• Hold down the Windows key and press R to bring up the Run dialog.
• Type gpedit.msc and press Enter. You will need administrator privileges to continue.
• Navigate to User Configuration > Administrative Templates > Windows Components > Attachment Manager.
• In the right-side pane, double-click "Do not preserve zone information in file attachments", set it to Enabled, then press OK.

wsl.exe --shutdown
cd ~\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\
optimize-vhd -Path .\ext4.vhdx -Mode full

Installing the prerequisites

sudo apt update
sudo apt upgrade
sudo apt install build-essential python3-dev python3-pip libseccomp-dev libxml2-dev libxslt1-dev zlib1g-dev gettext curl redis-server mariadb-server libmysqlclient-dev

nvm install 18
nvm alias default 18

Creating the database

sudo service mariadb start
sudo mysql_secure_installation
sudo mysql

CREATE USER 'dmoj'@'localhost' IDENTIFIED BY 'PASSWORD';
CREATE USER 'dmoj'@'%' IDENTIFIED BY 'PASSWORD';
CREATE DATABASE dmoj DEFAULT CHARACTER SET utf8mb4 DEFAULT COLLATE utf8mb4_general_ci;
GRANT ALL PRIVILEGES ON dmoj.* TO 'dmoj'@'localhost';
GRANT ALL PRIVILEGES ON dmoj.* TO 'dmoj'@'%';
exit

Cloning VNOJ

git clone --recursive https://github.com/VNOI-Admin/OJ.git
cd OJ

Installing prerequisites

We will create a virtual environment with pyenv and install the dependencies:

pyenv install 3.11.9
pyenv virtualenv 3.11.9 vnoj
pyenv local vnoj

pip install --upgrade pip setuptools wheel
pip install -r requirements.txt
pip install -r additional_requirements.txt
pip install flake8 flake8-import-order flake8-future-import flake8-commas flake8-logging-format flake8-quotes

npm install

Configuring

Start up the Redis server, which is needed by the Celery workers:

sudo service redis-server start

Download the sample settings file:

cd dmoj
wget https://github.com/DMOJ/docs/raw/master/sample_files/local_settings.py

You will now need to configure dmoj/local_settings.py. You need to update MySQL credentials and the secret key and uncommenting CELERY_BROKER_URL and CELERY_RESULT_BACKEND. By default, Redis listens on localhost port 6379, which is reflected in local_settings.py. You will need to update the addresses if you changed Redis's settings.

Now, verify that everything is going according to plan:

./manage.py check

Compiling assets

Compile and optimize the stylesheets:

./make_style.sh

Collect static files into STATIC_ROOT as specified in dmoj/local_settings.py:

./manage.py collectstatic --no-input

Generate internationalization files:

./manage.py compilemessages
./manage.py compilejsi18n

Setting up database tables

If you have a database backup, skip this step.

Generate the schema for the database and load some initial data:

./manage.py migrate
./manage.py loaddata navbar
./manage.py loaddata language_small
./manage.py loaddata demo

Create an admin account:

./manage.py createsuperuser

Running the server

You need to start MySQL and Redis after restart:

sudo service mariadb start
sudo service redis-server start

Let's run the server, and see if it all works:

./manage.py runserver 0.0.0.0:8000

Volatility is no longer packaged with Kali since 2020.4 release but can be manually installed.

sudo apt-get install pcregrep libpcre++-dev python-dev

git clone https://github.com/gdabah/distorm.git
cd distorm3
sudo python setup.py install

sudo apt-get install yara -y

wget https://ftp.dlitz.net/pub/dlitz/crypto/pycrypto/pycrypto-2.6.1.tar.gz
tar -xvzf pycrypto-2.6.1.tar.gz
cd pycrypto-2.6.1
sudo python setup.py install

wget https://github.com/volatilityfoundation/volatility/archive/refs/tags/2.6.1.tar.gz
tar -xvzf 2.6.1.tar.gz
cd volatility-2.6.1
sudo python setup.py install

Some web challenges require executing /readflag to get the flag. This executable will ask the user to compute some simple math. The timeout is very short, so the intended way to solve it is to write a script. However, there are better ways to solve it:

Solution 1: Trap the SIGALRM signal

$ trap "" 14 && /readflag 
Solve the easy challenge first (((((-623343)+(913340))+(-511878))+(791102))-(956792)) 
input your answer: -387571 
ok! here is your flag!! 

Solution 2: mkfifo trick

$ mkfifo pipe
$ cat pipe | ./readflag |(read l;read l;echo "$(($l))" > pipe;cat)
input your answer: 
ok! here is your flag!! 

Ref: https://balsn.tw/ctf_writeup/20190427-*ctf/#solve_readflag-(not-a-challenge)

sudo dpkg --add-architecture i386
sudo apt update
sudo apt install libc6:i386 libncurses5:i386 libstdc++6:i386
sudo apt install gcc-multilib g++-multilib # for compiling

In the spirit of OpenCourseWare and the Khan Academy, OpenSecurityTraining.info is dedicated to sharing training material for computer security classes, on any topic, that are at least one day long.

An inventory of tools and resources about CyberSecurity.

Install dependencies

sudo apt install build-essential texlive-latex-base openjdk-8-jdk-headless fp-compiler \
                 postgresql postgresql-contrib postgresql-client python3 python3-dev python3-pip \
                 cppreference-doc-en-html cgroup-lite wget curl llvm make tk-dev xz-utils zip \
                 libbz2-dev libcap-dev libcups2-dev libffi-dev libncursesw5-dev libpq-dev \
                 libreadline-dev libsqlite3-dev libssl-dev libxml2-dev libxmlsec1-dev libyaml-dev liblzma-dev zlib1g-dev

Install pyenv:

curl https://pyenv.run | bash

You may need to enable memory cgroup: https://github.com/canonical/microk8s/issues/1691#issuecomment-1279774327

Download CMS

cd ~
git clone --recursive https://github.com/ioi-2023/cms.git

Preparation

In order to run CMS, there are some preparation steps to run (like installing the sandbox, compiling localization files, creating the cmsuser group, and so on).

cd ~/cms
sudo python3 prerequisites.py install

Installing CMS and its Python dependencies

We'll install CMS in a virtual environment created by pyenv.

pyenv install 3.8.18
pyenv virtualenv 3.8.18 cms
pyenv local cms

pip install --upgrade pip setuptools wheel
pip install -r requirements.txt
python setup.py install

We also need to fix pycryptodomex:

2to3 -wWn --no-diffs ~/.pyenv/versions/cms/lib/python3.8/site-packages/Cryptodome

Configure the DB

We first need to start PostgreSQL:

sudo service postgresql start

The next thing to do is to create the user and the database. You need to log in as the postgres user first:

sudo su - postgres

Then, to create the user (which does not need to be a superuser, nor be able to create databases nor roles) and the database, run the following commands:

createuser --username=postgres --pwprompt cmsuser
createdb --username=postgres --owner=cmsuser cmsdb
psql --username=postgres --dbname=cmsdb --command='ALTER SCHEMA public OWNER TO cmsuser'
psql --username=postgres --dbname=cmsdb --command='GRANT SELECT ON pg_largeobject TO cmsuser'

The last two lines are required to give the PostgreSQL user some privileges which it does not have by default, despite being the database owner.

Enter exit to log out.

Configure CMS

Open /usr/local/etc/cms.conf and change the connection string given in database. This means to change username, password, and database with the ones you chose before.

Finally, you have to create the database schema for CMS:

cd ~/cms
cmsInitDB

Running CMS

Run WSLHostPatcher to make WSL2 listen for incoming connection on any interfaces (by default it only listens on localhost).

You need to create an admin user. This only needs to be done once:

cmsAddAdmin -p PASSWORD USERNAME

Start LogService:

cmsLogService

Start cmsAdminWebServer:

cmsAdminWebServer

Log in to the admin interface and create some contests. Now we can start all CMS services:

cmsResourceService -a