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
36RCSID("$Id$");
37
38static 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
50kadm5_ret_t
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
61kadm5_ret_t
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
77static kadm5_ret_t
78fetch_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
148kadm5_ret_t
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
172static kadm5_ret_t
173check_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
201kadm5_ret_t
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