Created
May 22, 2017 00:26
Star
You must be signed in to star a gist
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
import socket, struct, os, binascii, base64, hashlib | |
import telnetlib | |
import rsa | |
from gmpy2 import mpz, iroot, powmod, mul, t_mod | |
def readline(sc, show = True): | |
res = "" | |
while len(res) == 0 or res[-1] != "\n": | |
data = sc.recv(1) | |
if len(data) == 0: | |
print repr(res) | |
raise Exception("Server disconnected") | |
res += data | |
if show: | |
print repr(res[:-1]) | |
return res[:-1] | |
def read_until(sc, s): | |
res = "" | |
while not res.endswith(s): | |
data = sc.recv(1) | |
if len(data) == 0: | |
print repr(res) | |
raise Exception("Server disconnected") | |
res += data | |
return res[:-(len(s))] | |
def read_all(sc, n): | |
data = "" | |
while len(data) < n: | |
block = sc.recv(n - len(data)) | |
if len(block) == 0: | |
print repr(data) | |
raise Exception("Server disconnected") | |
data += block | |
return data | |
def I(n): | |
return struct.pack("<I", n) | |
def Q(n): | |
return struct.pack("<Q", n) | |
def to_bytes(n): | |
""" Return a bytes representation of a int """ | |
s = "" | |
while n > 0: | |
s = chr(n & 0xff) + s | |
n = n >> 8 | |
return s | |
def from_bytes(b): | |
""" Makes a int from a bytestring """ | |
return int(binascii.b2a_hex(b), 16) | |
def get_bit(n, b): | |
""" Returns the b-th rightmost bit of n """ | |
return ((1 << b) & n) >> b | |
def set_bit(n, b, x): | |
""" Returns n with the b-th rightmost bit set to x """ | |
if x == 0: return ~(1 << b) & n | |
if x == 1: return (1 << b) | n | |
def cube_root(n): | |
return int(iroot(mpz(n), 3)[0]) | |
message = "Rule110 baby!!".encode("ASCII") | |
message_hash = hashlib.md5(message).digest() | |
ASN1_blob = rsa.pkcs1.HASH_ASN1['MD5'] | |
suffix = b'\x00' + ASN1_blob + message_hash | |
assert ord(suffix[-1]) & 1 == 1 | |
sig_suffix = 1 | |
for b in range(len(suffix)*8): | |
if get_bit(sig_suffix ** 3, b) != get_bit(from_bytes(suffix), b): | |
sig_suffix = set_bit(sig_suffix, b, 1) | |
assert to_bytes(sig_suffix ** 3).endswith(suffix) | |
print len(to_bytes(sig_suffix ** 3)) * 8 | |
while True: | |
prefix = b'\x00\x01' + os.urandom(1024/8 - 2) | |
sig_prefix = to_bytes(cube_root(from_bytes(prefix)))[:-len(suffix)] + b'\x00' * len(suffix) | |
sig = sig_prefix[:-len(suffix)] + to_bytes(sig_suffix) | |
if b'\x00' not in to_bytes(from_bytes(sig) ** 3)[:-len(suffix)]: break | |
assert to_bytes(from_bytes(sig) ** 3).endswith(suffix) | |
assert to_bytes(from_bytes(sig) ** 3).startswith(b'\x01') | |
assert len(to_bytes(from_bytes(sig) ** 3)) == 1024/8 - 1 | |
assert b'\x00' not in to_bytes(from_bytes(sig) ** 3)[:-len(suffix)] | |
print binascii.hexlify(sig) | |
print binascii.hexlify(to_bytes(from_bytes(sig) ** 3)) | |
sc = socket.create_connection(("rsasign2.2017.teamrois.cn", 3001)) | |
read_until(sc, "Show me your magic words:") | |
sc.send(message + "\n") | |
read_until(sc, "Show me again:") | |
sc.send(binascii.b2a_hex(sig) + "\n") | |
# t = telnetlib.Telnet() | |
# t.sock = sc | |
# t.interact() | |
while True: | |
data = sc.recv(16384) | |
if len(data) == 0: | |
break | |
for line in data.split("\n"): | |
print repr(line) | |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment