Category: Pwnable Points: 150 Solves: 86 Description:

Do you like reading books? here we have the best collection ever! you can even save some books for future reading!! enjoy noob! library.polictf.it:80

GPG key: yowlijOshSuftEvawvIshgugdecWikBi

johns-library

For this challenge, we're given a file named "johns-library". That is a 32-bit unstripped ELF file. Strings doesn't give us much info. Let's run it and see what happens.

We get presented with the following challenge:

John bets nobody can find the passphrase to login!

GPG key: viphHowrirOmbugTudIbavMeuhacyet'

crack-me-if-you-can

 

The file extracts to an apk (Android package file). Running strings on it doesn't give us any insight into what's going on. Let's load it into Genymotion: