Visual Studio 2017 ships with its own version of Git. Unfortunately, it doesn\'t have support for SSH and it doesn\'t include a root certificate for the issuer for SSL
I have not found an answer to your direct question in bold, but I am having similar SSL certificate issues, which I have solved with help from the following link:
Git in VS2017 with self-signed SSL
In short: Find the location of the certs folder that Visual Studio is using. It will be something like this:
C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\Common7\IDE\CommonExtensions\Microsoft\TeamFoundation\Team Explorer\Git\mingw32\ssl\certs
I found this by going down to the /2017 directory and just searching from there.
Next: Open ca-bundle.crt and copy your full base64 encoded cert (including begin and end tags) in that file, and save.
Test with a fetch, or some such.
Hoping this solves at least half of your problem!