Fixed possible NULL pointer exception in ssl_get_ciphersuite()
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 6630ad8..dde0155 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -3482,6 +3482,9 @@
 
 const char *ssl_get_ciphersuite( const ssl_context *ssl )
 {
+    if( ssl == NULL || ssl->session == NULL )
+        return NULL;
+
     return ssl_get_ciphersuite_name( ssl->session->ciphersuite );
 }