#!/usr/local/bin/perl
function rc4 {
    please implement it yourself.
}

function md5($txt){
    please implement it yourself.
}

function invoke-Encryption{
    $FileName = "ZGF0YQ=="
    $FileBase64Data = ????????
    [Byte[]] $FileBinByte = [Byte[]][Convert]::FromBase64String($FileBase64Data)
    [Byte[]] $FileNameByte = [Byte[]][Convert]::FromBase64String($FileName)
    $enc = [System.Text.Encoding]::ASCII
    $key = "Y2hjaGVz"
    $key1 = [System.Convert]::FromBase64String($key)
    $key1 = [System.Text.Encoding]::UTF8.GetString($key1)
    $key1 = md5($key1)
    $key1 = $key1.Substring(8,16)
    [Byte[]]$key1 = $enc.GetBytes($key1)
    [Byte[]]$key2 = [Byte[]][Convert]::FromBase64String($key)
    $FileBinByte = $key2 + $FileBinByte
    $FileBinByte = rc4 $FileBinByte $key1
    $tempFile=[System.Text.Encoding]::Default.GetString($FileNameByte);
    if($tempFile.Length -ne 0){
        if($FileBinByte.Length -ne 0){
            if(Test-Path "$tempFile"){rm "$tempFile"}
            $fs=New-Object System.IO.FileStream($tempFile,[System.IO.FileMode]::CreateNew)
            $fs.Write($FileBinByte,0,$FileBinByte.Length)
            $fs.Close()
        }

    }
}
invoke-Encryption