@deftypefun {int} {gnutls_privkey_import_ext3} (gnutls_privkey_t @var{pkey}, void * @var{userdata}, gnutls_privkey_sign_func @var{sign_fn}, gnutls_privkey_decrypt_func @var{decrypt_fn}, gnutls_privkey_deinit_func @var{deinit_fn}, gnutls_privkey_info_func @var{info_fn}, unsigned int @var{flags})
@var{pkey}: The private key

@var{userdata}: private data to be provided to the callbacks

@var{sign_fn}: callback for signature operations

@var{decrypt_fn}: callback for decryption operations

@var{deinit_fn}: a deinitialization function

@var{info_fn}: returns info about the public key algorithm (should not be @code{NULL} )

@var{flags}: Flags for the import

This function will associate the given callbacks with the
@code{gnutls_privkey_t}  type. At least one of the two callbacks
must be non-null. If a deinitialization function is provided
then flags is assumed to contain @code{GNUTLS_PRIVKEY_IMPORT_AUTO_RELEASE} .

Note that the signing function is supposed to "raw" sign data, i.e.,
without any hashing or preprocessing. In case of RSA the DigestInfo
will be provided, and the signing function is expected to do the PKCS @code{1} 
1.5 padding and the exponentiation.

The  @code{info_fn} must provide information on the algorithms supported by
this private key, and should support the flags @code{GNUTLS_PRIVKEY_INFO_PK_ALGO}  and
@code{GNUTLS_PRIVKEY_INFO_SIGN_ALGO} . It must return -1 on unknown flags.

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

@strong{Since:} 3.4.0
@end deftypefun