Fix ENGINE use with OpenSSL 3.2, which appears to be broken due to a

refcounting issue in mod_ssl.

* modules/ssl/ssl_engine_pphrase.c (modssl_engine_cleanup):
  New function.
  (modssl_load_keypair_engine): Take pconf & ptemp arguments, don't
  call ENGINE_finish() immediately but register the above cleanup.
  (modssl_load_engine_keypair): Pass through pconf & ptemp.

* modules/ssl/ssl_engine_init.c (ssl_init_server_certs):
  Pass through pconf and ptemp to modssl_load_engine_keypair.

Github: closes #446


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1918024 13f79535-47bb-0310-9956-ffa450edef68

3 files changed, 28 insertions, 10 deletions

diff --git a/modules/ssl/ssl_engine_init.c b/modules/ssl/ssl_engine_init.c
index ace87522d7..33ef4c4d7b 100644
--- a/modules/ssl/ssl_engine_init.c
+++ b/modules/ssl/ssl_engine_init.c
@@ -1467,7 +1467,7 @@ static apr_status_t ssl_init_server_certs(server_rec *s,
         if (modssl_is_engine_id(keyfile)) {
             apr_status_t rv;
 
-            if ((rv = modssl_load_engine_keypair(s, ptemp, vhost_id,
+            if ((rv = modssl_load_engine_keypair(s, p, ptemp, vhost_id,
                                                  engine_certfile, keyfile,
                                                  &cert, &pkey))) {
                 return rv;
diff --git a/modules/ssl/ssl_engine_pphrase.c b/modules/ssl/ssl_engine_pphrase.c
index 5dd6bdda8d..4167c6f5d6 100644
--- a/modules/ssl/ssl_engine_pphrase.c
+++ b/modules/ssl/ssl_engine_pphrase.c
@@ -797,7 +797,17 @@ static UI_METHOD *get_passphrase_ui(apr_pool_t *p)
 #endif
 
 #if MODSSL_HAVE_ENGINE_API
-static apr_status_t modssl_load_keypair_engine(server_rec *s, apr_pool_t *p,
+static apr_status_t modssl_engine_cleanup(void *engine)
+{
+    ENGINE *e = engine;
+
+    ENGINE_finish(e);
+
+    return APR_SUCCESS;
+}
+
+static apr_status_t modssl_load_keypair_engine(server_rec *s, apr_pool_t *pconf,
+                                               apr_pool_t *ptemp,
                                                const char *vhostid,
                                                const char *certid,
                                                const char *keyid,
@@ -806,12 +816,12 @@ static apr_status_t modssl_load_keypair_engine(server_rec *s, apr_pool_t *p,
 {
     const char *c, *scheme;
     ENGINE *e;
-    UI_METHOD *ui_method = get_passphrase_ui(p);
+    UI_METHOD *ui_method = get_passphrase_ui(ptemp);
     pphrase_cb_arg_t ppcb;
 
     memset(&ppcb, 0, sizeof ppcb);
     ppcb.s = s;
-    ppcb.p = p;
+    ppcb.p = ptemp;
     ppcb.bPassPhraseDialogOnce = TRUE;
     ppcb.key_id = vhostid;
     ppcb.pkey_file = keyid;
@@ -824,7 +834,7 @@ static apr_status_t modssl_load_keypair_engine(server_rec *s, apr_pool_t *p,
         return ssl_die(s);
     }
 
-    scheme = apr_pstrmemdup(p, keyid, c - keyid);
+    scheme = apr_pstrmemdup(ptemp, keyid, c - keyid);
     if (!(e = ENGINE_by_id(scheme))) {
         ap_log_error(APLOG_MARK, APLOG_EMERG, 0, s, APLOGNO(10132)
                      "Init: Failed to load engine for private key %s",
@@ -873,7 +883,12 @@ static apr_status_t modssl_load_keypair_engine(server_rec *s, apr_pool_t *p,
         return ssl_die(s);
     }
 
-    ENGINE_finish(e);
+    /* Release the functional reference obtained by ENGINE_init() only
+     * when after the ENGINE is no longer used. */
+    apr_pool_cleanup_register(pconf, e, modssl_engine_cleanup, modssl_engine_cleanup);
+
+    /* Release the structural reference obtained by ENGINE_by_id()
+     * immediately. */
     ENGINE_free(e);
 
     return APR_SUCCESS;
@@ -974,7 +989,8 @@ static apr_status_t modssl_load_keypair_store(server_rec *s, apr_pool_t *p,
 }
 #endif
 
-apr_status_t modssl_load_engine_keypair(server_rec *s, apr_pool_t *p,
+apr_status_t modssl_load_engine_keypair(server_rec *s,
+                                        apr_pool_t *pconf, apr_pool_t *ptemp,
                                         const char *vhostid,
                                         const char *certid, const char *keyid,
                                         X509 **pubkey, EVP_PKEY **privkey)
@@ -986,11 +1002,12 @@ apr_status_t modssl_load_engine_keypair(server_rec *s, apr_pool_t *p,
      * support was not present compile-time, or if it's built but
      * SSLCryptoDevice is not configured. */
     if (mc->szCryptoDevice)
-        return modssl_load_keypair_engine(s, p, vhostid, certid, keyid,
+        return modssl_load_keypair_engine(s, pconf, ptemp,
+                                          vhostid, certid, keyid,
                                           pubkey, privkey);
 #endif
 #if MODSSL_HAVE_OPENSSL_STORE
-    return modssl_load_keypair_store(s, p, vhostid, certid, keyid,
+    return modssl_load_keypair_store(s, ptemp, vhostid, certid, keyid,
                                      pubkey, privkey);
 #else
     ap_log_error(APLOG_MARK, APLOG_EMERG, 0, s, APLOGNO(10496)
diff --git a/modules/ssl/ssl_private.h b/modules/ssl/ssl_private.h
index 2f8578be81..9cdf0c3754 100644
--- a/modules/ssl/ssl_private.h
+++ b/modules/ssl/ssl_private.h
@@ -1089,7 +1089,8 @@ apr_status_t ssl_load_encrypted_pkey(server_rec *, apr_pool_t *, int,
 /* Load public and/or private key from the configured ENGINE. Private
  * key returned as *pkey.  certid can be NULL, in which case *pubkey
  * is not altered.  Errors logged on failure. */
-apr_status_t modssl_load_engine_keypair(server_rec *s, apr_pool_t *p,
+apr_status_t modssl_load_engine_keypair(server_rec *s,
+                                        apr_pool_t *pconf, apr_pool_t *ptemp,
                                         const char *vhostid,
                                         const char *certid, const char *keyid,
                                         X509 **pubkey, EVP_PKEY **privkey);