Whilst 2.2 is, as advertised, source-compatible with 2.0 auth modules,
the current implementation requires that any auth configuration using
such modules is changed to add "AuthBasicAuthoritative off" otherwise
mod_auth_basic will see "no provider configured -> use default file
provider -> fails (since no AuthUserFile is configured) -> deny access".
(the failure mode for this is particularly ugly: after an upgrade, a
previously-working configuration turns into a 500 error with a weird
error message logged as ap_pcfg_openfile returns APR_EBADF when passed
the NULL filename by mod_authn_file)
There are lots of 2.0-compatible auth modules out there, and upgrades
which require admins to make changes to .htaccess files are not very
attractive, so I think it's worth solving this problem if possible.
Solutions I can see:
- only have mod_auth_basic be authoritative if AuthBasicProvider is
configured
- use some hack such that mod_auth_basic will DECLINE iff no provider is
configured and mod_authn_file throws the AUTHN_GENERAL_ERROR. (attached
as proof of concept)
Any thoughts, better ideas?
joe
--- httpd-2.2.0/modules/aaa/mod_authn_file.c.authnoprov
+++ httpd-2.2.0/modules/aaa/mod_authn_file.c
@@ -70,6 +70,10 @@
apr_status_t status;
char *file_password = NULL;
+ if (!conf->pwfile) {
+ return AUTH_GENERAL_ERROR;
+ }
+
status = ap_pcfg_openfile(&f, r->pool, conf->pwfile);
if (status != APR_SUCCESS) {
--- httpd-2.2.0/modules/aaa/mod_auth_basic.c.authnoprov
+++ httpd-2.2.0/modules/aaa/mod_auth_basic.c
@@ -252,6 +252,14 @@
return DECLINED;
}
+ /* If no providers were configured, and the default file
+ * provider gave a general error (which will happen only if
+ * has not been configured), presume that a non-provider-based
+ * authn module is configured, and get out of the way. */
+ if (!conf->providers && auth_result == AUTH_GENERAL_ERROR) {
+ return DECLINED;
+ }
+
switch (auth_result) {
case AUTH_DENIED:
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
