ʕ·ᴥ·ʔ

from pwn import *

p = remote("tamuctf.com", 443, ssl=True, sni="encryptinator")

p.sendlineafter(b"> ", b"1")
p.sendlineafter(b": ", b"A")

p.sendlineafter(b"> ", b"2")
p.sendlineafter(b": ", str(0).encode())
p.recvuntil(b":\n")
enc = p.recvline()[:64]

print(f"enc: {enc}")

p.sendlineafter(b"> ", b"2")
p.sendlineafter(b": ", str(-3112).encode())
p.recvuntil(b":\n")
iv = p.recvline()[:16]

print(f"iv: {iv}")

p.sendlineafter(b"> ", b"2")
p.sendlineafter(b": ", b"-3248")
p.recvuntil(b":\n")
rng = p.recvline()[:64]

print(f"rng: {rng}")

def unhex (s):
    assert(len(s) % 2 == 0)
    result = []
    for i in range(0, len(s), 2):
        result.append(int(s[i:i+2], 16))
    return result

enc = unhex(enc)
iv = unhex(iv)
rng = unhex(rng)
flag = ""

for i in range(len(enc)):
    flag += chr(enc[i] ^ rng[i] ^ iv[i % 8])

print(flag)