Add in BalancerNonce directive... useful for shared-secrets.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@936407 13f79535-47bb-0310-9956-ffa450edef68

CHANGES

@@ -28,6 +28,10 @@ Changes with Apache 2.3.7
      processing is completed, avoiding orphaned callback pointers.
      [Brett Gervasoni <brettg senseofsecurity.com>, Jeff Trawick]
 
+  *) mod_proxy_balancer: Add new directive BalancerNonce to allow admin
+     to control/set the nonce used in the balancer-manager application.
+     [Jim Jagielski]
+
   *) mod_proxy_connect: Support port ranges in AllowConnect. PR 23673.
      [Stefan Fritsch]
 

docs/manual/mod/mod_proxy_balancer.xml

@@ -183,4 +183,34 @@
     <code>http://your.server.name/balancer-manager</code></p>
 </section>
 
+<directivesynopsis>
+<name>BalancerNonce</name>
+<description>Set the nonce used in the balancer-manager application</description>
+<syntax>BalancerNonce Default|None|Set "value"</syntax>
+<default>ProxyStatus Default</default>
+<contextlist><context>server config</context>
+<context>virtual host</context>
+</contextlist>
+<compatibility>Available in version 2.4 and later</compatibility>
+
+<usage>
+    <p>This directive specifies the protective nonce used in the
+    <code>balancer-manager</code> application page.</p>
+    <p>The default is to use an automatically determined UUID-based
+    nonce, to provide for further protection for the page. If set
+    to <code>Set</code>, then the next argument sets the nonce to that
+    value. A setting of <code>None</code> disables all nonce checking.</p>
+    
+    <example>
+    BalancerNonce Set "RealGudSharedSecret"
+    </example>
+
+    <note><title>Note</title>
+      <p>In addition to the nonce, the <code>balancer-manager</code> page
+      should be protected via an ACL.</p>
+    </note>
+
+</usage>
+</directivesynopsis>
+
 </modulesynopsis>

modules/proxy/mod_proxy_balancer.c

@@ -659,23 +659,12 @@ static void recalc_factors(proxy_balancer *balancer)
     }
 }
 
-/* post_config hook: */
-static int balancer_init(apr_pool_t *p, apr_pool_t *plog,
-                         apr_pool_t *ptemp, server_rec *s)
+/* pre_config hook: */
+static int balancer_init(apr_pool_t *pconf, apr_pool_t *plog,
+                         apr_pool_t *ptemp)
 {
-    void *data;
-    const char *userdata_key = "mod_proxy_balancer_init";
     apr_uuid_t uuid;
 
-    /* balancer_init() will be called twice during startup.  So, only
-     * set up the static data the second time through. */
-    apr_pool_userdata_get(&data, userdata_key, s->process->pool);
-    if (!data) {
-        apr_pool_userdata_set((const void *)1, userdata_key,
-                               apr_pool_cleanup_null, s->process->pool);
-        return OK;
-    }
-
     /* Retrieve a UUID and store the nonce for the lifetime of
      * the process. */
     apr_uuid_get(&uuid);
@@ -730,8 +719,9 @@ static int balancer_handler(request_rec *r)
     
     /* Check that the supplied nonce matches this server's nonce;
      * otherwise ignore all parameters, to prevent a CSRF attack. */
-    if ((name = apr_table_get(params, "nonce")) == NULL 
-        || strcmp(balancer_nonce, name) != 0) {
+    if (*balancer_nonce &&
+        ((name = apr_table_get(params, "nonce")) == NULL 
+        || strcmp(balancer_nonce, name) != 0)) {
         apr_table_clear(params);
     }
 
@@ -972,6 +962,35 @@ static void child_init(apr_pool_t *p, server_rec *s)
 
 }
 
+static const char *set_balancer_nonce (cmd_parms *cmd, void *dummy, const char *arg,
+                                       const char *val)
+{
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+    if (err != NULL) {
+        return err;
+    }
+
+    if (!strcasecmp(arg, "None")) {
+        *balancer_nonce = '\0';
+    } else if (!strcasecmp(arg, "Set")) {
+        if (val) {
+            apr_cpystrn(balancer_nonce, val, sizeof(balancer_nonce));
+        } else {
+            return "BalancerNonce Set requires an argument";
+        }
+    } else if (strcasecmp(arg, "Default")) {
+        return "Bad argument for BalancerNonce: Must be 'Set', 'None' or 'Default'";
+    }
+    return NULL;
+}
+
+static const command_rec balancer_cmds[] =
+{
+    AP_INIT_TAKE12("BalancerNonce", set_balancer_nonce, NULL,
+       RSRC_CONF, "Set value for balancer-manager nonce"),
+    {NULL}
+};
+
 static void ap_proxy_balancer_register_hook(apr_pool_t *p)
 {
     /* Only the mpm_winnt has child init hook handler.
@@ -980,7 +999,7 @@ static void ap_proxy_balancer_register_hook(apr_pool_t *p)
      */
     static const char *const aszPred[] = { "mpm_winnt.c", NULL};
      /* manager handler */
-    ap_hook_post_config(balancer_init, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_pre_config(balancer_init, NULL, NULL, APR_HOOK_MIDDLE);
     ap_hook_handler(balancer_handler, NULL, NULL, APR_HOOK_FIRST);
     ap_hook_child_init(child_init, aszPred, NULL, APR_HOOK_MIDDLE);
     proxy_hook_pre_request(proxy_balancer_pre_request, NULL, NULL, APR_HOOK_FIRST);
@@ -994,6 +1013,6 @@ module AP_MODULE_DECLARE_DATA proxy_balancer_module = {
     NULL,       /* merge per-directory config structures */
     NULL,       /* create per-server config structure */
     NULL,       /* merge per-server config structures */
-    NULL,       /* command apr_table_t */
+    balancer_cmds,       /* command apr_table_t */
     ap_proxy_balancer_register_hook /* register hooks */
 };