1 files changed, 251 insertions, 0 deletions
diff --git a/source3/passdb/machine_sid.c b/source3/passdb/machine_sid.c
new file mode 100644
index 0000000..fa420d8
--- /dev/null
+++ b/source3/passdb/machine_sid.c
@@ -0,0 +1,251 @@
+/*
+   Unix SMB/CIFS implementation.
+   Password and authentication handling
+   Copyright (C) Jeremy Allison 		1996-2002
+   Copyright (C) Andrew Tridgell		2002
+   Copyright (C) Gerald (Jerry) Carter		2000
+   Copyright (C) Stefan (metze) Metzmacher	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/>.
+*/
+
+#include "includes.h"
+#include "passdb/machine_sid.h"
+#include "secrets.h"
+#include "dbwrap/dbwrap.h"
+#include "../libcli/security/security.h"
+
+/* NOTE! the global_sam_sid is the SID of our local SAM. This is only
+   equal to the domain SID when we are a DC, otherwise its our
+   workstation SID */
+static struct dom_sid *global_sam_sid=NULL;
+
+#undef DBGC_CLASS
+#define DBGC_CLASS DBGC_PASSDB
+
+/****************************************************************************
+ Read a SID from a file. This is for compatibility with the old MACHINE.SID
+ style of SID storage
+****************************************************************************/
+
+static bool read_sid_from_file(const char *fname, struct dom_sid *sid)
+{
+	char **lines;
+	int numlines;
+	bool ret;
+
+	lines = file_lines_load(fname, &numlines,0, NULL);
+
+	if (!lines || numlines < 1) {
+		TALLOC_FREE(lines);
+		return False;
+	}
+
+	ret = string_to_sid(sid, lines[0]);
+	TALLOC_FREE(lines);
+	return ret;
+}
+
+/*
+  generate a random sid - used to build our own sid if we don't have one
+*/
+static void generate_random_sid(struct dom_sid *sid)
+{
+	int i;
+	uchar raw_sid_data[12];
+
+	*sid = (struct dom_sid) {
+		.sid_rev_num = 1,
+		.id_auth[5] = 5,
+	};
+
+	sid->sub_auths[sid->num_auths++] = 21;
+
+	generate_random_buffer(raw_sid_data, 12);
+	for (i = 0; i < 3; i++)
+		sid->sub_auths[sid->num_auths++] = IVAL(raw_sid_data, i*4);
+}
+
+/****************************************************************************
+ Generate the global machine sid.
+****************************************************************************/
+
+static struct dom_sid *pdb_generate_sam_sid(void)
+{
+	struct dom_sid domain_sid;
+	char *fname = NULL;
+	struct dom_sid *sam_sid;
+
+	if(!(sam_sid=SMB_MALLOC_P(struct dom_sid)))
+		return NULL;
+
+	if ( IS_DC ) {
+		if (secrets_fetch_domain_sid(lp_workgroup(), &domain_sid)) {
+			sid_copy(sam_sid, &domain_sid);
+			return sam_sid;
+		}
+	}
+
+	if (secrets_fetch_domain_sid(lp_netbios_name(), sam_sid)) {
+
+		/* We got our sid. If not a pdc/bdc, we're done. */
+		if ( !IS_DC )
+			return sam_sid;
+
+		if (!secrets_fetch_domain_sid(lp_workgroup(), &domain_sid)) {
+
+			/* No domain sid and we're a pdc/bdc. Store it */
+
+			if (!secrets_store_domain_sid(lp_workgroup(), sam_sid)) {
+				DEBUG(0,("pdb_generate_sam_sid: Can't store domain SID as a pdc/bdc.\n"));
+				SAFE_FREE(sam_sid);
+				return NULL;
+			}
+			return sam_sid;
+		}
+
+		if (!dom_sid_equal(&domain_sid, sam_sid)) {
+
+			/* Domain name sid doesn't match global sam sid. Re-store domain sid as 'local' sid. */
+
+			DEBUG(0,("pdb_generate_sam_sid: Mismatched SIDs as a pdc/bdc.\n"));
+			if (!secrets_store_domain_sid(lp_netbios_name(), &domain_sid)) {
+				DEBUG(0,("pdb_generate_sam_sid: Can't re-store domain SID for local sid as PDC/BDC.\n"));
+				SAFE_FREE(sam_sid);
+				return NULL;
+			}
+			return sam_sid;
+		}
+
+		return sam_sid;
+	}
+
+	/* check for an old MACHINE.SID file for backwards compatibility */
+	if (asprintf(&fname, "%s/MACHINE.SID", lp_private_dir()) == -1) {
+		SAFE_FREE(sam_sid);
+		return NULL;
+	}
+
+	if (read_sid_from_file(fname, sam_sid)) {
+		/* remember it for future reference and unlink the old MACHINE.SID */
+		if (!secrets_store_domain_sid(lp_netbios_name(), sam_sid)) {
+			DEBUG(0,("pdb_generate_sam_sid: Failed to store SID from file.\n"));
+			SAFE_FREE(fname);
+			SAFE_FREE(sam_sid);
+			return NULL;
+		}
+		unlink(fname);
+		if ( !IS_DC ) {
+			if (!secrets_store_domain_sid(lp_workgroup(), sam_sid)) {
+				DEBUG(0,("pdb_generate_sam_sid: Failed to store domain SID from file.\n"));
+				SAFE_FREE(fname);
+				SAFE_FREE(sam_sid);
+				return NULL;
+			}
+		}
+
+		/* Stored the old sid from MACHINE.SID successfully.*/
+		SAFE_FREE(fname);
+		return sam_sid;
+	}
+
+	SAFE_FREE(fname);
+
+	/* we don't have the SID in secrets.tdb, we will need to
+           generate one and save it */
+	generate_random_sid(sam_sid);
+
+	if (!secrets_store_domain_sid(lp_netbios_name(), sam_sid)) {
+		DEBUG(0,("pdb_generate_sam_sid: Failed to store generated machine SID.\n"));
+		SAFE_FREE(sam_sid);
+		return NULL;
+	}
+	if ( IS_DC ) {
+		if (!secrets_store_domain_sid(lp_workgroup(), sam_sid)) {
+			DEBUG(0,("pdb_generate_sam_sid: Failed to store generated domain SID.\n"));
+			SAFE_FREE(sam_sid);
+			return NULL;
+		}
+	}
+
+	return sam_sid;
+}
+
+/* return our global_sam_sid */
+struct dom_sid *get_global_sam_sid(void)
+{
+	struct db_context *db;
+
+	if (global_sam_sid != NULL)
+		return global_sam_sid;
+
+	/*
+	 * memory for global_sam_sid is allocated in
+	 * pdb_generate_sam_sid() as needed
+	 *
+	 * Note: this is guarded by a transaction
+	 *       to prevent races on startup which
+	 *       can happen with some dbwrap backends
+	 */
+
+	db = secrets_db_ctx();
+	if (!db) {
+		smb_panic("could not open secrets db");
+	}
+
+	if (dbwrap_transaction_start(db) != 0) {
+		smb_panic("could not start transaction on secrets db");
+	}
+
+	if (!(global_sam_sid = pdb_generate_sam_sid())) {
+		dbwrap_transaction_cancel(db);
+		smb_panic("could not generate a machine SID");
+	}
+
+	if (dbwrap_transaction_commit(db) != 0) {
+		smb_panic("could not start commit secrets db");
+	}
+
+	return global_sam_sid;
+}
+
+/**
+ * Force get_global_sam_sid to requery the backends
+ */
+void reset_global_sam_sid(void) 
+{
+	SAFE_FREE(global_sam_sid);
+}
+
+/*****************************************************************
+ Check if the SID is our sam SID (S-1-5-21-x-y-z).
+*****************************************************************/
+
+bool sid_check_is_our_sam(const struct dom_sid *sid)
+{
+	return dom_sid_equal(sid, get_global_sam_sid());
+}
+
+/*****************************************************************
+ Check if the SID is our domain SID (S-1-5-21-x-y-z).
+*****************************************************************/
+
+bool sid_check_is_in_our_sam(const struct dom_sid *sid)
+{
+	struct dom_sid dom_sid;
+
+	sid_copy(&dom_sid, sid);
+	sid_split_rid(&dom_sid, NULL);
+	return sid_check_is_our_sam(&dom_sid);
+}