Amazon announced today a new library called “s2n”, an open source implementation of TLS/SSL, the cryptographic security protocols behind HTTPS, SSH, SFTP, secure SMTP, and many others. Weighing in at about 6k lines of code, it’s just a little more than 1% the size of OpenSSL, which is really good news in terms of security auditing and testing. OpenSSL isn’t going away, and Amazon has made clear that they will continue to support it. Notably, s2n does not provide all the additional cryptographic functions that OpenSSL provides in libcrypto, it only provides the SSL/TLS functions. Further more, it implements a relatively small subset of SSL/TLS features compared to OpenSSL.