hm0x14-ctf/ecb/crypto1/solution.py
2019-05-14 16:29:52 +02:00

38 lines
760 B
Python

from base64 import b64decode
import socket
from Crypto.Cipher import AES
server = '127.0.0.1'
port = 8000
chars = 'abcdefghijklmnopqrstuvwxyz01234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ{}_'
flag_blocks = 2
block_size = 16
index = {}
flag = ''
for i in range(block_size-1, 1, -1):
for j in chars:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((server, port))
data = s.recv(4096)
s.send(('a'*i).encode('ascii'))
value = b64decode(s.recv(4096)).hex()[0:32]
s.close()
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((server, port))
data = s.recv(4096)
s.send(('a'*i+flag+j).encode('ascii'))
test = b64decode(s.recv(4096)).hex()[0:32]
s.close()
if value == test:
flag += j
break
print(flag)