From 476c1198e8a5e31b9674da98e58061a84a677711 Mon Sep 17 00:00:00 2001
From: Waleed Elmelegy <waleed.elmelegy@arm.com>
Date: Thu, 12 Oct 2023 14:19:25 +0100
Subject: [PATCH] Fix possible NULL dereference issue in X509 cert_write
 program

Signed-off-by: Waleed Elmelegy <waleed.elmelegy@arm.com>
---
 programs/x509/cert_write.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/programs/x509/cert_write.c b/programs/x509/cert_write.c
index 40b1871f3..5e0d608bc 100644
--- a/programs/x509/cert_write.c
+++ b/programs/x509/cert_write.c
@@ -583,6 +583,9 @@ usage:
 
                 if ((subtype_value = strchr(q, ':')) != NULL) {
                     *subtype_value++ = '\0';
+                } else {
+                    mbedtls_printf("Invalid argument for option SAN: Entry should be seperated by a colon\n");
+                    goto usage;
                 }
                 if (strcmp(q, "RFC822") == 0) {
                     cur->node.type = MBEDTLS_X509_SAN_RFC822_NAME;