Hi, does ServiceStack supports Certificate Authentication? Is it planned? Is there some workaround to implement that myself?
It doesn't and there's no plan to which has never been requested.
Our Encrypted Messaging does use RSA Keys though.
Depending on your use-case the easiest option may be to validate it in a SSL terminating proxy which can set additional HTTP headers that can be accessed in downstream apps.
If you want to implement it in ServiceStack you could take a similar approach to how EncryptedMessagesFeature is implemented.