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/* Copyright 2003-2005 The Apache Software Foundation or its licensors, as
* applicable.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "apr_strings.h"
#include "apr_file_info.h"
#include "apr_user.h"
#include "ap_config.h"
#include "httpd.h"
#include "http_config.h"
#include "http_core.h"
#include "http_log.h"
#include "http_protocol.h"
#include "http_request.h"
#include "mod_auth.h" /* for AUTHZ_GROUP_NOTE */
typedef struct {
int authoritative;
} authz_owner_config_rec;
static void *create_authz_owner_dir_config(apr_pool_t *p, char *d)
{
authz_owner_config_rec *conf = apr_palloc(p, sizeof(*conf));
conf->authoritative = 1; /* keep the fortress secure by default */
return conf;
}
static const command_rec authz_owner_cmds[] =
{
AP_INIT_FLAG("AuthzOwnerAuthoritative", ap_set_flag_slot,
(void *)APR_OFFSETOF(authz_owner_config_rec, authoritative),
OR_AUTHCFG,
"Set to 'Off' to allow access control to be passed along to "
"lower modules. (default is On.)"),
{NULL}
};
module AP_MODULE_DECLARE_DATA authz_owner_module;
static int check_file_owner(request_rec *r)
{
authz_owner_config_rec *conf = ap_get_module_config(r->per_dir_config,
&authz_owner_module);
int m = r->method_number;
register int x;
const char *t, *w;
const apr_array_header_t *reqs_arr = ap_requires(r);
require_line *reqs;
int required_owner = 0;
apr_status_t status = 0;
char *reason = NULL;
if (!reqs_arr) {
return DECLINED;
}
reqs = (require_line *)reqs_arr->elts;
for (x = 0; x < reqs_arr->nelts; x++) {
/* if authoritative = On then break if a require already failed. */
if (reason && conf->authoritative) {
break;
}
if (!(reqs[x].method_mask & (AP_METHOD_BIT << m))) {
continue;
}
t = reqs[x].requirement;
w = ap_getword_white(r->pool, &t);
if (!strcmp(w, "file-owner")) {
#if !APR_HAS_USER
if ((required_owner & ~1) && conf->authoritative) {
break;
}
required_owner |= 1; /* remember the requirement */
reason = "'Require file-owner' is not supported on this platform.";
continue;
#else /* APR_HAS_USER */
char *owner = NULL;
apr_finfo_t finfo;
if ((required_owner & ~1) && conf->authoritative) {
break;
}
required_owner |= 1; /* remember the requirement */
if (!r->filename) {
reason = "no filename available";
continue;
}
status = apr_stat(&finfo, r->filename, APR_FINFO_USER, r->pool);
if (status != APR_SUCCESS) {
reason = apr_pstrcat(r->pool, "could not stat file ",
r->filename, NULL);
continue;
}
if (!(finfo.valid & APR_FINFO_USER)) {
reason = "no file owner information available";
continue;
}
status = apr_uid_name_get(&owner, finfo.user, r->pool);
if (status != APR_SUCCESS || !owner) {
reason = "could not get name of file owner";
continue;
}
if (strcmp(owner, r->user)) {
reason = apr_psprintf(r->pool, "file owner %s does not match.",
owner);
continue;
}
/* this user is authorized */
return OK;
#endif /* APR_HAS_USER */
}
/* file-group only figures out the file's group and lets
* other modules do the actual authorization (against a group file/db).
* Thus, these modules have to hook themselves after
* mod_authz_owner and of course recognize 'file-group', too.
*/
if (!strcmp(w, "file-group")) {
#if !APR_HAS_USER
if ((required_owner & ~6) && conf->authoritative) {
break;
}
required_owner |= 2; /* remember the requirement */
reason = "'Require file-group' is not supported on this platform.";
continue;
#else /* APR_HAS_USER */
char *group = NULL;
apr_finfo_t finfo;
if ((required_owner & ~6) && conf->authoritative) {
break;
}
required_owner |= 2; /* remember the requirement */
if (!r->filename) {
reason = "no filename available";
continue;
}
status = apr_stat(&finfo, r->filename, APR_FINFO_GROUP, r->pool);
if (status != APR_SUCCESS) {
reason = apr_pstrcat(r->pool, "could not stat file ",
r->filename, NULL);
continue;
}
if (!(finfo.valid & APR_FINFO_GROUP)) {
reason = "no file group information available";
continue;
}
status = apr_gid_name_get(&group, finfo.group, r->pool);
if (status != APR_SUCCESS || !group) {
reason = "could not get name of file group";
continue;
}
/* store group name in a note and let others decide... */
apr_table_setn(r->notes, AUTHZ_GROUP_NOTE, group);
required_owner |= 4;
continue;
#endif /* APR_HAS_USER */
}
}
if (!required_owner || !conf->authoritative) {
return DECLINED;
}
/* allow file-group passed to group db modules either if this is the
* only applicable requirement here or if a file-owner failed but we're
* not authoritative.
* This allows configurations like:
*
* AuthzOwnerAuthoritative Off
* require file-owner
* require file-group
*
* with the semantical meaning of "either owner or group must match"
* (inclusive or)
*
* [ 6 == 2 | 4; 7 == 1 | 2 | 4 ] should I use #defines instead?
*/
if (required_owner == 6 || (required_owner == 7 && !conf->authoritative)) {
return DECLINED;
}
ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r,
"Authorization of user %s to access %s failed, reason: %s",
r->user, r->uri, reason ? reason : "unknown");
ap_note_auth_failure(r);
return HTTP_UNAUTHORIZED;
}
static void register_hooks(apr_pool_t *p)
{
ap_hook_auth_checker(check_file_owner, NULL, NULL, APR_HOOK_MIDDLE);
}
module AP_MODULE_DECLARE_DATA authz_owner_module =
{
STANDARD20_MODULE_STUFF,
create_authz_owner_dir_config, /* dir config creater */
NULL, /* dir merger --- default is to override */
NULL, /* server config */
NULL, /* merge server config */
authz_owner_cmds, /* command apr_table_t */
register_hooks /* register hooks */
};
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