int gnutls_x509_crt_get_basic_constraints(gnutls_x509_crt_t cert, unsigned int * critical, int * ca, int * pathlen);
should contain a gnutls_x509_crt_t structure
unsigned int * critical
will be non zero if the extension is marked as critical
int * ca
pointer to output integer indicating CA status, may be NULL,
value is 1 if the certificate CA flag is set, 0 otherwise.
int * pathlen
pointer to output integer indicating path length (may be
NULL), non-negative values indicate a present pathLenConstraint
field and the actual value, -1 indicate that the field is absent.
This function will read the certificate's basic constraints, and
return the certificates CA status. It reads the basicConstraints
X.509 extension (188.8.131.52).
If the certificate is a CA a positive value will be
returned, or zero if the certificate does not have CA flag set. A
negative value may be returned in case of errors. If the
certificate does not contain the basicConstraints extension
GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE will be returned.