xref: /freebsd/crypto/heimdal/lib/gssapi/mech/gss_mech_switch.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*-
2  * Copyright (c) 2005 Doug Rabson
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  *	$FreeBSD: src/lib/libgssapi/gss_mech_switch.c,v 1.2 2006/02/04 09:40:21 dfr Exp $
27  */
28 
29 #include "mech_locl.h"
30 #include <heim_threads.h>
31 
32 #ifndef _PATH_GSS_MECH
33 #define _PATH_GSS_MECH	"/etc/gss/mech"
34 #endif
35 
36 struct _gss_mech_switch_list _gss_mechs = { NULL } ;
37 gss_OID_set _gss_mech_oids;
38 static HEIMDAL_MUTEX _gss_mech_mutex = HEIMDAL_MUTEX_INITIALIZER;
39 
40 /*
41  * Convert a string containing an OID in 'dot' form
42  * (e.g. 1.2.840.113554.1.2.2) to a gss_OID.
43  */
44 static int
45 _gss_string_to_oid(const char* s, gss_OID oid)
46 {
47 	int			number_count, i, j;
48 	size_t			byte_count;
49 	const char		*p, *q;
50 	char			*res;
51 
52 	oid->length = 0;
53 	oid->elements = NULL;
54 
55 	/*
56 	 * First figure out how many numbers in the oid, then
57 	 * calculate the compiled oid size.
58 	 */
59 	number_count = 0;
60 	for (p = s; p; p = q) {
61 		q = strchr(p, '.');
62 		if (q) q = q + 1;
63 		number_count++;
64 	}
65 
66 	/*
67 	 * The first two numbers are in the first byte and each
68 	 * subsequent number is encoded in a variable byte sequence.
69 	 */
70 	if (number_count < 2)
71 		return (EINVAL);
72 
73 	/*
74 	 * We do this in two passes. The first pass, we just figure
75 	 * out the size. Second time around, we actually encode the
76 	 * number.
77 	 */
78 	res = 0;
79 	for (i = 0; i < 2; i++) {
80 		byte_count = 0;
81 		for (p = s, j = 0; p; p = q, j++) {
82 			unsigned int number = 0;
83 
84 			/*
85 			 * Find the end of this number.
86 			 */
87 			q = strchr(p, '.');
88 			if (q) q = q + 1;
89 
90 			/*
91 			 * Read the number of of the string. Don't
92 			 * bother with anything except base ten.
93 			 */
94 			while (*p && *p != '.') {
95 				number = 10 * number + (*p - '0');
96 				p++;
97 			}
98 
99 			/*
100 			 * Encode the number. The first two numbers
101 			 * are packed into the first byte. Subsequent
102 			 * numbers are encoded in bytes seven bits at
103 			 * a time with the last byte having the high
104 			 * bit set.
105 			 */
106 			if (j == 0) {
107 				if (res)
108 					*res = number * 40;
109 			} else if (j == 1) {
110 				if (res) {
111 					*res += number;
112 					res++;
113 				}
114 				byte_count++;
115 			} else if (j >= 2) {
116 				/*
117 				 * The number is encoded in seven bit chunks.
118 				 */
119 				unsigned int t;
120 				unsigned int bytes;
121 
122 				bytes = 0;
123 				for (t = number; t; t >>= 7)
124 					bytes++;
125 				if (bytes == 0) bytes = 1;
126 				while (bytes) {
127 					if (res) {
128 						int bit = 7*(bytes-1);
129 
130 						*res = (number >> bit) & 0x7f;
131 						if (bytes != 1)
132 							*res |= 0x80;
133 						res++;
134 					}
135 					byte_count++;
136 					bytes--;
137 				}
138 			}
139 		}
140 		if (!res) {
141 			res = malloc(byte_count);
142 			if (!res)
143 				return (ENOMEM);
144 			oid->length = byte_count;
145 			oid->elements = res;
146 		}
147 	}
148 
149 	return (0);
150 }
151 
152 #define SYM(name)							\
153 do {									\
154 	m->gm_mech.gm_ ## name = dlsym(so, "gss_" #name);		\
155 	if (!m->gm_mech.gm_ ## name ||					\
156 	    m->gm_mech.gm_ ##name == gss_ ## name) {			\
157 		fprintf(stderr, "can't find symbol gss_" #name "\n");	\
158 		goto bad;						\
159 	}								\
160 } while (0)
161 
162 #define OPTSYM(name)							\
163 do {									\
164 	m->gm_mech.gm_ ## name = dlsym(so, "gss_" #name);		\
165 	if (m->gm_mech.gm_ ## name == gss_ ## name)			\
166 		m->gm_mech.gm_ ## name = NULL;				\
167 } while (0)
168 
169 #define OPTSPISYM(name)							\
170 do {									\
171 	m->gm_mech.gm_ ## name = dlsym(so, "gssspi_" #name);		\
172 } while (0)
173 
174 #define COMPATSYM(name)							\
175 do {									\
176 	m->gm_mech.gm_compat->gmc_ ## name = dlsym(so, "gss_" #name);	\
177 	if (m->gm_mech.gm_compat->gmc_ ## name == gss_ ## name)		\
178 		m->gm_mech.gm_compat->gmc_ ## name = NULL;		\
179 } while (0)
180 
181 #define COMPATSPISYM(name)						\
182 do {									\
183 	m->gm_mech.gm_compat->gmc_ ## name = dlsym(so, "gssspi_" #name);\
184 	if (m->gm_mech.gm_compat->gmc_ ## name == gss_ ## name)		\
185 		m->gm_mech.gm_compat->gmc_ ## name = NULL;		\
186 } while (0)
187 
188 /*
189  *
190  */
191 static int
192 add_builtin(gssapi_mech_interface mech)
193 {
194     struct _gss_mech_switch *m;
195     OM_uint32 minor_status;
196 
197     /* not registering any mech is ok */
198     if (mech == NULL)
199 	return 0;
200 
201     m = calloc(1, sizeof(*m));
202     if (m == NULL)
203 	return ENOMEM;
204     m->gm_so = NULL;
205     m->gm_mech = *mech;
206     m->gm_mech_oid = mech->gm_mech_oid; /* XXX */
207     gss_add_oid_set_member(&minor_status,
208 			   &m->gm_mech.gm_mech_oid, &_gss_mech_oids);
209 
210     /* pick up the oid sets of names */
211 
212     if (m->gm_mech.gm_inquire_names_for_mech)
213 	(*m->gm_mech.gm_inquire_names_for_mech)(&minor_status,
214 	    &m->gm_mech.gm_mech_oid, &m->gm_name_types);
215 
216     if (m->gm_name_types == NULL)
217 	gss_create_empty_oid_set(&minor_status, &m->gm_name_types);
218 
219     HEIM_SLIST_INSERT_HEAD(&_gss_mechs, m, gm_link);
220     return 0;
221 }
222 
223 /*
224  * Load the mechanisms file (/etc/gss/mech).
225  */
226 void
227 _gss_load_mech(void)
228 {
229 	OM_uint32	major_status, minor_status;
230 	FILE		*fp;
231 	char		buf[256];
232 	char		*p;
233 	char		*name, *oid, *lib, *kobj;
234 	struct _gss_mech_switch *m;
235 	void		*so;
236 	gss_OID_desc	mech_oid;
237 	int		found;
238 
239 
240 	HEIMDAL_MUTEX_lock(&_gss_mech_mutex);
241 
242 	if (HEIM_SLIST_FIRST(&_gss_mechs)) {
243 		HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
244 		return;
245 	}
246 
247 	major_status = gss_create_empty_oid_set(&minor_status,
248 	    &_gss_mech_oids);
249 	if (major_status) {
250 		HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
251 		return;
252 	}
253 
254 	add_builtin(__gss_krb5_initialize());
255 	add_builtin(__gss_spnego_initialize());
256 	add_builtin(__gss_ntlm_initialize());
257 
258 #ifdef HAVE_DLOPEN
259 	fp = fopen(_PATH_GSS_MECH, "r");
260 	if (!fp) {
261 		HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
262 		return;
263 	}
264 	rk_cloexec_file(fp);
265 
266 	while (fgets(buf, sizeof(buf), fp)) {
267 		_gss_mo_init *mi;
268 
269 		if (*buf == '#')
270 			continue;
271 		p = buf;
272 		name = strsep(&p, "\t\n ");
273 		if (p) while (isspace((unsigned char)*p)) p++;
274 		oid = strsep(&p, "\t\n ");
275 		if (p) while (isspace((unsigned char)*p)) p++;
276 		lib = strsep(&p, "\t\n ");
277 		if (p) while (isspace((unsigned char)*p)) p++;
278 		kobj = strsep(&p, "\t\n ");
279 		if (!name || !oid || !lib || !kobj)
280 			continue;
281 
282 		if (_gss_string_to_oid(oid, &mech_oid))
283 			continue;
284 
285 		/*
286 		 * Check for duplicates, already loaded mechs.
287 		 */
288 		found = 0;
289 		HEIM_SLIST_FOREACH(m, &_gss_mechs, gm_link) {
290 			if (gss_oid_equal(&m->gm_mech.gm_mech_oid, &mech_oid)) {
291 				found = 1;
292 				free(mech_oid.elements);
293 				break;
294 			}
295 		}
296 		if (found)
297 			continue;
298 
299 #ifndef RTLD_LOCAL
300 #define RTLD_LOCAL 0
301 #endif
302 
303 #ifndef RTLD_GROUP
304 #define RTLD_GROUP 0
305 #endif
306 
307 		so = dlopen(lib, RTLD_LAZY | RTLD_LOCAL | RTLD_GROUP);
308 		if (so == NULL) {
309 /*			fprintf(stderr, "dlopen: %s\n", dlerror()); */
310 			goto bad;
311 		}
312 
313 		m = calloc(1, sizeof(*m));
314 		if (m == NULL)
315 			goto bad;
316 
317 		m->gm_so = so;
318 		m->gm_mech.gm_mech_oid = mech_oid;
319 		m->gm_mech.gm_flags = 0;
320 		m->gm_mech.gm_compat = calloc(1, sizeof(struct gss_mech_compat_desc_struct));
321 		if (m->gm_mech.gm_compat == NULL)
322 			goto bad;
323 
324 		major_status = gss_add_oid_set_member(&minor_status,
325 		    &m->gm_mech.gm_mech_oid, &_gss_mech_oids);
326 		if (GSS_ERROR(major_status))
327 			goto bad;
328 
329 		SYM(acquire_cred);
330 		SYM(release_cred);
331 		SYM(init_sec_context);
332 		SYM(accept_sec_context);
333 		SYM(process_context_token);
334 		SYM(delete_sec_context);
335 		SYM(context_time);
336 		SYM(get_mic);
337 		SYM(verify_mic);
338 		SYM(wrap);
339 		SYM(unwrap);
340 		SYM(display_status);
341 		SYM(indicate_mechs);
342 		SYM(compare_name);
343 		SYM(display_name);
344 		SYM(import_name);
345 		SYM(export_name);
346 		SYM(release_name);
347 		SYM(inquire_cred);
348 		SYM(inquire_context);
349 		SYM(wrap_size_limit);
350 		SYM(add_cred);
351 		SYM(inquire_cred_by_mech);
352 		SYM(export_sec_context);
353 		SYM(import_sec_context);
354 		SYM(inquire_names_for_mech);
355 		SYM(inquire_mechs_for_name);
356 		SYM(canonicalize_name);
357 		SYM(duplicate_name);
358 		OPTSYM(inquire_cred_by_oid);
359 		OPTSYM(inquire_sec_context_by_oid);
360 		OPTSYM(set_sec_context_option);
361 		OPTSPISYM(set_cred_option);
362 		OPTSYM(pseudo_random);
363 		OPTSYM(wrap_iov);
364 		OPTSYM(unwrap_iov);
365 		OPTSYM(wrap_iov_length);
366 		OPTSYM(store_cred);
367 		OPTSYM(export_cred);
368 		OPTSYM(import_cred);
369 #if 0
370 		OPTSYM(acquire_cred_ext);
371 		OPTSYM(iter_creds);
372 		OPTSYM(destroy_cred);
373 		OPTSYM(cred_hold);
374 		OPTSYM(cred_unhold);
375 		OPTSYM(cred_label_get);
376 		OPTSYM(cred_label_set);
377 #endif
378 		OPTSYM(display_name_ext);
379 		OPTSYM(inquire_name);
380 		OPTSYM(get_name_attribute);
381 		OPTSYM(set_name_attribute);
382 		OPTSYM(delete_name_attribute);
383 		OPTSYM(export_name_composite);
384 		OPTSYM(pname_to_uid);
385 		OPTSPISYM(authorize_localname);
386 
387 		mi = dlsym(so, "gss_mo_init");
388 		if (mi != NULL) {
389 			major_status = mi(&minor_status, &mech_oid,
390 					  &m->gm_mech.gm_mo, &m->gm_mech.gm_mo_num);
391 			if (GSS_ERROR(major_status))
392 				goto bad;
393 		} else {
394 			/* API-as-SPI compatibility */
395 			COMPATSYM(inquire_saslname_for_mech);
396 			COMPATSYM(inquire_mech_for_saslname);
397 			COMPATSYM(inquire_attrs_for_mech);
398 			COMPATSPISYM(acquire_cred_with_password);
399 		}
400 
401 		/* pick up the oid sets of names */
402 
403 		if (m->gm_mech.gm_inquire_names_for_mech)
404 			(*m->gm_mech.gm_inquire_names_for_mech)(&minor_status,
405 			&m->gm_mech.gm_mech_oid, &m->gm_name_types);
406 
407 		if (m->gm_name_types == NULL)
408 			gss_create_empty_oid_set(&minor_status, &m->gm_name_types);
409 
410 		HEIM_SLIST_INSERT_HEAD(&_gss_mechs, m, gm_link);
411 		continue;
412 
413 	bad:
414 		if (m != NULL) {
415 			free(m->gm_mech.gm_compat);
416 			free(m->gm_mech.gm_mech_oid.elements);
417 			free(m);
418 		}
419 		dlclose(so);
420 		continue;
421 	}
422 	fclose(fp);
423 #endif
424 	HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
425 }
426 
427 gssapi_mech_interface
428 __gss_get_mechanism(gss_const_OID mech)
429 {
430         struct _gss_mech_switch	*m;
431 
432 	_gss_load_mech();
433 	HEIM_SLIST_FOREACH(m, &_gss_mechs, gm_link) {
434 		if (gss_oid_equal(&m->gm_mech.gm_mech_oid, mech))
435 			return &m->gm_mech;
436 	}
437 	return NULL;
438 }
439