xref: /freebsd/crypto/heimdal/kcm/client.c (revision cc68614da8232d8baaca0ae0d0dd8f890f06623e)
1 /*
2  * Copyright (c) 2005, PADL Software Pty Ltd.
3  * All rights reserved.
4  *
5  * Portions Copyright (c) 2009 Apple Inc. All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  *
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * 3. Neither the name of PADL Software nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY PADL SOFTWARE AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL PADL SOFTWARE OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include "kcm_locl.h"
36 #include <pwd.h>
37 
38 krb5_error_code
39 kcm_ccache_resolve_client(krb5_context context,
40 			  kcm_client *client,
41 			  kcm_operation opcode,
42 			  const char *name,
43 			  kcm_ccache *ccache)
44 {
45     krb5_error_code ret;
46 
47     ret = kcm_ccache_resolve(context, name, ccache);
48     if (ret) {
49 	kcm_log(1, "Failed to resolve cache %s: %s",
50 		name, krb5_get_err_text(context, ret));
51 	return ret;
52     }
53 
54     ret = kcm_access(context, client, opcode, *ccache);
55     if (ret) {
56 	ret = KRB5_FCC_NOFILE; /* don't disclose */
57 	kcm_release_ccache(context, *ccache);
58     }
59 
60     return ret;
61 }
62 
63 krb5_error_code
64 kcm_ccache_destroy_client(krb5_context context,
65 			  kcm_client *client,
66 			  const char *name)
67 {
68     krb5_error_code ret;
69     kcm_ccache ccache;
70 
71     ret = kcm_ccache_resolve(context, name, &ccache);
72     if (ret) {
73 	kcm_log(1, "Failed to resolve cache %s: %s",
74 		name, krb5_get_err_text(context, ret));
75 	return ret;
76     }
77 
78     ret = kcm_access(context, client, KCM_OP_DESTROY, ccache);
79     kcm_cleanup_events(context, ccache);
80     kcm_release_ccache(context, ccache);
81     if (ret)
82 	return ret;
83 
84     return kcm_ccache_destroy(context, name);
85 }
86 
87 krb5_error_code
88 kcm_ccache_new_client(krb5_context context,
89 		      kcm_client *client,
90 		      const char *name,
91 		      kcm_ccache *ccache_p)
92 {
93     krb5_error_code ret;
94     kcm_ccache ccache;
95 
96     /* We insist the ccache name starts with UID or UID: */
97     if (name_constraints != 0) {
98 	char prefix[64];
99 	size_t prefix_len;
100 	int bad = 1;
101 
102 	snprintf(prefix, sizeof(prefix), "%ld:", (long)client->uid);
103 	prefix_len = strlen(prefix);
104 
105 	if (strncmp(name, prefix, prefix_len) == 0)
106 	    bad = 0;
107 	else {
108 	    prefix[prefix_len - 1] = '\0';
109 	    if (strcmp(name, prefix) == 0)
110 		bad = 0;
111 	}
112 
113 	/* Allow root to create badly-named ccaches */
114 	if (bad && !CLIENT_IS_ROOT(client))
115 	    return KRB5_CC_BADNAME;
116     }
117 
118     ret = kcm_ccache_resolve(context, name, &ccache);
119     if (ret == 0) {
120 	if ((ccache->uid != client->uid ||
121 	     ccache->gid != client->gid) && !CLIENT_IS_ROOT(client))
122 	    return KRB5_FCC_PERM;
123     } else if (ret != KRB5_FCC_NOFILE && !(CLIENT_IS_ROOT(client) && ret == KRB5_FCC_PERM)) {
124 		return ret;
125     }
126 
127     if (ret == KRB5_FCC_NOFILE) {
128 	ret = kcm_ccache_new(context, name, &ccache);
129 	if (ret) {
130 	    kcm_log(1, "Failed to initialize cache %s: %s",
131 		    name, krb5_get_err_text(context, ret));
132 	    return ret;
133 	}
134 
135 	/* bind to current client */
136 	ccache->uid = client->uid;
137 	ccache->gid = client->gid;
138 	ccache->session = client->session;
139     } else {
140 	ret = kcm_zero_ccache_data(context, ccache);
141 	if (ret) {
142 	    kcm_log(1, "Failed to empty cache %s: %s",
143 		    name, krb5_get_err_text(context, ret));
144 	    kcm_release_ccache(context, ccache);
145 	    return ret;
146 	}
147 	kcm_cleanup_events(context, ccache);
148     }
149 
150     ret = kcm_access(context, client, KCM_OP_INITIALIZE, ccache);
151     if (ret) {
152 	kcm_release_ccache(context, ccache);
153 	kcm_ccache_destroy(context, name);
154 	return ret;
155     }
156 
157     /*
158      * Finally, if the user is root and the cache was created under
159      * another user's name, chown the cache to that user and their
160      * default gid.
161      */
162     if (CLIENT_IS_ROOT(client)) {
163 	unsigned long uid;
164 	int matches = sscanf(name,"%ld:",&uid);
165 	if (matches == 0)
166 	    matches = sscanf(name,"%ld",&uid);
167 	if (matches == 1) {
168 	    struct passwd *pwd = getpwuid(uid);
169 	    if (pwd != NULL) {
170 		gid_t gid = pwd->pw_gid;
171 		kcm_chown(context, client, ccache, uid, gid);
172 	    }
173 	}
174     }
175 
176     *ccache_p = ccache;
177     return 0;
178 }
179 
180