I am trying to get my Ubuntu machine to properly recognize and use the certificate from Fiddler as a trusted source so I can decryt HTTPS traffic (specifically to google-analytics). I had this working once before, but had to since reinstall Ubuntu and now have to re-setup Fiddler. I can't remember what I did in the first place and I've spent the better part of today trying to figure it out.
I think I am inching closer to getting this certificate to recognize. By that I mean that when I went to Google a few hours ago, while using Fiddler, I would see the 'Connection Not Secure message' - which I think means Google is just actively refusing to recognize Fiddler's certificate. Now, I am getting a This Site Can't Be Reached page (ERR_SOCKET_NOT_CONNECTED) page.
I have tried a number of different things today to try to get this to work, but this is what I did with my last attempt:
Used THIS SITE as a jumping off point to get Fiddler installed.
Installed mono 4.8.0
Did not run the '/usr/lib/mono//mozroots --import --sync' command from the Linux setup page since when I tried I got a message in Terminal saying that mozroots is depreciated and to use client_sync instead. (client_sync seems to just update the mono cert store with whatever CRT file you pass to it.
Installed Fiddler (Left it as default as I could - using 8888 as listing port)
Ticked the 'Decrpyt HTTPS' box in Fiddler
Exported the Fiddler certificate to the desktop
Converted the CER cert file to PEM format (CRT specifically) with openssl (update-ca-certificates on ubuntu needs a PEM formatted cert file and the CER file Fiddler exports is in a binary format.)
Copied the CRT file to /usr/share/ca-certificates/
From terminal ran 'sudo dpkg-reconfigure ca-certificates' (Clicked 'Ask' then 'OK') (this re configures ca-certificates, runs update-ca-certificate, and updates mono cert store (by running client_sync from mono and passes it the updated ca-certificates.crt file that this process creates). This places a PEM version of the Fiddler CRT file into /etc/ssl/ca-certificates/ and packages it into the bigger ca-certificates.conf file.
This is pretty much where I am at right now. Turning Fiddler off - I can get to Google just fine, turning it on gives me the page I mentioned at the top of this post. I can see all other HTTP requests as expected.
When I got this to work last time, I was reading a lot of suggestions of the web for how to get a CA certificate installed on Ubuntu and tried to pick that trail up again, but everything I read has since blended together. I do vaguely remember importing the Fiddler cert file into Firefox as a Person, exporting that cert, then importing the file I just exported back into FF as a CA trusted root, then deleted the person cert that I installed in the first place. I think I them used the cert exported from FF to import to the system with 'update-ca-certificates'. I have no idea if this was a critical step or not.
I was also playing around with mitmproxy at the same time which also needed a proxy - again, no idea if that helped the process at all.
I am basically throwing things at a wall right now and seeing what sticks.