quals | More Smoked Leet Chicken

A slow descent into the dark, into madness, futility, and despair. BLT.jar (not necessary) STDOUT Flag.java Summary: DSA with short secrets, lattice + meet-in-the-middle attack.

2017, bitCount, Bleichenbacher, BSGS, crypto, ctf, discrete logarithm, DSA, google, insanity, java, lattice, LLL, meet-in-the-middle, python, quals, sage, writeup
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Jun 19

Google CTF 2017 Quals – Crypto writeups

By hellman in Writeups

Scripts with short explanations for all crypto tasks (except RSA) from Google CTF Quals 2017: Crypto Backdoor Introspective CRC Shake It RSA CTF Challenge (no writeup, but I think it’s similar to this old one) Rubik Bleichenbacher’s Lattice Task (full writeup here)

2017, blake, BSGS, collection, CRC, crypto, ctf, gists, google, lattice, Pohlig-Hellman, python, quals, Rubik, rust, sage, short, writeup
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Mar 14

0CTF 2016 Quals – Equation (Crypto 2 pts)

By hellman in Writeups

Here is a RSA private key with its upper part masked. Can your recover the private key and decrypt the file? equation.zip Summary: recovering RSA key from part of the private key.

0ctf, 2016, corrupted key, crypto, libnum, openssl, partial exposure, python, quals, rsa, writeup
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Mar 13

0CTF 2016 Quals – RSA? (Crypto 2 pts)

By hellman in Writeups

It seems easy, right? rsa.zip Tip: openssl rsautl -encrypt -in FLAG -inkey public.pem -pubin -out flag.enc Summary: factoring 300-bit modulus into 3 primes, extracting cube roots.

0ctf, 2016, cado-nfs, Cipolla-Lehmer, crt, crypto, cube root, factorization, openssl, python, quals, rsa, sage, writeup
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Feb 26

CodeGate 2012 Quals Forensic 500 Write-up

By vos in Writeups

This file is Forensic file format which is generally used. Check the information of imaged DISK, find the GUIDs of every partition. Answer: strupr((part1_GUID) XOR (part2_GUID) XOR …) Download : B704361ACF90390C17F6103DF4811E2D Forensic 500 features EWF format container with EFI GPT partition table.

2012, codegate, compression, encase, forensic, gpt, partition, quals, trid, writeup, xor, zlib
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Feb 26

CodeGate 2012 Quals Vuln500 Write-up

By vos in Writeups

1.234.41.7:22 ID : yesMan PWD : ohyeah123 Download vulnerable binary. Vuln500 was a hardened format-string vuln with ASLR, NX-stack, no-DTORs, RO .dynamic

2012, aslr, binary, codegate, cookie, CTB, formatstring, nx, quals, stack, writeup
2 comments

Feb 26

CodeGate 2012 Quals – Vuln 400

By hellman in Writeups

Here’s a web-based crypto challenge. Summary: padding oracle attack, bit flipping

2012, 400, codegate, crypto, ctf, padding oracle, python, quals, web
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Feb 26

CodeGate 2012 Quals Net400 Write-up

By vos in Writeups

Because of vulnerability of site in Company A, database which contains user’s information was leaked. The file is dumped packet at the moment of attacking. Find the administrator’s account information which was leaked from the site. For reference, some parts of the packet was blind to XXXX. Answer : strupr(md5(database_name|table_name|decode(password_of_admin))) (‘|’is just a character) Download …