From: tb <tb@openbsd.org>
Date: Mon, 13 Mar 2023 07:31:09 +0000 (+0000)
Subject: Stop confusing out and asn_bio in BIO_new_NDEF()
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=282dcb706063792cec19ab7ed4b86a8216ce9e7f;p=openbsd

Stop confusing out and asn_bio in BIO_new_NDEF()

BIO_new_NDEF() sets up an ASN.1 BIO to the output chain and then adds even
more BIOs. Since BIO_push(bio, new_tail) returns bio on success, after the
if ((out = BIO_push(asn_bio, out)) != NULL) the 'out' BIO and the 'asn_bio'
are the same. The code then goes on and uses one or the other. This is very
confusing. Simply stop using out once it's appended to asn_bio.

ok jsing
---

diff --git a/lib/libcrypto/asn1/bio_ndef.c b/lib/libcrypto/asn1/bio_ndef.c
index 182ca529600..d6642e573ee 100644
--- a/lib/libcrypto/asn1/bio_ndef.c
+++ b/lib/libcrypto/asn1/bio_ndef.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: bio_ndef.c,v 1.16 2023/03/11 16:29:48 tb Exp $ */
+/* $OpenBSD: bio_ndef.c,v 1.17 2023/03/13 07:31:09 tb Exp $ */
 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project.
  */
@@ -116,7 +116,7 @@ BIO_new_NDEF(BIO *out, ASN1_VALUE *val, const ASN1_ITEM *it)
 	if ((asn_bio = BIO_new(BIO_f_asn1())) == NULL)
 		goto err;
 
-	if ((out = BIO_push(asn_bio, out)) == NULL)
+	if (BIO_push(asn_bio, out) == NULL)
 		goto err;
 	pop_bio = asn_bio;
 
@@ -127,7 +127,7 @@ BIO_new_NDEF(BIO *out, ASN1_VALUE *val, const ASN1_ITEM *it)
 	 * ASN1 structure needs.
 	 */
 
-	sarg.out = out;
+	sarg.out = asn_bio;
 	sarg.ndef_bio = NULL;
 	sarg.boundary = NULL;
 
@@ -138,7 +138,7 @@ BIO_new_NDEF(BIO *out, ASN1_VALUE *val, const ASN1_ITEM *it)
 	ndef_aux->it = it;
 	ndef_aux->ndef_bio = sarg.ndef_bio;
 	ndef_aux->boundary = sarg.boundary;
-	ndef_aux->out = out;
+	ndef_aux->out = asn_bio;
 
 	BIO_ctrl(asn_bio, BIO_C_SET_EX_ARG, 0, ndef_aux);