From 7894d15929745227705438c90a40c40d6bb3b3e1 Mon Sep 17 00:00:00 2001
From: Theo Buehler <tb@openbsd.org>
Date: Sat, 21 Oct 2023 07:59:44 +0200
Subject: [PATCH] Stop reaching into X509_ALGOR

While the struct is still public in all versions of OpenSSL and its
forks, this may well change in the future. Prepare for that case and
use the X509_ALGOR_get0() accessor which has been available with this
signature since OpenSSL 1.1.
---
 src/tls_openssl.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/tls_openssl.c b/src/tls_openssl.c
index 8691197e..929e5f01 100644
--- a/src/tls_openssl.c
+++ b/src/tls_openssl.c
@@ -412,8 +412,10 @@ _get_alg(const xmpp_ctx_t *ctx, X509 *err_cert, xmpp_cert_element_t el)
         alg_nid = OBJ_obj2nid(err_cert->sig_alg->algorithm);
 #else
         const X509_ALGOR *palg;
+        const ASN1_OBJECT *obj;
         X509_get0_signature(NULL, &palg, err_cert);
-        alg_nid = OBJ_obj2nid(palg->algorithm);
+        X509_ALGOR_get0(&obj, NULL, NULL, palg);
+        alg_nid = OBJ_obj2nid(obj);
 #endif
     } break;
     default: