GnuTLS

GnuTLS

• https://gnutls.org/

GnuTLS is a secure communications library implementing the SSL, TLS and DTLS protocols and technologies around them. It provides a simple C language application programming interface (API) to access the secure communications protocols as well as APIs to parse and write X.509, PKCS #12, and other required structures.

gnutls-cli

• https://gnutls.org/manual/html_node/gnutls_002dcli-Invocation.html#gnutls_002dcli-Invocation

example

$ gnutls-cli localhost --insecure </dev/null

see also

• https://gnutls.org/manual/html_node/Echo-server-with-X_002e509-authentication.html#Echo-server-with-X_002e509-authentication
• https://www.lulu.com/shop/http://www.lulu.com/shop/nikos-mavrogiannopoulos-and-simon-josefsson/the-gnutls-manual/paperback/product-22120178.html