Send new captcha over websocket with js

anonstream/static/anonstream.js

@@ -296,13 +296,31 @@ const chat_form_captcha_digest = document.getElementById("chat-form_js__captcha-
 const chat_form_captcha_image = document.getElementById("chat-form_js__captcha-image");
 const chat_form_captcha_answer = document.getElementById("chat-form_js__captcha-answer");
 chat_form_captcha_image.addEventListener("loadstart", (event) => {
+  chat_form_captcha_image.removeAttribute("title");
+  chat_form_captcha_image.removeAttribute("data-reloadable");
   chat_form_captcha_image.alt = "Loading...";
 });
 chat_form_captcha_image.addEventListener("load", (event) => {
   chat_form_captcha_image.removeAttribute("alt");
+  chat_form_captcha_image.dataset.reloadable = "";
+  chat_form_captcha_image.title = "Click for a new captcha";
 });
 chat_form_captcha_image.addEventListener("error", (event) => {
   chat_form_captcha_image.alt = "Captcha failed to load";
+  chat_form_captcha_image.dataset.reloadable = "";
+  chat_form_captcha_image.title = "Click for a new captcha";
+});
+chat_form_captcha_image.addEventListener("click", (event) => {
+  if (chat_form_captcha_image.dataset.reloadable === undefined) {
+    return;
+  }
+  chat_form_submit.disabled = true;
+  chat_form_captcha_image.alt = "Waiting...";
+  chat_form_captcha_image.removeAttribute("title");
+  chat_form_captcha_image.removeAttribute("data-reloadable");
+  chat_form_captcha_image.removeAttribute("src");
+  const payload = {type: "captcha"};
+  ws.send(JSON.stringify(payload));
 });
 const enable_captcha = (digest) => {
   chat_form_captcha_digest.value = digest;
@@ -313,6 +331,7 @@ const enable_captcha = (digest) => {
   chat_form_comment.required = false;
   chat_form_captcha_image.removeAttribute("src");
   chat_form_captcha_image.src = `/captcha.jpg?token=${encodeURIComponent(token)}&digest=${encodeURIComponent(digest)}`;
+  chat_form_submit.disabled = false;
   chat_form.dataset.captcha = "";
 }
 const disable_captcha = () => {
@@ -323,6 +342,7 @@ const disable_captcha = () => {
   chat_form_captcha_digest.value = "";
   chat_form_captcha_answer.value = "";
   chat_form_captcha_answer.required = false;
+  chat_form_submit.disabled = false;
   chat_form_captcha_image.removeAttribute("alt");
   chat_form_captcha_image.removeAttribute("src");
 }
@@ -373,6 +393,7 @@ const on_websocket_message = (event) => {
   switch (receipt.type) {
     case "error":
       console.log("ws error", receipt);
+      chat_form_submit.disabled = false;
       break;
 
     case "init":
@@ -394,6 +415,9 @@ const on_websocket_message = (event) => {
       // chat form captcha digest
       receipt.digest === null ? disable_captcha() : enable_captcha(receipt.digest);
 
+      // chat form submit button
+      chat_form_submit.disabled = false;
+
       // remove messages the server isn't acknowledging the existance of
       const seqs = new Set(receipt.messages.map((message) => {return message.seq;}));
       const to_delete = [];
@@ -486,6 +510,11 @@ const on_websocket_message = (event) => {
       update_user_tripcodes();
       break;
 
+    case "captcha":
+      console.log("ws captcha", receipt);
+      receipt.digest === null ? disable_captcha() : enable_captcha(receipt.digest);
+      break;
+
     default:
       console.log("incomprehensible websocket message", receipt);
   }
@@ -547,7 +576,8 @@ const chat_form_comment = document.getElementById("chat-form_js__comment");
 const chat_form_submit = document.getElementById("chat-form_js__submit");
 chat_form.addEventListener("submit", (event) => {
   event.preventDefault();
-  const payload = Object.fromEntries(new FormData(chat_form));
+  const form = Object.fromEntries(new FormData(chat_form));
+  const payload = {type: "message", form: form};
   chat_form_submit.disabled = true;
   ws.send(JSON.stringify(payload));
 });

anonstream/static/style.css

@@ -187,6 +187,9 @@ noscript {
   color: inherit;
   font-size: 8pt;
 }
+#chat-form_js__captcha-image[data-reloadable] {
+  cursor: pointer;
+}
 #chat-form_js__captcha-answer {
   width: 8ch;
 }

anonstream/utils/websocket.py

@@ -1,19 +1,31 @@
 class Malformed(Exception):
     pass
 
+def get(t, pairs, key, default=None):
+    value = pairs.get(key, default)
+    if isinstance(value, t):
+        return value
+    else:
+        raise Malformed(f'malformed {key}')
+
 def parse_websocket_data(receipt):
     if not isinstance(receipt, dict):
         raise Malformed('not a json object')
 
-    comment = receipt.get('comment')
-    if not isinstance(comment, str):
-        raise Malformed('malformed comment')
+    match receipt.get('type'):
+        case 'message':
+            form = get(dict, receipt, 'form')
+            nonce = get(str, form, 'nonce')
+            comment = get(str, form, 'comment')
+            digest = get(str, form, 'captcha-digest', '')
+            answer = get(str, form, 'captcha-answer', '')
+            return nonce, comment, digest, answer
 
-    nonce = receipt.get('nonce')
-    if not isinstance(nonce, str):
-        raise Malformed('malformed nonce')
+        case 'appearance':
+            raise NotImplemented
 
-    digest = receipt.get('captcha-digest', '')
-    answer = receipt.get('captcha-answer', '')
+        case 'captcha':
+            return None
 
-    return nonce, comment, digest, answer
+        case _:
+            raise Malformed('malformed type')

anonstream/websocket.py

@@ -44,7 +44,7 @@ async def websocket_inbound(queue, user):
         finally:
             see(user)
         try:
-            nonce, comment, digest, answer = parse_websocket_data(receipt)
+            parsed = parse_websocket_data(receipt)
         except Malformed as e:
             error , *_ = e.args
             payload = {
@@ -52,29 +52,47 @@ async def websocket_inbound(queue, user):
                 'because': error,
             }
         else:
-            try:
-                verification_happened = verify(user, digest, answer)
-            except BadCaptcha as e:
-                notice, *_ = e.args
-            else:
-                try:
-                    message_was_added = add_chat_message(
-                        user,
-                        nonce,
-                        comment,
-                        ignore_empty=verification_happened,
-                    )
-                except Rejected as e:
-                    notice, *_ = e.args
-                else:
-                    deverify(user)
-                    notice = None
-            payload = {
-                'type': 'ack',
-                'nonce': nonce,
-                'next': generate_nonce(),
-                'notice': notice,
-                'clear': message_was_added,
-                'digest': get_random_captcha_digest_for(user),
-            }
+            match parsed:
+                case [nonce, comment, digest, answer]:
+                    payload = handle_inbound_message(user, *parsed)
+
+                case None:
+                    payload = handle_inbound_captcha(user)
+
         queue.put_nowait(payload)
+
+def handle_inbound_captcha(user):
+    return {
+        'type': 'captcha',
+        'digest': get_random_captcha_digest_for(user),
+    }
+
+def handle_inbound_message(user, nonce, comment, digest, answer):
+    try:
+        verification_happened = verify(user, digest, answer)
+    except BadCaptcha as e:
+        notice, *_ = e.args
+        message_was_added = False
+    else:
+        try:
+            message_was_added = add_chat_message(
+                user,
+                nonce,
+                comment,
+                ignore_empty=verification_happened,
+            )
+        except Rejected as e:
+            notice, *_ = e.args
+            message_was_added = False
+        else:
+            notice = None
+            if message_was_added:
+                deverify(user)
+    return {
+        'type': 'ack',
+        'nonce': nonce,
+        'next': generate_nonce(),
+        'notice': notice,
+        'clear': message_was_added,
+        'digest': get_random_captcha_digest_for(user),
+    }