Alien Camp Writeup

Solved By : thewhiteh4t

• The challenge server sends a randomized set of emoji and value pair
• We can get all pairs from option 1
• After getting all pairs we can start calculating values for each question
• If you get EOF Error just restart the script
• After 500 questions we get the flag

    #!/usr/bin/env python3
    
    from pwn import *
    
    host = '46.101.82.40'
    port = 32156
    conn = remote(host, port)
    conn.recvuntil('>').decode()
    print('[+] Getting some help...')
    conn.send('1\n')
    out = conn.recvuntil('\n>').decode()
    help_arr = out.split('\n')
    help_txt = help_arr[2]
    store = help_txt.split(' ')
    emojis = []
    vals = []
    new_store = {}
    counter = 0
    for item in store[0::3]:
        if len(item) > 0:
            emojis.append(item)
    for item in store [2::3]:
        vals.append(item)
    for emo in emojis:
        new_store[emo] = vals[emojis.index(emo)]
    if len(new_store) != 0:
        print('[+] Help recieved!')
    conn.send('2\n')
    def solve(conn):
        global counter
        if counter != 500:
            q_txt = conn.recvuntil('?').decode()
            q_txt = q_txt.split('\n')
            q_txt = q_txt[-1]
            print(f'[Q:{counter}] {q_txt}')
            q_txt = q_txt.split('  =')
            q_txt = q_txt[0]
            q_emo = q_txt.split(' ')
            for elem in q_emo:
                if elem in new_store:
                    q_txt = q_txt.replace(elem, new_store[elem])
            ans = eval(q_txt)
            print(f'[+] Sending {ans}')
            conn.send(str(ans) + '\n')
        else:
            flag = conn.recvuntil('}').decode()
            print(flag)
            conn.close()
        counter += 1
    while counter <= 500:
        solve(conn)