Use TOR proxy with any linux command

There is an easy way to use the The Onion Router for any command under linux

First install TOR and proxychains4

$ sudo apt install tor proxychains4

You can configure proxychains.conf but the default config is good 🙂

$ sudo nano /etc/proxychains.conf

Then start the tor service

$ sudo systemctl start tor

And check your ip:

$ proxychains4 curl ifconfig.me

You can use any command you want. So if you want your firefox browser over tor:

$ proxychains4 firefox

To refresh your TOR IP simply restart the TOR service

Happy proxying 🙂

Powershell better tab autocomplete

With Powershell ISE you can use CTRL + SPACE for auto completion.

Powershell ISE Completion

But when you work in a native Powershell window you don’t have this option. And many often you cycle with tab completion trough the powershell and because you press the TAB button too soon you have to remove characters and cycle again trough all the commands.

Unit now 😉

There is an easy fix you can implement so the Powershell have the same auto completion like bash.

  • Type notepad $profile for Windows or gedit $profile for Linux
  • Add the line Set-PSReadlineKeyHandler -Key Tab -Function MenuComplete
Add line in $profile
  • Save the file and restart Powershell
  • And now you have a much better working tab completion
Linux Example
Windows Example

Happy coding 🙂

Repair Debian boot after Windows update

Today I update my dual boot system and unfortunately my Debian OS wasn’t booting anymore. The root cause was that Windows decide to reclaim the EFI boot.

The fix is quite easy.

Type mountvol P: /S

Check the EFI boot partition data

And fix your boot the this command:

bcdedit.exe /set {bootmgr} path \EFI\Debian\grubx64.efi

As you can see in the screenshot, this also work for EndeavourOS and Ubuntu and probably for a lot other Linux EFI boot systems.

Happy booting!

Corrupt SD Card Recovery

A friend of mine came back from vacation where he had taken a lot of pictures. When he got back home a large part of his Micro SD card (exFAT partition) was no longer accessible so he missed a couple of weeks of his photos and videos. His Windows Operating System froze completely when it hit a rotten cluster during a file copy action. So we had to find another solution to get his files back.

The first step I tried was to get the data from the SD card via Linux with ddrescue. With ddrecue, you create and complete dump of the SD card (or the sdb1 partition only). So you can do the data recovery on the image file (backup1.img) and not on the already corrupted SD Card.

The command you can use is:

ddrescue -d /dev/sdb1 /media/thomas/backup1.img /media/thomas/backup1.mapfile

But Linux also had also trouble reading when I hit a bad cluster. The only thing I could do during the read issues was a physical disconnect of the USB adapter, reconnect the adapter and restart the ddrescue process. The reason of was that a dual SD card adapter was used:

Micro SD > SD > SD > USB

(spoiler ALERT!: Never use multiple adapters for data recovery!!!)

Because ddrescue has a mapfile it goes further where he was stopped the last time.

While debugging I wrote a simple loop that forced a “physical” disconnection of the USB adapter wait one sec and reconnect the devices without touching anything.

Source of the USBReset (fork)

This works but is a very very slow process. This will takes months to recover so I had to find another way.

#!/bin/bash
## Steps to Prepare:
# lsusb check card reader and change the /dev/bus
# Start script in usbreset folder 
# Run as sudo
# mount disk (media / thomas)
while true
do
	echo "Let's try Again!"
	ddrescue -d /dev/sdb1 /media/thomas/4905eb31-1df4-49bb-bb75-ec4889641d20/backup1.img /media/thomas/4905eb31-1df4-49bb-bb75-ec4889641d20/backup1.mapfile
	sleep 1
	./usbreset /dev/bus/usb/001/004
	sleep 1
done

The funny thing is that it was Sinterklaas time and that my daughter had just received a vtech kiddy photo camera with a Micro SD to USB adapter included 😀

So I try new new adapter: Micro SD > USB and with success.

And after almost 15 hours the result 99.98% rescued rate 🙂

During my search for a solution I found some interesting articles:

Happy recovering!

OWASP ZAP Proxy with Android on Genymotion

It can be fun to reverse engineer some android applications. I think it’s better to do this on your workstation instead of your phone because it’s way more flexible and you don’t ruin your phone when you break things 😉

In my case, I use Debian 11. But of course, you can do this with any OS.

Requirements

  • An app you want to debug
  • OWASP ZAP Proxy
  • Genymotion
  • NPM
  • APK Export (Android App)

OWASP ZAP Proxy

I use the snap package for ZAP because it’s easy to install and you’ve always the latest version.

$ sudo snap install zaproxy --classic

Start ZAP and export the dynamic certificate (tools > options)

Dynamic SSL Certificate
  • Click on the save button an place the file somewhere on your disk.

You can check if the OWASP ZAP is running with:

$ netstat -tulpen | grep 8080
tcp6       0      0 127.0.0.1:8080          :::*                    LISTEN      1000       89190      14016/java    

Genymotion

Now the proxy is in place it’s time to install genymotion for the android emulation. First install virtualbox.

Install virtualbox APT keys

$ wget -q https://www.virtualbox.org/download/oracle_vbox_2016.asc -O- | sudo apt-key add -
$ wget -q https://www.virtualbox.org/download/oracle_vbox.asc -O- | sudo apt-key add -

Edit the /etc/apt/sources file and add this line:

deb [arch=amd64] https://download.virtualbox.org/virtualbox/debian bullseye contrib

Update the repo and install virtualbox

$ sudo apt-get update
$ sudo apt-get install virtualbox-6.1
  • Now go the the genymotion website and download the latest bin file
Download Genymotion
  • Make the file executable and run the installer
$ chmod +x genymotion-3.2.1-linux_x64.bin 
$ ./genymotion-3.2.1-linux_x64.bin
  • Follow the wizards, create an genymotion account and create a new virtual device. In my example I used a google Pixel 3 with Android 10.
Overview virtual devices

Now it’s time to configure the proxy within the android device!

Configure proxy in Android

Start the created virtual genymotion android device and copy the certificate file we create earlier with a simple drag and drop.

drag & drop the certificate file
Succesfull copy
  • Now we can can configure the proxy in the wifi settings.
  • Go to settings > search for certificate and install the certificate.
settings > find >certificates
Import the certificate

Edit the wifi connection, add the proxy and restart the wifi.

  • Edit the Wifi
  • Go to the advance options
  • Set the proxy to Manual
  • The IP is always: 10.0.3.2 This is the “localhost” setting for the genymotion host server
  • Port 8080
Genymotion Proxy Settings

When you (re)connect the the wifi you have the accept the proxy error (but this is a good thing).

Sign in the the wifi
Accept the warning

Now you will see all the traffic. But only the traffic for the apps who respect the android HTTP_PROXY settings. So this is what you can do when an app don’t respect this setting:

Rebuild the APK with APK-MITM

Now everything is in place. So the last thing we need to do is rebuild the APK file so we can proxing all the network traffic. So:

  • First export the APK file trough the APK Export
  • Place the APK somewhere on your disk
  • Install npm (at least version 14)
$ curl -sL https://deb.nodesource.com/setup_14.x | sudo bash -
$ sudo apt-get install nodejs npm
  • Install java
$ sudo apt install openjdk-17-jre openjdk-17-jdk 
  • And rebuild the APK
$ npx apk-mitm SomeAppName.apk 
Some nice MITM patching

And here we go!

Everything is in place now. So the only thing you have to do is drag & drop the *-patched.apk file to genymotion, install this file and you are fully in control 🙂

ZAP Proxy with MITM Apk

Happy hacking!

Ubuntu cannot connect to Cisco Router

Please follow these steps if you cannot can connect to a router. For example

ssh [email protected]

Output

Unable to negotiate with blog.wapnet.nl port 22: no matching key exchange method found. Their offer: diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1

use the -o parameter

ssh -o KexAlgorithms=+diffie-hellman-group1-sha1 [email protected]

Output:

Unable to negotiate with blog.wapnet.nl port 22: no matching cipher found. Their offer: aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc

and add the -c parameter

ssh -o KexAlgorithms=+diffie-hellman-group1-sha1 -c aes256-cbc  [email protected]

and you are connected 🙂

The authenticity of host 'blog.wapnet.nl' can't be established.
RSA key fingerprint is SHA256:XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Are you sure you want to continue connecting (yes/no/[fingerprint])?

Fix Screen Tearing in Linux

It cost me a lot of time to troubleshoot the screen tearing. So I want to share my solution for everyone with the same frustrating tearing issues. My private setup is a Lenovo Ideapad (gaming) with Nvidia and Intel (Prime) GPU. I use the laptop screen and an external 24″ HDMI display.

In Windows 10 everything goes smooth but when I switch my dual boot to Linux than the frustrations begin.

I tried a lot of different Linux distributions (Fedora, Solus, Ubuntu, Pop_OS!, Arch Linux, OpenSuse, and Zorin OS) and I try KDE Plasma, Gnome, and Budgie a lot of hacks for all these systems to get a smooth Linux GUI without screen tearing or other lag.

But I don’t like manual modifications/hacks to get the Nvidia setup smooth. Especially the proprietary Nvidia drivers can break your system easily. So this fix is easy to remember and easy to switch if you want the power saver back to full and use the Intel driver instead of the Nvidia one.

Important, choose your display!

What you have to keep in mind when you have a lot of screen tearing is to make a decision. Use your laptop display or external display. You can fix both displays but not at the same time in a smooth way. If I found a solution in the feature I will post it on my blog. But in the meanwhile, I use only one screen at the same time.

This procedure is for Ubuntu 20.04 LTS but it will work for other distributions for sure.

Install the driver

After a fresh ubuntu installation, Nvidia and HDMI do not work as they should be. So, kick off the first command and reboot.

$ sudo ubuntu-drivers autoinstall

And reboot!

Configure Nvidia driver Part I

Now configure the Nvidia/Intel prime in on-demand mode. So you can do further configuration in the nvidia-settings gui

$ sudo prime-select on-demand

  • And reboot again
  • Now start Nvidia settings and switch to NVIDIA (Performance Mode)
  • Click save and….. reboot!

Turn off one display

Go to your KDE or Gnome display settings and turn off one display. KDE saves these settings so when you plug out the HDMI cable afterward KDE will activate your laptop display. And of course, when you plug in your HDMI cable next time he will turn off your laptop display.

Configure Nvidia driver Part II

These steps are optional but needed for a better performance.

  • Start nvidia-settings > GPU 0 > PowerMixer
  • Change the Preffered Mode to “Prefer Maximum Performance”

Last but not least: Firefox hardware rendering

For some compatibility reasons, hardware rendering in Firefox is turned off by default. So you have to enable it.

  • about:config
  • Set layers.acceleration.force-enabled to true
  • Quit Firefox and restart it

Some debug information

I always use this YouTube video to check if the screen tearing is varnished completely

When you want to see if your have the right drivers loaded, use this command:

$ lspci -k | grep -EA3 'VGA|3D|Display'

And you can start an application with max video power with this command. Change gears to your own program off course. But I like gears because you can see the FPS realtime (see the screen what a differance 😉 )

$ __NV_PRIME_RENDER_OFFLOAD=1 glxgears

With nvidia-smi you can see if nvidia is running the application

Enjoy your tearing free Linux 🙂

/edit

Hahaha I saw this video today 🙂 Exactly my thoughts

Install Synology Drive Client on Solus Linux

The current 3rth party repo is deprecated so I’ve created my own fork for version: 2.0.4-11112

sudo eopkg bi --ignore-safety https://raw.githubusercontent.com/L0g0ff/3rd-party/master/network/download/synology-drive-client/pspec.xml
sudo eopkg it synology-drive-client*.eopkg;sudo rm synology-drive-client*.eopkg

Have fun!

504 Gateway Timeout on Synology NAS

Looks familiar?

I want to move this blog to my own NAS because I have plenty enough bandwidth and with Cloudflare as reverse proxy it is secure enough also (and I like to hobby off course 😉 ).

I tried to use the Duplicator WordPress plugin to make a dump of my website and do a restore in the Synology Webstation. But during the database restore in step 2 every time I was getting a 504 gateway timeout after a minute (exactly 60 seconds).

What I could have done was a manual (ftp & database) copy and restore the files. But I was sure I was getting other errors in the future when I had to update WordPress or other plugins. So fixing this timeout issue was the only solution.

On different places on the internet, I found that I had change the Nginx site settings. So I put the timeout settings in the associated “/etc/nginx/conf.d/site.conf” and restart Nginx and restore the database Nginx was still was failing.

    proxy_connect_timeout 600s;
    proxy_send_timeout 600s;
    proxy_read_timeout 600s;
    send_timeout 600s;

Then I’ll try to put these lines in the “/etc/nginx/nginx.conf” but when I restart the nginx the settings were overwritten and my changes are gone.

Every time you restart, Nginx Synology make use of a file “/usr/syno/share/nginx/nginx.mustache” to create a new nginx.conf file. I change the lines in that file and *boom* everything was working 🙂

So TLDR;

sudo su -
vim /usr/syno/share/nginx/nginx.mustache

#add these lines
    send_timeout                  600s;
    proxy_connect_timeout         600s;
    proxy_send_timeout            600s;
    proxy_read_timeout            600s;

synoservice --restart nginx

If you want to see the current Nginx config

nginx -T 

Have fun 🙂