Raw USB is a Chrome-only extension, Safari and Firefox don't support it because it's an awful idea. Even so, it's much easier to make a meaningful permission di

Raw USB is a Chrome-only extension, Safari and Firefox don't support it because it's an awful idea. Even so, it's much easier to make a meaningful permission dialog for USB than for a TCP or UDP connection. With USB there's a limited set of devices you can connect to, and they somewhat human-readable names or vendor IDs that can be translated into names, and there's no way to do something like a DNS rebinding attack with them since the browser can detect when the device is unplugged. It is entirely possible to make a secure SSH or IMAP client in the browser, just proxy the encrypted data and do TLS or the SSH protocol in Javascript.