finally works!

app.py

@@ -1,52 +1,128 @@
 from flask import Flask, render_template, request, make_response, redirect
-from numpy import real
 from freecaptcha import captcha
 import uuid
 import os
+from cryptography.fernet import Fernet
+import jwt
+import base64
+
+# Generate a new AES key
+key = Fernet.generate_key()
+
+JWT_SECRET_KEY = 'obviously this needs to be an env variable secret thingie.'
+
+# Create an instance of the Fernet cipher with the key
+cipher = Fernet(key)
+
+# Encrypt a message
+message = b'This is a secret message.'
+ciphertext = cipher.encrypt(message)
+
+# Decrypt the ciphertext
+
+
 
 app = Flask(__name__, static_url_path='', static_folder='static',)
 
-captcha_solutions = {}
-captcha_solved = []
-
-@app.route("/captcha2", methods=['GET'])
-def captcha2():
-    with open('templates/captcha2play.html') as play_template_file:
-        return play_template_file.read()
-
-@app.route("/captcha3", methods=['GET'])
-def captcha3():
-    return captcha.generate_captcha_html(os.listdir('static/images/'))
 
 @app.route("/captcha", methods=['GET', 'POST'])
+def captcha_handler():
+    if request.method == "POST":
+        captcha_attempt = len(list(request.form))
+        token = request.cookies.get('Authorization').split('Bearer ')[-1]
+        try:
+            # TODO: set JWT to expire very soon.
+            payload = jwt.decode(token, JWT_SECRET_KEY, algorithms=['HS256'])
+            b64_and_encrypted_correct_answer = payload['encrypted_correct_answer']
+            encrypted_correct_answer_bytes = base64.b64decode(b64_and_encrypted_correct_answer)
+            correct_answer = cipher.decrypt(encrypted_correct_answer_bytes).decode('utf-8').split('|||')[0]
+            return f'''
+            The correct answer was {correct_answer}
+            You flipped it {captcha_attempt}
+            '''
+
+        except jwt.ExpiredSignatureError:
+            return 'Token expired. Please log in again.'
+
+        except jwt.InvalidTokenError:
+            return 'Invalid token. Authentication required.'
+        ## Get their guess from POST body
+        ## Get JWT cookie
+        ## Decrypt payload
+        ## Check if guess (from post body) == correct answer (from decrypted JWT payload)
+        ## If so: give them a new JWT for winning the CAPTCHA, and forward them to the URL they originally wanted to access precaptcha (just like oauth does)
+        ## If not: Redirect them to the GET version of this same URL, with warning enabled to tell them they failed
+    if request.method == "GET":
+        image_path = captcha.random_image()
+        answer, options = captcha.captchafy(image_path)
+        print('the correct answer is: ', answer)
+        # remember to store the salt since we'll need it when we compare the hashes
+        salt = uuid.uuid4()
+        plaintext_bytes = bytes(str(answer) + '|||' + str(salt), 'utf-8')
+        encrypted_bytes = cipher.encrypt(plaintext_bytes)
+
+        ciphertext = base64.b64encode(encrypted_bytes).decode('utf-8')
+        token = jwt.encode({
+            'encrypted_correct_answer': ciphertext,
+            'salt': str(salt)
+        }, JWT_SECRET_KEY, algorithm='HS256')
+
+        # Set the Authorization header cookie with the JWT
+        resp = make_response(captcha.generate_captcha_html(list(options)))
+        resp.set_cookie('Authorization', f'Bearer {token}')
+
+        return resp
+        # Set JWT with encrypted answer as HTTP cookie
+        # issue: they could compare our encrypted answer with how we encrypt all numbers 1-6, since they will have seem them before.
+        # We could solve this with a salt, but then we have to store salts. We could include the salt in plaintext, but then they could build a rainbow table of our guess + salts (since there are only 6 possible guesses)
+        # the solution is to use salts big enough that we don't have to fear them repeating / being turned into a rainbow table.
+        # We will use UUID's as the salts.
+        #
+        # Anyway, we pass the data to our Jinja template and render it.
+    # Flask should take care of unsupported methods for us.
+
+
+
+    ## Handle cookie
+
+    ## Get random image
+    ## Generate 
+    return captcha.generate_captcha_html(os.listdir('static/images/'))
+
+@app.route("/captcha_old", methods=['GET', 'POST'])
 def login():
     # This means they just submitted a CAPTCHA
     # We need to see if they got it right
     incorrect_captcha = False
     if request.method == 'POST':
-        captcha_quess = request.form.get('captcha', None)
+        captcha_guess = len(list(request.form))
+        print(request.form.get('captcha'))
+        # What if they POST with the cookie below absent? Uh oh...
         captcha_cookie = request.cookies.get('freecaptcha_cookie')
+
         real_answer = captcha_solutions.get(captcha_cookie, None)
         if real_answer is not None:
-            if int(captcha_quess) == int(real_answer):
+            if captcha_guess == int(real_answer):
                 captcha_solved.append(captcha_cookie)
                 return redirect("/", code=302)
             else:
                 incorrect_captcha = True
                 
+
     # Select an image
     image_path = captcha.random_image()
 
     # Generate list of rotated versions of image
     # and save which one is correct
+    # change answer to be the number of turns needed?
     answer, options = captcha.captchafy(image_path)
+    print(answer)
 
     # Provide the CAPTCHA options to the web page using the CAPTCHA
     resp = make_response(render_template("index.html", captcha_options=options, incorrect_captcha=incorrect_captcha))
-
+    resp = make_response(captcha.generate_captcha_html(list(options)))
     # Track this user with a cookie and store the correct answer
-    # by linking the cookie with the answer, we can check their answer
+    # by linking the cookie with the answer, we can check their answer later
-    # later
     freecaptcha_cookie = str(uuid.uuid4())
     resp.set_cookie('freecaptcha_cookie', freecaptcha_cookie)
     captcha_solutions[freecaptcha_cookie] = answer

freecaptcha/captcha.py

@@ -3,6 +3,7 @@ import os
 from PIL import Image
 import base64
 from io import BytesIO
+from collections import deque
 
 import os
 
@@ -13,7 +14,7 @@ def generate_layers(images, index=0):
     
     return f'''<label>
             <input id="layer{index}" type="radio" name="captcha{index}" value="{index}">
-            <img src="images/{images[0]}"></img>
+            <img src="data:image/png;base64,{images[0]}"></img>
             {generate_layers(images[1:], index+1)}
         </label>
         '''
@@ -102,22 +103,14 @@ def rotate_img(img_path, angle):
 def captchafy(img_path, n=6):
     angles = calculate_angles(n)
 
-    rotated_imgs = [
+    rotated_imgs = deque(
-        {
+        [rotate_img(img_path, angle) for angle in angles][::-1] * 3
-            'original': False, 
+    )
-            'image': rotate_img(img_path, angle)
+    random_shift = random.randint(1, n)
-        } for angle in angles]
 
-    rotated_imgs[0]['original'] = True
+    rotated_imgs.rotate(-random_shift)
+    return random_shift % n, rotated_imgs
 
-    random.shuffle(rotated_imgs)
-
-    correct_img = None
-    for index, img in enumerate(rotated_imgs):
-        if img['original']:
-            correct_img = index
-
-    return correct_img, [img['image'] for img in rotated_imgs]
 
 def random_image(dir='images/'):
     dir_contents = os.listdir(dir)