Ejercicios de seguridad: simular el funcionamiento de un proxy caché mediante una conexión UDP entre un cliente y un servidor que solicitan una imagen y si la imagen ya se ha descargado se indica en un mensaje | Operating systems, scripting, PowerShell and security

Contenidos

Servidor
Cliente

Servidor

##Server
$port=2020
$endpoint = new-object System.Net.IPEndPoint ([IPAddress]::Any,$port)
$udpclient=new-Object System.Net.Sockets.UdpClient $port
$content=$udpclient.Receive([ref]$endpoint)
$udpclient.Close()
$imagen = [Text.Encoding]::ASCII.GetString($content)
if(Test-Path $imagen)
{
    $port=2020
    $endpoint = new-object System.Net.IPEndPoint ([IPAddress]::Loopback,$port)
    $udpclient=new-Object System.Net.Sockets.UdpClient
    $b=[Text.Encoding]::ASCII.GetBytes('esta perro')
    $bytesSent=$udpclient.Send($b,$b.length,$endpoint)
    $udpclient.Close()
}
else
{
    iwr "https://www.jesusninoc.com/wp-content/uploads/2017/01/Cliente-Ejecutar-un-cmdlet-remotamente-en-un-equipos-utilizando-sockets-UDP.png" -OutFile perro.jpg
    $port=2020
    $endpoint = new-object System.Net.IPEndPoint ([IPAddress]::Loopback,$port)
    $udpclient=new-Object System.Net.Sockets.UdpClient
    $b=[Text.Encoding]::ASCII.GetBytes('no estaba perro')
    $bytesSent=$udpclient.Send($b,$b.length,$endpoint)
    $udpclient.Close()
}

##Server

$port=2020

$endpoint = new-object System.Net.IPEndPoint ([IPAddress]::Any,$port)

$udpclient=new-Object System.Net.Sockets.UdpClient $port

$content=$udpclient.Receive([ref]$endpoint)

$udpclient.Close()

$imagen = [Text.Encoding]::ASCII.GetString($content)

if(Test-Path $imagen)

{

$port=2020

$endpoint = new-object System.Net.IPEndPoint ([IPAddress]::Loopback,$port)

$udpclient=new-Object System.Net.Sockets.UdpClient

$b=[Text.Encoding]::ASCII.GetBytes('esta perro')

$bytesSent=$udpclient.Send($b,$b.length,$endpoint)

$udpclient.Close()

}

else

{

iwr "https://www.jesusninoc.com/wp-content/uploads/2017/01/Cliente-Ejecutar-un-cmdlet-remotamente-en-un-equipos-utilizando-sockets-UDP.png" -OutFile perro.jpg

$port=2020

$endpoint = new-object System.Net.IPEndPoint ([IPAddress]::Loopback,$port)

$udpclient=new-Object System.Net.Sockets.UdpClient

$b=[Text.Encoding]::ASCII.GetBytes('no estaba perro')

$bytesSent=$udpclient.Send($b,$b.length,$endpoint)

$udpclient.Close()

}

Cliente

##Client
$port=2020
$endpoint = new-object System.Net.IPEndPoint ([IPAddress]::Loopback,$port)
$udpclient=new-Object System.Net.Sockets.UdpClient
$b=[Text.Encoding]::ASCII.GetBytes('perro.jpg')
$bytesSent=$udpclient.Send($b,$b.length,$endpoint)
$udpclient.Close()

$port=2020
$endpoint = new-object System.Net.IPEndPoint ([IPAddress]::Any,$port)
$udpclient=new-Object System.Net.Sockets.UdpClient $port
$content=$udpclient.Receive([ref]$endpoint)
$udpclient.Close()
$imagen = [Text.Encoding]::ASCII.GetString($content)
$imagen

##Client

$port=2020

$endpoint = new-object System.Net.IPEndPoint ([IPAddress]::Loopback,$port)

$udpclient=new-Object System.Net.Sockets.UdpClient

$b=[Text.Encoding]::ASCII.GetBytes('perro.jpg')

$bytesSent=$udpclient.Send($b,$b.length,$endpoint)

$udpclient.Close()

$port=2020

$endpoint = new-object System.Net.IPEndPoint ([IPAddress]::Any,$port)

$udpclient=new-Object System.Net.Sockets.UdpClient $port

$content=$udpclient.Receive([ref]$endpoint)

$udpclient.Close()

$imagen = [Text.Encoding]::ASCII.GetString($content)

$imagen

Publicado el día 15 de enero de 2021

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