How SSL / TLS certificates work

Question

I would like to know how SSL certificates work, specifically I would like to know how the browser certifies that these certificates are valid and signed by a valid certification body, how does it get them safely? Why is it rare for an IoT device to have this capability ?

Answer 1

The browsers have a list of valid certificates, installed and updated with the browser code itself. Plus, it also has a local list, where the user can add his own trusted certificates.

Answer 2

The browser updates already deal with the ones it mantains. If you add certificates manually, then you have to update manually - add the new ones and remove the expired ones.

Answer 3

How do I update other certificates when certificates expire?

Answer 4

I use Fiddler as a proxy to read my browser traffic, could the certificate I installed could undermine the security on other connections to other servers?

Answer 5

I don't know Fiddler. But only your browser uses the certificates installed in it - it doesn't affect proxies, even local. Except, obviously, if you install a certificate from a harmful domain which attacks proxies, but I don't think one would do this.