svn commit: r1937109 - httpd/httpd/trunk/modules/aaa

Author: jorton
Date: Thu Aug 13 15:16:01 2026
New Revision: 1937109

Log:
* modules/aaa/mod_auth_digest.c (client_generate): Skip a client id
  of zero, which the counter hands out once it wraps: zero means "no
  client", so add_client() refuses it.

Assisted-by: Claude Opus 5 (1M context) <[email protected]>
GitHub: PR #705

Modified:
   httpd/httpd/trunk/modules/aaa/mod_auth_digest.c

Modified: httpd/httpd/trunk/modules/aaa/mod_auth_digest.c
==============================================================================
--- httpd/httpd/trunk/modules/aaa/mod_auth_digest.c	Thu Aug 13 15:15:56 2026	(r1937108)
+++ httpd/httpd/trunk/modules/aaa/mod_auth_digest.c	Thu Aug 13 15:16:01 2026	(r1937109)
@@ -1149,6 +1149,12 @@ static client_id_t client_generate(const
     client_id_t op = apr_atomic_inc32(client_id_counter);
     client_entry new_entry = { 0, NULL, 0, 0 };
 
+    /* The counter wraps after 2^32 clients: skip an id of zero, which means
+     * "no client" and which add_client() would refuse. */
+    if (op == 0) {
+        op = apr_atomic_inc32(client_id_counter);
+    }
+
     if (!add_client(op, &new_entry, r->server)) {
         ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01769)
                       "unable to allocate a client entry - failing the "