[ Docker ] Krypton Wargame 만들기 - 1번 문제 ( 3 / 8 )

1. Krypton1 목표

The password for level 2 is in the file ‘krypton2’.
It is ‘encrypted’ using a simple rotation.
It is also in non-standard ciphertext format.
When using alpha characters for cipher text it is normal to group the letters 
into 5 letter clusters, regardless of word boundaries. 
This helps obfuscate any patterns. 
This file has kept the plain text word boundaries and carried them to the cipher text.
Enjoy!

 

2. Krypton1 구현

# 비밀번호 root 입력 접속
ssh -oStrictHostKeyChecking=no root@localhost -p 2231

mkdir -p /krypton/krypton1

echo YRIRY GJB CNFFJBEQ EBGGRA > /krypton/krypton1/krypton2 

cat <<'EOF' > /krypton/krypton1/README
Welcome to Krypton!

This game is intended to give hands on experience with cryptography
and cryptanalysis.  The levels progress from classic ciphers, to modern,
easy to harder.

Although there are excellent public tools, like cryptool,to perform
the simple analysis, we strongly encourage you to try and do these
without them for now.  We will use them in later excercises.

** Please try these levels without cryptool first **


The first level is easy.  The password for level 2 is in the file
'krypton2'.  It is 'encrypted' using a simple rotation called ROT13.
It is also in non-standard ciphertext format.  When using alpha characters for
cipher text it is normal to group the letters into 5 letter clusters,
regardless of word boundaries.  This helps obfuscate any patterns.

This file has kept the plain text word boundaries and carried them to
the cipher text.

Enjoy!
EOF

chown krypton1:krypton1 /krypton/krypton1/*

chmod 640 /krypton/krypton1/*

# krypton2 유저를 생성하여 준다.
useradd krypton2 && echo -e "ROTTEN\nROTTEN" | passwd krypton2

echo 'ROTTEN' > /etc/krypton_pass/krypton2

chown krypton2:krypton2 /etc/krypton_pass/krypton2

chmod 400 /etc/krypton_pass/krypton2

 

3. Krypton1 문제풀의

# 비밀번호 : KRYPTONISGREAT
# ssh krypton1@krypton.labs.overthewire.org -p 2231
ssh krypton1@localhost -p 2231

# 힌트 확인(ROT13 하는 것을 확인)
cat /krypton/krypton1/README | grep ROT13

# 비밀번호 확인 : ROTTEN
cat /krypton/krypton1/krypton2 | tr 'A-Za-z' 'N-ZA-Mn-za-m' | awk '{ print $NF }'