1 /* $NetBSD: client.c,v 1.4 2023/06/19 21:41:41 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 #include <pwd.h>
39
40 krb5_error_code
kcm_ccache_resolve_client(krb5_context context,kcm_client * client,kcm_operation opcode,const char * name,kcm_ccache * ccache)41 kcm_ccache_resolve_client(krb5_context context,
42 kcm_client *client,
43 kcm_operation opcode,
44 const char *name,
45 kcm_ccache *ccache)
46 {
47 krb5_error_code ret;
48 const char *estr;
49
50 ret = kcm_ccache_resolve(context, name, ccache);
51 if (ret) {
52 estr = krb5_get_error_message(context, ret);
53 kcm_log(1, "Failed to resolve cache %s: %s", name, estr);
54 krb5_free_error_message(context, estr);
55 return ret;
56 }
57
58 ret = kcm_access(context, client, opcode, *ccache);
59 if (ret) {
60 ret = KRB5_FCC_NOFILE; /* don't disclose */
61 kcm_release_ccache(context, *ccache);
62 }
63
64 return ret;
65 }
66
67 krb5_error_code
kcm_ccache_destroy_client(krb5_context context,kcm_client * client,const char * name)68 kcm_ccache_destroy_client(krb5_context context,
69 kcm_client *client,
70 const char *name)
71 {
72 krb5_error_code ret;
73 kcm_ccache ccache;
74 const char *estr;
75
76 ret = kcm_ccache_resolve(context, name, &ccache);
77 if (ret) {
78 estr = krb5_get_error_message(context, ret);
79 kcm_log(1, "Failed to resolve cache %s: %s", name, estr);
80 krb5_free_error_message(context, estr);
81 return ret;
82 }
83
84 ret = kcm_access(context, client, KCM_OP_DESTROY, ccache);
85 kcm_cleanup_events(context, ccache);
86 kcm_release_ccache(context, ccache);
87 if (ret)
88 return ret;
89
90 return kcm_ccache_destroy(context, name);
91 }
92
93 krb5_error_code
kcm_ccache_new_client(krb5_context context,kcm_client * client,const char * name,kcm_ccache * ccache_p)94 kcm_ccache_new_client(krb5_context context,
95 kcm_client *client,
96 const char *name,
97 kcm_ccache *ccache_p)
98 {
99 krb5_error_code ret;
100 kcm_ccache ccache;
101 const char *estr;
102
103 /* We insist the ccache name starts with UID or UID: */
104 if (name_constraints != 0) {
105 char prefix[64];
106 size_t prefix_len;
107 int bad = 1;
108
109 snprintf(prefix, sizeof(prefix), "%ld:", (long)client->uid);
110 prefix_len = strlen(prefix);
111
112 if (strncmp(name, prefix, prefix_len) == 0)
113 bad = 0;
114 else {
115 prefix[prefix_len - 1] = '\0';
116 if (strcmp(name, prefix) == 0)
117 bad = 0;
118 }
119
120 /* Allow root to create badly-named ccaches */
121 if (bad && !CLIENT_IS_ROOT(client))
122 return KRB5_CC_BADNAME;
123 }
124
125 ret = kcm_ccache_resolve(context, name, &ccache);
126 if (ret == 0) {
127 if ((ccache->uid != client->uid ||
128 ccache->gid != client->gid) && !CLIENT_IS_ROOT(client))
129 return KRB5_FCC_PERM;
130 } else if (ret != KRB5_FCC_NOFILE && !(CLIENT_IS_ROOT(client) && ret == KRB5_FCC_PERM)) {
131 return ret;
132 }
133
134 if (ret == KRB5_FCC_NOFILE) {
135 ret = kcm_ccache_new(context, name, &ccache);
136 if (ret) {
137 estr = krb5_get_error_message(context, ret);
138 kcm_log(1, "Failed to initialize cache %s: %s", name, estr);
139 krb5_free_error_message(context, estr);
140 return ret;
141 }
142
143 /* bind to current client */
144 ccache->uid = client->uid;
145 ccache->gid = client->gid;
146 ccache->session = client->session;
147 } else {
148 ret = kcm_zero_ccache_data(context, ccache);
149 if (ret) {
150 estr = krb5_get_error_message(context, ret);
151 kcm_log(1, "Failed to empty cache %s: %s", name, estr);
152 krb5_free_error_message(context, estr);
153 kcm_release_ccache(context, ccache);
154 return ret;
155 }
156 kcm_cleanup_events(context, ccache);
157 }
158
159 ret = kcm_access(context, client, KCM_OP_INITIALIZE, ccache);
160 if (ret) {
161 kcm_release_ccache(context, ccache);
162 kcm_ccache_destroy(context, name);
163 return ret;
164 }
165
166 /*
167 * Finally, if the user is root and the cache was created under
168 * another user's name, chown the cache to that user and their
169 * default gid.
170 */
171 if (CLIENT_IS_ROOT(client)) {
172 unsigned long uid;
173 int matches = sscanf(name,"%ld:",&uid);
174 if (matches == 0)
175 matches = sscanf(name,"%ld",&uid);
176 if (matches == 1) {
177 struct passwd pw, *pwd = NULL;
178 char pwbuf[2048];
179
180 if (rk_getpwuid_r(getuid(), &pw, pwbuf, sizeof(pwbuf), &pwd) == 0) {
181 gid_t gid = pwd->pw_gid;
182 kcm_chown(context, client, ccache, uid, gid);
183 }
184 }
185 }
186
187 *ccache_p = ccache;
188 return 0;
189 }
190
191