39 lines
2.0 KiB
Markdown
39 lines
2.0 KiB
Markdown
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# mapleCTF 2023
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what IS UP chat we're back at it again with another writeup post
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last weekend i played [MapleCTF 2023](https://ctf2023.maplebacon.org) with my team
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[BLÅHAJ](https://blahaj.awoo.systems) (raised from the dead, i don't remember when the last time i
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played as/with BLÅHAJ was but it's been like. a hot second)
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there were a couple of interesting challenges in this CTF. BLÅHAJ ended up placing 5th, with a team
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of like just a handful of people, which i thought was actually pretty impressive
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the challenges we solved that were valued the most points at the end of the CTF were
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- flakey ci (misc, 489 points). this was surprising! flakey ci was literally trivial, so i'm
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surprised more people didn't solve it. maybe they were scared of nix. perhaps i had an unfair
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advantage being a nix user.....
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- merkle (crypto, 472 points). also surprising! i'm not sure i would classify merkle as a crypto
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challenge, it was more just implementing state recovery of internal data structures using
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probabalistic output. it was not the most time consuming ever to solve, by far
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- lost-in-space (pwn, 456 points). still surprising,,, like this was a fairly straightforward
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challenge that required you to implement a graph search algorithm in shellcode with a limited
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amount of program memory/stack. it was interesting, but it wasn't *hard* imo
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- AaaS (misc, 436 points). i wasn't involved in solving this one, but it was basically just python
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trivia. a writeup on this wouldn't be very involved
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- **coinflip** (misc, 425 points). this one was actually really interesting imo. the discussion on
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this challenge goes into some depth
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so basically here's a writeup on coinflip. the writeup is structured in a way to guide you through
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the background information required to develop a solution and the thought process involved, so if
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you don't rly care about that you can skip to the end with the actual solution script
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enjoy~
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<!--
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writeup index:
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- [misc: coinflip](#manipulating-python-rng-using-the-seed-coinflip)
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-->
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