acl.c revision 178826 
1/*
2 * Copyright (c) 2005, PADL Software Pty Ltd.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * 3. Neither the name of PADL Software nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY PADL SOFTWARE AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL PADL SOFTWARE OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include "kcm_locl.h"
34
35RCSID("$Id: acl.c 20472 2007-04-20 10:43:25Z lha $");
36
37krb5_error_code
38kcm_access(krb5_context context,
39	   kcm_client *client,
40	   kcm_operation opcode,
41	   kcm_ccache ccache)
42{
43    int read_p = 0;
44    int write_p = 0;
45    uint16_t mask;
46    krb5_error_code ret;
47
48    KCM_ASSERT_VALID(ccache);
49
50    switch (opcode) {
51    case KCM_OP_INITIALIZE:
52    case KCM_OP_DESTROY:
53    case KCM_OP_STORE:
54    case KCM_OP_REMOVE_CRED:
55    case KCM_OP_SET_FLAGS:
56    case KCM_OP_CHOWN:
57    case KCM_OP_CHMOD:
58    case KCM_OP_GET_INITIAL_TICKET:
59    case KCM_OP_GET_TICKET:
60	write_p = 1;
61	read_p = 0;
62	break;
63    case KCM_OP_NOOP:
64    case KCM_OP_GET_NAME:
65    case KCM_OP_RESOLVE:
66    case KCM_OP_GEN_NEW:
67    case KCM_OP_RETRIEVE:
68    case KCM_OP_GET_PRINCIPAL:
69    case KCM_OP_GET_FIRST:
70    case KCM_OP_GET_NEXT:
71    case KCM_OP_END_GET:
72    case KCM_OP_MAX:
73	write_p = 0;
74	read_p = 1;
75	break;
76    }
77
78    if (ccache->flags & KCM_FLAGS_OWNER_IS_SYSTEM) {
79	/* System caches cannot be reinitialized or destroyed by users */
80	if (opcode == KCM_OP_INITIALIZE ||
81	    opcode == KCM_OP_DESTROY ||
82	    opcode == KCM_OP_REMOVE_CRED) {
83	    ret = KRB5_FCC_PERM;
84	    goto out;
85	}
86
87	/* Let root always read system caches */
88	if (client->uid == 0) {
89	    ret = 0;
90	    goto out;
91	}
92    }
93
94    mask = 0;
95
96    /* Root may do whatever they like */
97    if (client->uid == ccache->uid || CLIENT_IS_ROOT(client)) {
98	if (read_p)
99	    mask |= S_IRUSR;
100	if (write_p)
101	    mask |= S_IWUSR;
102    } else if (client->gid == ccache->gid || CLIENT_IS_ROOT(client)) {
103	if (read_p)
104	    mask |= S_IRGRP;
105	if (write_p)
106	    mask |= S_IWGRP;
107    } else {
108	if (read_p)
109	    mask |= S_IROTH;
110	if (write_p)
111	    mask |= S_IWOTH;
112    }
113
114    ret = ((ccache->mode & mask) == mask) ? 0 : KRB5_FCC_PERM;
115
116out:
117    if (ret) {
118	kcm_log(2, "Process %d is not permitted to call %s on cache %s",
119		client->pid, kcm_op2string(opcode), ccache->name);
120    }
121
122    return ret;
123}
124
125krb5_error_code
126kcm_chmod(krb5_context context,
127	  kcm_client *client,
128	  kcm_ccache ccache,
129	  uint16_t mode)
130{
131    KCM_ASSERT_VALID(ccache);
132
133    /* System cache mode can only be set at startup */
134    if (ccache->flags & KCM_FLAGS_OWNER_IS_SYSTEM)
135	return KRB5_FCC_PERM;
136
137    if (ccache->uid != client->uid)
138	return KRB5_FCC_PERM;
139
140    if (ccache->gid != client->gid)
141	return KRB5_FCC_PERM;
142
143    HEIMDAL_MUTEX_lock(&ccache->mutex);
144
145    ccache->mode = mode;
146
147    HEIMDAL_MUTEX_unlock(&ccache->mutex);
148
149    return 0;
150}
151
152krb5_error_code
153kcm_chown(krb5_context context,
154	  kcm_client *client,
155	  kcm_ccache ccache,
156	  uid_t uid,
157	  gid_t gid)
158{
159    KCM_ASSERT_VALID(ccache);
160
161    /* System cache owner can only be set at startup */
162    if (ccache->flags & KCM_FLAGS_OWNER_IS_SYSTEM)
163	return KRB5_FCC_PERM;
164
165    if (ccache->uid != client->uid)
166	return KRB5_FCC_PERM;
167
168    if (ccache->gid != client->gid)
169	return KRB5_FCC_PERM;
170
171    HEIMDAL_MUTEX_lock(&ccache->mutex);
172
173    ccache->uid = uid;
174    ccache->gid = gid;
175
176    HEIMDAL_MUTEX_unlock(&ccache->mutex);
177
178    return 0;
179}
180
181