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/*
Unix SMB/CIFS implementation.
Password and authentication handling
Copyright (C) Andrew Bartlett <abartlet@samba.org> 2001-2010
Copyright (C) Stefan Metzmacher 2005
Copyright (C) Matthias Dieter Wallnöfer 2009
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "includes.h"
#include "auth/auth.h"
#include <ldb.h>
#include "dsdb/samdb/samdb.h"
#include "libcli/security/security.h"
#include "dsdb/common/util.h"
/* This function tests if a SID structure "sids" contains the SID "sid" */
static bool sids_contains_sid(const struct dom_sid *sids,
const unsigned int num_sids,
const struct dom_sid *sid)
{
unsigned int i;
for (i = 0; i < num_sids; i++) {
if (dom_sid_equal(&sids[i], sid))
return true;
}
return false;
}
/*
* This function generates the transitive closure of a given SAM object "dn_val"
* (it basically expands nested memberships).
* If the object isn't located in the "res_sids" structure yet and the
* "only_childs" flag is false, we add it to "res_sids".
* Then we've always to consider the "memberOf" attributes. We invoke the
* function recursively on each of it with the "only_childs" flag set to
* "false".
* The "only_childs" flag is particularly useful if you have a user object and
* want to include all it's groups (referenced with "memberOf") but not itself
* or considering if that object matches the filter.
*
* At the beginning "res_sids" should reference to a NULL pointer.
*/
NTSTATUS dsdb_expand_nested_groups(struct ldb_context *sam_ctx,
struct ldb_val *dn_val, const bool only_childs, const char *filter,
TALLOC_CTX *res_sids_ctx, struct dom_sid **res_sids,
unsigned int *num_res_sids)
{
const char * const attrs[] = { "memberOf", NULL };
unsigned int i;
int ret;
bool already_there;
struct ldb_dn *dn;
struct dom_sid sid;
TALLOC_CTX *tmp_ctx;
struct ldb_result *res;
NTSTATUS status;
const struct ldb_message_element *el;
if (*res_sids == NULL) {
*num_res_sids = 0;
}
if (!sam_ctx) {
DEBUG(0, ("No SAM available, cannot determine local groups\n"));
return NT_STATUS_INVALID_SYSTEM_SERVICE;
}
tmp_ctx = talloc_new(res_sids_ctx);
dn = ldb_dn_from_ldb_val(tmp_ctx, sam_ctx, dn_val);
if (dn == NULL) {
talloc_free(tmp_ctx);
DEBUG(0, (__location__ ": we failed parsing DN %.*s, so we cannot calculate the group token\n",
(int)dn_val->length, dn_val->data));
return NT_STATUS_INTERNAL_DB_CORRUPTION;
}
status = dsdb_get_extended_dn_sid(dn, &sid, "SID");
if (NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_NOT_FOUND)) {
/* If we fail finding a SID then this is no error since it could
* be a non SAM object - e.g. a group with object class
* "groupOfNames" */
talloc_free(tmp_ctx);
return NT_STATUS_OK;
} else if (!NT_STATUS_IS_OK(status)) {
DEBUG(0, (__location__ ": when parsing DN '%s' we failed to parse it's SID component, so we cannot calculate the group token: %s\n",
ldb_dn_get_extended_linearized(tmp_ctx, dn, 1),
nt_errstr(status)));
talloc_free(tmp_ctx);
return status;
}
if (!ldb_dn_minimise(dn)) {
talloc_free(tmp_ctx);
return NT_STATUS_INTERNAL_DB_CORRUPTION;
}
if (only_childs) {
ret = dsdb_search_dn(sam_ctx, tmp_ctx, &res, dn, attrs,
DSDB_SEARCH_SHOW_EXTENDED_DN);
} else {
/* This is an O(n^2) linear search */
already_there = sids_contains_sid(*res_sids,
*num_res_sids, &sid);
if (already_there) {
talloc_free(tmp_ctx);
return NT_STATUS_OK;
}
ret = dsdb_search(sam_ctx, tmp_ctx, &res, dn, LDB_SCOPE_BASE,
attrs, DSDB_SEARCH_SHOW_EXTENDED_DN, "%s",
filter);
}
/*
* We have the problem with the caller creating a <SID=S-....>
* DN for ForeignSecurityPrincipals as they also have
* duplicate objects with the SAME SID under CN=Configuration.
* This causes a SID= DN to fail with NO_SUCH_OBJECT on Samba
* and on Windows. So, we allow this to fail, and
* double-check if we can find it with a search in the main
* domain partition.
*/
if (ret == LDB_ERR_NO_SUCH_OBJECT && only_childs) {
char *sid_string = dom_sid_string(tmp_ctx,
&sid);
if (!sid_string) {
talloc_free(tmp_ctx);
return NT_STATUS_OK;
}
ret = dsdb_search(sam_ctx, tmp_ctx, &res,
ldb_get_default_basedn(sam_ctx),
LDB_SCOPE_SUBTREE,
attrs, DSDB_SEARCH_SHOW_EXTENDED_DN,
"(&(objectClass=foreignSecurityPrincipal)(objectSID=%s))",
sid_string);
}
if (ret == LDB_ERR_NO_SUCH_OBJECT) {
talloc_free(tmp_ctx);
return NT_STATUS_OK;
}
if (ret != LDB_SUCCESS) {
DEBUG(1, (__location__ ": dsdb_search for %s failed: %s\n",
ldb_dn_get_extended_linearized(tmp_ctx, dn, 1),
ldb_errstring(sam_ctx)));
talloc_free(tmp_ctx);
return NT_STATUS_INTERNAL_DB_CORRUPTION;
}
/* We may get back 0 results, if the SID didn't match the filter - such as it wasn't a domain group, for example */
if (res->count != 1) {
talloc_free(tmp_ctx);
return NT_STATUS_OK;
}
/* We only apply this test once we know the SID matches the filter */
if (!only_childs) {
*res_sids = talloc_realloc(res_sids_ctx, *res_sids,
struct dom_sid, *num_res_sids + 1);
NT_STATUS_HAVE_NO_MEMORY_AND_FREE(*res_sids, tmp_ctx);
(*res_sids)[*num_res_sids] = sid;
++(*num_res_sids);
}
el = ldb_msg_find_element(res->msgs[0], "memberOf");
for (i = 0; el && i < el->num_values; i++) {
status = dsdb_expand_nested_groups(sam_ctx, &el->values[i],
false, filter, res_sids_ctx, res_sids, num_res_sids);
if (!NT_STATUS_IS_OK(status)) {
talloc_free(tmp_ctx);
return status;
}
}
talloc_free(tmp_ctx);
return NT_STATUS_OK;
}
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