From bcedd65a31667a25427ad6f12ccdbf88d01af3a6 Mon Sep 17 00:00:00 2001
From: Andreas Steffen <andreas.steffen@strongswan.org>
Date: Thu, 28 Jul 2022 11:18:54 +0200
Subject: [PATCH] pkcs7: Allow for missing optional content field

The content field of type OCTET STRING of a ContentInfo object
with ContentType Data

  ContentInfo ::= SEQUENCE {
     contentType ContentType,
     content
        [0] EXPLICIT OCTET STRING OPTIONAL

is optional and can be missing if no data is available
---
 src/libstrongswan/plugins/pkcs7/pkcs7_data.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/libstrongswan/plugins/pkcs7/pkcs7_data.c b/src/libstrongswan/plugins/pkcs7/pkcs7_data.c
index 235b9fe30..98af13805 100644
--- a/src/libstrongswan/plugins/pkcs7/pkcs7_data.c
+++ b/src/libstrongswan/plugins/pkcs7/pkcs7_data.c
@@ -60,6 +60,13 @@ METHOD(container_t, get_data, bool,
 	chunk_t chunk;
 
 	chunk = this->content;
+
+	/* The content field is optional */
+	if (chunk.len == 0)
+	{
+		*data = chunk_empty;
+		return TRUE;
+	}
 	if (asn1_unwrap(&chunk, &chunk) == ASN1_OCTET_STRING)
 	{
 		*data = chunk_clone(chunk);