII->GetString( decodedBytes ) );
Console::WriteLine( L"Sample ended successfully; "
L"press Enter to continue." );
Console::ReadLine();
}
private:
// Encode the specified byte array by using CryptoAPITranform.
static array<Byte>^ EncodeBytes( array<Byte>^sourceBytes )
{
int currentPosition = 0;
array<Byte>^targetBytes = gcnew array<Byte>(1024);
int sourceByteLength = sourceBytes->Length;
// Create a DES encryptor from this instance to perform encryption.
CryptoAPITransform^ cryptoTransform =
static_cast<CryptoAPITransform^>(des->CreateEncryptor());
// Retrieve the block size to read the bytes.
int inputBlockSize = cryptoTransform->InputBlockSize;
// Retrieve the key handle.
IntPtr keyHandle = cryptoTransform->KeyHandle;
// Retrieve the block size to write the bytes.
int outputBlockSize = cryptoTransform->OutputBlockSize;
try
{
// Determine if multiple blocks can be transformed.
if ( cryptoTransform->CanTransformMultipleBlocks )
{
int numBytesRead = 0;
while ( sourceByteLength - currentPosition >= inputBlockSize )
{
// Transform the bytes from currentPosition in the
// sourceBytes array, writing the bytes to the targetBytes
// array.
numBytesRead = cryptoTransform->TransformBlock(
sourceBytes, currentPosition, inputBlockSize,
targetBytes, currentPosition );
// Advance the current position in the sourceBytes array.
currentPosition += numBytesRead;
}
// Transform the final block of bytes.
array<Byte>^finalBytes = cryptoTransform->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( L"Caught unexpected exception:{0}", ex );
}
// Determine if the current transform can be reused.
if ( !cryptoTransform->CanReuseTransform )
{
// Free up any used resources.
cryptoTransform->Clear();
}
// Trim the extra bytes in the array that were not used.
return TrimArray( targetBytes );
}
// Decode the specified byte array using CryptoAPITranform.
static array<Byte>^ DecodeBytes( array<Byte>^sourceBytes )
{
array<Byte>^targetBytes = gcnew array<Byte>(1024);
int currentPosition = 0;
// Create a DES decryptor from this instance to perform decryption.
CryptoAPITransform^ cryptoTransform =
static_cast<CryptoAPITransform^>(des->CreateDecryptor());
int inputBlockSize = cryptoTransform->InputBlockSize;
int sourceByteLength = sourceBytes->Length;
try
{
int numBytesRead = 0;
while ( sourceByteLength - currentPosition >= inputBlockSize )
{
// Transform the bytes from currentposition in the
// sourceBytes array, writing the bytes to the targetBytes
// array.
numBytesRead = cryptoTransform->TransformBlock(
sourceBytes, currentPosition, inputBlockSize,
targetBytes, currentPosition );
// Advance the current position in the source array.
currentPosition += numBytesRead;
}
// Transform the final block of bytes.
array<Byte>^finalBytes = cryptoTransform->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( L"Caught unexpected exception:{0}", ex );
}
// Strip out the second block of bytes.
Array::Copy(targetBytes, (inputBlockSize * 2), targetBytes, inputBlockSize, targetBytes->Length - (inputBlockSize * 2));
// Trim the extra bytes in the array that were not used.
return TrimArray( targetBytes );
}
// Resize the dimensions of the array to a size that contains only valid
// bytes.
static array<Byte>^ TrimArray( array<Byte>^targetArray )
{
IEnumerator^ enum1 = targetArray->GetEnumerator();
int i = 0;
while ( enum1->MoveNext() )
{
if ( enum1->Current->ToString()->Equals( L"0" ) )
{
break;
}
i++;
}
// Create a new array with the number of valid bytes.
array<Byte>^returnedArray = gcnew array<Byte>(i);
for ( int j = 0; j < i; j++ )
{
returnedArray[ j ] = targetArray[ j ];
}
return returnedArray;
}
};
int main()
{
Members::Main();
}
//
// This sample produces the following output:
//
// ** Phrase to be encoded: 012345678901234567890
// ** Phrase after encoding: AIGC(+b7X?^djAU?15ve?o
// ** Phrase after decoding: 012345678901234567890
// Sample ended successfully; press Enter to continue.
using System;
using System.Security.Cryptography;
using System.Collections;
using System.Text;
class Members
{
// Use a public service provider for encryption and decryption.
static DESCryptoServiceProvider des = new DESCryptoServiceProvider();
[STAThread]
static void Main(string[] args)
{
string message = "012345678901234567890";
byte[] sourceBytes = Encoding.ASCII.GetBytes(message);
Console.WriteLine("** Phrase to be encoded: " + message);
byte[] encodedBytes = EncodeBytes(sourceBytes);
Console.WriteLine("** Phrase after encoding: " +
Encoding.ASCII.GetString(encodedBytes));
byte[] decodedBytes = DecodeBytes(encodedBytes);
Console.WriteLine("** Phrase after decoding: " +
Encoding.ASCII.GetString(decodedBytes));
Console.WriteLine("Sample ended successfully; " +
"press Enter to continue.");
Console.ReadLine();
}
// Encode the specified byte array by using CryptoAPITranform.
private static byte[] EncodeBytes(byte[] sourceBytes)
{
int currentPosition = 0;
byte[] targetBytes = new byte[1024];
int sourceByteLength = sourceBytes.Length;
// Create a DES encryptor from this instance to perform encryption.
CryptoAPITransform cryptoTransform =
(CryptoAPITransform)des.CreateEncryptor();
// Retrieve the block size to read the bytes.
int inputBlockSize = cryptoTransform.InputBlockSize;
// Retrieve the key handle.
IntPtr keyHandle = cryptoTransform.KeyHandle;
// Retrieve the block size to write the bytes.
int outputBlockSize = cryptoTransform.OutputBlockSize;
try
{
// Determine if multiple blocks can be transformed.
if (cryptoTransform.CanTransformMultipleBlocks)
{
int numBytesRead = 0;
while (sourceByteLength - currentPosition >= inputBlockSize)
{
// Transform the bytes from currentPosition in the
// sourceBytes array, writing the bytes to the targetBytes
// array.
numBytesRead = cryptoTransform.TransformBlock(
sourceBytes,
currentPosition,
inputBlockSize,
targetBytes,
currentPosition);
// Advance the current position in the sourceBytes array.
currentPosition += numBytesRead;
}
// Transform the final block of bytes.
byte[] finalBytes = cryptoTransform.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 (!cryptoTransform.CanReuseTransform)
{
// Free up any used resources.
cryptoTransform.Clear();
}
// Trim the extra bytes in the array that were not used.
return TrimArray(targetBytes);
}
// Decode the specified byte array using CryptoAPITranform.
private static byte[] DecodeBytes(byte[] sourceBytes)
{
byte[] targetBytes = new byte[1024];
int currentPosition = 0;
// Create a DES decryptor from this instance to perform decryption.
CryptoAPITransform cryptoTransform =
(CryptoAPITransform)des.CreateDecryptor();
int inputBlockSize = cryptoTransform.InputBlockSize;
int sourceByteLength = sourceBytes.Length;
try
{
int numBytesRead = 0;
while (sourceByteLength - currentPosition >= inputBlockSize)
{
// Transform the bytes from current position in the
// sourceBytes array, writing the bytes to the targetBytes
// array.
numBytesRead = cryptoTransform.TransformBlock(
sourceBytes,
currentPosition,
inputBlockSize,
targetBytes,
currentPosition);
// Advance the current position in the source array.
currentPosition += numBytesRead;
}
// Transform the final block of bytes.
byte[] finalBytes = cryptoTransform.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());
}
// Strip out the second block of bytes.
Array.Copy(targetBytes, (inputBlockSize * 2), targetBytes, inputBlockSize, targetBytes.Length - (inputBlockSize * 2));
// Trim the extra bytes in the array that were not used.
return TrimArray(targetBytes);
}
// Resize the dimensions of the array to a size that contains only valid
// bytes.
private static byte[] TrimArray(byte[] targetArray)
{
IEnumerator enum1 = targetArray.GetEnumerator();
int i = 0;
while (enum1.MoveNext())
{
if (enum1.Current.ToString().Equals("0"))
{
break;
}
i++;
}
// Create a new array with the number of valid bytes.
byte[] returnedArray = new byte[i];
for (int j = 0; j < i; j++)
{
returnedArray[j] = targetArray[j];
}
return returnedArray;
}
}
//
// This sample produces the following output:
//
// ** Phrase to be encoded: 012345678901234567890
// ** Phrase after encoding: AIGC(+b7X?^djAU?15ve?o
// ** Phrase after decoding: 012345678901234567890
// Sample ended successfully; press Enter to continue.
Imports System.Security.Cryptography
Imports System.Collections
Imports System.Text
Public Class Form1
Inherits System.Windows.Forms.Form
' Use a public service provider for encryption and decryption.
Dim desCSP As New DESCryptoServiceProvider
' 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 message As String = "01234567890123456789"
Dim sourceBytes() As Byte = Encoding.ASCII.GetBytes(message)
tbxOutput.AppendText("** Phrase to be encoded: " + message + vbCrLf)
Dim encodedBytes() As Byte = EncodeBytes(sourceBytes)
tbxOutput.AppendText("** Phrase after encoding: " + _
Encoding.ASCII.GetString(encodedBytes) + vbCrLf)
Dim decodedBytes() As Byte = DecodeBytes(encodedBytes)
tbxOutput.AppendText("** Phrase after decoding: " + _
Encoding.ASCII.GetString(decodedBytes) + vbCrLf)
tbxOutput.AppendText(vbCrLf + "Sample ended successfully; " + _
"press Enter to continue.")
tbxOutput.Cursor = Cursors.Default
End Sub
' Encode the specified byte array by using CryptoAPITranform.
Private Function EncodeBytes(ByVal sourceBytes() As Byte) As Byte()
Dim currentPosition As Int16 = 0
Dim targetBytes(1024) As Byte
Dim sourceByteLength As Integer = sourceBytes.Length
' Create a DES encryptor from this instance to perform encryption.
Dim cryptoTransform As CryptoAPITransform
cryptoTransform = CType(desCSP.CreateEncryptor(), CryptoAPITransform)
' Retrieve the block size to read the bytes.
Dim inputBlockSize As Integer = cryptoTransform.InputBlockSize
' Retrieve the key handle.
Dim keyHandle As IntPtr = cryptoTransform.KeyHandle
' Retrieve the block size to write the bytes.
Dim outputBlockSize As Integer = cryptoTransform.OutputBlockSize
Try
' Determine if multiple blocks can be transformed.
If (cryptoTransform.CanTransformMultipleBlocks) Then
Dim numBytesRead As Int16 = 0
While (sourceByteLength - currentPosition >= inputBlockSize)
' Transform the bytes from currentposition in the
' sourceBytes array, writing the bytes to the targetBytes
' array.
numBytesRead = cryptoTransform.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
finalBytes = cryptoTransform.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
tbxOutput.AppendText("Caught unexpected exception:" + _
ex.ToString() + vbCrLf)
End Try
' Determine if the current transform can be reused.
If (Not cryptoTransform.CanReuseTransform) Then
' Free up any used resources.
cryptoTransform.Clear()
End If
' Trim the extra bytes in the array that were not used.
Return TrimArray(targetBytes)
End Function
' Decode the specified byte array using CryptoAPITranform.
Private Function DecodeBytes(ByVal sourceBytes() As Byte) As Byte()
Dim currentPosition As Int16 = 0
Dim targetBytes(1024) As Byte
Dim sourceByteLength As Integer = sourceBytes.Length
' Create a DES decryptor from this instance to perform decryption.
Dim cryptoTransform As CryptoAPITransform
cryptoTransform = CType(desCSP.CreateDecryptor(), CryptoAPITransform)
Dim inputBlockSize As Integer = cryptoTransform.InputBlockSize
Try
' Determine if multiple blocks can be transformed.
If (cryptoTransform.CanTransformMultipleBlocks) Then
Dim numBytesRead As Int16 = 0
While (sourceByteLength - currentPosition >= inputBlockSize)
' Transform the bytes from currentPosition in the
' sourceBytes array, writing the bytes to the targetBytes
' array.
numBytesRead = cryptoTransform.TransformBlock( _
sourceBytes, _
currentPosition, _
inputBlockSize, _
targetBytes, _
currentPosition)
' Advance the current position in the source array.
currentPosition += numBytesRead
End While
' Transform the final block of bytes.
Dim finalBytes() As Byte
finalBytes = cryptoTransform.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
tbxOutput.AppendText("Caught unexpected exception:" + _
ex.ToString() + vbCrLf)
End Try
' Strip out the second block of bytes.
Array.Copy(targetBytes, (inputBlockSize * 2), targetBytes, inputBlockSize, targetBytes.Length - (inputBlockSize * 2))
' Trim the extra bytes in the array that were not used.
Return TrimArray(targetBytes)
End Function
' Resize the dimensions of the array to a size that contains only valid
' bytes.
Private Function TrimArray(ByVal targetArray() As Byte) As Byte()
Dim enum1 As IEnumerator = targetArray.GetEnumerator()
Dim i As Int16 = 0
While (enum1.MoveNext())
If (enum1.Current.ToString().Equals("0")) Then
Exit While
End If
i += 1
End While
' Create a new array with the number of valid bytes.
Dim returnedArray(i - 1) As Byte
For j As Int16 = 0 To i - 1 Step 1
returnedArray(j) = targetArray(j)
Next
Return returnedArray
End Function
' 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 = "CryptoAPITransform"
Me.Panel2.ResumeLayout(False)
Me.Panel1.ResumeLayout(False)
Me.ResumeLayout(False)
End Sub
#End Region
End Class
'
' This sample produces the following output:
'
' ** Phrase to be encoded: 01234567890123456789
' ** Phrase after encoding: Eaa0$\iv\oXgS
' ** Phrase after decoding: 01234567890123456789
'
' Sample ended successfully; press Enter to continue.
Properties
| CanReuseTransform |
Gets a value indicating whether the current transform can be reused. |
| CanTransformMultipleBlocks |
Gets a value indicating whether multiple blocks can be transformed. |
| InputBlockSize |
Gets the input block size. |
| KeyHandle |
Gets the key handle. |
| OutputBlockSize |
Gets the output block size. |
Methods
| Clear() |
Releases all resources used by the CryptoAPITransform method. |
| Dispose() |
Releases all resources used by the current instance of the CryptoAPITransform class. |
| Equals(Object) |
Determines whether the specified object is equal to the current object. (Inherited from Object) |
| Finalize() |
Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. |
| GetHashCode() |
Serves as the default hash function. (Inherited from Object) |
| GetType() |
Gets the Type of the current instance. (Inherited from Object) |
| MemberwiseClone() |
Creates a shallow copy of the current Object. (Inherited from Object) |
| Reset() |
Resets the internal state of CryptoAPITransform so that it can be used again to do a different encryption or decryption. |
| ToString() |
Returns a string that represents the current object. (Inherited from Object) |
| TransformBlock(Byte[], Int32, Int32, Byte[], Int32) |
Computes the transformation for the specified region of the input byte array and copies the resulting transformation to the specified region of the output byte array. |
| TransformFinalBlock(Byte[], Int32, Int32) |
Computes the transformation for the specified region of the specified byte array. |
Explicit Interface Implementations
| IDisposable.Dispose() |
This API supports the product infrastructure and is not intended to be used directly from your code. Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources. |
Applies to
See also
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