rgbCTF Writeup(Rev/Pwn)
Hello everyone, i'm sh4d0wless and here is my writeup for some challenges in rgbCTF 2020. I joined this ctf for our ctf team Hex2Text( https://ctftime.org/team/84925 )Sorry for my really bad english :) Too Slow(Pwn/Rev) I've made this flag decryptor! It's super secure, but it runs a little slow. Check given binary with file command. file a.out a.out: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/l, BuildID[sha1]=462dfe207acdfe1da2133cac6b69b45de5169ee2, for GNU/Linux 3.2.0, not stripped İts 64 bit ELF binary. Lets run it When we run it, it says generating key but dont return anything :/ Yes, its "Too Slow" but we don't want to wait. Lets check the binary in ghidra. İn main function, it prints something and get key to uVar1 variable and run "win" function with this value. İn getKey function (i rename the variable names as i and x), it start a while loops with i=0 value and make the first loop contin