This is more of a security question, but I currently know way more people on ruby.social than infosec.exchange. I want to use a #Yubikey for #SMIME or #GPG signing on #iOS & #iPadOS, but can't find:
Any documentation about how to integrate it with Apple Mail.
Anyplace that offers #x509 certificates for S/MIME at zero or minimal cost the way @letsencrypt offers free #SSL certs.
Self-signed S/MIME certs are a non-starter, and there are no full-featured #OpenPGP apps on iOS. Suggestions?
