[Spam Prevention] Add username confirmation and simple, frictionless anti-spam mechanism

1 files changed, 54 insertions, 0 deletions

diff --git a/public/registration.js b/public/registration.js
new file mode 100644
index 000000000..a82ec09c2
--- /dev/null
+++ b/public/registration.js
@@ -0,0 +1,54 @@
+function dragon(message) {
+  const msgBuffer = new TextEncoder('utf-8').encode(message);
+  return crypto.subtle.digest('SHA-512', msgBuffer).then(hashBuffer => {
+    const hashArray = Array.from(new Uint8Array(hashBuffer));
+    const hashHex = hashArray.map(b => ('00' + b.toString(16)).slice(-2)).join('');
+    return hashHex;
+  });
+}
+
+function getForm() {
+  return document.getElementById('registration_new_user') || document.getElementById('new_user');
+}
+
+function getField(name) {
+  return document.getElementById(`registration_user_${name}`) || document.getElementById(`user_${name}`);
+}
+
+function handleSubmit(e) {
+  e.preventDefault();
+
+  const form = getForm();
+  const u1 = getField('account_attributes_username');
+  const u2 = getField('username');
+  const kobold = getField('kobold');
+
+  if (!!u1 && !!u2 && u1.value.toLowerCase() === u2.value.toLowerCase()) {
+    u2.value = u1.value;
+  }
+
+  let values = [];
+
+  for (let i = 0; i < form.elements.length; i++) {
+    const element = form.elements[i];
+    const value = element.value;
+
+    if (!!element && ['text', 'email', 'textarea'].includes(element.type) && !!value) {
+      values.push(value.trim().toLowerCase());
+    }
+  }
+
+  const value = values.join('\u{F0666}');
+  dragon(value).then(digest => {
+    if (!!kobold) { kobold.value = digest.toUpperCase(); }
+    form.submit();
+  }, _ => { form.submit(); });
+}
+
+function addSubmitHandler() {
+  const form = getForm();
+  if (!!form) { form.addEventListener('submit', handleSubmit); }
+}
+
+window.addEventListener("load", addSubmitHandler);
+