gss_mech_switch.c revision 1.3 
1/*	$NetBSD: gss_mech_switch.c,v 1.3 2023/06/19 21:41:43 christos 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 (byte_count == 0)
143                    return EINVAL;
144		if (!res) {
145			res = malloc(byte_count);
146			if (!res)
147				return (ENOMEM);
148			oid->length = byte_count;
149			oid->elements = res;
150		}
151	}
152
153	return (0);
154}
155
156#define SYM(name)							\
157do {									\
158	m->gm_mech.gm_ ## name = dlsym(so, "gss_" #name);		\
159	if (!m->gm_mech.gm_ ## name ||					\
160	    m->gm_mech.gm_ ##name == gss_ ## name) {			\
161		fprintf(stderr, "can't find symbol gss_" #name "\n");	\
162		goto bad;						\
163	}								\
164} while (0)
165
166#define OPTSYM(name)							\
167do {									\
168	m->gm_mech.gm_ ## name = dlsym(so, "gss_" #name);		\
169	if (m->gm_mech.gm_ ## name == gss_ ## name)			\
170		m->gm_mech.gm_ ## name = NULL;				\
171} while (0)
172
173#define OPTSPISYM(name)							\
174do {									\
175	m->gm_mech.gm_ ## name = dlsym(so, "gssspi_" #name);		\
176} while (0)
177
178#define COMPATSYM(name)							\
179do {									\
180	m->gm_mech.gm_compat->gmc_ ## name = dlsym(so, "gss_" #name);	\
181	if (m->gm_mech.gm_compat->gmc_ ## name == gss_ ## name)		\
182		m->gm_mech.gm_compat->gmc_ ## name = NULL;		\
183} while (0)
184
185#define COMPATSPISYM(name)						\
186do {									\
187	m->gm_mech.gm_compat->gmc_ ## name = dlsym(so, "gssspi_" #name);\
188	if (m->gm_mech.gm_compat->gmc_ ## name == gss_ ## name)		\
189		m->gm_mech.gm_compat->gmc_ ## name = NULL;		\
190} while (0)
191
192/*
193 *
194 */
195static int
196add_builtin(gssapi_mech_interface mech)
197{
198    struct _gss_mech_switch *m;
199    OM_uint32 minor_status;
200
201    /* not registering any mech is ok */
202    if (mech == NULL)
203	return 0;
204
205    m = calloc(1, sizeof(*m));
206    if (m == NULL)
207	return ENOMEM;
208    m->gm_so = NULL;
209    m->gm_mech = *mech;
210    m->gm_mech_oid = mech->gm_mech_oid; /* XXX */
211    gss_add_oid_set_member(&minor_status,
212			   &m->gm_mech.gm_mech_oid, &_gss_mech_oids);
213
214    /* pick up the oid sets of names */
215
216    if (m->gm_mech.gm_inquire_names_for_mech)
217	(*m->gm_mech.gm_inquire_names_for_mech)(&minor_status,
218	    &m->gm_mech.gm_mech_oid, &m->gm_name_types);
219
220    if (m->gm_name_types == NULL)
221	gss_create_empty_oid_set(&minor_status, &m->gm_name_types);
222
223    HEIM_SLIST_INSERT_HEAD(&_gss_mechs, m, gm_link);
224    return 0;
225}
226
227/*
228 * Load the mechanisms file (/etc/gss/mech).
229 */
230void
231_gss_load_mech(void)
232{
233	OM_uint32	major_status, minor_status;
234	FILE		*fp;
235	char		buf[256];
236	char		*p;
237	char		*name, *oid, *lib, *kobj;
238	struct _gss_mech_switch *m;
239	void		*so;
240	gss_OID_desc	mech_oid;
241	int		found;
242
243
244	HEIMDAL_MUTEX_lock(&_gss_mech_mutex);
245
246	if (HEIM_SLIST_FIRST(&_gss_mechs)) {
247		HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
248		return;
249	}
250
251	major_status = gss_create_empty_oid_set(&minor_status,
252	    &_gss_mech_oids);
253	if (major_status) {
254		HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
255		return;
256	}
257
258	add_builtin(__gss_krb5_initialize());
259	add_builtin(__gss_spnego_initialize());
260	add_builtin(__gss_ntlm_initialize());
261
262#ifdef HAVE_DLOPEN
263	fp = fopen(_PATH_GSS_MECH, "r");
264	if (!fp) {
265		HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
266		return;
267	}
268	rk_cloexec_file(fp);
269
270	while (fgets(buf, sizeof(buf), fp)) {
271		_gss_mo_init *mi;
272
273		if (*buf == '#')
274			continue;
275		p = buf;
276		name = strsep(&p, "\t\n ");
277		if (p) while (isspace((unsigned char)*p)) p++;
278		oid = strsep(&p, "\t\n ");
279		if (p) while (isspace((unsigned char)*p)) p++;
280		lib = strsep(&p, "\t\n ");
281		if (p) while (isspace((unsigned char)*p)) p++;
282		kobj = strsep(&p, "\t\n ");
283		if (!name || !oid || !lib || !kobj)
284			continue;
285
286		if (_gss_string_to_oid(oid, &mech_oid))
287			continue;
288
289		/*
290		 * Check for duplicates, already loaded mechs.
291		 */
292		found = 0;
293		HEIM_SLIST_FOREACH(m, &_gss_mechs, gm_link) {
294			if (gss_oid_equal(&m->gm_mech.gm_mech_oid, &mech_oid)) {
295				found = 1;
296				free(mech_oid.elements);
297				break;
298			}
299		}
300		if (found)
301			continue;
302
303#ifndef RTLD_LOCAL
304#define RTLD_LOCAL 0
305#endif
306
307#ifndef RTLD_GROUP
308#define RTLD_GROUP 0
309#endif
310
311		so = dlopen(lib, RTLD_LAZY | RTLD_LOCAL | RTLD_GROUP);
312		if (so == NULL) {
313/*			fprintf(stderr, "dlopen: %s\n", dlerror()); */
314			goto bad;
315		}
316
317		m = calloc(1, sizeof(*m));
318		if (m == NULL)
319			goto bad;
320
321		m->gm_so = so;
322		m->gm_mech_oid = mech_oid;
323		m->gm_mech.gm_name = strdup(name);
324		m->gm_mech.gm_mech_oid = mech_oid;
325		m->gm_mech.gm_flags = 0;
326		m->gm_mech.gm_compat = calloc(1, sizeof(struct gss_mech_compat_desc_struct));
327		if (m->gm_mech.gm_compat == NULL)
328			goto bad;
329
330		major_status = gss_add_oid_set_member(&minor_status,
331		    &m->gm_mech.gm_mech_oid, &_gss_mech_oids);
332		if (GSS_ERROR(major_status))
333			goto bad;
334
335		SYM(acquire_cred);
336		SYM(release_cred);
337		SYM(init_sec_context);
338		SYM(accept_sec_context);
339		SYM(process_context_token);
340		SYM(delete_sec_context);
341		SYM(context_time);
342		SYM(get_mic);
343		SYM(verify_mic);
344		SYM(wrap);
345		SYM(unwrap);
346		SYM(display_status);
347		SYM(indicate_mechs);
348		SYM(compare_name);
349		SYM(display_name);
350		SYM(import_name);
351		SYM(export_name);
352		SYM(release_name);
353		SYM(inquire_cred);
354		SYM(inquire_context);
355		SYM(wrap_size_limit);
356		SYM(add_cred);
357		SYM(inquire_cred_by_mech);
358		SYM(export_sec_context);
359		SYM(import_sec_context);
360		SYM(inquire_names_for_mech);
361		SYM(inquire_mechs_for_name);
362		SYM(canonicalize_name);
363		SYM(duplicate_name);
364		OPTSYM(inquire_cred_by_oid);
365		OPTSYM(inquire_sec_context_by_oid);
366		OPTSYM(set_sec_context_option);
367		OPTSPISYM(set_cred_option);
368		OPTSYM(pseudo_random);
369		OPTSYM(wrap_iov);
370		OPTSYM(unwrap_iov);
371		OPTSYM(wrap_iov_length);
372		OPTSYM(store_cred);
373		OPTSYM(export_cred);
374		OPTSYM(import_cred);
375#if 0
376		OPTSYM(acquire_cred_ext);
377		OPTSYM(iter_creds);
378		OPTSYM(destroy_cred);
379		OPTSYM(cred_hold);
380		OPTSYM(cred_unhold);
381		OPTSYM(cred_label_get);
382		OPTSYM(cred_label_set);
383#endif
384		OPTSYM(display_name_ext);
385		OPTSYM(inquire_name);
386		OPTSYM(get_name_attribute);
387		OPTSYM(set_name_attribute);
388		OPTSYM(delete_name_attribute);
389		OPTSYM(export_name_composite);
390		OPTSYM(localname);
391		OPTSPISYM(authorize_localname);
392
393		mi = dlsym(so, "gss_mo_init");
394		if (mi != NULL) {
395			major_status = mi(&minor_status, &mech_oid,
396					  &m->gm_mech.gm_mo, &m->gm_mech.gm_mo_num);
397			if (GSS_ERROR(major_status))
398				goto bad;
399		} else {
400			/* API-as-SPI compatibility */
401			COMPATSYM(inquire_saslname_for_mech);
402			COMPATSYM(inquire_mech_for_saslname);
403			COMPATSYM(inquire_attrs_for_mech);
404			COMPATSPISYM(acquire_cred_with_password);
405		}
406
407		/* pick up the oid sets of names */
408
409		if (m->gm_mech.gm_inquire_names_for_mech)
410			(*m->gm_mech.gm_inquire_names_for_mech)(&minor_status,
411			&m->gm_mech.gm_mech_oid, &m->gm_name_types);
412
413		if (m->gm_name_types == NULL)
414			gss_create_empty_oid_set(&minor_status, &m->gm_name_types);
415
416		HEIM_SLIST_INSERT_HEAD(&_gss_mechs, m, gm_link);
417		continue;
418
419	bad:
420		if (m != NULL) {
421			free(m->gm_mech.gm_compat);
422			free(m->gm_mech.gm_mech_oid.elements);
423			free((char *)m->gm_mech.gm_name);
424			free(m);
425		}
426		dlclose(so);
427		continue;
428	}
429	fclose(fp);
430#endif
431	HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
432}
433
434gssapi_mech_interface
435__gss_get_mechanism(gss_const_OID mech)
436{
437        struct _gss_mech_switch	*m;
438
439	_gss_load_mech();
440	HEIM_SLIST_FOREACH(m, &_gss_mechs, gm_link) {
441		if (gss_oid_equal(&m->gm_mech.gm_mech_oid, mech))
442			return &m->gm_mech;
443	}
444	return NULL;
445}
446