RTCP - HOOOOOOOOOOMEEEEEE RUNNNNNNNNNNNNN!!!!!

Posted on sam. 25 janvier 2020 in CTF

solves : 605

Point : 50
AND JAKE IS ROUNDING THE BASES
HE PASSES BASE 32!!!
HE ROUNDS BASE 64!!!!!!!
WE'RE WITNESSING A MIRACLE!!!!!!!!!!!!!

Just one more base to go ;D

Hint : Ecbf1HZ_kd8jR5K?[";(7;aJp?[4>J?Slk3<+n'pF]W^,F>._lB/=r

We are looking for the a new base encoding and this base is the next one after base64. It's not base128 and should be a base between 64 et 128.

After some research, we found that the base85 exists. We can use it with the code found in github : https://github.com/judsonx/base85.

We clone, build and make the code from the source. We can put the hint within a file or use | to avoit it.

$ echo "Ecbf1HZ_kd8jR5K?[\";(7;aJp?[4>J?Slk3<+n'pF]W^,F>._lB/=r" | ./build/ascii85 -d
rtcp{uH_JAk3_w3REn't_y0u_4t_Th3_uWust0r4g3}