1 /*
2 * Copyright (c) 1997 - 2001 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #include "kadm5_locl.h"
35
36 RCSID("$Id$");
37
38 static struct units acl_units[] = {
39 { "all", KADM5_PRIV_ALL },
40 { "change-password",KADM5_PRIV_CPW },
41 { "cpw", KADM5_PRIV_CPW },
42 { "list", KADM5_PRIV_LIST },
43 { "delete", KADM5_PRIV_DELETE },
44 { "modify", KADM5_PRIV_MODIFY },
45 { "add", KADM5_PRIV_ADD },
46 { "get", KADM5_PRIV_GET },
47 { NULL, 0 }
48 };
49
50 kadm5_ret_t
_kadm5_string_to_privs(const char * s,uint32_t * privs)51 _kadm5_string_to_privs(const char *s, uint32_t* privs)
52 {
53 int flags;
54 flags = parse_flags(s, acl_units, 0);
55 if(flags < 0)
56 return KADM5_FAILURE;
57 *privs = flags;
58 return 0;
59 }
60
61 kadm5_ret_t
_kadm5_privs_to_string(uint32_t privs,char * string,size_t len)62 _kadm5_privs_to_string(uint32_t privs, char *string, size_t len)
63 {
64 if(privs == 0)
65 strlcpy(string, "none", len);
66 else
67 unparse_flags(privs, acl_units + 1, string, len);
68 return 0;
69 }
70
71 /*
72 * retrieve the right for the current caller on `princ' (NULL means all)
73 * and store them in `ret_flags'
74 * return 0 or an error.
75 */
76
77 static kadm5_ret_t
fetch_acl(kadm5_server_context * context,krb5_const_principal princ,unsigned * ret_flags)78 fetch_acl (kadm5_server_context *context,
79 krb5_const_principal princ,
80 unsigned *ret_flags)
81 {
82 FILE *f;
83 krb5_error_code ret = 0;
84 char buf[256];
85
86 *ret_flags = 0;
87
88 /* no acl file -> no rights */
89 f = fopen(context->config.acl_file, "r");
90 if (f == NULL)
91 return 0;
92
93 while(fgets(buf, sizeof(buf), f) != NULL) {
94 char *foo = NULL, *p;
95 krb5_principal this_princ;
96 unsigned flags = 0;
97
98 p = strtok_r(buf, " \t\n", &foo);
99 if(p == NULL)
100 continue;
101 if (*p == '#') /* comment */
102 continue;
103 ret = krb5_parse_name(context->context, p, &this_princ);
104 if(ret)
105 break;
106 if(!krb5_principal_compare(context->context,
107 context->caller, this_princ)) {
108 krb5_free_principal(context->context, this_princ);
109 continue;
110 }
111 krb5_free_principal(context->context, this_princ);
112 p = strtok_r(NULL, " \t\n", &foo);
113 if(p == NULL)
114 continue;
115 ret = _kadm5_string_to_privs(p, &flags);
116 if (ret)
117 break;
118 p = strtok_r(NULL, " \t\n", &foo);
119 if (p == NULL) {
120 *ret_flags = flags;
121 break;
122 }
123 if (princ != NULL) {
124 krb5_principal pattern_princ;
125 krb5_boolean match;
126
127 ret = krb5_parse_name (context->context, p, &pattern_princ);
128 if (ret)
129 break;
130 match = krb5_principal_match (context->context,
131 princ, pattern_princ);
132 krb5_free_principal (context->context, pattern_princ);
133 if (match) {
134 *ret_flags = flags;
135 break;
136 }
137 }
138 }
139 fclose(f);
140 return ret;
141 }
142
143 /*
144 * set global acl flags in `context' for the current caller.
145 * return 0 on success or an error
146 */
147
148 kadm5_ret_t
_kadm5_acl_init(kadm5_server_context * context)149 _kadm5_acl_init(kadm5_server_context *context)
150 {
151 krb5_principal princ;
152 krb5_error_code ret;
153
154 ret = krb5_parse_name(context->context, KADM5_ADMIN_SERVICE, &princ);
155 if (ret)
156 return ret;
157 ret = krb5_principal_compare(context->context, context->caller, princ);
158 krb5_free_principal(context->context, princ);
159 if(ret != 0) {
160 context->acl_flags = KADM5_PRIV_ALL;
161 return 0;
162 }
163
164 return fetch_acl (context, NULL, &context->acl_flags);
165 }
166
167 /*
168 * check if `flags' allows `op'
169 * return 0 if OK or an error
170 */
171
172 static kadm5_ret_t
check_flags(unsigned op,unsigned flags)173 check_flags (unsigned op,
174 unsigned flags)
175 {
176 unsigned res = ~flags & op;
177
178 if(res & KADM5_PRIV_GET)
179 return KADM5_AUTH_GET;
180 if(res & KADM5_PRIV_ADD)
181 return KADM5_AUTH_ADD;
182 if(res & KADM5_PRIV_MODIFY)
183 return KADM5_AUTH_MODIFY;
184 if(res & KADM5_PRIV_DELETE)
185 return KADM5_AUTH_DELETE;
186 if(res & KADM5_PRIV_CPW)
187 return KADM5_AUTH_CHANGEPW;
188 if(res & KADM5_PRIV_LIST)
189 return KADM5_AUTH_LIST;
190 if(res)
191 return KADM5_AUTH_INSUFFICIENT;
192 return 0;
193 }
194
195 /*
196 * return 0 if the current caller in `context' is allowed to perform
197 * `op' on `princ' and otherwise an error
198 * princ == NULL if it's not relevant.
199 */
200
201 kadm5_ret_t
_kadm5_acl_check_permission(kadm5_server_context * context,unsigned op,krb5_const_principal princ)202 _kadm5_acl_check_permission(kadm5_server_context *context,
203 unsigned op,
204 krb5_const_principal princ)
205 {
206 kadm5_ret_t ret;
207 unsigned princ_flags;
208
209 ret = check_flags (op, context->acl_flags);
210 if (ret == 0)
211 return ret;
212 ret = fetch_acl (context, princ, &princ_flags);
213 if (ret)
214 return ret;
215 return check_flags (op, princ_flags);
216 }
217