## MODERN CLUELESS CHILD The main idea finding the flag is decryption using XOR keys. #### Step-1: After reading the given message: ```bash I was surfing the crimson wave and oh my gosh I was totally bugging. I also tried out the lilac hair trend but it didn't work out. That's not to say you are any better, you are a snob and a half. But let's get back to the main question here- Who am I? (You don't know my name) Ciphertext = "52f41f58f51f47f57f49f48f5df46f6ef53f43f57f6cf50f6df53f53f40f58f51f6ef42f56f43f41f5ef5cf4e" (hex) Key = "12123" ``` #### Step-2: I quickly removed the `f` from cipher text as looked like it was used for space. So I wrote a script `sub.py` to replace `f` with `''`. ```python ciphertext = "52f41f58f51f47f57f49f48f5df46f6ef53f43f57f6cf50f6df53f53f40f58f51f6ef42f56f43f41f5ef5cf4e" sub = ciphertext.replace('f','') print(sub) ``` On running `python3 sub.py` this, it gave me `52415851475749485d466e5343576c506d53534058516e425643415e5c4e`. #### Step-3: I had to check if I am not missing any cipher text so I cross check the flag by XOR checks. So, I wrote this `xor1.py` script get the `csictf{` code: ```python from pwn import xor flag = bytes.fromhex('52415851475749485d466e5343576c506d53534058516e425643415e5c4e') print(xor(flag, 'csictf{'.encode())) ``` Output: ```bash b"1212312+./\r'%,\x0f#\x040'\x1d+57'%?=" ``` #### Step-4: Since we got the key `1212312` means we are right path as key has cyclic property key (12123). Now it was just replacement on the key with ASCII. `exlpoit.py` to get flag: ```python from pwn import xor flag = bytes.fromhex('52415851475749485d466e5343576c506d53534058516e425643415e5c4e') print(xor(flag, '12123'.encode())) ``` On running `python3 exploit.py`, Voila! I got the flag. ```bash b'csictf{you_are_a_basic_person}' ``` #### Step-5: Finally the flag becomes: `csictf{you_are_a_basic_person}`