@deftypefun {int} {gnutls_x509_crt_set_spki} (gnutls_x509_crt_t @var{crt}, const gnutls_x509_spki_t @var{spki}, unsigned int @var{flags})
@var{crt}: a certificate of type @code{gnutls_x509_crt_t} 

@var{spki}: a SubjectPublicKeyInfo structure of type @code{gnutls_x509_spki_t} 

@var{flags}: must be zero

This function will set the certificate's subject public key
information explicitly. This is intended to be used in the cases
where a single public key (e.g., RSA) can be used for multiple
signature algorithms (RSA PKCS1-1.5, and RSA-PSS).

To export the public key (i.e., the SubjectPublicKeyInfo part), check
@code{gnutls_pubkey_import_x509()} .

@strong{Returns:} On success, @code{GNUTLS_E_SUCCESS}  (0) is returned, otherwise a
negative error value.

@strong{Since:} 3.6.0
@end deftypefun