Setting Up the Root Certificate for Electron Applications on Ubuntu

Environment

Fiddler Everywhere	1.0.0 and above
3rd-party application	Any electron-based application
Operating System	Ubuntu 18.0.4 and above

Description

Electron applications CA management is different from the operating system CA management used by default by Fiddler. Electron-based applications (like MS Teams) use Electron CA management, so the folder where the Fiddler Everywhere trust certificate must be installed is in ~/.pki/nssdb. How can I capture HTTPS traffic by moving the certificate to that folder and then use the certutil tool to install and trust it?

Solution

1. Verify that your Ubuntu has the certutil tool. Install the tool through the following command:

   sudo apt install libnss3-tools
   

2. Install and trust the certificate with the following command, which assumes that the certificate is already available in /usr/share/ca-certificates/extra.

   If not, install and trust the certificate as shown in the configuration article, so that you can capture HTTPS traffic from other applications and not only from electron applications.

   certutil -A -n "ROOT-CA" -t "TCu,Cu,Tu" -i /usr/share/ca-certificates/extra/Fiddler_Root_Certificate_Authority.crt -d sql:/home/${USER}/.pki/nssdb
   

3. Restart Fiddler Everywhere and start capturing HTTPS traffic from MS Teams or other Electron-based applications.