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
36struct _gss_mech_switch_list _gss_mechs = { NULL } ;
37gss_OID_set _gss_mech_oids;
38static 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 */
44static 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)							\
153do {									\
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)							\
163do {									\
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)							\
170do {									\
171	m->gm_mech.gm_ ## name = dlsym(so, "gssspi_" #name);		\
172} while (0)
173
174#define COMPATSYM(name)							\
175do {									\
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)						\
182do {									\
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 */
191static int
192add_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 */
226void
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
427gssapi_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