gnutls_x509_crt_get_subject_key_id man page

gnutls_x509_crt_get_subject_key_id — API function


#include <gnutls/x509.h>

int gnutls_x509_crt_get_subject_key_id(gnutls_x509_crt_t cert, void * ret, size_t * ret_size, unsigned int * critical);


gnutls_x509_crt_t cert

should contain a gnutls_x509_crt_t type

void * ret

The place where the identifier will be copied

size_t * ret_size

Holds the size of the result field.

unsigned int * critical

will be non-zero if the extension is marked as critical (may be null)


This function will return the X.509v3 certificate's subject key identifier.  This is obtained by the X.509 Subject Key identifier extension field (


On success, GNUTLS_E_SUCCESS (0) is returned, GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE if the extension is not present, otherwise a negative error value.

Reporting Bugs

Report bugs to <>.
Home page:

See Also

The full documentation for gnutls is maintained as a Texinfo manual. If the /usr/share/doc/gnutls/ directory does not contain the HTML form visit


3.6.2 gnutls