blog.lse.epita.fr
Parallelism - LSE Blog
https://blog.lse.epita.fr/cat/tutorials/parallelism/index.html
Operating systems, computer security, languages theory, and even more! CSAW CTF 2012 Quals. Implementing generic double-word compare and swap for x86/x86-64. Written by Marwan Burelle. Since the introduction of multi-core processors, parallel computing is growing in attention. While lock-based techniques have been studied for a long time, modern HPC require more scalable data structures. Lock-free data structures have proven better scaling by avoiding thread blocking. Implementing a double-word CAS is te...
blog.lse.epita.fr
DEFCON 2013 Quals - LSE Blog
https://blog.lse.epita.fr/cat/writeups/defcon-2013-quals/index.html
Operating systems, computer security, languages theory, and even more! CSAW CTF 2012 Quals. DEFCON 2013 Quals: Linked - Shellcode ( xff xe4 xcc) 3. Written by Ivan Delalande. Score 3 Link http:/ assets.shallweplayaga.me/linked.txt. This challenge was very simple in itself and didn't involve reversing a binary or finding a vulnerability :. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20. 1 2 3 4 5 6 7 8 9 10 11 12 13. Mov eax, ebx 8. To do that in less than 16 bytes, we had to replace our two first pop...
lse.epita.fr
EPITA Systems Laboratory - C!
https://www.lse.epita.fr/projects/c!.html
Is a programming language designed with system programming in mind and more specifically kernel programming. Is greatly inspired by C, but its syntax differs in a few key points in order to suppress a few ambiguities. Moreover it extends C with constructs which aims at simplifying system programming, such as syntactic sugar for often used constructs. C! Also adds object-oriented features. It enables us to focus on the frontend, and leaves machine code optimisation to tools that are proven reliable. AddPo...
blog.lse.epita.fr
NDH2K13 Quals - LSE Blog
https://blog.lse.epita.fr/cat/writeups/ndh2k13-quals/index.html
Operating systems, computer security, languages theory, and even more! CSAW CTF 2012 Quals. Written by Bruno Pujos. Reverse of a vm for finding the password Score 500 Link http:/ quals.nuitduhack.com/files/attachments/crackme.zip. The program was an elf x86 64, statically linked executable. When launching the crackme it just prints some stuff, then asks for a password on the standart input and finally writes "Bad Password". Corrupted section header size. After some time spent understanding how the vm wor...
blog.lse.epita.fr
Events - LSE Blog
https://blog.lse.epita.fr/cat/events/index.html
Operating systems, computer security, languages theory, and even more! CSAW CTF 2012 Quals. LSE Week 2016 Announcement. Written by Gabriel Laskar. For the sixth year, we are organising the LSE Summer Week mid-July to show the work we are doing here at the LSE, about various themes we like, have encountered or overall judge interesting. The presentations will be held in French as usual and we will try to record everything. All details are on the main page of the event: LSE Summer Week 2016. Heartbleed, te...
blog.lse.epita.fr
Tutorials - LSE Blog
https://blog.lse.epita.fr/cat/tutorials/index.html
Operating systems, computer security, languages theory, and even more! CSAW CTF 2012 Quals. Implementing generic double-word compare and swap for x86/x86-64. Written by Marwan Burelle. Since the introduction of multi-core processors, parallel computing is growing in attention. While lock-based techniques have been studied for a long time, modern HPC require more scalable data structures. Lock-free data structures have proven better scaling by avoiding thread blocking. Implementing a double-word CAS is te...
blog.lse.epita.fr
CSAW CTF 2012 Quals - LSE Blog
https://blog.lse.epita.fr/cat/writeups/csaw-ctf-2012-quals/index.html
Operating systems, computer security, languages theory, and even more! CSAW CTF 2012 Quals. CSAW CTF 2012: Web 400 writeup. Written by Pierre Bourdon. Note: this article uses MathJax to display formulas written in TeX. Please enable Javascript in order to see the formulas correctly. Now that we know this algorithm uses XOR as its main operation, we can use a very interesting property of this binary operator:. Plain oplus Key = Cipher Leftrightarrow Plain oplus Cipher = Key$. And it gives us. It turns out...
blog.lse.epita.fr
SecuInside2K12 Prequals - LSE Blog
https://blog.lse.epita.fr/cat/writeups/secuinside2k12-prequals/index.html
Operating systems, computer security, languages theory, and even more! CSAW CTF 2012 Quals. SecuInside2K12 Prequals: classico writeup. Written by Samuel Chevet. Like dethstarr, we had to fully reverse a given binary to understand how the protocol works. As usual, we have to pass a lot of checks. The first one can be summed up to the following C code:. 1 2 3 4 5 6 7 8 9 10 11 12 13. C read(0, buff, 0x50); if (*(DWORD*)buff = 0x182) if (*(DWORD*)buff 0x181) if (! Is created using the following function :.
blog.lse.epita.fr
NDH2K12 Prequals - LSE Blog
https://blog.lse.epita.fr/cat/writeups/ndh2k12-prequals/index.html
Operating systems, computer security, languages theory, and even more! CSAW CTF 2012 Quals. Written by Nicolas Hureau. We deemed it was a good idea to have some content to open our blog, therefore we chose to put it online right after the Nuit du Hack 2012 CTF prequals which happened March 24-25th. After the Codegate where we finished at the 14th place and first French team, we were confident that we could achieve a similar ranking during the NdH2k12 prequals. Written by Franck Michea. First binary of th...
blog.lse.epita.fr
Olympic-CTF 2014 - LSE Blog
https://blog.lse.epita.fr/cat/writeups/olympic-ctf-2014/index.html
Operating systems, computer security, languages theory, and even more! CSAW CTF 2012 Quals. Olympic-CTF 2014: zpwn (200 points). Written by Remi Audebert. This exercise was based on an IBM s/390 ELF running on a remote server which listens on UDP port 31337. The first thing we did was to setup. At first sight, the binary seems to send the entire buffer sent by the client via UDP. After disassembling it, we saw that the buffer is hashed and compared to a constant value: if the hash is equal to. Then, we d...