Most TLS sessions make use of ephemeral DH parameters to effect the key exchange between the client and the server. These objects are created on the server side of a TLS session.

x::gnutls::dhparams is a reference to a reference-counted object that represents an ephemeral DH parameter. x::gnutls::pkparams is a reference to a generic superclass that implements the public key parameter interface, for future extensibility, such as generate(), which generates a new parameter. At this time, the only subclass is x::gnutls::dhparams; the temporary RSA parameter implementation has been obsoleted. get_pk_algorithm() returns GNUTLS_PK_DSA, that indicates the implementing subclass of x::gnutls::pkparams.