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| from Crypto.Cipher import AES
from Crypto.Util.number import long_to_bytes
from datetime import datetime, timedelta
from pickle import loads
from hashlib import md5
from requests import *
from math import floor
from libnum import n2s
import time
A = md5(b'A').hexdigest()[:16]
B = md5(b'B').hexdigest()[:16]
S = md5(b'S').hexdigest()[:16]
delta_8_hours = timedelta(hours=8)
url = 'http://8.147.131.163:15917'
token_A = A
token_B = B
def regist(url,token):
print(f'[+] use token : {token}')
prefix = '/register'
params = {'token':token}
result = get(url+prefix,params)
print(result.text)
cur_key = eval(result.text)["key_to_server"]
print(f'[+] get key : {cur_key}')
return cur_key
def send_msg(url,token,target_token,target,cur_key_token):
prefix = '/send_message'
timestamp_minus_8_hours = datetime.fromtimestamp(time.time()) - delta_8_hours
t = timestamp_minus_8_hours.timestamp()
t = n2s(int(t)).rjust(16, b'0')
source = bytes.fromhex(target_token)
key = b'\x00' * 16
pad = b'\x00' * 8
msg = t + source + key + pad
Cipher = AES.new(bytes.fromhex(cur_key_token), AES.MODE_ECB)
message = Cipher.encrypt(msg)
payload = message.hex()
assert len(payload) == 16 * 3 * 2
if not len(payload) == 16 * 3 * 2:print('?')
params = {'token':token,'to':target,'message':payload}
result = get(url+prefix,params)
return result.text
def send_flag(url,token):
prefix = '/send_flag'
params = {'token':token}
result = get(url+prefix,params)
return result.text
def exchange(url,token):
prefix = '/A_and_B'
params = {'token':token}
result = get(url+prefix,params)
return result.text
def view_history(url,token):
prefix = '/view_history'
params = {'token':token}
result = get(url+prefix,params)
return(result.text)
'''
#打法一，直接伪造A对B的发信密钥，让A和B交换一次会话密钥，用发信密钥解密，之后通话就随便监听了
A_key = regist(url,A)
#B_key = regist(url,B)
print(f'A_key={A_key}')
#print(f'B_key={B_key}')
exchange(url,A)
#view_history(A)
send_flag(url,A)
print(view_history(url,A))
'''
'''
#打法二，利用send_message函数去控制双方的会话密钥，强行让他们相等
A_key = regist(url,A)
send_msg(url,A,B,'A',A_Key)
send_msg(url,A,A,'B',A_Key)
send_flag(url,A)
print(view_history(url,A))
#凭记忆写的，可能流程不太对，大致这个思路能过，好处是直接一次性拿下会话密钥。
'''
'''
print(A)
key = '5fa11352bb62df887404c4da9a8357c9'
Cipher = AES.new(bytes.fromhex(key),AES.MODE_ECB)
orin_key_cipher = 'ad6c4e00649df28c1e89ea2c19ed49c8257e4cf9d66ed7b76fc76b17254fd5859c10b0c5983f4b3d35e78ac8d2649594'
print(bytes.fromhex(orin_key_cipher))
key_ = Cipher.decrypt(bytes.fromhex(orin_key_cipher))
print(key_)
print(key_[32: 48].hex())
key0 = 'b5768d25a0c3a76516136dc81e852300'
Cipher = AES.new(bytes.fromhex(key0),AES.MODE_ECB)
orin_cipher = '90ceb8ced60d9ed6d244edb9345505273ec51c9e32ff15bfd4bba14b0b1cbefdeb699c3a18affbf5fab5b91051f893f6'
flag = Cipher.decrypt(bytes.fromhex(orin_cipher))
print(flag)
'''
|