Aes256Stream encryption/decryption example | C# Online Compiler

Aes256Stream encryption/decryption example by Anonymous

Imports System
Imports System.IO
Imports System.Security.Cryptography
Imports System.Runtime.InteropServices

Public Module MainModule
	Public Sub Main()
		
		'Generic.
		Dim Key As Byte() = System.Text.Encoding.UTF8.GetBytes("verysecretpassword") 'If you actually use a password here do hash it first!

		Dim TextToEncrypt As String = "Hello World! How are you?"
		Dim DataToEncrypt As Byte() = System.Text.Encoding.UTF8.GetBytes(TextToEncrypt)
		
		Console.WriteLine("== Text to encrypt ==" & Environment.NewLine & TextToEncrypt)
		Console.WriteLine()
		
		
		'Encryption.
		EncryptFile("encrypted.txt", DataToEncrypt, Key)
		
		Dim EncryptedData As Byte() = File.ReadAllBytes("encrypted.txt")
		Dim EncryptedText As String = System.Text.Encoding.UTF8.GetString(EncryptedData).Replace(Convert.ToChar(0).ToString(), "[NUL]")
		
		Console.WriteLine("== Encrypted text ==" & Environment.NewLine & EncryptedText)
		Console.WriteLine()
		
		
		'Decryption.
		Dim DecryptedData As Byte() = DecryptFile("encrypted.txt", Key)
		Dim DecryptedText As String = System.Text.Encoding.UTF8.GetString(DecryptedData)
		
		Console.WriteLine("== Decrypted text ==" & Environment.NewLine & DecryptedText)
		Console.WriteLine()
	End Sub
	
	
	
	Public Sub EncryptFile(ByVal File As String, ByVal Data As Byte(), ByVal Key As Byte())
		Using OutputStream As New FileStream(File, FileMode.Create, FileAccess.Write, FileShare.None)
			Using AesStream As Aes256Stream = Aes256Stream.CreateEncryptionStream(OutputStream, Key)
				AesStream.Write(Data, 0, Data.Length)
			End Using
		End Using
	End Sub
	
	Public Function DecryptFile(ByVal File As String, ByVal Key As Byte()) As Byte()
		Using InputStream As New FileStream(File, FileMode.Open, FileAccess.Read, FileShare.Read)
			Using DecryptedStream As New MemoryStream
				Using AesStream As Aes256Stream = Aes256Stream.CreateDecryptionStream(InputStream, Key)
	
					Dim Buffer As Byte() = New Byte(4096 - 1) {}
					While AesStream.Position < AesStream.Length
						Dim BytesRead As Integer = AesStream.Read(Buffer, 0, Buffer.Length)
						DecryptedStream.Write(Buffer, 0, BytesRead)
					End While
	
					Return DecryptedStream.ToArray()
	
				End Using
			End Using
		End Using
	End Function
End Module







'+---------------------------------------------------------------------------------+'
'|                               === Aes256Stream ===                              |'
'|                                                                                 |'
'|                  Created by Vincent "Visual Vincent" Bengtsson                  |'
'|                      Website: https://www.mydoomsite.com/                       |'
'|                                                                                 |'
'|                                                                                 |'
'|                            === COPYRIGHT LICENSE ===                            |'
'|                                                                                 |'
'| Copyright (c) 2016-2017, Vincent Bengtsson                                      |'
'| All rights reserved.                                                            |'
'|                                                                                 |'
'| Redistribution and use in source and binary forms, with or without              |'
'| modification, are permitted provided that the following conditions are met:     |'
'|                                                                                 |'
'| 1. Redistributions of source code must retain the above copyright notice, this  |'
'|    list of conditions and the following disclaimer.                             |'
'| 2. Redistributions in binary form must reproduce the above copyright notice,    |'
'|    this list of conditions and the following disclaimer in the documentation    |'
'|    and/or other materials provided with the distribution.                       |'
'|                                                                                 |'
'| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND |'
'| ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED   |'
'| WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE          |'
'| DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR |'
'| ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES  |'
'| (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;    |'
'| LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND     |'
'| ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT      |'
'| (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS   |'
'| SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.                    |'
'+---------------------------------------------------------------------------------+'

Public Class Aes256Stream
    Inherits CryptoStream

#Region "Fields"
    Private _underlyingStream As Stream
    Private AES As RijndaelManaged
    Private Transform As ICryptoTransform
#End Region

#Region "Properties"
    ''' <summary>
    ''' Gets the block size, in bits, used by the stream's AES algorithm.
    ''' </summary>
    ''' <remarks></remarks>
    Public ReadOnly Property BlockSize As Integer
        Get
            Return AES.BlockSize
        End Get
    End Property

    ''' <summary>
    ''' Gets the key size, in bits, used by the stream's AES algorithm.
    ''' </summary>
    ''' <remarks></remarks>
    Public ReadOnly Property KeySize As Integer
        Get
            Return AES.KeySize
        End Get
    End Property

    ''' <summary>
    ''' Gets the length in bytes of the underlying stream.
    ''' </summary>
    ''' <remarks></remarks>
    Public Overrides ReadOnly Property Length As Long
        Get
            Return _underlyingStream.Length
        End Get
    End Property

    ''' <summary>
    ''' Gets or sets the position within the underlying stream.
    ''' </summary>
    ''' <remarks></remarks>
    Public Overrides Property Position As Long
        Get
            If _underlyingStream.CanSeek = False Then Throw New NotSupportedException("The underlying stream doesn't support seeking!")
            Return _underlyingStream.Position
        End Get
        Set(value As Long)
            If _underlyingStream.CanSeek = False Then Throw New NotSupportedException("The underlying stream doesn't support seeking!")
            _underlyingStream.Position = value
        End Set
    End Property

    ''' <summary>
    ''' Gets the underlying stream.
    ''' </summary>
    ''' <remarks></remarks>
    Public ReadOnly Property UnderlyingStream As Stream
        Get
            Return _underlyingStream
        End Get
    End Property
#End Region

#Region "Constructors"
    Private Sub New(ByVal UnderlyingStream As Stream, _
                    ByVal AES As RijndaelManaged, _
                    ByVal CryptoTransform As ICryptoTransform, _
                    ByVal Mode As CryptoStreamMode)
        MyBase.New(UnderlyingStream, CryptoTransform, Mode)
        Me._underlyingStream = UnderlyingStream
        Me.AES = AES
        Me.Transform = CryptoTransform
    End Sub
#End Region

#Region "Methods"

#Region "Instance"
    ''' <summary>
    ''' Sets the length of the underlying stream.
    ''' </summary>
    ''' <param name="value">The desired length of  underlying stream in bytes.</param>
    ''' <remarks></remarks>the
    Public Overrides Sub SetLength(value As Long)
        _underlyingStream.SetLength(value)
    End Sub
#End Region

#Region "Shared"
    ''' <summary>
    ''' Creates an AES-256 encryption stream.
    ''' </summary>
    ''' <param name="UnderlyingStream">The underlying stream to write the encrypted data to.</param>
    ''' <param name="Key">The encryption key to use when encrypting the data (automatically padded or truncated to KeySize/8 bytes).</param>
    ''' <remarks></remarks>
    Public Shared Function CreateEncryptionStream(ByVal UnderlyingStream As Stream, ByVal Key As Byte()) As Aes256Stream
        Dim AES As New RijndaelManaged
        AES.KeySize = 256
        AES.BlockSize = 128

        AES.Key = Aes256Stream.PadOrTruncate(Key, AES.KeySize / 8)
        AES.GenerateIV()

        AES.Mode = CipherMode.CBC
        AES.Padding = PaddingMode.PKCS7

        'Write the IV to the underlying stream.
        If UnderlyingStream.CanWrite = True Then
            Dim LengthIV As Byte() = BitConverter.GetBytes(AES.IV.Length) 'Convert the IV.Length Integer to a byte array.
            UnderlyingStream.Write(LengthIV, 0, LengthIV.Length) 'Write the length of the IV.
            UnderlyingStream.Write(AES.IV, 0, AES.IV.Length) 'Write the IV.
        Else
            Throw New IOException("Underlying stream is not writable!")
        End If

        Return New Aes256Stream(UnderlyingStream, AES, AES.CreateEncryptor(), CryptoStreamMode.Write)
    End Function

    ''' <summary>
    ''' Creates an AES-256 decryption stream.
    ''' </summary>
    ''' <param name="UnderlyingStream">The underlying stream to decrypt the data from.</param>
    ''' <param name="Key">The encryption key to use when encrypting the data (automatically padded or truncated to KeySize/8 bytes).</param>
    ''' <remarks></remarks>
    Public Shared Function CreateDecryptionStream(ByVal UnderlyingStream As Stream, ByVal Key As Byte()) As Aes256Stream
        Dim AES As New RijndaelManaged
        AES.KeySize = 256
        AES.BlockSize = 128

        AES.Key = Aes256Stream.PadOrTruncate(Key, AES.KeySize / 8)

        'Read the IV from the underlying stream.
        If UnderlyingStream.CanRead = True Then
            Dim BytesReadIV As Integer = 0
            Dim BufferIV As Byte() = New Byte(Marshal.SizeOf(GetType(Integer)) - 1) {}
            Dim LengthIV As Integer

            'Read the IV's length.
            While BytesReadIV < BufferIV.Length
                Dim BytesRead As Integer = UnderlyingStream.Read(BufferIV, BytesReadIV, BufferIV.Length - BytesReadIV)
                BytesReadIV += BytesRead

                If BytesRead = 0 AndAlso BytesReadIV < BufferIV.Length Then _
                    Throw New IOException("End of stream reached before IV could be parsed!")
            End While

            'Convert the bytes to an Integer.
            LengthIV = BitConverter.ToInt32(BufferIV, 0)

            'Reset the variables.
            BytesReadIV = 0
            BufferIV = New Byte(LengthIV - 1) {}

            'Read the IV.
            While BytesReadIV < BufferIV.Length
                Dim BytesRead As Integer = UnderlyingStream.Read(BufferIV, BytesReadIV, BufferIV.Length - BytesReadIV)
                BytesReadIV += BytesRead

                If BytesRead = 0 AndAlso BytesReadIV < BufferIV.Length Then _
                    Throw New IOException("End of stream reached before IV could be parsed!")
            End While

            'Set the IV.
            AES.IV = BufferIV
        Else
            Throw New IOException("Underlying stream is not readable!")
        End If

        AES.Mode = CipherMode.CBC
        AES.Padding = PaddingMode.PKCS7

        Return New Aes256Stream(UnderlyingStream, AES, AES.CreateDecryptor(), CryptoStreamMode.Read)
    End Function

    Private Shared Function PadOrTruncate(ByVal Input As Byte(), ByVal PreferredLength As Integer) As Byte()
        If Input.Length < PreferredLength Then 'Pad with zeros.
            Dim PreviousLength As Integer = Input.Length

            Array.Resize(Input, Input.Length + (PreferredLength - Input.Length))
            For i = PreviousLength To Input.Length - 1
                Input(i) = 0
            Next

            Return Input

        ElseIf Input.Length > PreferredLength Then 'Truncate.
            Array.Resize(Input, PreferredLength)
            Return Input

        End If

        Return Input 'Do nothing.
    End Function
#End Region

#End Region

#Region "Dispose()"
    Protected Overrides Sub Dispose(disposing As Boolean)
        MyBase.Dispose(disposing)
        If disposing Then
            Try
                If Transform IsNot Nothing Then
                    Transform.Dispose()
                    Transform = Nothing
                End If
            Catch
            End Try

            Try
                If AES IsNot Nothing Then
                    AES.Dispose()
                    AES = Nothing
                End If
            Catch
            End Try
        End If
    End Sub
#End Region

End Class

​x
 
Imports System
Imports System.IO
Imports System.Security.Cryptography
Imports System.Runtime.InteropServices
​
Public Module MainModule
    Public Sub Main()
        
        'Generic.
        Dim Key As Byte() = System.Text.Encoding.UTF8.GetBytes("verysecretpassword") 'If you actually use a password here do hash it first!
​
        Dim TextToEncrypt As String = "Hello World! How are you?"
        Dim DataToEncrypt As Byte() = System.Text.Encoding.UTF8.GetBytes(TextToEncrypt)
        
        Console.WriteLine("== Text to encrypt ==" & Environment.NewLine & TextToEncrypt)
        Console.WriteLine()
        
        
        'Encryption.
        EncryptFile("encrypted.txt", DataToEncrypt, Key)
        
        Dim EncryptedData As Byte() = File.ReadAllBytes("encrypted.txt")
        Dim EncryptedText As String = System.Text.Encoding.UTF8.GetString(EncryptedData).Replace(Convert.ToChar(0).ToString(), "[NUL]")
        
        Console.WriteLine("== Encrypted text ==" & Environment.NewLine & EncryptedText)
        Console.WriteLine()
        
        
        'Decryption.
        Dim DecryptedData As Byte() = DecryptFile("encrypted.txt", Key)
        Dim DecryptedText As String = System.Text.Encoding.UTF8.GetString(DecryptedData)
        
        Console.WriteLine("== Decrypted text ==" & Environment.NewLine & DecryptedText)
        Console.WriteLine()
    End Sub
    
    
    
    Public Sub EncryptFile(ByVal File As String, ByVal Data As Byte(), ByVal Key As Byte())
        Using OutputStream As New FileStream(File, FileMode.Create, FileAccess.Write, FileShare.None)
            Using AesStream As Aes256Stream = Aes256Stream.CreateEncryptionStream(OutputStream, Key)
                AesStream.Write(Data, 0, Data.Length)
            End Using
        End Using
    End Sub
    
    Public Function DecryptFile(ByVal File As String, ByVal Key As Byte()) As Byte()
        Using InputStream As New FileStream(File, FileMode.Open, FileAccess.Read, FileShare.Read)
            Using DecryptedStream As New MemoryStream
                Using AesStream As Aes256Stream = Aes256Stream.CreateDecryptionStream(InputStream, Key)
    
                    Dim Buffer As Byte() = New Byte(4096 - 1) {}
                    While AesStream.Position < AesStream.Length
                        Dim BytesRead As Integer = AesStream.Read(Buffer, 0, Buffer.Length)
                        DecryptedStream.Write(Buffer, 0, BytesRead)
                    End While
    
                    Return DecryptedStream.ToArray()
    
                End Using
            End Using
        End Using
    End Function
End Module
​
​
​
​
​
​
​
'+---------------------------------------------------------------------------------+'
'|                               === Aes256Stream ===                              |'
'|                                                                                 |'
'|                  Created by Vincent "Visual Vincent" Bengtsson                  |'
'|                      Website: https://www.mydoomsite.com/                       |'
'|                                                                                 |'
'|                                                                                 |'
'|                            === COPYRIGHT LICENSE ===                            |'
'|                                                                                 |'
'| Copyright (c) 2016-2017, Vincent Bengtsson                                      |'
'| All rights reserved.                                                            |'
'|                                                                                 |'
'| Redistribution and use in source and binary forms, with or without              |'
'| modification, are permitted provided that the following conditions are met:     |'
'|                                                                                 |'
'| 1. Redistributions of source code must retain the above copyright notice, this  |'
'|    list of conditions and the following disclaimer.                             |'
'| 2. Redistributions in binary form must reproduce the above copyright notice,    |'
'|    this list of conditions and the following disclaimer in the documentation    |'
'|    and/or other materials provided with the distribution.                       |'
'|                                                                                 |'
'| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND |'
'| ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED   |'
'| WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE          |'
'| DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR |'
'| ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES  |'
'| (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;    |'
'| LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND     |'
'| ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT      |'
'| (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS   |'
'| SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.                    |'
'+---------------------------------------------------------------------------------+'
​
Public Class Aes256Stream
    Inherits CryptoStream
​
#Region "Fields"
    Private _underlyingStream As Stream
    Private AES As RijndaelManaged
    Private Transform As ICryptoTransform
#End Region
​
#Region "Properties"
    ''' <summary>
    ''' Gets the block size, in bits, used by the stream's AES algorithm.
    ''' </summary>
    ''' <remarks></remarks>
    Public ReadOnly Property BlockSize As Integer
        Get
            Return AES.BlockSize
        End Get
    End Property
​
    ''' <summary>
    ''' Gets the key size, in bits, used by the stream's AES algorithm.
    ''' </summary>
    ''' <remarks></remarks>
    Public ReadOnly Property KeySize As Integer
        Get
            Return AES.KeySize
        End Get
    End Property
​
    ''' <summary>
    ''' Gets the length in bytes of the underlying stream.
    ''' </summary>
    ''' <remarks></remarks>
    Public Overrides ReadOnly Property Length As Long
        Get
            Return _underlyingStream.Length
        End Get
    End Property
​
    ''' <summary>
    ''' Gets or sets the position within the underlying stream.
    ''' </summary>
    ''' <remarks></remarks>
    Public Overrides Property Position As Long
        Get
            If _underlyingStream.CanSeek = False Then Throw New NotSupportedException("The underlying stream doesn't support seeking!")
            Return _underlyingStream.Position
        End Get
        Set(value As Long)
            If _underlyingStream.CanSeek = False Then Throw New NotSupportedException("The underlying stream doesn't support seeking!")
            _underlyingStream.Position = value
        End Set
    End Property
​
    ''' <summary>
    ''' Gets the underlying stream.
    ''' </summary>
    ''' <remarks></remarks>
    Public ReadOnly Property UnderlyingStream As Stream
        Get
            Return _underlyingStream
        End Get
    End Property
#End Region
​
#Region "Constructors"
    Private Sub New(ByVal UnderlyingStream As Stream, _
                    ByVal AES As RijndaelManaged, _
                    ByVal CryptoTransform As ICryptoTransform, _
                    ByVal Mode As CryptoStreamMode)
        MyBase.New(UnderlyingStream, CryptoTransform, Mode)
        Me._underlyingStream = UnderlyingStream
        Me.AES = AES
        Me.Transform = CryptoTransform
    End Sub
#End Region
​
#Region "Methods"
​
#Region "Instance"
    ''' <summary>
    ''' Sets the length of the underlying stream.
    ''' </summary>
    ''' <param name="value">The desired length of  underlying stream in bytes.</param>
    ''' <remarks></remarks>the
    Public Overrides Sub SetLength(value As Long)
        _underlyingStream.SetLength(value)
    End Sub
#End Region
​
#Region "Shared"
    ''' <summary>
    ''' Creates an AES-256 encryption stream.
    ''' </summary>
    ''' <param name="UnderlyingStream">The underlying stream to write the encrypted data to.</param>
    ''' <param name="Key">The encryption key to use when encrypting the data (automatically padded or truncated to KeySize/8 bytes).</param>
    ''' <remarks></remarks>
    Public Shared Function CreateEncryptionStream(ByVal UnderlyingStream As Stream, ByVal Key As Byte()) As Aes256Stream
        Dim AES As New RijndaelManaged
        AES.KeySize = 256
        AES.BlockSize = 128
​
        AES.Key = Aes256Stream.PadOrTruncate(Key, AES.KeySize / 8)
        AES.GenerateIV()
​
        AES.Mode = CipherMode.CBC
        AES.Padding = PaddingMode.PKCS7
​
        'Write the IV to the underlying stream.
        If UnderlyingStream.CanWrite = True Then
            Dim LengthIV As Byte() = BitConverter.GetBytes(AES.IV.Length) 'Convert the IV.Length Integer to a byte array.
            UnderlyingStream.Write(LengthIV, 0, LengthIV.Length) 'Write the length of the IV.
            UnderlyingStream.Write(AES.IV, 0, AES.IV.Length) 'Write the IV.
        Else
            Throw New IOException("Underlying stream is not writable!")
        End If
​
        Return New Aes256Stream(UnderlyingStream, AES, AES.CreateEncryptor(), CryptoStreamMode.Write)
    End Function
​
    ''' <summary>
    ''' Creates an AES-256 decryption stream.
    ''' </summary>
    ''' <param name="UnderlyingStream">The underlying stream to decrypt the data from.</param>
    ''' <param name="Key">The encryption key to use when encrypting the data (automatically padded or truncated to KeySize/8 bytes).</param>
    ''' <remarks></remarks>
    Public Shared Function CreateDecryptionStream(ByVal UnderlyingStream As Stream, ByVal Key As Byte()) As Aes256Stream
        Dim AES As New RijndaelManaged
        AES.KeySize = 256
        AES.BlockSize = 128
​
        AES.Key = Aes256Stream.PadOrTruncate(Key, AES.KeySize / 8)
​
        'Read the IV from the underlying stream.
        If UnderlyingStream.CanRead = True Then
            Dim BytesReadIV As Integer = 0
            Dim BufferIV As Byte() = New Byte(Marshal.SizeOf(GetType(Integer)) - 1) {}
            Dim LengthIV As Integer
​
            'Read the IV's length.
            While BytesReadIV < BufferIV.Length
                Dim BytesRead As Integer = UnderlyingStream.Read(BufferIV, BytesReadIV, BufferIV.Length - BytesReadIV)
                BytesReadIV += BytesRead
​
                If BytesRead = 0 AndAlso BytesReadIV < BufferIV.Length Then _
                    Throw New IOException("End of stream reached before IV could be parsed!")
            End While
​
            'Convert the bytes to an Integer.
            LengthIV = BitConverter.ToInt32(BufferIV, 0)
​
            'Reset the variables.
            BytesReadIV = 0
            BufferIV = New Byte(LengthIV - 1) {}
​
            'Read the IV.
            While BytesReadIV < BufferIV.Length
                Dim BytesRead As Integer = UnderlyingStream.Read(BufferIV, BytesReadIV, BufferIV.Length - BytesReadIV)
                BytesReadIV += BytesRead
​
                If BytesRead = 0 AndAlso BytesReadIV < BufferIV.Length Then _
                    Throw New IOException("End of stream reached before IV could be parsed!")
            End While
​
            'Set the IV.
            AES.IV = BufferIV
        Else
            Throw New IOException("Underlying stream is not readable!")
        End If
​
        AES.Mode = CipherMode.CBC
        AES.Padding = PaddingMode.PKCS7
​
        Return New Aes256Stream(UnderlyingStream, AES, AES.CreateDecryptor(), CryptoStreamMode.Read)
    End Function
​
    Private Shared Function PadOrTruncate(ByVal Input As Byte(), ByVal PreferredLength As Integer) As Byte()
        If Input.Length < PreferredLength Then 'Pad with zeros.
            Dim PreviousLength As Integer = Input.Length
​
            Array.Resize(Input, Input.Length + (PreferredLength - Input.Length))
            For i = PreviousLength To Input.Length - 1
                Input(i) = 0
            Next
​
            Return Input
​
        ElseIf Input.Length > PreferredLength Then 'Truncate.
            Array.Resize(Input, PreferredLength)
            Return Input
​
        End If
​
        Return Input 'Do nothing.
    End Function
#End Region
​
#End Region
​
#Region "Dispose()"
    Protected Overrides Sub Dispose(disposing As Boolean)
        MyBase.Dispose(disposing)
        If disposing Then
            Try
                If Transform IsNot Nothing Then
                    Transform.Dispose()
                    Transform = Nothing
                End If
            Catch
            End Try
​
            Try
                If AES IsNot Nothing Then
                    AES.Dispose()
                    AES = Nothing
                End If
            Catch
            End Try
        End If
    End Sub
#End Region
​
End Class

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