SekaiCTF 2024 Challenges

Co-authored-by: 3dsboy08 <[email protected]>
Co-authored-by: Ankur Sundara <[email protected]>
Co-authored-by: Himanshu Sheoran <[email protected]>
Co-authored-by: Dimas Maulana <[email protected]>
Co-authored-by: ElleuchX1 <[email protected]>
Co-authored-by: hfz <[email protected]>
Co-authored-by: Arsenii es3n1n <[email protected]>
Co-authored-by: enscribe <[email protected]>
Co-authored-by: irogirctf <[email protected]>
Co-authored-by: t0m7r00z <[email protected]>
Co-authored-by: kanon <[email protected]>
Co-authored-by: Justin Applegate <[email protected]>
Co-authored-by: Aimar Adhitya <[email protected]>
Co-authored-by: Thijs Molendijk <[email protected]>
Co-authored-by: Adib Surani <[email protected]>
Co-authored-by: Allen Wu <[email protected]>
Co-authored-by: Bien Pham <[email protected]>
Co-authored-by: Quasar0147 <[email protected]>
Co-authored-by: rycbar <[email protected]>
Co-authored-by: Xiaohai Xu <[email protected]>
Co-authored-by: sun <[email protected]>
Co-authored-by: YanhuiJessica <[email protected]>
Co-authored-by: Zafir Rasyidi Taufik <[email protected]>

Author: 23 people

LICENSE

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+<div align="center">
+
+# ![Banner][Banner]
+
+![Code License: AGPL v3][Code License]
+![Non-Code License: CC BY-NC-SA 4.0][Non-Code License]
+![Stars][Stars]
+
+This repository contains official **source code** and **writeups** for challenges from [SekaiCTF 2024][CTFTime Event].
+
+[CTFTime Event][CTFTime Event] •
+[Website][Website] •
+[Discord][Discord] •
+[Blog][Blog] •
+[Twitter][Twitter]
+
+---
+
+</div>
+
+## Blockchains
+
+<img src="https://2024.ctf.sekai.team/themes/luna-vite/static/img/categories/Blockchains.svg" align="right" width=250>
+
+| Name                                           | Author | Difficulty | Solves |
+| ---------------------------------------------- | ------ | ---------- | ------ |
+| [Play to Earn](blockchains/play-to-earn)\*     | Y4nhu1 | Normal (2) | 68     |
+| [イベント！](blockchains/ibennto)\* (Ibennto!) | Y4nhu1 | Hard (3)   | 5      |
+| [SURVIVE](blockchains/survive)\*               | Y4nhu1 | Expert (4) | 5      |
+| [Zoo](blockchains/zoo)\*                       | snwo   | Expert (4) | 13     |
+
+## Cryptography
+
+<img src="https://2024.ctf.sekai.team/themes/luna-vite/static/img/categories/Crypto.svg" align="right" width=250>
+
+| Name                                                   | Author     | Difficulty | Solves |
+| ------------------------------------------------------ | ---------- | ---------- | ------ |
+| [Some Trick](crypto/some-trick)                        | deut-erium | Easy (1)   | 127    |
+| [はやぶさ](crypto/hayabusa) (Hayabusa)                 | kanon      | Hard (3)   | 38     |
+| [マスタースパーク](crypto/master-spark) (Master Spark) | kanon      | Hard (3)   | 23     |
+| [Squares vs. Cubes](crypto/squares-vs-cubes)           | Neobeo     | Expert (4) | 2      |
+| [√163](crypto/sqrt163)                                 | Neobeo     | Master (5) | 3      |
+| [zerodaycrypto](crypto/zerodaycrypto)\*                | Neobeo     | Append (6) | 4      |
+
+## Miscellaneous
+
+<img src="https://2024.ctf.sekai.team/themes/luna-vite/static/img/categories/Misc.svg" align="right" width=250>
+
+| Name                        | Author | Difficulty | Solves |
+| --------------------------- | ------ | ---------- | ------ |
+| [calcql](misc/calcql)       | irogir | Normal (2) | 32     |
+| [Hijacker](misc/hijacker)   | Marc   | Expert (4) | 13     |
+| [Miku Jail](misc/miku-jail) | Quasar | Master (5) | 5      |
+
+## PPC
+
+<img src="https://2024.ctf.sekai.team/themes/luna-vite/static/img/categories/PPC.png" align="right" width=250>
+
+| Name                                    | Author   | Difficulty | Solves |
+| --------------------------------------- | -------- | ---------- | ------ |
+| [Miku vs. Machine](ppc/miku-vs-machine) | null_awe | Easy (1)   | 176    |
+| [Nokotan](ppc/nokotan)                  | null_awe | Hard (3)   | 55     |
+| [Railgun](ppc/railgun)                  | null_awe | Master (5) | 18     |
+
+## Binary Exploitation
+
+<img src="https://2024.ctf.sekai.team/themes/luna-vite/static/img/categories/Pwn.svg" align="right" width=250>
+
+| Name                                     | Author      | Difficulty | Solves |
+| ---------------------------------------- | ----------- | ---------- | ------ |
+| [nolibc](pwn/nolibc)                     | Marc        | Normal (2) | 56     |
+| [speedpwn](pwn/speedpwn)\*               | Zafirr      | Normal (2) | 27     |
+| [Life Simulator 2](pwn/life-simulator-2) | Zafirr      | Hard (3)   | 15     |
+| [Process Flipper](pwn/process-flipper)   | nyancat0131 | Expert (4) | 3      |
+| [Context Reducer](pwn/context-reducer)\* | rycbar      | Append (6) | 1      |
+
+## Reverse Engineering
+
+<img src="https://2024.ctf.sekai.team/themes/luna-vite/static/img/categories/Reverse.svg" align="right" width=250>
+
+| Name                                         | Author       | Difficulty | Solves |
+| -------------------------------------------- | ------------ | ---------- | ------ |
+| [Crack Me](reverse/crack-me)                 | sahuang      | Normal (2) | 187    |
+| [X64 Extension](reverse/x64-extension)       | Iyed         | Hard (3)   | 64     |
+| [Magnum Opus](reverse/magnum-opus)           | Legoclones   | Expert (4) | 22     |
+| [Secure Computing](reverse/secure-computing) | molenzwiebel | Master (5) | 6      |
+| [Sekai Licensing](reverse/sekai-licensing)\* | 3dsboy08     | Master (5) | 0      |
+
+## Web
+
+<img src="https://2024.ctf.sekai.team/themes/luna-vite/static/img/categories/Web.svg" align="right" width=250>
+
+| Name                           | Author       | Difficulty | Solves |
+| ------------------------------ | ------------ | ---------- | ------ |
+| [Tagless](web/tagless)         | ElleuchX1    | Easy (1)   | 160    |
+| [Funny lfr](web/funny-lfr)     | irogir       | Normal (2) | 36     |
+| [Intruder](web/intruder)       | Marc         | Hard (3)   | 89     |
+| [lookup](web/lookup)           | irogir       | Hard (3)   | 5      |
+| [NDWPP](web/ndwpp)             | DimasMaulana | Expert (4) | 8      |
+| [htmlsandbox](web/htmlsandbox) | arxenix      | Master (5) | 4      |
+
+> [!NOTE]
+> Challenges marked with an asterisk (`*`) had a bounty placed on them either during the CTF or afterwards.
+
+## License
+
+Any **program** and/or **source code** in this repository is licensed under the [GNU Affero General Public License version 3][agpl]:
+
+<blockquote>
+
+SEKAI CTF 2024 Challenges and Solutions  
+Copyright (C) 2024 Project SEKAI CTF team and contributors
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published
+by the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+</blockquote>
+
+Any **non-code/program content** (writeups, READMEs, descriptions) in this repository is licensed under a [Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License (CC BY-NC-SA 4.0)](cc-by-nc-sa):
+
+> [SEKAI CTF 2024 Challenges and Solutions](https://github.com/project-sekai-ctf/sekaictf-2024/) by Project SEKAI CTF team and contributors is licensed under a [Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License][cc-by-nc-sa].
+
+[Banner]: https://files.catbox.moe/sps53u.png
+[Stars]: https://img.shields.io/github/stars/project-sekai-ctf/sekaictf-2024?color=FFA803&style=for-the-badge
+[CTFTime Event]: https://ctftime.org/event/2243
+[Website]: https://ctf.sekai.team/
+[Blog]: https://sekai.team/
+[Twitter]: https://twitter.com/projectsekaictf
+[Discord]: https://discord.gg/6gk7jhCgGX
+[agpl]: https://www.gnu.org/licenses/agpl-3.0.en.html
+[cc-by-nc-sa]: https://creativecommons.org/licenses/by-nc-sa/4.0/
+[Non-Code License]: https://img.shields.io/badge/non--code%20license-CC%20BY--NC--SA%204.0-3cc4c7?style=for-the-badge
+[Code License]: https://img.shields.io/badge/code%20license-AGPL--3.0-db67d2?style=for-the-badge

LICENSE.content.md

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+# Blockchains
+
+<img src="https://2024.ctf.sekai.team/themes/luna-vite/static/img/categories/Blockchains.svg" align="right" width=300>
+
+| Name                             | Author | Difficulty | Solves |
+| -------------------------------- | ------ | ---------- | ------ |
+| [Play to Earn](play-to-earn)     | Y4nhu1 | Normal (2) | 68     |
+| [イベント！ (Ibennto!)](ibennto) | Y4nhu1 | Hard (3)   | 5      |
+| [SURVIVE](survive)               | Y4nhu1 | Hard (4)   | 5      |
+| [Zoo](zoo)                       | snwo   | Expert (4) | 13     |

README.md

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+## イベント！ (Ibennto!)
+
+| Author | Difficulty | Points | Solves | First Blood | Time to Blood |
+| ------ | ---------- | ------ | ------ | ----------- | ------------- |
+| Y4nhu1 | Hard (3)   | 423    | 5      | Nu1L        | 2 hours       |
+
+---
+
+### Description
+
+Tags: `Bounty`, `SEKAI`
+
+<blockquote>
+
+The event has started! :D
+
+> ❖ **Note**  
+> Blockchain bounties apply to this challenge.
+
+<!-- <details closed>
+<summary><b>Hint(s)</b>:</summary>
+
+1. Hint 1
+2. Hint 2
+
+</details> -->
+</blockquote>
+
+### Challenge Files
+
+- [dist.zip](dist)
+
+### Blockchain Bounty
+
+| Blood  | Bounty (USD) | Team Name | Time to Blood |
+| ------ | ------------ | --------- | ------------- |
+| First  | $100         | Nu1L      | 2 hours       |
+| Second | $50          | idek      | +5 hours      |
+| Third  | $30          | CyKor     | +28 minutes   |

blockchains/README.md

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+FROM debian:bullseye-slim
+COPY --from=krallin/ubuntu-tini /usr/bin/tini /tini
+ENTRYPOINT ["/tini", "--"]
+
+RUN apt-get update && \
+    apt-get -y install libudev-dev libssl-dev pkg-config && \
+    rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+COPY . .
+RUN chmod +x server
+
+EXPOSE 1337
+USER nobody
+CMD ["/app/server"]

blockchains/ibennto/README.md

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+SEKAI{mY_h4nd5_10vE_12hy7hm_G4m3s_:3}