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RC2CryptoServiceProvider Class

Updated: February 2009

Defines a wrapper object to access the cryptographic service provider (CSP) implementation of the RC2 algorithm. This class cannot be inherited.

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

'Declaration
<ComVisibleAttribute(True)> _
Public NotInheritable Class RC2CryptoServiceProvider _
	Inherits RC2
'Usage
Dim instance As RC2CryptoServiceProvider

The RC2CryptoServiceProvider implementation supports key lengths from 40 bits to 128 bits in increments of 8 bits.

The RC2CryptoServiceProvider object is a block cipher that encrypts and decrypts data in blocks of 8 bytes. This class pads the final block of data if it is less than 8 bytes. As a result of this padding, the length of encrypted data could be greater than the original plaintext.

Note that the RC2CryptoServiceProvider object does not use salt.

NoteNote:

A newer symmetric encryption algorithm, Advanced Encryption Standard (AES), is available. Consider using the AesCryptoServiceProvider class instead of the RC2CryptoServiceProvider class.

The following code example encrypts and then decrypts a string.

Imports System
Imports System.IO
Imports System.Text
Imports System.Security.Cryptography



Module Crypto

    Sub Main()

        ' Create a new instance of the RC2CryptoServiceProvider class 
        ' and automatically generate a Key and IV. 
        Dim rc2CSP As New RC2CryptoServiceProvider()

        Console.WriteLine("Effective key size is {0} bits.", rc2CSP.EffectiveKeySize)

        ' Get the key and IV. 
        Dim key As Byte() = rc2CSP.Key
        Dim IV As Byte() = rc2CSP.IV

        ' Get an encryptor. 
        Dim encryptor As ICryptoTransform = rc2CSP.CreateEncryptor(key, IV)

        ' Encrypt the data as an array of encrypted bytes in memory. 
        Dim msEncrypt As New MemoryStream()
        Dim csEncrypt As New CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write)

        ' Convert the data to a byte array. 
        Dim original As String = "Here is some data to encrypt." 
        Dim toEncrypt As Byte() = Encoding.ASCII.GetBytes(original)

        ' Write all data to the crypto stream and flush it.
        csEncrypt.Write(toEncrypt, 0, toEncrypt.Length)
        csEncrypt.FlushFinalBlock()

        ' Get the encrypted array of bytes. 
        Dim encrypted As Byte() = msEncrypt.ToArray()

        ''''''''''''''''''''''''''''''''''''''''''''''''''''''' 
        ' This is where the data could be transmitted or saved.           
        ''''''''''''''''''''''''''''''''''''''''''''''''''''''' 

        'Get a decryptor that uses the same key and IV as the encryptor. 
        Dim decryptor As ICryptoTransform = rc2CSP.CreateDecryptor(key, IV)

        ' Now decrypt the previously encrypted message using the decryptor 
        ' obtained in the above step. 
        Dim msDecrypt As New MemoryStream(encrypted)
        Dim csDecrypt As New CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)

        ' Read the decrypted bytes from the decrypting stream 
        ' and place them in a StringBuilder class. 
        Dim roundtrip As New StringBuilder()

        Dim b As Integer = 0

        Do
            b = csDecrypt.ReadByte()

            If b <> -1 Then
                roundtrip.Append(ChrW(b))
            End If 
        Loop While b <> -1

        ' Display the original data and the decrypted data.
        Console.WriteLine("Original:   {0}", original)
        Console.WriteLine("Round Trip: {0}", roundtrip)

        Console.ReadLine()

    End Sub 
End Module

System.Object
  System.Security.Cryptography.SymmetricAlgorithm
    System.Security.Cryptography.RC2
      System.Security.Cryptography.RC2CryptoServiceProvider

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC

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.

.NET Framework

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

.NET Compact Framework

Supported in: 3.5, 2.0

Date

History

Reason

February 2009

Added note about newer AES algorithm.

Information enhancement.

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