Saving the serialized context to a file

Signed-off-by: Piotr Nowicki <piotr.nowicki@arm.com>
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 924384f..df3f53b 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -958,6 +958,8 @@
 
 cleanup() {
     rm -f $CLI_OUT $SRV_OUT $PXY_OUT $SESSION
+    rm -f context_srv.txt
+    rm -f context_cli.txt
     test -n "${SRV_PID:-}" && kill $SRV_PID >/dev/null 2>&1
     test -n "${PXY_PID:-}" && kill $PXY_PID >/dev/null 2>&1
     test -n "${CLI_PID:-}" && kill $CLI_PID >/dev/null 2>&1
@@ -1628,6 +1630,16 @@
             -c "Deserializing connection..." \
             -s "Deserializing connection..."
 
+requires_config_enabled MBEDTLS_SSL_CONTEXT_SERIALIZATION
+run_test    "Saving the serialized context to a file" \
+            "$P_SRV dtls=1 serialize=1 context_file=context_srv.txt" \
+            "$P_CLI dtls=1 serialize=1 context_file=context_cli.txt" \
+            0 \
+            -s "Save serialized context to a file... ok" \
+            -c "Save serialized context to a file... ok"
+rm -f context_srv.txt
+rm -f context_cli.txt
+
 # Tests for DTLS Connection ID extension
 
 # So far, the CID API isn't implemented, so we can't