From 3877db7bcf8a180f8dcb1c36baf5f77dc29cbf1d Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Mon, 23 Feb 2026 09:11:18 +0100
Subject: [PATCH] openssl: fix compiler warning with OpenSSL master
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vtls/openssl.c:469:15: error: assignment discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]

X509_get_X509_PUBKEY() now returns a const pointer - but only on OpenSSL
3, we must keep the non-const version for all forks.

Closes #20681
---
 lib/vtls/openssl.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/lib/vtls/openssl.c b/lib/vtls/openssl.c
index f1f8843b9a..4142e937a2 100644
--- a/lib/vtls/openssl.c
+++ b/lib/vtls/openssl.c
@@ -389,6 +389,13 @@ static CURLcode get_pkey_dh(struct Curl_easy *data,
   return result;
 }
 
+#ifdef HAVE_OPENSSL3
+/* from OpenSSL commit fc756e594ed5a27af378 */
+typedef const X509_PUBKEY pubkeytype_t;
+#else
+typedef X509_PUBKEY pubkeytype_t;
+#endif
+
 static CURLcode ossl_certchain(struct Curl_easy *data, SSL *ssl)
 {
   CURLcode result;
@@ -453,7 +460,7 @@ static CURLcode ossl_certchain(struct Curl_easy *data, SSL *ssl)
 
     {
       const X509_ALGOR *sigalg = NULL;
-      X509_PUBKEY *xpubkey = NULL;
+      pubkeytype_t *xpubkey = NULL;
       ASN1_OBJECT *pubkeyoid = NULL;
 
       X509_get0_signature(&psig, &sigalg, x);