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/*
Unix SMB/CIFS implementation.
Copyright (C) Andrew Tridgell 1992-2001
Copyright (C) Andrew Bartlett 2002
Copyright (C) Rafal Szczesniak 2002
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/>.
*/
/* the Samba secrets database stores any generated, private information
such as the local SID and machine trust password */
#include "includes.h"
#include "secrets.h"
#include "param/param.h"
#include "system/filesys.h"
#include "tdb_wrap.h"
#include "lib/ldb/include/ldb.h"
#include "../tdb/include/tdb.h"
#include "../lib/util/util_tdb.h"
#include "../lib/util/util_ldb.h"
#include "librpc/gen_ndr/ndr_security.h"
#include "dsdb/samdb/samdb.h"
#include "dsdb/common/util.h"
#include "dsdb/common/proto.h"
/**
* Use a TDB to store an incrementing random seed.
*
* Initialised to the current pid, the very first time Samba starts,
* and incremented by one each time it is needed.
*
* @note Not called by systems with a working /dev/urandom.
*/
static void get_rand_seed(struct tdb_wrap *secretsdb, int *new_seed)
{
*new_seed = getpid();
if (secretsdb != NULL) {
tdb_change_int32_atomic(secretsdb->tdb, "INFO/random_seed", new_seed, 1);
}
}
/**
* open up the secrets database
*/
struct tdb_wrap *secrets_init(TALLOC_CTX *mem_ctx, struct loadparm_context *lp_ctx)
{
char *fname;
uint8_t dummy;
struct tdb_wrap *tdb;
fname = private_path(mem_ctx, lp_ctx, "secrets.tdb");
tdb = tdb_wrap_open(mem_ctx, fname, 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0600);
if (!tdb) {
DEBUG(0,("Failed to open %s\n", fname));
talloc_free(fname);
return NULL;
}
talloc_free(fname);
/**
* Set a reseed function for the crypto random generator
*
* This avoids a problem where systems without /dev/urandom
* could send the same challenge to multiple clients
*/
set_rand_reseed_callback((void (*) (void *, int *))get_rand_seed, tdb);
/* Ensure that the reseed is done now, while we are root, etc */
generate_random_buffer(&dummy, sizeof(dummy));
return tdb;
}
/**
connect to the secrets ldb
*/
struct ldb_context *secrets_db_connect(TALLOC_CTX *mem_ctx,
struct tevent_context *ev_ctx,
struct loadparm_context *lp_ctx)
{
char *path;
const char *url;
struct ldb_context *ldb;
url = lp_secrets_url(lp_ctx);
if (!url || !url[0]) {
return NULL;
}
path = private_path(mem_ctx, lp_ctx, url);
if (!path) {
return NULL;
}
/* Secrets.ldb *must* always be local. If we call for a
* system_session() we will recurse */
ldb = ldb_init(mem_ctx, ev_ctx);
if (!ldb) {
talloc_free(path);
return NULL;
}
ldb_set_modules_dir(ldb,
talloc_asprintf(ldb, "%s/ldb", lp_modulesdir(lp_ctx)));
if (ldb_connect(ldb, path, 0, NULL) != 0) {
talloc_free(path);
return NULL;
}
/* the update_keytab module relies on this being setup */
if (ldb_set_opaque(ldb, "loadparm", lp_ctx) != LDB_SUCCESS) {
talloc_free(path);
talloc_free(ldb);
return NULL;
}
talloc_free(path);
return ldb;
}
/**
* Retrieve the domain SID from the secrets database.
* @return pointer to a SID object if the SID could be obtained, NULL otherwise
*/
struct dom_sid *secrets_get_domain_sid(TALLOC_CTX *mem_ctx,
struct tevent_context *ev_ctx,
struct loadparm_context *lp_ctx,
const char *domain,
char **errstring)
{
struct ldb_context *ldb;
struct ldb_message *msg;
int ldb_ret;
const char *attrs[] = { "objectSid", NULL };
struct dom_sid *result = NULL;
const struct ldb_val *v;
enum ndr_err_code ndr_err;
*errstring = NULL;
ldb = secrets_db_connect(mem_ctx, ev_ctx, lp_ctx);
if (ldb == NULL) {
DEBUG(5, ("secrets_db_connect failed\n"));
return NULL;
}
ldb_ret = dsdb_search_one(ldb, ldb, &msg,
ldb_dn_new(mem_ctx, ldb, SECRETS_PRIMARY_DOMAIN_DN),
LDB_SCOPE_ONELEVEL,
attrs, 0, SECRETS_PRIMARY_DOMAIN_FILTER, domain);
if (ldb_ret != LDB_SUCCESS) {
*errstring = talloc_asprintf(mem_ctx, "Failed to find record for %s in %s: %s: %s",
domain, (char *) ldb_get_opaque(ldb, "ldb_url"),
ldb_strerror(ldb_ret), ldb_errstring(ldb));
return NULL;
}
v = ldb_msg_find_ldb_val(msg, "objectSid");
if (v == NULL) {
*errstring = talloc_asprintf(mem_ctx, "Failed to find a SID on record for %s in %s",
domain, (char *) ldb_get_opaque(ldb, "ldb_url"));
return NULL;
}
result = talloc(mem_ctx, struct dom_sid);
if (result == NULL) {
talloc_free(ldb);
return NULL;
}
ndr_err = ndr_pull_struct_blob(v, result, result,
(ndr_pull_flags_fn_t)ndr_pull_dom_sid);
if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
*errstring = talloc_asprintf(mem_ctx, "Failed to parse SID on record for %s in %s",
domain, (char *) ldb_get_opaque(ldb, "ldb_url"));
talloc_free(result);
talloc_free(ldb);
return NULL;
}
return result;
}
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