OpenSSL is a framework which implements the secure socket layer. It ships with a program/library which gives you access to all those functions.

wolfSSL is described as '(formerly CyaSSL) is a small, fast, portable implementation of TLS/SSL for embedded devices to the cloud. http://www.wolfssl.com' and is a cryptography library. There are five alternatives to wolfSSL for a variety of platforms, including Windows, Linux, BSD, Mac and Haiku apps. The best wolfSSL alternative is OpenSSL, which is both free and Open Source. Other great apps like wolfSSL are LibreSSL, mbed TLS, GnuTLS and SharkSSL.
OpenSSL is a framework which implements the secure socket layer. It ships with a program/library which gives you access to all those functions.

LibreSSL is a version of the TLS/crypto stack forked from OpenSSL in 2014, with goals of modernizing the codebase, improving security, and applying best practice development processes.
Mbed TLS (formerly known as PolarSSL) makes it trivially easy for developers to include cryptographic and SSL/TLS capabilities in their (embedded) products, facilitating this functionality with a minimal coding footprint.
GnuTLS (the GNU Transport Layer Security Library) is a free software implementation of the SSL, TLS and DTLS protocols. It offers an application programming interface (API) for applications to enable secure communication over their network transport layer, as well as interfaces...
The SSL/TLS and Certificate tutorial for Windows enables you to fast track your understanding of the SSL/TLS protocol, Certificate Management, and secure communication. The download includes many C source code examples, including a secure WebSocket tutorial.
