pub unsafe extern "C" fn x509_crt_verify( crt: *mut x509_crt, trust_ca: *mut x509_crt, ca_crl: *mut x509_crl, cn: *const c_char, flags: *mut u32, f_vrfy: Option<unsafe extern "C" fn(arg1: *mut c_void, arg2: *mut x509_crt, arg3: c_int, arg4: *mut u32) -> c_int>, p_vrfy: *mut c_void) -> c_int