Sanitized custom message fields

.common/utils/helpers.js

@@ -709,4 +709,57 @@ function VersionCheck(requiredVersion, installedVersion) {
     // 4. PERFECT: Installed version meets or exceeds the required baseline.
     console.log(`VersionCheck: Installed version meets or exceeds the required baseline. Required: ${requiredVersion}, Installed: ${installedVersion}`);
     return 'compatible';
+}
+
+function SanitizeHTML(htmlString) {
+    // 1. Parse the string into a temporary DOM document
+    const parser = new DOMParser();
+    const doc = parser.parseFromString(htmlString, 'text/html');
+
+    // 2. Define allowed tags and attributes
+    const allowedTags = ['IMG', 'SPAN', 'B', 'I', 'BR', 'EM', 'STRONG'];
+    const allowedAttrs = ['src', 'class'];
+
+    // 3. Walk through all elements in the parsed document
+    const allElements = doc.body.querySelectorAll('*');
+    allElements.forEach(el => {
+        // Check if it's an <img> tag and enforce class restrictions
+        if (el.tagName === 'IMG') {
+            const className = el.getAttribute('class') || '';
+            // Split classes by whitespace in case there are multiple (e.g., class="emote custom")
+            const classes = className.split(/\s+/);
+            
+            // Must contain either 'emote' or 'bits' to be allowed
+            const hasValidClass = classes.includes('emote') || classes.includes('bits');
+            
+            if (!hasValidClass) {
+                // Unwrap or remove the unauthorized <img> tag
+                const parent = el.parentNode;
+                while (el.firstChild) {
+                    parent.insertBefore(el.firstChild, el);
+                }
+                parent.removeChild(el);
+                return;
+            }
+        }
+
+        // If any other tag isn't in our allowed list, unwrap it
+        if (!allowedTags.includes(el.tagName)) {
+            const parent = el.parentNode;
+            while (el.firstChild) {
+                parent.insertBefore(el.firstChild, el);
+            }
+            parent.removeChild(el);
+            return;
+        }
+
+        // Strip out any attributes not explicitly allowed (like onerror, onload, etc.)
+        Array.from(el.attributes).forEach(attr => {
+            if (!allowedAttrs.includes(attr.name.toLowerCase())) {
+                el.removeAttribute(attr.name);
+            }
+        });
+    });
+
+    return doc.body.innerHTML;
 }

printer-bot/contents/script.js

@@ -51,7 +51,7 @@ async function CustomEvent(data) {
                 subtitleEl.innerText = `${data.user}`;
 
                 const messageEl = document.createElement('div');
-                messageEl.innerHTML = data.message;
+                messageEl.innerHTML = SanitizeHTML(data.message);
 
                 // Render emotes
                 for (i in data.emotes) {
@@ -116,7 +116,7 @@ async function CustomEvent(data) {
                 const messageEl = document.createElement('div');
                 messageEl.innerHTML = `<b>${data.cumulative} months${data.monthStreak > 1 ? ' (' + data.monthStreak + ' in a row!)' : ''}</b>`;
                 if (data.messageStripped)
-                    messageEl.innerHTML += `<br><br><i>${data.messageStripped}</i>`;
+                    messageEl.innerHTML += `<br><br><i>${SanitizeHTML(data.messageStripped)}</i>`;
 
                 contentEl.appendChild(messageEl);
 
@@ -196,7 +196,7 @@ async function CustomEvent(data) {
                 subtitleEl.innerText = `${data.user}`;
 
                 const messageEl = document.createElement('div');
-                messageEl.innerHTML = data.rawInput;
+                messageEl.innerHTML = SanitizeHTML(data.rawInput);
 
                 // // Render emotes
                 // for (i in data.emotes) {
@@ -284,7 +284,7 @@ async function CustomEvent(data) {
                 const messageEl = document.createElement('div');
                 messageEl.innerHTML = `<b>${data.user}</b><br>sent a Super Chat!`;
                 if (data.message)
-                    messageEl.innerHTML += `<br><br><i>${data.message}</i>`;
+                    messageEl.innerHTML += `<br><br><i>${SanitizeHTML(data.message)}</i>`;
 
                 contentEl.appendChild(messageEl);
 
@@ -424,7 +424,7 @@ async function CustomEvent(data) {
 
                 if (data.tipMessage) {
                     const messageEl = document.createElement('div');
-                    messageEl.innerHTML = `<i>${data.tipMessage}</i>`;
+                    messageEl.innerHTML = `<i>${SanitizeHTML(data.tipMessage)}</i>`;
 
                     contentEl.appendChild(messageEl);
                 }
@@ -448,7 +448,7 @@ async function CustomEvent(data) {
 
                 if (data.donationMessage) {
                     const messageEl = document.createElement('div');
-                    messageEl.innerHTML = `<i>${data.donationMessage}</i>`;
+                    messageEl.innerHTML = `<i>${SanitizeHTML(data.donationMessage)}</i>`;
 
                     contentEl.appendChild(messageEl);
                 }
@@ -475,7 +475,7 @@ async function CustomEvent(data) {
 
                 if (data["fw.message"]) {
                     const messageEl = document.createElement('div');
-                    messageEl.innerHTML = `<i>${data["fw.message"]}</i>`;
+                    messageEl.innerHTML = `<i>${SanitizeHTML(data["fw.message"])}</i>`;
 
                     contentEl.appendChild(messageEl);
                 }
@@ -537,7 +537,7 @@ async function CustomEvent(data) {
                 if (customMessage) {
                     const txt = document.createElement("textarea");
                     txt.innerHTML = customMessage;
-                    customMessageEl.innerHTML += `<br><i>${txt.value}</i>`;
+                    customMessageEl.innerHTML += `<br><i>${SanitizeHTML(txt.value)}</i>`;
                 }
 
                 // Add a cute thank you message because you're uwu like that