soal_pwn_ksl_seleksi/service_agent/Dockerfile

# Use ubuntu 16.04
FROM ubuntu:16.04

RUN apt-get update && apt-get -y dist-upgrade --fix-missing --fix-broken

# install socat editor ssh
RUN apt-get install curl netcat-openbsd vim nano openssh-server socat lib32ncurses5 python python-pip python-dev ruby-full -y

RUN adduser --disabled-password --gecos "" ksl
RUN echo "ksl:sebuahrahasiamas" | chpasswd

ADD chall/. /chall #membuat direktory chall
WORKDIR /chall #direktory chall akan digunakan sebagai tempat kerja

RUN cp /usr/bin/ruby /usr/local/bin/
RUN echo 'KSL{t3RM1naL_Linux_3azy}'  > /chall/flag.txt # ubah isi flagnya

# Secure ENV

RUN echo 'alias kill="echo no kill please!"' >> ~/.bashrc
RUN chmod 700 /tmp /usr/bin/* /bin/* /dev/shm #memberi hak akses 
RUN chmod 755 /usr/bin/env /bin/dash /bin/bash /bin/sh /bin/nc /bin/cat /usr/bin/curl /usr/bin/groups /usr/bin/id /bin/ls /usr/bin/python /usr/bin/ruby


RUN chown root:ksl /chall/service_agent.rb # ubah nama file
RUN chmod 775 /chall/service_agent.rb # ubah nama file

# Run Service

RUN echo '#!/bin/bash'"\n(socat TCP-LISTEN:7000,reuseaddr,fork EXEC:"/chall/service_agent.rb,su=nobody")" > /var/tmp/.start.sh && chmod +x /var/tmp/.start.sh

CMD ["/var/tmp/.start.sh"]