1/*
2   Unix SMB/CIFS implementation.
3   Password and authentication handling
4   Copyright (C) Jeremy Allison 		1996-2002
5   Copyright (C) Andrew Tridgell		2002
6   Copyright (C) Gerald (Jerry) Carter		2000
7   Copyright (C) Stefan (metze) Metzmacher	2002
8
9   This program is free software; you can redistribute it and/or modify
10   it under the terms of the GNU General Public License as published by
11   the Free Software Foundation; either version 2 of the License, or
12   (at your option) any later version.
13
14   This program is distributed in the hope that it will be useful,
15   but WITHOUT ANY WARRANTY; without even the implied warranty of
16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17   GNU General Public License for more details.
18
19   You should have received a copy of the GNU General Public License
20   along with this program; if not, write to the Free Software
21   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22*/
23
24#include "includes.h"
25
26/* NOTE! the global_sam_sid is the SID of our local SAM. This is only
27   equal to the domain SID when we are a DC, otherwise its our
28   workstation SID */
29static DOM_SID *global_sam_sid=NULL;
30
31#undef DBGC_CLASS
32#define DBGC_CLASS DBGC_PASSDB
33
34/****************************************************************************
35 Read a SID from a file. This is for compatibility with the old MACHINE.SID
36 style of SID storage
37****************************************************************************/
38static BOOL read_sid_from_file(const char *fname, DOM_SID *sid)
39{
40	char **lines;
41	int numlines;
42	BOOL ret;
43
44	lines = file_lines_load(fname, &numlines);
45
46	if (!lines || numlines < 1) {
47		if (lines) file_lines_free(lines);
48		return False;
49	}
50
51	ret = string_to_sid(sid, lines[0]);
52	file_lines_free(lines);
53	return ret;
54}
55
56/*
57  generate a random sid - used to build our own sid if we don't have one
58*/
59static void generate_random_sid(DOM_SID *sid)
60{
61	int i;
62	uchar raw_sid_data[12];
63
64	memset((char *)sid, '\0', sizeof(*sid));
65	sid->sid_rev_num = 1;
66	sid->id_auth[5] = 5;
67	sid->num_auths = 0;
68	sid->sub_auths[sid->num_auths++] = 21;
69
70	generate_random_buffer(raw_sid_data, 12);
71	for (i = 0; i < 3; i++)
72		sid->sub_auths[sid->num_auths++] = IVAL(raw_sid_data, i*4);
73}
74
75/****************************************************************************
76 Generate the global machine sid.
77****************************************************************************/
78
79static DOM_SID *pdb_generate_sam_sid(void)
80{
81	DOM_SID domain_sid;
82	char *fname = NULL;
83	BOOL is_dc = False;
84	DOM_SID *sam_sid;
85
86	if(!(sam_sid=SMB_MALLOC_P(DOM_SID)))
87		return NULL;
88
89	generate_wellknown_sids();
90
91	switch (lp_server_role()) {
92	case ROLE_DOMAIN_PDC:
93	case ROLE_DOMAIN_BDC:
94		is_dc = True;
95		break;
96	default:
97		is_dc = False;
98		break;
99	}
100
101	if (is_dc) {
102		if (secrets_fetch_domain_sid(lp_workgroup(), &domain_sid)) {
103			sid_copy(sam_sid, &domain_sid);
104			return sam_sid;
105		}
106	}
107
108	if (secrets_fetch_domain_sid(global_myname(), sam_sid)) {
109
110		/* We got our sid. If not a pdc/bdc, we're done. */
111		if (!is_dc)
112			return sam_sid;
113
114		if (!secrets_fetch_domain_sid(lp_workgroup(), &domain_sid)) {
115
116			/* No domain sid and we're a pdc/bdc. Store it */
117
118			if (!secrets_store_domain_sid(lp_workgroup(), sam_sid)) {
119				DEBUG(0,("pdb_generate_sam_sid: Can't store domain SID as a pdc/bdc.\n"));
120				SAFE_FREE(sam_sid);
121				return NULL;
122			}
123			return sam_sid;
124		}
125
126		if (!sid_equal(&domain_sid, sam_sid)) {
127
128			/* Domain name sid doesn't match global sam sid. Re-store domain sid as 'local' sid. */
129
130			DEBUG(0,("pdb_generate_sam_sid: Mismatched SIDs as a pdc/bdc.\n"));
131			if (!secrets_store_domain_sid(global_myname(), &domain_sid)) {
132				DEBUG(0,("pdb_generate_sam_sid: Can't re-store domain SID for local sid as PDC/BDC.\n"));
133				SAFE_FREE(sam_sid);
134				return NULL;
135			}
136			return sam_sid;
137		}
138
139		return sam_sid;
140
141	}
142
143	/* check for an old MACHINE.SID file for backwards compatibility */
144	asprintf(&fname, "%s/MACHINE.SID", lp_private_dir());
145
146	if (read_sid_from_file(fname, sam_sid)) {
147		/* remember it for future reference and unlink the old MACHINE.SID */
148		if (!secrets_store_domain_sid(global_myname(), sam_sid)) {
149			DEBUG(0,("pdb_generate_sam_sid: Failed to store SID from file.\n"));
150			SAFE_FREE(fname);
151			SAFE_FREE(sam_sid);
152			return NULL;
153		}
154		unlink(fname);
155		if (is_dc) {
156			if (!secrets_store_domain_sid(lp_workgroup(), sam_sid)) {
157				DEBUG(0,("pdb_generate_sam_sid: Failed to store domain SID from file.\n"));
158				SAFE_FREE(fname);
159				SAFE_FREE(sam_sid);
160				return NULL;
161			}
162		}
163
164		/* Stored the old sid from MACHINE.SID successfully.*/
165		SAFE_FREE(fname);
166		return sam_sid;
167	}
168
169	SAFE_FREE(fname);
170
171	/* we don't have the SID in secrets.tdb, we will need to
172           generate one and save it */
173	generate_random_sid(sam_sid);
174
175	if (!secrets_store_domain_sid(global_myname(), sam_sid)) {
176		DEBUG(0,("pdb_generate_sam_sid: Failed to store generated machine SID.\n"));
177		SAFE_FREE(sam_sid);
178		return NULL;
179	}
180	if (is_dc) {
181		if (!secrets_store_domain_sid(lp_workgroup(), sam_sid)) {
182			DEBUG(0,("pdb_generate_sam_sid: Failed to store generated domain SID.\n"));
183			SAFE_FREE(sam_sid);
184			return NULL;
185		}
186	}
187
188	return sam_sid;
189}
190
191/* return our global_sam_sid */
192DOM_SID *get_global_sam_sid(void)
193{
194	if (global_sam_sid != NULL)
195		return global_sam_sid;
196
197	/* memory for global_sam_sid is allocated in
198	   pdb_generate_sam_sid() as needed */
199
200	if (!(global_sam_sid = pdb_generate_sam_sid())) {
201		smb_panic("Could not generate a machine SID\n");
202	}
203
204	return global_sam_sid;
205}
206
207/**
208 * Force get_global_sam_sid to requery the backends
209 */
210void reset_global_sam_sid(void)
211{
212	SAFE_FREE(global_sam_sid);
213}
214