If I want to send an S/MIME encrypted email using openssl_pkcs7_encrypt from my webserver to a list of customers. Where do I get the public key of the recievers from?
I read about a Certificate Revocation List but not sure how to access it. Also it looks like it’s only contains invalid keys.
If found this search form but no idea…
You’d need your customers to provide their public keys. There’s no canonical way of obtaining these.