fix(data-uri): Do not use regular expressions for parsing data URI sc…

…hemes
nodemailer · Feb 22, 2024 · 12e65e9 · 12e65e9
1 parent dd8f5e8
commit 12e65e9
Showing 1 changed file with 56 additions and 8 deletions.
diff --git a/lib/mail-composer/index.js b/lib/mail-composer/index.js
@@ -537,12 +537,17 @@ class MailComposer {
      * @return {Object} Parsed element
      */
     _processDataUrl(element) {
-        let parts = (element.path || element.href).match(/^data:((?:[^;]*;){0,20}(?:[^,]*)),(.*)$/i);
-        if (!parts) {
+        let parsedDataUri;
+        if ((element.path || element.href).match(/^data:/)) {
+            parsedDataUri = this.parseDataURI(element.path || element.href);
+        }
+
+        if (!parsedDataUri) {
             return element;
         }
 
-        element.content = /\bbase64$/i.test(parts[1]) ? Buffer.from(parts[2], 'base64') : Buffer.from(decodeURIComponent(parts[2]));
+        element.content = parsedDataUri.data;
+        element.contentType = element.contentType || parsedDataUri.contentType;
 
         if ('path' in element) {
             element.path = false;
@@ -552,13 +557,56 @@ class MailComposer {
             element.href = false;
         }
 
-        parts[1].split(';').forEach(item => {
-            if (/^\w+\/[^/]+$/i.test(item)) {
-                element.contentType = element.contentType || item.toLowerCase();
+        return element;
+    }
+
+    parseDataURI(uri) {
+        let input = uri;
+        let commaPos = input.indexOf(',');
+        if (!commaPos) {
+            return uri;
+        }
+
+        let data = input.substring(commaPos + 1);
+        let metaStr = input.substring('data:'.length, commaPos);
+
+        let encoding;
+
+        let metaEntries = metaStr.split(';');
+        let lastMetaEntry = metaEntries.length > 1 ? metaEntries[metaEntries.length - 1] : false;
+        if (lastMetaEntry && lastMetaEntry.indexOf('=') < 0) {
+            encoding = lastMetaEntry.toLowerCase();
+            metaEntries.pop();
+        }
+
+        let contentType = metaEntries.shift() || 'application/octet-stream';
+        let params = {};
+        for (let entry of metaEntries) {
+            let sep = entry.indexOf('=');
+            if (sep >= 0) {
+                let key = entry.substring(0, sep);
+                let value = entry.substring(sep + 1);
+                params[key] = value;
             }
-        });
+        }
 
-        return element;
+        switch (encoding) {
+            case 'base64':
+                data = Buffer.from(data, 'base64');
+                break;
+            case 'utf8':
+                data = Buffer.from(data);
+                break;
+            default:
+                try {
+                    data = Buffer.from(decodeURIComponent(data));
+                } catch (err) {
+                    data = Buffer.from(data);
+                }
+                data = Buffer.from(data);
+        }
+
+        return { data, encoding, contentType, params };
     }
 }