CyaSSL

The CyaSSL embedded SSL library is a lightweight SSL library written in ANSI standard C and targeted for embedded and RTOS environments - primarily because of its small size, speed, and feature set. It is commonly used in standard operating environments as well because of its royalty free pricing and cross platform support. CyaSSL supports industry standards up to the current TLS 1.2 level, is up to 20 times smaller than OpenSSL, and offers progressive ciphers such as HC-128, RABBIT, and NTRU. User benchmarking and feedback reports dramatically better performance when using CyaSSL over OpenSSL. It is available under both GPLv2 and commercial licenses, like MySQL, making it ideal for a wide variety of projects.