From aa5715c96c457686015e476e775057a0acd5b072 Mon Sep 17 00:00:00 2001
From: tb <tb@openbsd.org>
Date: Thu, 9 Mar 2023 18:20:10 +0000
Subject: [PATCH] Add missing error checking in PKCS7

Check the return value of BIO_set_md(). Prompted by OpenSSL's fix for
CVE-2023-0401 (the crash in that bug is an OpenSSL 3-only problem due
to provider design).

ok beck jsing
---
 lib/libcrypto/pkcs7/pk7_doit.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/lib/libcrypto/pkcs7/pk7_doit.c b/lib/libcrypto/pkcs7/pk7_doit.c
index 1fcc37a983f..d5edaedbd04 100644
--- a/lib/libcrypto/pkcs7/pk7_doit.c
+++ b/lib/libcrypto/pkcs7/pk7_doit.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: pk7_doit.c,v 1.51 2023/02/16 08:38:17 tb Exp $ */
+/* $OpenBSD: pk7_doit.c,v 1.52 2023/03/09 18:20:10 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -112,6 +112,7 @@ PKCS7_bio_add_digest(BIO **pbio, X509_ALGOR *alg)
 {
 	BIO *btmp;
 	const EVP_MD *md;
+
 	if ((btmp = BIO_new(BIO_f_md())) == NULL) {
 		PKCS7error(ERR_R_BIO_LIB);
 		goto err;
@@ -123,7 +124,11 @@ PKCS7_bio_add_digest(BIO **pbio, X509_ALGOR *alg)
 		goto err;
 	}
 
-	BIO_set_md(btmp, md);
+	if (BIO_set_md(btmp, md) <= 0) {
+		PKCS7error(ERR_R_BIO_LIB);
+		goto err;
+	}
+
 	if (*pbio == NULL)
 		*pbio = btmp;
 	else if (!BIO_push(*pbio, btmp)) {
@@ -497,7 +502,10 @@ PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
 				goto err;
 			}
 
-			BIO_set_md(btmp, evp_md);
+			if (BIO_set_md(btmp, evp_md) <= 0) {
+				PKCS7error(ERR_R_BIO_LIB);
+				goto err;
+			}
 			if (out == NULL)
 				out = btmp;
 			else
-- 
2.20.1