1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2005 Doug Rabson
5 * 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 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <gssapi/gssapi.h>
30 #include <ctype.h>
31 #include <dlfcn.h>
32 #include <errno.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36
37 #include "mech_switch.h"
38 #include "utils.h"
39
40 #ifndef _PATH_GSS_MECH
41 #define _PATH_GSS_MECH "/etc/gss/mech"
42 #endif
43
44 struct _gss_mech_switch_list _gss_mechs =
45 SLIST_HEAD_INITIALIZER(_gss_mechs);
46 gss_OID_set _gss_mech_oids;
47
48 /*
49 * Convert a string containing an OID in 'dot' form
50 * (e.g. 1.2.840.113554.1.2.2) to a gss_OID.
51 */
52 static int
_gss_string_to_oid(const char * s,gss_OID oid)53 _gss_string_to_oid(const char* s, gss_OID oid)
54 {
55 int number_count, i, j;
56 int byte_count;
57 const char *p, *q;
58 char *res;
59
60 oid->length = 0;
61 oid->elements = NULL;
62
63 /*
64 * First figure out how many numbers in the oid, then
65 * calculate the compiled oid size.
66 */
67 number_count = 0;
68 for (p = s; p; p = q) {
69 q = strchr(p, '.');
70 if (q) q = q + 1;
71 number_count++;
72 }
73
74 /*
75 * The first two numbers are in the first byte and each
76 * subsequent number is encoded in a variable byte sequence.
77 */
78 if (number_count < 2)
79 return (EINVAL);
80
81 /*
82 * We do this in two passes. The first pass, we just figure
83 * out the size. Second time around, we actually encode the
84 * number.
85 */
86 res = NULL;
87 for (i = 0; i < 2; i++) {
88 byte_count = 0;
89 for (p = s, j = 0; p; p = q, j++) {
90 unsigned int number = 0;
91
92 /*
93 * Find the end of this number.
94 */
95 q = strchr(p, '.');
96 if (q) q = q + 1;
97
98 /*
99 * Read the number of of the string. Don't
100 * bother with anything except base ten.
101 */
102 while (*p && *p != '.') {
103 number = 10 * number + (*p - '0');
104 p++;
105 }
106
107 /*
108 * Encode the number. The first two numbers
109 * are packed into the first byte. Subsequent
110 * numbers are encoded in bytes seven bits at
111 * a time with the last byte having the high
112 * bit set.
113 */
114 if (j == 0) {
115 if (res)
116 *res = number * 40;
117 } else if (j == 1) {
118 if (res) {
119 *res += number;
120 res++;
121 }
122 byte_count++;
123 } else if (j >= 2) {
124 /*
125 * The number is encoded in seven bit chunks.
126 */
127 unsigned int t;
128 int bytes;
129
130 bytes = 0;
131 for (t = number; t; t >>= 7)
132 bytes++;
133 if (bytes == 0) bytes = 1;
134 while (bytes) {
135 if (res) {
136 int bit = 7*(bytes-1);
137
138 *res = (number >> bit) & 0x7f;
139 if (bytes != 1)
140 *res |= 0x80;
141 res++;
142 }
143 byte_count++;
144 bytes--;
145 }
146 }
147 }
148 if (!res) {
149 res = malloc(byte_count);
150 if (!res)
151 return (ENOMEM);
152 oid->length = byte_count;
153 oid->elements = res;
154 }
155 }
156
157 return (0);
158 }
159
160
161 #define SYM(name) \
162 do { \
163 snprintf(buf, sizeof(buf), "%s_%s", \
164 m->gm_name_prefix, #name); \
165 m->gm_ ## name = dlsym(so, buf); \
166 if (!m->gm_ ## name) { \
167 fprintf(stderr, "can't find symbol %s\n", buf); \
168 goto bad; \
169 } \
170 } while (0)
171
172 #define OPTSYM(name) \
173 do { \
174 snprintf(buf, sizeof(buf), "%s_%s", \
175 m->gm_name_prefix, #name); \
176 m->gm_ ## name = dlsym(so, buf); \
177 } while (0)
178
179 /*
180 * Load the mechanisms file (/etc/gss/mech).
181 */
182 void
_gss_load_mech(void)183 _gss_load_mech(void)
184 {
185 OM_uint32 major_status, minor_status;
186 FILE *fp;
187 char buf[256];
188 char *p;
189 char *name, *oid, *lib, *kobj;
190 struct _gss_mech_switch *m;
191 void *so;
192 const char *(*prefix_fn)(void);
193
194 if (SLIST_FIRST(&_gss_mechs))
195 return;
196
197 major_status = gss_create_empty_oid_set(&minor_status,
198 &_gss_mech_oids);
199 if (major_status)
200 return;
201
202 fp = fopen(_PATH_GSS_MECH, "r");
203 if (!fp) {
204 perror(_PATH_GSS_MECH);
205 return;
206 }
207
208 while (fgets(buf, sizeof(buf), fp)) {
209 if (*buf == '#')
210 continue;
211 p = buf;
212 name = strsep(&p, "\t\n ");
213 if (p) while (isspace(*p)) p++;
214 oid = strsep(&p, "\t\n ");
215 if (p) while (isspace(*p)) p++;
216 lib = strsep(&p, "\t\n ");
217 if (p) while (isspace(*p)) p++;
218 kobj = strsep(&p, "\t\n ");
219 if (!name || !oid || !lib || !kobj)
220 continue;
221
222 so = dlopen(lib, RTLD_LOCAL);
223 if (!so) {
224 fprintf(stderr, "dlopen: %s\n", dlerror());
225 continue;
226 }
227
228 m = malloc(sizeof(struct _gss_mech_switch));
229 if (!m)
230 break;
231 m->gm_so = so;
232 if (_gss_string_to_oid(oid, &m->gm_mech_oid)) {
233 free(m);
234 continue;
235 }
236
237 prefix_fn = (const char *(*)(void))
238 dlsym(so, "_gss_name_prefix");
239 if (prefix_fn)
240 m->gm_name_prefix = prefix_fn();
241 else
242 m->gm_name_prefix = "gss";
243
244 major_status = gss_add_oid_set_member(&minor_status,
245 &m->gm_mech_oid, &_gss_mech_oids);
246 if (major_status) {
247 free(m->gm_mech_oid.elements);
248 free(m);
249 continue;
250 }
251
252 SYM(acquire_cred);
253 SYM(release_cred);
254 SYM(init_sec_context);
255 SYM(accept_sec_context);
256 SYM(process_context_token);
257 SYM(delete_sec_context);
258 SYM(context_time);
259 SYM(get_mic);
260 SYM(verify_mic);
261 SYM(wrap);
262 SYM(unwrap);
263 SYM(display_status);
264 OPTSYM(indicate_mechs);
265 SYM(compare_name);
266 SYM(display_name);
267 SYM(import_name);
268 SYM(export_name);
269 SYM(release_name);
270 SYM(inquire_cred);
271 SYM(inquire_context);
272 SYM(wrap_size_limit);
273 SYM(add_cred);
274 SYM(inquire_cred_by_mech);
275 SYM(export_sec_context);
276 SYM(import_sec_context);
277 SYM(inquire_names_for_mech);
278 SYM(inquire_mechs_for_name);
279 SYM(canonicalize_name);
280 SYM(duplicate_name);
281 OPTSYM(inquire_sec_context_by_oid);
282 OPTSYM(inquire_cred_by_oid);
283 OPTSYM(set_sec_context_option);
284 OPTSYM(set_cred_option);
285 OPTSYM(pseudo_random);
286 OPTSYM(pname_to_uid);
287
288 SLIST_INSERT_HEAD(&_gss_mechs, m, gm_link);
289 continue;
290
291 bad:
292 free(m->gm_mech_oid.elements);
293 free(m);
294 dlclose(so);
295 continue;
296 }
297 fclose(fp);
298 }
299
300 struct _gss_mech_switch *
_gss_find_mech_switch(gss_OID mech)301 _gss_find_mech_switch(gss_OID mech)
302 {
303 struct _gss_mech_switch *m;
304
305 _gss_load_mech();
306 SLIST_FOREACH(m, &_gss_mechs, gm_link) {
307 if (gss_oid_equal(&m->gm_mech_oid, mech))
308 return m;
309 }
310 return (0);
311 }
312