System32.kr [HardCrypto] 풀이

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system32.kr의 HardCrypto 문제 풀이입니다.

HardCrypto.md

Do you know Hard Crypto? 
Find the Flag!! 
Ex)FLAG{ABCEDFG} 

Make my pental

Do_you_know_Crypto.txt

c075121115114075121115114075121115114075049115043075122052114075121115043075121115114075121115114075122052114075121115114075121115114075121115114080068119056080067049100080106052043076105115114075121115114075121052116076083048116076083048116076083048116076083052114075121115114075121115117080105115114075121115114075121115114075121115114075121115114075121115114075121115114075121115114076106119116076083048116076083052043076083048116076083048116076083048116076105048116076083048116076083048116076083048116076083048116076083048116076106119116076083048116076083048116076083048116076083048116076083048116076083052043075121115114075121115114075121115114075121115114075121052056075121115114075121115114075121115114075121115114075121115114075121115114075121115114076106052114075121115114075121115114076105048116076083048116076083048116076083048116076083048116076083048116076083052114075121115114075121115114075121052116076083048116076083048116076083048116076083048117080068119114075121115114075121115114075121115114075121115114075121115114075121115114076106052043075121115114075121115114075121115114075121115114075121115114075121115114075121115117076083048116076083048116076083048116076083048116076083048116076083048116076083048117080067052043075121115114075121115114075121115114075121115114075121115114075121115114075121115114075121052116076083048116076083048116076105052114075121115114075121115114075121115114075121052056075121115114075121115114075121115114075121115114075121115114075121115114075121115114075121115114075121052056075121115114075121115114075121115114075121115114075121115114075121115114076106052043076083048116076083048116076083052114075121115114075121115114076105048116076083048116076083048116076083052114075121115114076106119056076083048116076083048116076083048116076083048116076083048116076083048116076083052043080105115114075121115114075121115114075121052061

으어.... 일단 dec 2 string을 해보았습니다.

아스키로 보니 

KysrKysrKysrK1s+Kz4rKys+KysrKysrKz4rKysrKysrKysrPDw8PC1dPj4+LisrKysrKy4tLS0tLS0tLS0tLS4rKysrKysuPisrKysrKysrKysrKysrKysrKysrKysrLjwtLS0tLS4+LS0tLS0tLS0tLi0tLS0tLS0tLS0tLS0tLS0tLjwtLS0tLS0tLS0tLS0tLS0tLS4+KysrKysrKysrKysrKy48KysrKysrKysrKysrKysrKysrKysrLj4rKysrKysrLi0tLS0tLS0tLS0tLS0tLS0tLS4rKysrKysrKy4tLS0tLS0tLS0tLS0uPDwrKysrKysrKysrKysrKysrKysrLj4+KysrKysrKysrKysrKysrKysrKysuLS0tLS0tLS0tLS0tLS0tLS0tLS0uPC4+KysrKysrKysrKysrKysrKysrKysrKy4tLS0tLS0tLi4rKysrKysrKysrKy48KysrKysrKysrKysrKysrKysrKysrKysrKy48KysrKysrKysrKysrKysrKysrLj4+LS0tLS0tLS4rKysrKysrLi0tLS0tLS0tLS4rKysrLjw8LS0tLS0tLS0tLS0tLS0tLS0tLS4+PisrKysrKysrKy4=

처음엔 이 루트가 아닌줄 알았으나.. 마지막에 =을 보고 base64로 디코딩~

++++++++++[>+>+++>+++++++>++++++++++<<<<-]>>>.++++++.-----------.++++++.>+++++++++++++++++++++++.<-----.>---------.-----------------.<-----------------.>+++++++++++++.<+++++++++++++++++++++.>+++++++.------------------.++++++++.------------.<<+++++++++++++++++++.>>++++++++++++++++++++.--------------------.<.>++++++++++++++++++++++.-------..+++++++++++.<+++++++++++++++++++++++++.<++++++++++++++++++.>>-------.+++++++.---------.++++.<<-------------------.>>+++++++++.

이건...예전에 어떤 CTF에서 나왔던 문제였다는게 기억났는데...

뭐지뭐지 하다가 brainfuck 언어라는게 기억나서 바로 디코딩했습니다!

FLAG : FLAG{Bra1nFuck_1s_Funny_Crypt0}