Add test without server certificate

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 9d84844..6041f1a 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -11329,6 +11329,17 @@
         -s "=> write hello retry request" \
         -s "<= write hello retry request"
 
+requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_3
+requires_config_enabled MBEDTLS_DEBUG_C
+requires_config_enabled MBEDTLS_SSL_SRV_C
+requires_config_enabled MBEDTLS_SSL_CLI_C
+run_test    "TLS 1.3: Server side check, no server certificate available" \
+            "$P_SRV debug_level=4 crt_file=none key_file=none force_version=tls13" \
+            "$P_CLI debug_level=4 force_version=tls13" \
+            1 \
+            -s "tls13 server state: MBEDTLS_SSL_SERVER_CERTIFICATE" \
+            -s "No certificate available."
+
 for i in opt-testcases/*.sh
 do
     TEST_SUITE_NAME=${i##*/}