@deftypefun {int} {gnutls_x509_trust_list_add_trust_dir} (gnutls_x509_trust_list_t @var{list}, const char * @var{ca_dir}, const char * @var{crl_dir}, gnutls_x509_crt_fmt_t @var{type}, unsigned int @var{tl_flags}, unsigned int @var{tl_vflags})
@var{list}: The list

@var{ca_dir}: A directory containing the CAs (optional)

@var{crl_dir}: A directory containing a list of CRLs (optional)

@var{type}: The format of the certificates

@var{tl_flags}: flags from @code{gnutls_trust_list_flags_t} 

@var{tl_vflags}: gnutls_certificate_verify_flags if flags specifies GNUTLS_TL_VERIFY_CRL

This function will add the given certificate authorities
to the trusted list. Only directories are accepted by
this function.

@strong{Returns:} The number of added elements is returned.

@strong{Since:} 3.3.6
@end deftypefun