Add recaptcha v2 to verify guest logins (#55)

webapp/config.example.py

@@ -8,6 +8,10 @@ config = {
     # Rest API in https://developer.paypal.com/developer/applications
     'paypal-client-id': "Paypal client id",
     'paypal-client-secret': "Paypal client secret",
+    
+    # V2 reCAPTCHA from https://www.google.com/recaptcha/admin
+    'recaptcha-site-key': "reCAPTCHA v2 Site Key",
+    'recaptcha-secret-key': "reCAPTCHA v2 Secret Key",
 
     'app-location': "/var/www/Titan/webapp/",
     'app-secret': "Type something random here, go wild.",

webapp/titanembeds/blueprints/api/api.py

@@ -3,12 +3,14 @@ from titanembeds.decorators import valid_session_required, discord_users_only
 from titanembeds.utils import check_guild_existance, guild_accepts_visitors, guild_query_unauth_users_bool, get_client_ipaddr, discord_api, rate_limiter, channel_ratelimit_key, guild_ratelimit_key, user_unauthenticated, checkUserRevoke, checkUserBanned, update_user_status, check_user_in_guild, get_guild_channels, guild_webhooks_enabled
 from titanembeds.oauth import user_has_permission, generate_avatar_url, check_user_can_administrate_guild
 from flask import Blueprint, abort, jsonify, session, request, url_for
+from flask import current_app as app
 from flask_socketio import emit
 from sqlalchemy import and_
 import random
 import json
 import datetime
 import re
+import requests
 from config import config
 
 api = Blueprint("api", __name__)
@@ -270,6 +272,17 @@ def post():
     response.status_code = status_code
     return response
 
+def verify_captcha_request(captcha_response, ip_address):
+    payload = {
+        "secret": config["recaptcha-secret-key"],
+        "response": captcha_response,
+        "remoteip": ip_address,
+    }
+    if app.config["DEBUG"]:
+        del payload["remoteip"]
+    r = requests.post("https://www.google.com/recaptcha/api/siteverify", data=payload).json()
+    return r["success"]
+
 @api.route("/create_unauthenticated_user", methods=["POST"])
 @rate_limiter.limit("3 per 30 minute", key_func=guild_ratelimit_key)
 def create_unauthenticated_user():
@@ -278,6 +291,9 @@ def create_unauthenticated_user():
     guild_id = request.form['guild_id']
     ip_address = get_client_ipaddr()
     username = username.strip()
+    captcha_response = request.form['captcha_response']
+    if not verify_captcha_request(captcha_response, request.remote_addr):
+        abort(412)
     if len(username) < 2 or len(username) > 32:
         abort(406)
     if not all(x.isalnum() or x.isspace() or "-" == x or "_" == x for x in username):

webapp/titanembeds/blueprints/embed/embed.py

@@ -65,11 +65,13 @@ def guild_embed(guild_id):
         customcss = get_custom_css()
         return render_template("embed.html.j2",
             login_greeting=get_logingreeting(),
-            guild_id=guild_id, guild=guild_dict,
+            guild_id=guild_id,
+            guild=guild_dict,
             generate_guild_icon=generate_guild_icon_url,
             unauth_enabled=guild_query_unauth_users_bool(guild_id),
             visitors_enabled=guild_accepts_visitors(guild_id),
             client_id=config['client-id'],
+            recaptcha_site_key=config["recaptcha-site-key"],
             css=customcss,
             cssvariables=parse_css_variable(customcss)
         )

webapp/titanembeds/static/css/embedstyle.css

@@ -490,6 +490,11 @@ p.mentioned span.chatmessage {
   top: -5px;
 }
 
+#google-recaptcha {
+  margin: 0 auto;
+  width: 302px;
+}
+
 /* CSS Variables */
 :root {
   /*--<var>: <value>*/

webapp/titanembeds/static/js/embed.js

@@ -11,6 +11,7 @@
 /* global io */
 /* global twemoji */
 /* global jQuery */
+/* global grecaptcha */
 
 (function () {
     const theme_options = ["DiscordDark", "BetterTitan"]; // All the avaliable theming names
@@ -73,12 +74,12 @@
         return funct.promise();
     }
 
-    function create_unauthenticated_user(username) {
+    function create_unauthenticated_user(username, captchaResponse) {
         var funct = $.ajax({
             method: "POST",
             dataType: "json",
             url: "/api/create_unauthenticated_user",
-            data: {"username": username, "guild_id": guild_id}
+            data: {"username": username, "guild_id": guild_id, "captcha_response": captchaResponse}
         });
         return funct.promise();
     }
@@ -142,6 +143,14 @@
           }
         );
         $('#loginmodal').modal('open');
+        $("#recaptchamodal").modal({
+            dismissible: true,
+            opacity: .5,
+            inDuration: 400,
+            outDuration: 400,
+            startingTop: '40%',
+            endingTop: '30%',
+        });
         $("#userembedmodal").modal({
             dismissible: true,
             opacity: .5,
@@ -948,7 +957,7 @@
         lock_login_fields();
         wait_for_discord_login();
     });
-
+    
     $("#custom_username_field").keyup(function(event){
         if (event.keyCode == 13) {
             if (!(new RegExp(/^[a-z\d\-_\s]+$/i).test($(this).val()))) {
@@ -956,28 +965,36 @@
                 return;
             }
             if($(this).val().length >= 2 && $(this).val().length <= 32) {
-                lock_login_fields();
+                $("#custom_username_field").blur();
-                var usr = create_unauthenticated_user($(this).val());
+                $('#recaptchamodal').modal('open');
-                usr.done(function(data) {
-                    setVisitorMode(false);
-                    initialize_embed();
-                });
-                usr.fail(function(data) {
-                    if (data.status == 429) {
-                        Materialize.toast('Sorry! You are allowed to log in as a guest three times in a span of 30 minutes.', 10000);
-                    } else if (data.status == 403) {
-                        Materialize.toast('Authentication error! You have been banned.', 10000);
-                    } else if (data.status == 406) {
-                        Materialize.toast('Illegal username provided! Only alphanumeric, spaces, dashes, and underscores allowed in usernames.', 10000);
-                    } else if (data.status == 422) {
-                        Materialize.toast("Attempting to add you into the server has failed. Either you are banned, reached 100 servers in Discord, or something else bad has happened.", 10000);
-                    }
-                    unlock_login_fields();
-                    setVisitorMode(true);
-                });
             }
         }
     });
+
+    $("#submit-unauthenticated-captcha-btn").click(function(){
+        lock_login_fields();
+        var usr = create_unauthenticated_user($("#custom_username_field").val(), grecaptcha.getResponse());
+        usr.done(function(data) {
+            grecaptcha.reset();
+            setVisitorMode(false);
+            initialize_embed();
+        });
+        usr.fail(function(data) {
+            if (data.status == 429) {
+                Materialize.toast('Sorry! You are allowed to log in as a guest three times in a span of 30 minutes.', 10000);
+            } else if (data.status == 403) {
+                Materialize.toast('Authentication error! You have been banned.', 10000);
+            } else if (data.status == 406) {
+                Materialize.toast('Illegal username provided! Only alphanumeric, spaces, dashes, and underscores allowed in usernames.', 10000);
+            } else if (data.status == 422) {
+                Materialize.toast("Attempting to add you into the server has failed. Either you are banned, reached 100 servers in Discord, or something else bad has happened.", 10000);
+            } else if (data.status == 412) {
+                Materialize.toast("reCAPTCHA reponse has failed. Try again?", 10000);
+            }
+            unlock_login_fields();
+            setVisitorMode(true);
+        });
+    });
     
     $("#change_username_field").keyup(function(event){
         if (event.keyCode == 13) {
@@ -1283,3 +1300,8 @@
         }
     }
 })();
+
+function submit_unauthenticated_captcha() { // To be invoked when recaptcha is completed
+    $('#recaptchamodal').modal('close');
+    $("#submit-unauthenticated-captcha-btn").click();
+}

webapp/titanembeds/templates/embed.html.j2

@@ -18,6 +18,7 @@
 
     <title>{{ guild['name'] }} - Embed - Titan Embeds for Discord</title>
     {% include 'google_analytics.html.j2' %}
+    <script src='https://www.google.com/recaptcha/api.js'></script>
     
     <style id="user-defined-css">
       {% if css is not none %}
@@ -145,6 +146,14 @@
       </div>
     </div>
     
+    <div id="recaptchamodal" class="modal">
+      <div class="modal-content">
+        <h4 class="center-align">Just one more step...</h4>
+        <div id="google-recaptcha" class="g-recaptcha" data-sitekey="{{ recaptcha_site_key }}" data-callback="submit_unauthenticated_captcha"></div>
+        <input type="hidden" id="submit-unauthenticated-captcha-btn" />
+      </div>
+    </div>
+    
     <div id="emoji-picker">
       <div id="emoji-picker-content">
         <div class="row">