implement content-security-policy, static assets cache bust, and fix

stripe back button ratchet issue

because the only way to use stripe checkout is to run their proprietary
JS, and we arent using a SPA, naturally what happens is, when you land
on the stripe payment page if you hit the back button it goes back to
the same page where you got re-directed to stripe. this commit fixes
that.

capsulflask/__init__.py

@@ -2,12 +2,15 @@ import logging
 from logging.config import dictConfig as logging_dict_config
 
 import os
+import hashlib
 
 import stripe
 from dotenv import load_dotenv, find_dotenv
 from flask import Flask
 from flask_mail import Mail
 from flask import render_template
+from flask import url_for
+from flask import current_app
 
 from capsulflask import virt_model, cli
 from capsulflask.btcpay import client as btcpay
@@ -45,19 +48,19 @@ app.config.from_mapping(
 )
 
 logging_dict_config({
-    'version': 1,
-    'formatters': {'default': {
-        'format': '[%(asctime)s] %(levelname)s in %(module)s: %(message)s',
-    }},
-    'handlers': {'wsgi': {
-        'class': 'logging.StreamHandler',
-        'stream': 'ext://flask.logging.wsgi_errors_stream',
-        'formatter': 'default'
-    }},
-    'root': {
-        'level': app.config['LOG_LEVEL'],
-        'handlers': ['wsgi']
-    }
+  'version': 1,
+  'formatters': {'default': {
+    'format': '[%(asctime)s] %(levelname)s in %(module)s: %(message)s',
+  }},
+  'handlers': {'wsgi': {
+    'class': 'logging.StreamHandler',
+    'stream': 'ext://flask.logging.wsgi_errors_stream',
+    'formatter': 'default'
+  }},
+  'root': {
+    'level': app.config['LOG_LEVEL'],
+    'handlers': ['wsgi']
+  }
 })
 
 # app.logger.critical("critical")
@@ -72,9 +75,9 @@ stripe.api_version = app.config['STRIPE_API_VERSION']
 app.config['FLASK_MAIL_INSTANCE'] = Mail(app)
 
 if app.config['VIRTUALIZATION_MODEL'] == "shell_scripts":
-    app.config['VIRTUALIZATION_MODEL'] = virt_model.ShellScriptVirtualization()
+  app.config['VIRTUALIZATION_MODEL'] = virt_model.ShellScriptVirtualization()
 else:
-    app.config['VIRTUALIZATION_MODEL'] = virt_model.MockVirtualization()
+  app.config['VIRTUALIZATION_MODEL'] = virt_model.MockVirtualization()
 
 app.config['BTCPAY_CLIENT'] = btcpay.Client(api_uri=app.config['BTCPAY_URL'], pem=app.config['BTCPAY_PRIVATE_KEY'])
 
@@ -93,3 +96,49 @@ app.register_blueprint(cli.bp)
 
 app.add_url_rule("/", endpoint="index")
 
+@app.after_request
+def security_headers(response):
+  response.headers['X-Frame-Options'] = 'SAMEORIGIN'
+  if 'Content-Security-Policy' not in response.headers:
+    response.headers['Content-Security-Policy'] = "default-src 'self'"
+  response.headers['X-Content-Type-Options'] = 'nosniff'
+  return response
+
+
+@app.context_processor
+def override_url_for():
+  """
+  override the url_for function built into flask 
+  with our own custom implementation that busts the cache correctly when files change 
+  """
+  return dict(url_for=url_for_with_cache_bust)
+
+
+
+def url_for_with_cache_bust(endpoint, **values):
+  """
+  Add a query parameter based on the hash of the file, this acts as a cache bust
+  """
+  
+  if endpoint == 'static':
+    filename = values.get('filename', None)
+    if filename:
+      if 'STATIC_FILE_HASH_CACHE' not in current_app.config:
+        current_app.config['STATIC_FILE_HASH_CACHE'] = dict()
+      
+      if filename not in current_app.config['STATIC_FILE_HASH_CACHE']:
+        filepath = os.path.join(current_app.root_path, endpoint, filename)
+        #print(filepath)
+        if os.path.isfile(filepath) and os.access(filepath, os.R_OK):
+          
+          with open(filepath, 'rb') as file:
+            hasher = hashlib.md5()
+            hasher.update(file.read())
+            current_app.config['STATIC_FILE_HASH_CACHE'][filename] = hasher.hexdigest()[-6:]
+            
+      values['q'] = current_app.config['STATIC_FILE_HASH_CACHE'][filename]
+
+  return url_for(endpoint, **values)
+
+
+  

capsulflask/console.py

@@ -217,12 +217,13 @@ def ssh_public_keys():
       if method == "POST":
         parts = re.split(" +", request.form["content"])
         if len(parts) > 2 and len(parts[2].strip()) > 0:
-          name = parts[2]
+          name = parts[2].strip()
         else:
-          name = parts[0]
+          name = parts[0].strip()
       else:
         errors.append("Name is required")
-    if not re.match(r"^[0-9A-Za-z_@\. -]+$", name):
+    if not re.match(r"^[0-9A-Za-z_@. -]+$", name):
+      print(name)
       errors.append("Name must match \"^[0-9A-Za-z_@. -]+$\"")
 
     if method == "POST":
@@ -231,7 +232,7 @@ def ssh_public_keys():
         errors.append("Content is required")
       else:
         content = content.replace("\r", "").replace("\n", "")
-        if not re.match(r"^(ssh|ecdsa)-[0-9A-Za-z+/_=@\. -]+$", content):
+        if not re.match(r"^(ssh|ecdsa)-[0-9A-Za-z+/_=@. -]+$", content):
           errors.append("Content must match \"^(ssh|ecdsa)-[0-9A-Za-z+/_=@. -]+$\"")
 
       if get_model().ssh_public_key_name_exists(session["account"], name):

capsulflask/db.py

@@ -40,7 +40,7 @@ def init_app(app):
   hasSchemaVersionTable = False
   actionWasTaken = False
   schemaVersion = 0
-  desiredSchemaVersion = 4
+  desiredSchemaVersion = 5
 
   cursor = connection.cursor()
 

capsulflask/db_model.py

@@ -175,6 +175,21 @@ class DBModel:
       self.cursor.fetchall()
     ))
 
+  def payment_session_redirect(self, email, id):
+    self.cursor.execute("SELECT redirected FROM payment_sessions WHERE email = %s AND id = %s", 
+      (email, id)
+    )
+    row = self.cursor.fetchone()
+    if row:
+      self.cursor.execute("UPDATE payment_sessions SET redirected = TRUE WHERE email = %s AND id = %s", 
+        (email, id)
+      )
+      self.connection.commit()
+      return row[0]
+    
+    return None
+
+
   def consume_payment_session(self, payment_type, id, dollars):
     self.cursor.execute("SELECT email, dollars FROM payment_sessions WHERE id = %s AND type = %s", (id, payment_type))
     row = self.cursor.fetchone()

capsulflask/payment.py

@@ -2,9 +2,11 @@ import stripe
 import json
 import time
 import decimal
-from time import sleep
+import re
 
+from time import sleep
 from flask import Blueprint
+from flask import make_response
 from flask import request
 from flask import current_app
 from flask import session
@@ -165,14 +167,46 @@ def stripe_payment():
 
       #return redirect(f"https://checkout.stripe.com/pay/{stripe_checkout_session_id}")
 
+      return redirect(f"/payment/stripe/{stripe_checkout_session_id}")
+
   for error in errors:
     flash(error)
 
-  return render_template(
+  return render_template("stripe.html")
+
+@bp.route("/stripe/<string:stripe_checkout_session_id>")
+@account_required
+def redirect_to_stripe(stripe_checkout_session_id):
+
+  if stripe_checkout_session_id and not re.match(r"^[a-zA-Z0-9_=-]+$", stripe_checkout_session_id):
+    stripe_checkout_session_id = '___________'
+
+  response = make_response(render_template(
     "stripe.html",
     stripe_checkout_session_id=stripe_checkout_session_id,
     stripe_public_key=current_app.config["STRIPE_PUBLISHABLE_KEY"]
-  )
+  ))
+
+  if stripe_checkout_session_id is not None:
+    response.headers['Content-Security-Policy'] = "default-src 'self' https://js.stripe.com"
+  
+  return response
+
+@bp.route("/stripe/<string:stripe_checkout_session_id>/json")
+@account_required
+def stripe_checkout_session_json(stripe_checkout_session_id):
+
+  if stripe_checkout_session_id and not re.match(r"^[a-zA-Z0-9_=-]+$", stripe_checkout_session_id):
+    stripe_checkout_session_id = '___________'
+
+  has_redirected_already = get_model().payment_session_redirect(session['account'], stripe_checkout_session_id)
+
+  if has_redirected_already is None:
+    abort(404, "Not Found")
+
+  return jsonify(dict(hasRedirectedAlready=has_redirected_already))
+
+
 
 def validate_stripe_checkout_session(stripe_checkout_session_id):
   checkout_session_completed_events = stripe.Event.list(

capsulflask/schema_migrations/05_down_stripe_payment_redirect.sql

@@ -0,0 +1,3 @@
+ALTER TABLE payment_sessions DROP COLUMN redirected;
+
+UPDATE schemaversion SET version = 4;

capsulflask/schema_migrations/05_up_stripe_payment_redirect.sql

@@ -0,0 +1,4 @@
+ALTER TABLE payment_sessions 
+ADD COLUMN redirected BOOLEAN NOT NULL DEFAULT FALSE;
+
+UPDATE schemaversion SET version = 5;

capsulflask/static/create-capsul.js

@@ -0,0 +1,9 @@
+
+window.addEventListener('DOMContentLoaded', function(event) {
+  var submitButton = document.getElementById('submit-button');
+  var submitButtonClicked = document.getElementById('submit-button-clicked');
+  document.getElementById('submit-button').onclick = function() {
+    submitButton.className = "display-none";
+    submitButtonClicked.className = "waiting-pulse";
+  }
+});

capsulflask/static/pay-with-stripe.js

@@ -0,0 +1,39 @@
+
+window.addEventListener('DOMContentLoaded', function(event) {
+
+  var httpRequest = new XMLHttpRequest();
+  httpRequest.onloadend = () => {
+    if (httpRequest.status < 300) {
+      try {
+        responseObject = JSON.parse(httpRequest.responseText);
+
+        if(!responseObject.hasRedirectedAlready) {
+          Stripe(document.getElementById("stripe_public_key").value)
+          .redirectToCheckout({
+            sessionId: document.getElementById("stripe_checkout_session_id").value,
+          })
+          .then(function(result) {
+            if (result.error) {
+              alert("Stripe.redirectToCheckout() failed with: " + result.error.message)
+            }
+          });
+        } else {
+          location.href = '/payment/stripe';
+        }
+
+      } catch (err) {
+        alert("could not redirect to stripe because capsul did not return valid json");
+      }
+    } else {
+      alert("could not redirect to stripe because capsul returned HTTP" + httpRequest.status + ", expected HTTP 200");
+    }
+  };
+
+  httpRequest.ontimeout = () => {
+    alert("could not redirect to stripe because capsul timed out");
+  };
+
+  httpRequest.open("GET", "/payment/stripe/"+document.getElementById("stripe_checkout_session_id").value+"/json?q="+String(Math.random()).substring(2, 8));
+  httpRequest.timeout = 10000;
+  httpRequest.send();
+});

capsulflask/static/style.css

@@ -150,11 +150,7 @@ select {
   -webkit-appearance: none;
   -moz-appearance: none;
   appearance: none;
-  /* 
-    re-generate the following line from the source image with: 
-    echo "background-image: url(data:image/png;base64,$(cat capsulflask/static/dropdown-handle.png | base64 -w 0));" 
-  */
-  background-image: url(data:image/png;base64,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); 
+  background-image: url(/static/dropdown-handle.png); 
   background-repeat: no-repeat;
   background-position: bottom 0.65em right 0.8em;
   background-size: 0.5em;

capsulflask/templates/base.html

@@ -1,6 +1,5 @@
 <html lang="en">
 <head>
-  <link href="data:image/gif;base64,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" rel="icon">
   <title>{% block title %}{% endblock %}{% if self.title() %} - {% endif %}Capsul</title>
   <meta charset="utf-8">
   <meta name="viewport" content="width=device-width,initial-scale=1.0">

capsulflask/templates/create-capsul.html

@@ -67,16 +67,7 @@
         <input id="submit-button" type="submit" value="Create">
         <span  id="submit-button-clicked" class="display-none">..Creating...</span>
       </div>
-      <script>
-        window.addEventListener('DOMContentLoaded', function(event) {
-            var submitButton = document.getElementById('submit-button');
-            var submitButtonClicked = document.getElementById('submit-button-clicked');
-            document.getElementById('submit-button').onclick = function() {
-              submitButton.className = "display-none";
-              submitButtonClicked.className = "waiting-pulse";
-            }
-        });
-      </script>
+      <script src="{{ url_for('static', filename='create-capsul.js') }}"></script>
     </form>
   {% endif %}
 

capsulflask/templates/stripe.html

@@ -10,33 +10,30 @@
 
 
 {% block content %}
-<div class="row third-margin">
-  <h1>PAY WITH STRIPE</h1>
-</div>
-<div class="row half-margin">
-  <form method="post">
-    <div class="row justify-start">
-      <label for="dollars">$</label>
-      <input type="number" id="dollars" name="dollars"></input> 
-    </div>
-    <div class="row justify-end">
-      <input type="submit" value="Pay With Stripe">
-    </div>
-  </form>
-</div>
+
 
 {% if stripe_checkout_session_id %}
-  <script>
-    Stripe("{{ stripe_public_key }}")
-    .redirectToCheckout({
-      sessionId: "{{ stripe_checkout_session_id }}",
-    })
-    .then(function(result) {
-      if (result.error) {
-        alert("Stripe.redirectToCheckout() failed with: " + result.error.message)
-      }
-    });
-  </script>
+  <div class="row third-margin">
+    <h1>REDIRECTING...</h1>
+  </div>
+  <input id="stripe_public_key" type="hidden" value="{{ stripe_public_key }}"/>
+  <input id="stripe_checkout_session_id" type="hidden" value="{{ stripe_checkout_session_id }}"/>
+  <script src="{{ url_for('static', filename='pay-with-stripe.js') }}"></script>
+{% else %}
+  <div class="row third-margin">
+    <h1>PAY WITH STRIPE</h1>
+  </div>
+  <div class="row half-margin">
+    <form method="post">
+      <div class="row justify-start">
+        <label for="dollars">$</label>
+        <input type="number" id="dollars" name="dollars"></input> 
+      </div>
+      <div class="row justify-end">
+        <input type="submit" value="Pay With Stripe">
+      </div>
+    </form>
+  </div>
 {% endif %}
 
 {% endblock %}