FROM ubuntu:24.04 ARG PASSWORD ENV DEBIAN_FRONTEND noninteractive RUN echo root:${PASSWORD} | chpasswd COPY apt-insecure.conf /etc/apt/apt.conf.d/99gemastik-insecure RUN apt-get -o Acquire::AllowInsecureRepositories=true update && apt-get install -y openssh-server lib32z1 xinetd cmake gcc curl RUN echo "PasswordAuthentication yes" >> /etc/ssh/sshd_config RUN echo "PermitRootLogin yes" >> /etc/ssh/sshd_config RUN service ssh start RUN useradd -m ctf WORKDIR /ctf RUN echo "Connection blocked" > /etc/banner_fail COPY ctf.xinetd /etc/xinetd.d/ctf COPY ./src/main.c ./ COPY ./start.sh ./ RUN gcc /ctf/main.c -no-pie -fno-stack-protector -Wl,-z,relro,-z,now -o /ctf/main RUN touch /flag.txt RUN chmod -R 755 /ctf RUN chmod +x /ctf/start.sh ENTRYPOINT [] CMD ["/usr/sbin/xinetd", "-dontfork"] EXPOSE 8000