Picotls is a TLS 1.3 implementation written in C.
At the moment, the library implements Draft 16 of the specification (1-RTT ECDH + server-certificate + AES128-GCM only).
Primary goal of the project is to create a fast, tiny TLS 1.3 implementation that can be used with the HTTP/2 protocol stack and possibly the upcoming QUIC stack of the H2O HTTP/2 server.
The library only implements the communication protocol. Cryptographic operations are delegated to OpenSSL using callbacks. It would be easy to write binding to other crypto engines.
Build using cmake:
% cmake
% make
% make check
Run the test server (at 127.0.0.1:8443):
% ./cli -c /path/to/certificate.pem -k /path/to/private-key.pem 127.0.0.1 8443
Connect to the test server:
% ./cli 127.0.0.1 8443
MIT