Fix 69939 EVP_PKEY_is_a() crashes with NULL key on OpenSSL 3.0.x

https://bz.apache.org/bugzilla/show_bug.cgi?id=69939

Author: markt-asf

native/src/sslutils.c

@@ -190,7 +190,7 @@ EVP_PKEY *SSL_dh_GetParamFromFile(const char *file)
         return NULL;
     evp = PEM_read_bio_Parameters_ex(bio, NULL, NULL, NULL);
     BIO_free(bio);
-    if (!EVP_PKEY_is_a(evp, "DH")) {
+    if (evp && !EVP_PKEY_is_a(evp, "DH")) {
         EVP_PKEY_free(evp);
         return NULL;
     }

xdocs/miscellaneous/changelog.xml

@@ -62,6 +62,10 @@
       Improve performance for the rare case of handling large OCSP responses.
       (markt)
     </scode>
+    <fix>
+      <bug>69939</bug>: Fix the cause of a crash with OpenSSL 3.0.x when a
+      certificate PEM file does not contain explicit DH parameters. (markt)
+    </fix>
   </changelog>
 </section>
 <section name="2.0.12" rtext="2026-01-12">