Examples — real CTF challenges solved with this toolkit

Every example is reproducible offline (no live server, no sage) and uses lib/crypto_utils.py / lib/net.py where applicable. Solved by distilling patterns from the public p4-team/ctf archive.

Challenge	Event	Category	Vuln	Flag
`ps_and_qs`	SECCON 2017 Quals	Crypto	Two RSA keys share a prime (`gcd(n1,n2)=p`)	`SECCON{1234567890ABCDEF}`
`lost_modulus`	HITCON 2019 Quals	Crypto	RSA leaks `e,d,iqmp,ipmq` but not `n` — recover `n`	`hitcon{1t_is_50_easy_t0_find_th3_modulus_back@@!!@!@!@@!}`
`a2s`	Pwn2Win 2021	Crypto	2-round reduced AES — differential attack recovers key	`CTF-BR{bu7_1f_7h0u6h7_c0rrup75_l4n6u463,_l4n6u463_c4n_4l50_c0rrup7_7h0u6h7}`
`russian_threesome`	Hack.lu 2020	RE/Misc	Inverse-permutation fixed-point on a drum dump (CP1251)	`Кто хочет много знать, тому мало спать.`
`mask`	TokyoWesterns 2020	Misc	Host bits of `IP/mask` list → base64 → flag	`TWCTF{Are-you-using-a-mask?}`

Run them

cd /home/code/ctfkit

# crypto — self contained
python3 examples/ps_and_qs.py
python3 examples/lost_modulus/solve.py

# a2s — runs the differential attack then extracts the flag
cd examples/a2s && python3 solve.py && cd ../..

# russian_threesome — permutation fixed point
python3 examples/russian_threesome/solve.py

# mask — IP/mask host bits -> base64
python3 examples/mask/solve.py

1.5 KiB Raw Blame History

Examples — real CTF challenges solved with this toolkit

Run them

1.5 KiB

Raw Blame History