gss_mech_switch.c revision 1.1.1.1.10.1 
1/*	$NetBSD: gss_mech_switch.c,v 1.1.1.1.10.1 2014/08/19 23:45:17 tls Exp $	*/
2
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 *	$FreeBSD: src/lib/libgssapi/gss_mech_switch.c,v 1.2 2006/02/04 09:40:21 dfr Exp $
29 */
30
31#include "mech_locl.h"
32#include <heim_threads.h>
33
34#ifndef _PATH_GSS_MECH
35#define _PATH_GSS_MECH	"/etc/gss/mech"
36#endif
37
38struct _gss_mech_switch_list _gss_mechs = { NULL } ;
39gss_OID_set _gss_mech_oids;
40static HEIMDAL_MUTEX _gss_mech_mutex = HEIMDAL_MUTEX_INITIALIZER;
41
42/*
43 * Convert a string containing an OID in 'dot' form
44 * (e.g. 1.2.840.113554.1.2.2) to a gss_OID.
45 */
46static int
47_gss_string_to_oid(const char* s, gss_OID oid)
48{
49	int			number_count, i, j;
50	size_t			byte_count;
51	const char		*p, *q;
52	char			*res;
53
54	oid->length = 0;
55	oid->elements = NULL;
56
57	/*
58	 * First figure out how many numbers in the oid, then
59	 * calculate the compiled oid size.
60	 */
61	number_count = 0;
62	for (p = s; p; p = q) {
63		q = strchr(p, '.');
64		if (q) q = q + 1;
65		number_count++;
66	}
67
68	/*
69	 * The first two numbers are in the first byte and each
70	 * subsequent number is encoded in a variable byte sequence.
71	 */
72	if (number_count < 2)
73		return (EINVAL);
74
75	/*
76	 * We do this in two passes. The first pass, we just figure
77	 * out the size. Second time around, we actually encode the
78	 * number.
79	 */
80	res = 0;
81	for (i = 0; i < 2; i++) {
82		byte_count = 0;
83		for (p = s, j = 0; p; p = q, j++) {
84			unsigned int number = 0;
85
86			/*
87			 * Find the end of this number.
88			 */
89			q = strchr(p, '.');
90			if (q) q = q + 1;
91
92			/*
93			 * Read the number of of the string. Don't
94			 * bother with anything except base ten.
95			 */
96			while (*p && *p != '.') {
97				number = 10 * number + (*p - '0');
98				p++;
99			}
100
101			/*
102			 * Encode the number. The first two numbers
103			 * are packed into the first byte. Subsequent
104			 * numbers are encoded in bytes seven bits at
105			 * a time with the last byte having the high
106			 * bit set.
107			 */
108			if (j == 0) {
109				if (res)
110					*res = number * 40;
111			} else if (j == 1) {
112				if (res) {
113					*res += number;
114					res++;
115				}
116				byte_count++;
117			} else if (j >= 2) {
118				/*
119				 * The number is encoded in seven bit chunks.
120				 */
121				unsigned int t;
122				unsigned int bytes;
123
124				bytes = 0;
125				for (t = number; t; t >>= 7)
126					bytes++;
127				if (bytes == 0) bytes = 1;
128				while (bytes) {
129					if (res) {
130						int bit = 7*(bytes-1);
131
132						*res = (number >> bit) & 0x7f;
133						if (bytes != 1)
134							*res |= 0x80;
135						res++;
136					}
137					byte_count++;
138					bytes--;
139				}
140			}
141		}
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)							\
155do {									\
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)							\
165do {									\
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)							\
172do {									\
173	m->gm_mech.gm_ ## name = dlsym(so, "gssspi_" #name);		\
174} while (0)
175
176#define COMPATSYM(name)							\
177do {									\
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)						\
184do {									\
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 */
193static int
194add_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 */
228void
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
429gssapi_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