mbedtls_x509_crt_ext_cb_t
The type of certificate extension callbacks. Callbacks of this type are passed to and used by the mbedtls_x509_crt_parse_der_with_ext_cb() routine when it encounters either an unsupported extension or a "certificate policies" extension containing any unsupported certificate policies. Future versions of the library may invoke the callback in other cases, if and when the need arises.
Syntax
typedef int (*mbedtls_x509_crt_ext_cb_t)(void *p_ctx,
mbedtls_x509_crt const *crt,
mbedtls_x509_buf const *oid,
int critical,
const unsigned char *p,
const unsigned char *end);