@c gnutls_certificate_type_t
@table @code
@item GNUTLS_@-CRT_@-UNKNOWN
Unknown certificate type.
@item GNUTLS_@-CRT_@-X509
X.509 Certificate.
@item GNUTLS_@-CRT_@-OPENPGP
OpenPGP certificate.
@item GNUTLS_@-CRT_@-RAW
Raw public key (SubjectPublicKey)
@end table