When using Secure Web Gateway (SWG) for Umbrella Chromebook Client (UCC), file upload & download for applications such as Gmail, Google Drive fail.
SWG Umbrella Chromebook Client - The Way it Works
The primary purpose of the SWG extension is to register the client with Umbrella, download proxy configuration and setup proxy on Chromebook thus protecting it from online threats.
The proxy that is setup by the SWG Umbrella Chromebook client is at the ChromeOS layer.
Hence web traffic from the Chrome browser as well any other apps installed on the device get proxied to Umbrella. Also, the UCC for SWG handles proxy auth challenge. However, other apps (like Google Drive) cannot handle auth challenge.
Why does file upload/download from Android apps such as Google Drive fail?
1. Let's assume a scenario where you try to upload a non-cached version of a file from Google drive installed in the Chromebook.
2. Google drive makes a call to "googleapis.com" to download the file from the remote server. This request gets proxied to the SWG proxy server. Since the auth header, which is cached in Google chrome browser, is not available with the Google drive, the googleapis.com request is sent to SWG Proxy server without auth headers. Because steps 1 through 5 in the below picture did not happen from Google drive, the request gets rejected with 401, not authorized error. (Marked as step#7 in the picture below)
3. Since the file cannot be downloaded from Google Drive, the file upload from the Google Drive to Gmail fails.
To resolve the file upload issue, use external domains management list to bypass the domain googleapis.com.