wolfSSL supports use with Intel® SGX on both Windows and Linux. In addition to being available on both operating systems the Linux example includes running a full TLS connection in a secure Enclave. Examples can be found on GitHub under wolfssl/wolfssl-examples located here (https://github.com/wolfSSL/wolfssl-examples). One of the exciting upcoming features this year, is that wolfSSL is planning to be FIPS certified while running inside a secure Enclave.
If there are questions about current support or the future roadmap feel free to let us know at firstname.lastname@example.org.