tls13: Add Certificate msg parsing tests with invalid vector lengths

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/library/ssl_tls13_invasive.h b/library/ssl_tls13_invasive.h
index 4e39f90..55fc958 100644
--- a/library/ssl_tls13_invasive.h
+++ b/library/ssl_tls13_invasive.h
@@ -80,6 +80,10 @@
                                       const unsigned char *info, size_t info_len,
                                       unsigned char *okm, size_t okm_len );
 
+MBEDTLS_CHECK_RETURN_CRITICAL
+int mbedtls_ssl_tls13_parse_certificate( mbedtls_ssl_context *ssl,
+                                         const unsigned char *buf,
+                                         const unsigned char *end );
 #endif /* MBEDTLS_TEST_HOOKS */
 
 #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */