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Create Method (String)
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RC2.Create Method (String)

Creates an instance of a cryptographic object to perform the specified implementation of the RC2 algorithm.

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

'Declaration
Public Shared Function Create ( _
	AlgName As String _
) As RC2

Parameters

AlgName
Type: System.String

The name of the specific implementation of RC2 to use.

Return Value

Type: System.Security.Cryptography.RC2
An instance of a cryptographic object.

ExceptionCondition
TargetInvocationException

The algorithm described by the algName parameter was used with Federal Information Processing Standards (FIPS) mode enabled, but is not FIPS compatible.

Use this method to create an instance of the RC2 class that you can use to encrypt and decrypt data.

The following example shows how to create and use an RC2 object to encrypt and decrypt data in a file.

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

Module RC2Sample

    Sub Main()
        Try 
            ' Create a new RC2 object to generate a key  
            ' and initialization vector (IV).  Specify one  
            ' of the recognized simple names for this  
            ' algorithm. 
            Dim RC2alg As RC2 = RC2.Create("RC2")

            ' Create a string to encrypt. 
            Dim sData As String = "Here is some data to encrypt." 
            Dim FileName As String = "CText.txt" 

            ' Encrypt text to a file using the file name, key, and IV.
            EncryptTextToFile(sData, FileName, RC2alg.Key, RC2alg.IV)

            ' Decrypt the text from a file using the file name, key, and IV. 
            Dim Final As String = DecryptTextFromFile(FileName, RC2alg.Key, RC2alg.IV)

            ' Display the decrypted string to the console.
            Console.WriteLine(Final)
        Catch e As Exception
            Console.WriteLine(e.Message)
        End Try 
    End Sub 


    Sub EncryptTextToFile(ByVal Data As String, ByVal FileName As String, ByVal Key() As Byte, ByVal IV() As Byte)
        Try 
            ' Create or open the specified file. 
            Dim fStream As FileStream = File.Open(FileName, FileMode.OpenOrCreate)

            ' Create a new RC2 object. 
            Dim RC2alg As RC2 = RC2.Create

            ' Create a CryptoStream using the FileStream  
            ' and the passed key and initialization vector (IV). 
            Dim cStream As New CryptoStream(fStream, _
                                           RC2alg.CreateEncryptor(Key, IV), _
                                           CryptoStreamMode.Write)

            ' Create a StreamWriter using the CryptoStream. 
            Dim sWriter As New StreamWriter(cStream)

            ' Write the data to the stream  
            ' to encrypt it.
            sWriter.WriteLine(Data)

            ' Close the streams and 
            ' close the file.
            sWriter.Close()
            cStream.Close()
            fStream.Close()
        Catch e As CryptographicException
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
        Catch e As UnauthorizedAccessException
            Console.WriteLine("A file error occurred: {0}", e.Message)
        End Try 
    End Sub 


    Function DecryptTextFromFile(ByVal FileName As String, ByVal Key() As Byte, ByVal IV() As Byte) As String 
        Try 
            ' Create or open the specified file.  
            Dim fStream As FileStream = File.Open(FileName, FileMode.OpenOrCreate)

            ' Create a new RC2 object. 
            Dim RC2alg As RC2 = RC2.Create

            ' Create a CryptoStream using the FileStream  
            ' and the passed key and initialization vector (IV). 
            Dim cStream As New CryptoStream(fStream, _
                                            RC2alg.CreateDecryptor(Key, IV), _
                                            CryptoStreamMode.Read)

            ' Create a StreamReader using the CryptoStream. 
            Dim sReader As New StreamReader(cStream)

            ' Read the data from the stream  
            ' to decrypt it. 
            Dim val As String = sReader.ReadLine()

            ' Close the streams and 
            ' close the file.
            sReader.Close()
            cStream.Close()
            fStream.Close()

            ' Return the string.  
            Return val
        Catch e As CryptographicException
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
            Return Nothing 
        Catch e As UnauthorizedAccessException
            Console.WriteLine("A file error occurred: {0}", e.Message)
            Return Nothing 
        End Try 
    End Function 
End Module

The following example shows how to create and use an RC2 object to encrypt and decrypt data in memory.

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

Module RC2PSample

    Sub Main()
        Try 
            ' Create a new RC2 object to generate a key  
            ' and initialization vector (IV).  Specify one  
            ' of the recognized simple names for this  
            ' algorithm. 
            Dim RC2alg As RC2 = RC2.Create("RC2")

            ' Create a string to encrypt. 
            Dim sData As String = "Here is some data to encrypt." 

            ' Encrypt the string to an in-memory buffer. 
            Dim Data As Byte() = EncryptTextToMemory(sData, RC2alg.Key, RC2alg.IV)

            ' Decrypt the buffer back to a string. 
            Dim Final As String = DecryptTextFromMemory(Data, RC2alg.Key, RC2alg.IV)

            ' Display the decrypted string to the console.
            Console.WriteLine(Final)
        Catch e As Exception
            Console.WriteLine(e.Message)
        End Try 
    End Sub 


    Function EncryptTextToMemory(ByVal Data As String, ByVal Key() As Byte, ByVal IV() As Byte) As Byte()
        Try 
            ' Create a MemoryStream. 
            Dim mStream As New MemoryStream

            ' Create a new RC2 object. 
            Dim RC2alg As RC2 = RC2.Create

            ' Create a CryptoStream using the MemoryStream  
            ' and the passed key and initialization vector (IV). 
            Dim cStream As New CryptoStream(mStream, _
                                            RC2alg.CreateEncryptor(Key, IV), _
                                            CryptoStreamMode.Write)

            ' Convert the passed string to a byte array. 
            Dim toEncrypt As Byte() = New ASCIIEncoding().GetBytes(Data)

            ' Write the byte array to the crypto stream and flush it.
            cStream.Write(toEncrypt, 0, toEncrypt.Length)
            cStream.FlushFinalBlock()

            ' Get an array of bytes from the  
            ' MemoryStream that holds the  
            ' encrypted data. 
            Dim ret As Byte() = mStream.ToArray()

            ' Close the streams.
            cStream.Close()
            mStream.Close()

            ' Return the encrypted buffer. 
            Return ret
        Catch e As CryptographicException
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
            Return Nothing 
        End Try 
    End Function 


    Function DecryptTextFromMemory(ByVal Data() As Byte, ByVal Key() As Byte, ByVal IV() As Byte) As String 
        Try 
            ' Create a new MemoryStream using the passed  
            ' array of encrypted data. 
            Dim msDecrypt As New MemoryStream(Data)

            ' Create a new RC2 object. 
            Dim RC2alg As RC2 = RC2.Create

            ' Create a CryptoStream using the MemoryStream  
            ' and the passed key and initialization vector (IV). 
            Dim csDecrypt As New CryptoStream(msDecrypt, _
                                              RC2alg.CreateDecryptor(Key, IV), _
                                              CryptoStreamMode.Read)

            ' Create buffer to hold the decrypted data. 
            Dim fromEncrypt(Data.Length) As Byte 

            ' Read the decrypted data out of the crypto stream 
            ' and place it into the temporary buffer.
            csDecrypt.Read(fromEncrypt, 0, fromEncrypt.Length)

            'Convert the buffer into a string and return it. 
            Return New ASCIIEncoding().GetString(fromEncrypt)
        Catch e As CryptographicException
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
            Return Nothing 
        End Try 
    End Function 
End Module

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1
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