RFC - automatically load CA Certs from SPIFFS or PROGMEM for WiFiClientSecure/ESP8266HTTPClient

[liebman]

After the discussion on #3933 I started looking at making it easier to handle CA Certificates.
My thinking is to add a new function to the axtls library that would return the name of the certificate that needs to be loaded using ca_cert_dn from the last cert in the chain. Then use that to load data either from SPIFFS or PROGMEM.
Has anyone looked at this or something similar? Thoughts?

[igrr]

I'm working on igrr/axtls-8266#44, which has similar goals, but uses authority key identifier instead of the CA certificate name.

[liebman]

With the integration of bearssl I think this can be closed.