From e94e0fbb15c662d3e9bd04f790235d60fedfef09 Mon Sep 17 00:00:00 2001
From: Joe Orton <jorton@apache.org>
Date: Mon, 17 Jun 2024 14:21:04 +0000
Subject: [PATCH] Merge r1916863 from trunk:

* Ensure that we set the default DH parameters for the key

Replace else with an if as the if branch no longer ensures that
custome DH parameters have been loaded.
This fixes a regression that causes the default DH parameters for a key
no longer set and thus effectively disabling DH ciphers when no explicit
DH parameters are set.

PR: 68863
Submitted by: rpluem
Reviewed by: rpluem, jorton, ylavic


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1918385 13f79535-47bb-0310-9956-ffa450edef68
---
 changes-entries/pr68863.txt   |  3 +++
 modules/ssl/ssl_engine_init.c | 11 ++++++-----
 2 files changed, 9 insertions(+), 5 deletions(-)
 create mode 100644 changes-entries/pr68863.txt

diff --git a/changes-entries/pr68863.txt b/changes-entries/pr68863.txt
new file mode 100644
index 00000000000..d45ffc708cc
--- /dev/null
+++ b/changes-entries/pr68863.txt
@@ -0,0 +1,3 @@
+  *) mod_ssl: Fix a regression that causes the default DH parameters for a key
+     no longer set and thus effectively disabling DH ciphers when no explicit
+     DH parameters are set. PR 68863 [Ruediger Pluem]
diff --git a/modules/ssl/ssl_engine_init.c b/modules/ssl/ssl_engine_init.c
index c2ec048f527..12c767cac0f 100644
--- a/modules/ssl/ssl_engine_init.c
+++ b/modules/ssl/ssl_engine_init.c
@@ -1346,6 +1346,7 @@ static apr_status_t ssl_init_server_certs(server_rec *s,
     const char *vhost_id = mctx->sc->vhost_id, *key_id, *certfile, *keyfile;
     int i;
     EVP_PKEY *pkey;
+    int custom_dh_done = 0;
 #ifdef HAVE_ECC
     EC_GROUP *ecgroup = NULL;
     int curve_nid = 0;
@@ -1518,14 +1519,14 @@ static apr_status_t ssl_init_server_certs(server_rec *s,
      */
     certfile = APR_ARRAY_IDX(mctx->pks->cert_files, 0, const char *);
     if (certfile && !modssl_is_engine_id(certfile)) {
-        int done = 0, num_bits = 0;
+        int num_bits = 0;
 #if OPENSSL_VERSION_NUMBER < 0x30000000L
         DH *dh = modssl_dh_from_file(certfile);
         if (dh) {
             num_bits = DH_bits(dh);
             SSL_CTX_set_tmp_dh(mctx->ssl_ctx, dh);
             DH_free(dh);
-            done = 1;
+            custom_dh_done = 1;
         }
 #else
         pkey = modssl_dh_pkey_from_file(certfile);
@@ -1535,18 +1536,18 @@ static apr_status_t ssl_init_server_certs(server_rec *s,
                 EVP_PKEY_free(pkey);
             }
             else {
-                done = 1;
+                custom_dh_done = 1;
             }
         }
 #endif
-        if (done) {
+        if (custom_dh_done) {
             ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(02540)
                          "Custom DH parameters (%d bits) for %s loaded from %s",
                          num_bits, vhost_id, certfile);
         }
     }
 #if !MODSSL_USE_OPENSSL_PRE_1_1_API
-    else {
+    if (!custom_dh_done) {
         /* If no parameter is manually configured, enable auto
          * selection. */
         SSL_CTX_set_dh_auto(mctx->ssl_ctx, 1);