--- title: local flag --- # flag server ```python= from flask import Flask, request, jsonify import hashlib import time def hash(data): m = hashlib.md5() m.update(data.encode('utf-8')) return m.hexdigest() def get_start_time(): t = open("start_time.txt",'r') start_time = t.readline() t.close() return start_time app = Flask(__name__) try: start_time = get_start_time() except: t = open("start_time.txt",'w') t.write(str(time.time())) t.close() start_time = get_start_time() @app.route("/get_flag",methods=['POST']) def get_flag(): if request.method == 'POST': ip = request.remote_addr flag = hash(ip + str((time.time() - float(start_time))//(30*60)) + "OQGKJ") return flag app.run(port=8080,debug=True) ``` # flag.exe ```python= import requests import time r = requests.post("http://127.0.0.1:8080/get_flag") t = open("flag_{}.txt".format(time.time()),'w') t.write(r.text) t.close() ```