The OpenSSL Project is a collaborative effort to develop a robust, commercial-grade, fully featured, and Open Source toolkit implementing the Secure Sockets Layer (SSLv2/v3) and Transport Layer Security (TLSv1) as well as a full-strength general-purpose cryptography library.
major feature: Suite B support for TLS 1.2 and DTLS 1.2
Support for DTLS 1.2
TLS automatic EC curve selection.
API to set TLS supported signature algorithms and curves
SSL_CONF configuration API.
TLS Brainpool support.
ALPN support.
CMS support for RSA-PSS, RSA-OAEP, ECDH and X9.42 DH.
Other ssl tls cryptography security libraries aes rsa sha1 communications