Usability-wise (I do not need many features or compliance for FIPS) I have been happy with Botan: https://botan.randombit.net/
> I have been happy with Botan
Botan is under rated.
It is nowhere as optimized as OpenSSL but its APIs are one order of magnitude better to use.
The team behind also demonstrated a pretty serious handling of non-trivial issues like timing attacks.
Can confirm, used Botan in the past and I didn't curse at it a lot. Certainly less than OpenSSL.
> I have been happy with Botan
Botan is under rated.
It is nowhere as optimized as OpenSSL but its APIs are one order of magnitude better to use.
The team behind also demonstrated a pretty serious handling of non-trivial issues like timing attacks.