Powershell Steganography Module

Function Get-ConfigInfo {
    $cfg = 0 | select TempFolder
    $cfg.TempFolder = join-path $env:temp "Steganographer"
    mkdir $cfg.TempFolder -force -ErrorAction SilentlyContinue | Out-Null
    $cfg
}

Function Add-SteganographyType {
$code =@"
using System;
using System.IO;
using System.Drawing;
using System.Collections.Generic;
using System.Text;
using System.Drawing.Imaging;

namespace Neptune
{
    class BitmapHelper
    {

        public static  byte [] getBytes(Bitmap imgSource)
        {

            MemoryStream ms = new MemoryStream();
            imgSource.Save(ms, ImageFormat.Bmp);
            return ms.ToArray();
        }
        public static Bitmap getBitmap(byte [] arrData){
            MemoryStream ms = new MemoryStream(arrData);

            Bitmap bmp = new Bitmap(ms);

            return bmp;
        }

    }
    public class Steganographer
    {
        public static string ExtractText(Bitmap bmp)
        {
            byte[] data = BitmapHelper.getBytes(bmp);
            StringBuilder builder=new StringBuilder();
            int i = 54;
            int argb = 0;
            byte c;
            while (true)
            {
                c = 0;
                int j = 0;
                while(j<8)
                {
                    if ((argb == 3))
                    {
                        // Skip the alpha byte
                        argb = ((argb + 1) % 4);
                        i++;
                    }

                        byte temp = data[i];
                        temp &= 0x01;
                        temp = (byte)(temp << j);
                        c |= temp;
                        argb = ((argb + 1) % 4);
                        i++;
                        j++;


                }
                // Character is completed
                if (c == 0)
                    break;
                else
                    builder.Append((char)c);

            }
            return builder.ToString();
        }

        public static Bitmap HideText(Bitmap imgSource, String txtMessage)
        {
            byte [] data=BitmapHelper.getBytes(imgSource);
            // Strip the least significant bit
            int i;
            for ( i = 54; i < data.Length; i++)
            {

                data[i] &= 0xfe;
            }

             i = 54;
             int argb = 0;
            foreach(char c in txtMessage.ToCharArray()){

                char ch = c;

                for (int b = 0; b < 8; b++)
                {
                    if (argb == 3)
                    {
                        // Skip the Alpha byte
                        i++;
                        argb = ((argb + 1) % 4);
                    }
                    data[i++] |= (byte)(ch & 0x01);
                    ch = (char)(ch >> 1);
                    argb = ((argb + 1) % 4);

                }

            }

            return BitmapHelper.getBitmap(data);


        }
    }
}

"@
    try {
        [void][Neptune.Steganographer]
    } catch {
        add-type -TypeDefinition $code -ReferencedAssemblies "System.Drawing","mscorlib" | Out-Null
    }
    add-type -AssemblyName "System.Drawing" -ErrorAction SilentlyContinue| Out-Null
}
Add-SteganographyType
Function  Get-SteganographyMessage {
    [CmdletBinding(DefaultParameterSetName="URL")]
    param(
        [Parameter(Mandatory=$true,ParameterSetName="URL", ValueFromPipeline=$true)]
        [uri]$URL,
        [Parameter(Mandatory=$true,ParameterSetName="Path")]
        [string]$Path
    )
    $cfg = Get-ConfigInfo
    if($PSCmdlet.ParameterSetName -eq "URL"){
        $wc = New-Object System.Net.WebClient
        $imgFile = Join-Path $cfg.TempFolder $($URL.Segments | select -Last 1)
        $wc.DownloadFile($URL.AbsoluteUri,$imgFile)
        $bitmap = [System.Drawing.Bitmap]::FromFile($imgFile)
        [Neptune.Steganographer]::ExtractText($bitmap)
        $bitmap.Dispose()
        Remove-Item $imgFile
    } else {
        if(Test-Path $Path) {
            [io.fileinfo]$Path = Get-ChildItem $Path
        } else {
            throw "Can't find file $Path"
        }
        $bitmap = [System.Drawing.Bitmap]::FromFile($Path.FullName)
        [Neptune.Steganographer]::ExtractText($bitmap)
    }
}

Function  Set-SteganographyMessage {
    [CmdletBinding(DefaultParameterSetName="URL")]
    param(
        [Parameter(Mandatory=$true,ParameterSetName="URL", ValueFromPipeline=$true)]
        [uri]$URL,
        [Parameter(Mandatory=$true,ParameterSetName="Path")]
        [string]$Path,
        [Parameter(Mandatory=$true)]
        [string]$Message,
        [Parameter(Mandatory=$true)]
        [string]$TargetPath,
        [switch]$Force
    )
    $cfg = Get-ConfigInfo
    if($PSCmdlet.ParameterSetName -eq "URL"){
        $wc = New-Object System.Net.WebClient
        $filename = $($URL.Segments | select -Last 1)
        [io.fileinfo]$Path = Join-Path $cfg.TempFolder $filename
        $wc.DownloadFile($URL.AbsoluteUri,$Path.FullName)
    } else {
        if(Test-Path $Path) {
            [io.fileinfo]$Path = Get-ChildItem $Path
        } else {
            throw "Can't find file $Path"
        }
    }
    if(Test-Path $TargetPath) {
        if($Force) {
            Remove-Item $TargetPath
        } else {
            throw "File $TargetPath already exist. Try overwriting it with -Force or specify another -TargetPath"
        }
    }
    $bitmap = [System.Drawing.Bitmap]::FromFile($Path.FullName)
    $outBitmap = [Neptune.Steganographer]::HideText($bitmap,$Message)
    $targetFolder = resolve-path (split-path (join-path ".\" $TargetPath))
    $targetFile = Split-Path -Leaf $TargetPath
    $TargetPath = Join-Path $targetFolder $targetFile
    $outBitmap.Save($TargetPath)
    $bitmap.Dispose()
    $outBitmap.Dispose()
    Get-ChildItem $TargetPath
}

Export-ModuleMember -Function "Get-SteganographyMessage","Set-SteganographyMessage"