From cb8c7647ca4381273765ea6d5de750940e2ab248 Mon Sep 17 00:00:00 2001
From: Jakub Jelen <jjelen@redhat.com>
Date: Thu, 21 May 2020 16:28:48 +0200
Subject: [PATCH] asn1: Do not crash on invalid arguments

---
 src/libopensc/asn1.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/libopensc/asn1.c b/src/libopensc/asn1.c
index c96fcfdb..315a74fe 100644
--- a/src/libopensc/asn1.c
+++ b/src/libopensc/asn1.c
@@ -1991,6 +1991,10 @@ static int asn1_encode(sc_context_t *ctx, const struct sc_asn1_entry *asn1,
 	u8 *obj = NULL, *buf = NULL, *tmp;
 	size_t total = 0, objsize;
 
+	if (asn1 == NULL) {
+		return SC_ERROR_INVALID_ARGUMENTS;
+	}
+
 	for (idx = 0; asn1[idx].name != NULL; idx++) {
 		r = asn1_encode_entry(ctx, &asn1[idx], &obj, &objsize, depth);
 		if (r) {