Hi Alex,
I consulted this topic with one of our application engineer who is TCP/IP expert and he told me following:
WolfSSL is independent library which does not need any hardware support (if hw acceleration for crypto algorithms is not used). The best way, how to implement this library is to use TCP/IP stack, which contains Socket Layer (interface for application, which uses TCP communication). This Socket layer is set of standardized function (for example look at the Linux specification). This is the easiest way, how to connect wolfSSL to TCP/IP stack.
I assume, it is possible to implement wolfSSL without operating system, but it will be more difficult than you use OS.
Regards,
Martin