Update mbedtls_ssl_handshake_free()

Signed-off-by: Xiaofei Bai <xiaofei.bai@arm.com>
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 5e8b60b..91767fb 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -5579,7 +5579,14 @@
         mbedtls_free( (void*) handshake->sig_algs );
     handshake->sig_algs = NULL;
 #endif /* MBEDTLS_DEPRECATED_REMOVED */
-
+#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
+    if( ssl->handshake->certificate_request_context )
+    {
+        mbedtls_free( (void*) handshake->certificate_request_context );
+    }
+    handshake->certificate_request_context = NULL;
+    handshake->certificate_request_context_len = 0;
+#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
 #endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
 
 #if defined(MBEDTLS_SSL_ASYNC_PRIVATE)