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/*
ldb database library
Copyright (C) Andrew Bartlett 2005
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 2 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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
* Name: ldb
*
* Component: ldb kludge ACL module
*
* Description: Simple module to enforce a simple form of access
* control, sufficient for securing a default Samba4
* installation.
*
* Author: Andrew Bartlett
*/
#include "includes.h"
#include "ldb/include/ldb.h"
#include "ldb/include/ldb_errors.h"
#include "ldb/include/ldb_private.h"
#include "auth/auth.h"
/* Kludge ACL rules:
*
* - System can read passwords
* - Administrators can write anything
* - Users can read anything that is not a password
*
*/
const char *password_attribs[] = {
"sambaPassword",
"ntPwdHash",
"sambaNTPwdHistory",
"lmPwdHash",
"sambaLMPwdHistory",
"krb5key"
};
enum user_is {
ANONYMOUS,
USER,
ADMINISTRATOR,
SYSTEM
};
struct private_data {
char *some_private_data;
};
static enum user_is what_is_user(struct ldb_module *module)
{
struct auth_session_info *session_info
= ldb_get_opaque(module->ldb, "sessionInfo");
if (!session_info) {
return ANONYMOUS;
}
if (is_system_token(session_info->security_token)) {
return SYSTEM;
}
if (is_administrator_token(session_info->security_token)) {
return SYSTEM;
}
if (is_authenticated_token(session_info->security_token)) {
return USER;
}
if (is_anonymous_token(session_info->security_token)) {
return ANONYMOUS;
}
return ANONYMOUS;
}
/* search */
static int kludge_acl_search(struct ldb_module *module, struct ldb_request *req)
{
enum user_is user_type;
int ret = ldb_next_request(module, req);
struct ldb_message *msg;
int i, j;
if (ret != LDB_SUCCESS) {
return ret;
}
user_type = what_is_user(module);
switch (user_type) {
case SYSTEM:
case ADMINISTRATOR:
return ret;
default:
/* For every message, remove password attributes */
for (i=0; i < req->op.search.res->count; i++) {
msg = req->op.search.res->msgs[i];
for (j=0; j < ARRAY_SIZE(password_attribs); j++) {
ldb_msg_remove_attr(msg, password_attribs[j]);
}
}
}
return ret;
}
/* ANY change type */
static int kludge_acl_change(struct ldb_module *module, struct ldb_request *req){
enum user_is user_type = what_is_user(module);
switch (user_type) {
case SYSTEM:
case ADMINISTRATOR:
return ldb_next_request(module, req);
default:
ldb_set_errstring(module,
talloc_asprintf(req, "kludge_acl_change: "
"attempted database modify not permitted. User is not SYSTEM or an administrator"));
return LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
}
}
/* start a transaction */
static int kludge_acl_start_trans(struct ldb_module *module)
{
return ldb_next_start_trans(module);
}
/* end a transaction */
static int kludge_acl_end_trans(struct ldb_module *module)
{
return ldb_next_end_trans(module);
}
/* delete a transaction */
static int kludge_acl_del_trans(struct ldb_module *module)
{
return ldb_next_del_trans(module);
}
static int kludge_acl_destructor(void *module_ctx)
{
struct ldb_module *ctx = talloc_get_type(module_ctx, struct ldb_module);
struct private_data *data = talloc_get_type(ctx->private_data, struct private_data);
/* put your clean-up functions here */
if (data->some_private_data) talloc_free(data->some_private_data);
return 0;
}
static int kludge_acl_request(struct ldb_module *module, struct ldb_request *req)
{
switch (req->operation) {
case LDB_REQ_SEARCH:
return kludge_acl_search(module, req);
case LDB_REQ_REGISTER:
return ldb_next_request(module, req);
default:
/* anything else must be a change of some kind */
return kludge_acl_change(module, req);
}
}
static const struct ldb_module_ops kludge_acl_ops = {
.name = "kludge_acl",
.request = kludge_acl_request,
.start_transaction = kludge_acl_start_trans,
.end_transaction = kludge_acl_end_trans,
.del_transaction = kludge_acl_del_trans,
};
struct ldb_module *kludge_acl_module_init(struct ldb_context *ldb, const char *options[])
{
struct ldb_module *ctx;
struct private_data *data;
ctx = talloc(ldb, struct ldb_module);
if (!ctx)
return NULL;
data = talloc(ctx, struct private_data);
if (data == NULL) {
talloc_free(ctx);
return NULL;
}
data->some_private_data = NULL;
ctx->private_data = data;
ctx->ldb = ldb;
ctx->prev = ctx->next = NULL;
ctx->ops = &kludge_acl_ops;
talloc_set_destructor (ctx, kludge_acl_destructor);
return ctx;
}
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