p = remote("crypto.hsctf.com",8111) s = p.recvline_contains("secret")[-106:] print"secret message: " + s flag = "" j = 0
whileTrue: for i in range(33,127): #p.recvuntil('encrypt: ') p.sendline(flag+chr(i)) p.recvuntil('Encrypted: ') r = p.recvline() #print flag+chr(i) #print r #print s[j:j+2] if s[j:j+2] == r.strip()[-2:]: print"Gotta." flag += chr(i) print flag j += 2 print j if j == 104: print"solved!" break print flag