1/*	$NetBSD: acl.c,v 1.2 2017/01/28 21:31:44 christos Exp $	*/
2
3/*
4 * Copyright (c) 2005, PADL Software Pty Ltd.
5 * All rights reserved.
6 *
7 * Portions Copyright (c) 2009 Apple Inc. All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 *
20 * 3. Neither the name of PADL Software nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY PADL SOFTWARE AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL PADL SOFTWARE OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#include "kcm_locl.h"
38
39krb5_error_code
40kcm_access(krb5_context context,
41	   kcm_client *client,
42	   kcm_operation opcode,
43	   kcm_ccache ccache)
44{
45    int read_p = 0;
46    int write_p = 0;
47    uint16_t mask;
48    krb5_error_code ret;
49
50    KCM_ASSERT_VALID(ccache);
51
52    switch (opcode) {
53    case KCM_OP_INITIALIZE:
54    case KCM_OP_DESTROY:
55    case KCM_OP_STORE:
56    case KCM_OP_REMOVE_CRED:
57    case KCM_OP_SET_FLAGS:
58    case KCM_OP_CHOWN:
59    case KCM_OP_CHMOD:
60    case KCM_OP_GET_INITIAL_TICKET:
61    case KCM_OP_GET_TICKET:
62    case KCM_OP_MOVE_CACHE:
63    case KCM_OP_SET_DEFAULT_CACHE:
64    case KCM_OP_SET_KDC_OFFSET:
65	write_p = 1;
66	read_p = 0;
67	break;
68    case KCM_OP_NOOP:
69    case KCM_OP_GET_NAME:
70    case KCM_OP_RESOLVE:
71    case KCM_OP_GEN_NEW:
72    case KCM_OP_RETRIEVE:
73    case KCM_OP_GET_PRINCIPAL:
74    case KCM_OP_GET_CRED_UUID_LIST:
75    case KCM_OP_GET_CRED_BY_UUID:
76    case KCM_OP_GET_CACHE_UUID_LIST:
77    case KCM_OP_GET_CACHE_BY_UUID:
78    case KCM_OP_GET_DEFAULT_CACHE:
79    case KCM_OP_GET_KDC_OFFSET:
80	write_p = 0;
81	read_p = 1;
82	break;
83    default:
84	ret = KRB5_FCC_PERM;
85	goto out;
86    }
87
88    if (ccache->flags & KCM_FLAGS_OWNER_IS_SYSTEM) {
89	/* System caches cannot be reinitialized or destroyed by users */
90	if (opcode == KCM_OP_INITIALIZE ||
91	    opcode == KCM_OP_DESTROY ||
92	    opcode == KCM_OP_REMOVE_CRED ||
93	    opcode == KCM_OP_MOVE_CACHE) {
94	    ret = KRB5_FCC_PERM;
95	    goto out;
96	}
97
98	/* Let root always read system caches */
99	if (CLIENT_IS_ROOT(client)) {
100	    ret = 0;
101	    goto out;
102	}
103    }
104
105    /* start out with "other" mask */
106    mask = S_IROTH|S_IWOTH;
107
108    /* root can do anything */
109    if (CLIENT_IS_ROOT(client)) {
110	if (read_p)
111	    mask |= S_IRUSR|S_IRGRP|S_IROTH;
112	if (write_p)
113	    mask |= S_IWUSR|S_IWGRP|S_IWOTH;
114    }
115    /* same session same as owner */
116    if (kcm_is_same_session(client, ccache->uid, ccache->session)) {
117	if (read_p)
118	    mask |= S_IROTH;
119	if (write_p)
120	    mask |= S_IWOTH;
121    }
122    /* owner */
123    if (client->uid == ccache->uid) {
124	if (read_p)
125	    mask |= S_IRUSR;
126	if (write_p)
127	    mask |= S_IWUSR;
128    }
129    /* group */
130    if (client->gid == ccache->gid) {
131	if (read_p)
132	    mask |= S_IRGRP;
133	if (write_p)
134	    mask |= S_IWGRP;
135    }
136
137    ret = (ccache->mode & mask) ? 0 : KRB5_FCC_PERM;
138
139out:
140    if (ret) {
141	kcm_log(2, "Process %d is not permitted to call %s on cache %s",
142		client->pid, kcm_op2string(opcode), ccache->name);
143    }
144
145    return ret;
146}
147
148krb5_error_code
149kcm_chmod(krb5_context context,
150	  kcm_client *client,
151	  kcm_ccache ccache,
152	  uint16_t mode)
153{
154    KCM_ASSERT_VALID(ccache);
155
156    /* System cache mode can only be set at startup */
157    if (ccache->flags & KCM_FLAGS_OWNER_IS_SYSTEM)
158	return KRB5_FCC_PERM;
159
160    if (ccache->uid != client->uid)
161	return KRB5_FCC_PERM;
162
163    if (ccache->gid != client->gid)
164	return KRB5_FCC_PERM;
165
166    HEIMDAL_MUTEX_lock(&ccache->mutex);
167
168    ccache->mode = mode;
169
170    HEIMDAL_MUTEX_unlock(&ccache->mutex);
171
172    return 0;
173}
174
175krb5_error_code
176kcm_chown(krb5_context context,
177	  kcm_client *client,
178	  kcm_ccache ccache,
179	  uid_t uid,
180	  gid_t gid)
181{
182    KCM_ASSERT_VALID(ccache);
183
184    /* System cache owner can only be set at startup */
185    if (ccache->flags & KCM_FLAGS_OWNER_IS_SYSTEM)
186	return KRB5_FCC_PERM;
187
188    if (ccache->uid != client->uid)
189	return KRB5_FCC_PERM;
190
191    if (ccache->gid != client->gid)
192	return KRB5_FCC_PERM;
193
194    HEIMDAL_MUTEX_lock(&ccache->mutex);
195
196    ccache->uid = uid;
197    ccache->gid = gid;
198
199    HEIMDAL_MUTEX_unlock(&ccache->mutex);
200
201    return 0;
202}
203
204