xref: /freebsd/crypto/heimdal/lib/gssapi/mech/gss_mech_switch.c (revision aa1a8ff2d6dbc51ef058f46f3db5a8bb77967145)
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 (byte_count == 0)
141                     return EINVAL;
142 		if (!res) {
143 			res = malloc(byte_count);
144 			if (!res)
145 				return (ENOMEM);
146 			oid->length = byte_count;
147 			oid->elements = res;
148 		}
149 	}
150 
151 	return (0);
152 }
153 
154 #define SYM(name)							\
155 do {									\
156 	m->gm_mech.gm_ ## name = dlsym(so, "gss_" #name);		\
157 	if (!m->gm_mech.gm_ ## name ||					\
158 	    m->gm_mech.gm_ ##name == gss_ ## name) {			\
159 		fprintf(stderr, "can't find symbol gss_" #name "\n");	\
160 		goto bad;						\
161 	}								\
162 } while (0)
163 
164 #define OPTSYM(name)							\
165 do {									\
166 	m->gm_mech.gm_ ## name = dlsym(so, "gss_" #name);		\
167 	if (m->gm_mech.gm_ ## name == gss_ ## name)			\
168 		m->gm_mech.gm_ ## name = NULL;				\
169 } while (0)
170 
171 #define OPTSPISYM(name)							\
172 do {									\
173 	m->gm_mech.gm_ ## name = dlsym(so, "gssspi_" #name);		\
174 } while (0)
175 
176 #define COMPATSYM(name)							\
177 do {									\
178 	m->gm_mech.gm_compat->gmc_ ## name = dlsym(so, "gss_" #name);	\
179 	if (m->gm_mech.gm_compat->gmc_ ## name == gss_ ## name)		\
180 		m->gm_mech.gm_compat->gmc_ ## name = NULL;		\
181 } while (0)
182 
183 #define COMPATSPISYM(name)						\
184 do {									\
185 	m->gm_mech.gm_compat->gmc_ ## name = dlsym(so, "gssspi_" #name);\
186 	if (m->gm_mech.gm_compat->gmc_ ## name == gss_ ## name)		\
187 		m->gm_mech.gm_compat->gmc_ ## name = NULL;		\
188 } while (0)
189 
190 /*
191  *
192  */
193 static int
194 add_builtin(gssapi_mech_interface mech)
195 {
196     struct _gss_mech_switch *m;
197     OM_uint32 minor_status;
198 
199     /* not registering any mech is ok */
200     if (mech == NULL)
201 	return 0;
202 
203     m = calloc(1, sizeof(*m));
204     if (m == NULL)
205 	return ENOMEM;
206     m->gm_so = NULL;
207     m->gm_mech = *mech;
208     m->gm_mech_oid = mech->gm_mech_oid; /* XXX */
209     gss_add_oid_set_member(&minor_status,
210 			   &m->gm_mech.gm_mech_oid, &_gss_mech_oids);
211 
212     /* pick up the oid sets of names */
213 
214     if (m->gm_mech.gm_inquire_names_for_mech)
215 	(*m->gm_mech.gm_inquire_names_for_mech)(&minor_status,
216 	    &m->gm_mech.gm_mech_oid, &m->gm_name_types);
217 
218     if (m->gm_name_types == NULL)
219 	gss_create_empty_oid_set(&minor_status, &m->gm_name_types);
220 
221     HEIM_SLIST_INSERT_HEAD(&_gss_mechs, m, gm_link);
222     return 0;
223 }
224 
225 /*
226  * Load the mechanisms file (/etc/gss/mech).
227  */
228 void
229 _gss_load_mech(void)
230 {
231 	OM_uint32	major_status, minor_status;
232 	FILE		*fp;
233 	char		buf[256];
234 	char		*p;
235 	char		*name, *oid, *lib, *kobj;
236 	struct _gss_mech_switch *m;
237 	void		*so;
238 	gss_OID_desc	mech_oid;
239 	int		found;
240 
241 
242 	HEIMDAL_MUTEX_lock(&_gss_mech_mutex);
243 
244 	if (HEIM_SLIST_FIRST(&_gss_mechs)) {
245 		HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
246 		return;
247 	}
248 
249 	major_status = gss_create_empty_oid_set(&minor_status,
250 	    &_gss_mech_oids);
251 	if (major_status) {
252 		HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
253 		return;
254 	}
255 
256 	add_builtin(__gss_krb5_initialize());
257 	add_builtin(__gss_spnego_initialize());
258 	add_builtin(__gss_ntlm_initialize());
259 
260 #ifdef HAVE_DLOPEN
261 	fp = fopen(_PATH_GSS_MECH, "r");
262 	if (!fp) {
263 		HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
264 		return;
265 	}
266 	rk_cloexec_file(fp);
267 
268 	while (fgets(buf, sizeof(buf), fp)) {
269 		_gss_mo_init *mi;
270 
271 		if (*buf == '#')
272 			continue;
273 		p = buf;
274 		name = strsep(&p, "\t\n ");
275 		if (p) while (isspace((unsigned char)*p)) p++;
276 		oid = strsep(&p, "\t\n ");
277 		if (p) while (isspace((unsigned char)*p)) p++;
278 		lib = strsep(&p, "\t\n ");
279 		if (p) while (isspace((unsigned char)*p)) p++;
280 		kobj = strsep(&p, "\t\n ");
281 		if (!name || !oid || !lib || !kobj)
282 			continue;
283 
284 		if (_gss_string_to_oid(oid, &mech_oid))
285 			continue;
286 
287 		/*
288 		 * Check for duplicates, already loaded mechs.
289 		 */
290 		found = 0;
291 		HEIM_SLIST_FOREACH(m, &_gss_mechs, gm_link) {
292 			if (gss_oid_equal(&m->gm_mech.gm_mech_oid, &mech_oid)) {
293 				found = 1;
294 				free(mech_oid.elements);
295 				break;
296 			}
297 		}
298 		if (found)
299 			continue;
300 
301 #ifndef RTLD_LOCAL
302 #define RTLD_LOCAL 0
303 #endif
304 
305 #ifndef RTLD_GROUP
306 #define RTLD_GROUP 0
307 #endif
308 
309 		so = dlopen(lib, RTLD_LAZY | RTLD_LOCAL | RTLD_GROUP);
310 		if (so == NULL) {
311 /*			fprintf(stderr, "dlopen: %s\n", dlerror()); */
312 			goto bad;
313 		}
314 
315 		m = calloc(1, sizeof(*m));
316 		if (m == NULL)
317 			goto bad;
318 
319 		m->gm_so = so;
320 		m->gm_mech.gm_mech_oid = mech_oid;
321 		m->gm_mech.gm_flags = 0;
322 		m->gm_mech.gm_compat = calloc(1, sizeof(struct gss_mech_compat_desc_struct));
323 		if (m->gm_mech.gm_compat == NULL)
324 			goto bad;
325 
326 		major_status = gss_add_oid_set_member(&minor_status,
327 		    &m->gm_mech.gm_mech_oid, &_gss_mech_oids);
328 		if (GSS_ERROR(major_status))
329 			goto bad;
330 
331 		SYM(acquire_cred);
332 		SYM(release_cred);
333 		SYM(init_sec_context);
334 		SYM(accept_sec_context);
335 		SYM(process_context_token);
336 		SYM(delete_sec_context);
337 		SYM(context_time);
338 		SYM(get_mic);
339 		SYM(verify_mic);
340 		SYM(wrap);
341 		SYM(unwrap);
342 		SYM(display_status);
343 		SYM(indicate_mechs);
344 		SYM(compare_name);
345 		SYM(display_name);
346 		SYM(import_name);
347 		SYM(export_name);
348 		SYM(release_name);
349 		SYM(inquire_cred);
350 		SYM(inquire_context);
351 		SYM(wrap_size_limit);
352 		SYM(add_cred);
353 		SYM(inquire_cred_by_mech);
354 		SYM(export_sec_context);
355 		SYM(import_sec_context);
356 		SYM(inquire_names_for_mech);
357 		SYM(inquire_mechs_for_name);
358 		SYM(canonicalize_name);
359 		SYM(duplicate_name);
360 		OPTSYM(inquire_cred_by_oid);
361 		OPTSYM(inquire_sec_context_by_oid);
362 		OPTSYM(set_sec_context_option);
363 		OPTSPISYM(set_cred_option);
364 		OPTSYM(pseudo_random);
365 		OPTSYM(wrap_iov);
366 		OPTSYM(unwrap_iov);
367 		OPTSYM(wrap_iov_length);
368 		OPTSYM(store_cred);
369 		OPTSYM(export_cred);
370 		OPTSYM(import_cred);
371 #if 0
372 		OPTSYM(acquire_cred_ext);
373 		OPTSYM(iter_creds);
374 		OPTSYM(destroy_cred);
375 		OPTSYM(cred_hold);
376 		OPTSYM(cred_unhold);
377 		OPTSYM(cred_label_get);
378 		OPTSYM(cred_label_set);
379 #endif
380 		OPTSYM(display_name_ext);
381 		OPTSYM(inquire_name);
382 		OPTSYM(get_name_attribute);
383 		OPTSYM(set_name_attribute);
384 		OPTSYM(delete_name_attribute);
385 		OPTSYM(export_name_composite);
386 		OPTSYM(pname_to_uid);
387 		OPTSPISYM(authorize_localname);
388 
389 		mi = dlsym(so, "gss_mo_init");
390 		if (mi != NULL) {
391 			major_status = mi(&minor_status, &mech_oid,
392 					  &m->gm_mech.gm_mo, &m->gm_mech.gm_mo_num);
393 			if (GSS_ERROR(major_status))
394 				goto bad;
395 		} else {
396 			/* API-as-SPI compatibility */
397 			COMPATSYM(inquire_saslname_for_mech);
398 			COMPATSYM(inquire_mech_for_saslname);
399 			COMPATSYM(inquire_attrs_for_mech);
400 			COMPATSPISYM(acquire_cred_with_password);
401 		}
402 
403 		/* pick up the oid sets of names */
404 
405 		if (m->gm_mech.gm_inquire_names_for_mech)
406 			(*m->gm_mech.gm_inquire_names_for_mech)(&minor_status,
407 			&m->gm_mech.gm_mech_oid, &m->gm_name_types);
408 
409 		if (m->gm_name_types == NULL)
410 			gss_create_empty_oid_set(&minor_status, &m->gm_name_types);
411 
412 		HEIM_SLIST_INSERT_HEAD(&_gss_mechs, m, gm_link);
413 		continue;
414 
415 	bad:
416 		if (m != NULL) {
417 			free(m->gm_mech.gm_compat);
418 			free(m->gm_mech.gm_mech_oid.elements);
419 			free(m);
420 		}
421 		dlclose(so);
422 		continue;
423 	}
424 	fclose(fp);
425 #endif
426 	HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
427 }
428 
429 gssapi_mech_interface
430 __gss_get_mechanism(gss_const_OID mech)
431 {
432         struct _gss_mech_switch	*m;
433 
434 	_gss_load_mech();
435 	HEIM_SLIST_FOREACH(m, &_gss_mechs, gm_link) {
436 		if (gss_oid_equal(&m->gm_mech.gm_mech_oid, mech))
437 			return &m->gm_mech;
438 	}
439 	return NULL;
440 }
441