说明：  PolarSSL源码，也许是最小巧的ssl代码库。高效、便于移植和集成。尤其适合嵌入式应用。
(PolarSSL is a light-weight open source cryptographic and SSL/TLS library written in C. PolarSSL makes it easy for developers to include cryptographic and SSL/TLS capabilities in their (embedded) applications with as little hassle as possible. Loose coupling of the components inside the library means that it is easy to seperate the parts that are needed, without needing to include the total library. PolarSSL is written with embedded systems in mind and has been ported on a number of architectures, including ARM, PowerPC, MIPS and Motorola 68000.)