hxp CTF 2022 hxp

2022

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secure_flag_dispenser

by kirschju
misc rev crypto

Difficulty estimate: easy - easy

Points: round(1000 Ā· min(1, 10 / (9 + [15 solves]))) = 417 points

Description:

With all that recent hype about VPNs and everything good olā€™ hxp had to up their crypto game, so we added network-based security to this flag dispenser. We think thatā€“despite our ageā€“weā€™re still perfectly capable of producing flawless C code, but to be extra safe, we cranked up the compiler-based defenses during compilation of the server and enabled clangā€™s safe stack.

Besides the server we provide captured traffic from and to that port for you to analyse, could you please check that we got it right?

Note: We did not modify the source code of the statically linked crypto library.


Download:

secure_flag_dispenser-3e953071990b9bd6.tar.xz (1.5 MiB)

Solved by:

# Team Time
secure_flag_dispenser released 2023-03-10 16:00
šŸ„‡ thehackerscrew 2023-03-10 19:38
šŸ„ˆ pasten 2023-03-10 21:31
šŸ„‰ copy 2023-03-10 23:37
4 Aali 2023-03-11 03:08
5 PLUS 2023-03-11 09:27
6 Kalmarunionen 2023-03-11 10:10
7 Blue Water 2023-03-11 11:18
8 Dragon Sector 2023-03-11 14:50
9 Zer0Tolerance 2023-03-11 18:01
10 ALLES! 2023-03-11 21:21
11 KITCTF 2023-03-11 21:25
12 idek 2023-03-12 10:54
13 r3kapig 2023-03-12 11:33
14 purf3ct 2023-03-12 12:16
15 RedRocket 2023-03-12 12:41