gnutls-bin 3.5.18-1ubuntu1 (amd64 binary) in ubuntu bionic

 GnuTLS is a portable library which implements the Transport Layer
 Security (TLS 1.0, 1.1, 1.2) and Secure Sockets Layer (SSL) 3.0 and Datagram
 Transport Layer Security (DTLS 1.0, 1.2) protocols.
 .
 GnuTLS features support for:
  - TLS extensions: server name indication, max record size, opaque PRF
    input, etc.
  - authentication using the SRP protocol.
  - authentication using both X.509 certificates and OpenPGP keys.
  - TLS Pre-Shared-Keys (PSK) extension.
  - Inner Application (TLS/IA) extension.
  - X.509 and OpenPGP certificate handling.
  - X.509 Proxy Certificates (RFC 3820).
  - all the strong encryption algorithms (including SHA-256/384/512 and
    Camellia (RFC 4132)).
 .
 This package contains a commandline interface to the GNU TLS library, which
 can be used to set up secure connections from e.g. shell scripts, debugging
 connection issues or managing certificates.
 .
 Useful utilities include:
  - TLS termination: gnutls-cli, gnutls-serv
  - key and certificate management: certtool, ocsptool, p11tool
  - credential management: srptool, psktool