Category: Ubuntu/Debian

Stuff about Ubuntu and Debian GNU/Linux

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How to install cockpit dashboard on older Raspberry Pi 3, running Bookworm

Cockpit dashboard is a convenient dashboard for home user or enthusiasts for monitoring several SOHO servers. It supports multiple Linux based operating system, however there are some caveats in installing in Raspberry Pi 3 as it runs on older Bookworm based operating system.

first your need to add bookworm-backports.

echo "deb http://deb.debian.org/debian ${VERSION_CODENAME}-backports main" | sudo tee /etc/apt/sources.list.d/backports.list

Then you need to configure the keyring

curl -O http://http.us.debian.org/debian/pool/main/d/debian-archive-keyring/debian-archive-keyring_2023.4_all.deb 

sudo dpkg -i debian-archive-keyring_2023.4_all.deb

Afterwards, you need to run this combo command to update software packages list

apt update  && apt -y upgrade

Then finally you install cockpit via bookworm-backports

apt install -t bookworm-backports cockpit

After everything is done, you may check cockpit dashboard by going to:
http://<ip address>:9090. and log in using your system username and password.

sample screenshot of cockpit on raspberry pi 3 / bookworm
sample screenshot of cockpit on raspberry pi 3 / bookworm
sample screenshot of cockpit on raspberry pi 3 / bookworm
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Solving DKIM verification FAILED with Bad Format in Gmail email messages

DKIM (Domain keys identified Mail) is a scheme for which allows a receiver to verify that the email originated (or authorized) by the domain’s owner via a digital signature.

Having DKIM signature adds credibility to the email messages sent from the origin host/domain, which is crucial for automated emailing system to avoid the messages from being suspected as SPAM email or spoofed email.

I managed to set up DKIM for an academic journal website which I’ve managed. The journal’s runs on Open Journal System web application, the addition of DKIM is crucial to avoid GMail or Microsoft Live from labeling the automated emails sent from the academic journal from being labeled as spam.

At first I found that the DKIM scheme that I’ve setup was running fine and the email messages was verified correctly from my Organizational email domain. However, I’ve noticed a problem when the automated email sent from OJS is not properly verified by Gmail-addressed account (@gmail.com). Upon inspection in the email header, I’ve noticed that the GMail marked the DKIM signature sent from my domain as “bad format”. Example below:

DKIM:	'FAIL' with domain jcrinn.com

dkim=neutral (bad format) header.i=@example.com header.s=mail header.b=AbCdE5g;

After hours of searching and debugging, including referring to the DKIM NS TXT record for reference, I finally found out that Gmail treat the “g=*” optional parameter as required, and thus I’ve to append “;g=*” to the DKIM TXT record on my domains’ DNS record.

So it become similar like this:

TXT default._domainkey  v=DKIM1; p=yourPublicKeywHiCHi5+abit+1OnG; g=*

After altering the records, it seems GMAIL finally able to verify the automated emails sent from my OJS-based web application

The “signed-by” is visible when DKIM is successfully validated by GMail

Hopefully this will work out fine for you too!

P/S: DigitalOcean has an excellent tutorial on DKIM installation and setup in GNU/Linux operating system.

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How to Update Nmap scanner database

Nmap (or Network Mapper) is probably the most popular network mapper around. However if you are running a very stable long-term support server, there are chances that your nmap database installation isn’t keep up to that.

Updating Nmap database

Nmap detection database consists of these files:

  • nmap-os-db
  • nmap-mac-prefixes
  • nmap-payloads
  • nmap-protocols
  • nmap-rpc
  • nmap-service-probes
  • nmap-services

What you need to do is to download  these files from Nmap Github project  page and copy it to /usr/share/nmap/ folder.

Alternatively, you can use this script ‘nmap-update.sh’ which I’ve created based on this gist.

Copy all the files to /usr/share/nmap/ once all of them have been downloaded.

(y) (y)

 

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Automatically generate gallery with llgal

LLGAL (llgal) is an tool which can automatically generate gallery on your website. llgal is handy if you want to generate photo album out of photos organized in directories/folders.

Running llgal from the console is easy as typing the llgal command at the root directory of your photos.

llgal --exif --li -L -R --title "Album Name" --sx 960 --sy 720 --tx 250 --ty 150

In Ubuntu, the gallery’s theme is located in “/usr/share/llgal/” directory and my customized theme which supports mobile phone can be downloaded here: llgal.zip (mobile enabled)

llgal Screenshot

Personally, i use llgal to generate cctv tiles automatically on my Ubuntu server from which my TP-LINK NC450 and NC250 IP camera uploads through its FTP functions when it detects movements/motion.

 

Installation

llgal can be installed on Ubuntu by running this command

apt -y install llgal

Alternatively you can compile and install llgal directly from its repository
https://github.com/bgoglin/llgal

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crack zip password with cracker-ng

Cracking zip password can be made easy with cracker-ng

Installation

Installation is simple, assuming you use Debian, Ubuntu or any other similar operating system :


$ git clone https://github.com/BoboTiG/cracker-ng.git
$ cd cracker-ng

# For testers and contributors, always work with on the devel branch:
$ git checkout devel

$ make

Cracking

Cracking is relatively simple, assuming you have downloaded the awesome Crackstation’s wordlist dictionary.


$ zipcracker-ng -f targetfile.zip -w crackstation-human-only.txt

Additionally zipcracker-ng can also be used with other brute-forcing cracking tool such as john and 

$ john --incremental --stdout | zipcracker-ng -f FILE -

$ crunch 1 8 -f charset.lst lalpha | zipcracker-ng -f FILE -

Screenshot of zipcracker-ng in action

crunch