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 (byte_count == 0)
141			return EINVAL;
142		if (!res) {
143			res = malloc(byte_count);
144			if (!res)
145				return (ENOMEM);
146			oid->length = (OM_uint32)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    /* give sane defaults */
219    if (m->gm_name_types == NULL) {
220	gss_create_empty_oid_set(&minor_status, &m->gm_name_types);
221	gss_add_oid_set_member(&minor_status, GSS_C_NT_USER_NAME, &m->gm_name_types);
222	gss_add_oid_set_member(&minor_status, GSS_C_NT_HOSTBASED_SERVICE, &m->gm_name_types);
223    }
224
225    HEIM_SLIST_INSERT_HEAD(&_gss_mechs, m, gm_link);
226    return 0;
227}
228
229/*
230 * Load the mechanisms file (/etc/gss/mech).
231 */
232void
233_gss_load_mech(void)
234{
235	OM_uint32	major_status, minor_status;
236	FILE		*fp;
237	char		buf[256];
238	char		*p;
239	char		*name, *oid, *lib, *kobj;
240	struct _gss_mech_switch *m;
241	void		*so;
242	gss_OID_desc	mech_oid;
243	int		found;
244
245
246	HEIMDAL_MUTEX_lock(&_gss_mech_mutex);
247
248	if (HEIM_SLIST_FIRST(&_gss_mechs)) {
249		HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
250		return;
251	}
252
253	major_status = gss_create_empty_oid_set(&minor_status,
254	    &_gss_mech_oids);
255	if (major_status) {
256		HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
257		return;
258	}
259
260	/*
261	 * order is reverse order of where they will appear in
262	 * gss_indicate_mechs(), kerberos is first in the list to
263	 * please SAP w/o configuration on what mech to use.
264	 */
265	add_builtin(__gss_pku2u_initialize());
266	add_builtin(__gss_iakerb_initialize());
267	add_builtin(__gss_ntlm_initialize());
268	add_builtin(__gss_scram_initialize());
269	add_builtin(__gss_netlogon_initialize());
270	add_builtin(__gss_spnego_initialize());
271	add_builtin(__gss_krb5_initialize());
272
273#ifdef HAVE_DLOPEN
274	fp = fopen(_PATH_GSS_MECH, "r");
275	if (!fp) {
276		HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
277		return;
278	}
279	rk_cloexec_file(fp);
280
281	while (fgets(buf, sizeof(buf), fp)) {
282		_gss_mo_init *mi;
283
284		if (*buf == '#')
285			continue;
286		p = buf;
287		name = strsep(&p, "\t\n ");
288		if (p) while (isspace((unsigned char)*p)) p++;
289		oid = strsep(&p, "\t\n ");
290		if (p) while (isspace((unsigned char)*p)) p++;
291		lib = strsep(&p, "\t\n ");
292		if (p) while (isspace((unsigned char)*p)) p++;
293		kobj = strsep(&p, "\t\n ");
294		if (!name || !oid || !lib || !kobj)
295			continue;
296
297		if (_gss_string_to_oid(oid, &mech_oid))
298			continue;
299
300		/*
301		 * Check for duplicates, already loaded mechs.
302		 */
303		found = 0;
304		HEIM_SLIST_FOREACH(m, &_gss_mechs, gm_link) {
305			if (gss_oid_equal(&m->gm_mech.gm_mech_oid, &mech_oid)) {
306				found = 1;
307				free(mech_oid.elements);
308				break;
309			}
310		}
311		if (found)
312			continue;
313
314#ifndef RTLD_LOCAL
315#define RTLD_LOCAL 0
316#endif
317
318#ifndef RTLD_GROUP
319#define RTLD_GROUP 0
320#endif
321
322		so = dlopen(lib, RTLD_LAZY | RTLD_LOCAL | RTLD_GROUP);
323		if (so == NULL) {
324/*			fprintf(stderr, "dlopen: %s\n", dlerror()); */
325			goto bad;
326		}
327
328		m = calloc(1, sizeof(*m));
329		if (m == NULL)
330			goto bad;
331
332		m->gm_so = so;
333		m->gm_mech_oid = mech_oid;
334		m->gm_mech.gm_mech_oid = mech_oid;
335		m->gm_mech.gm_flags = 0;
336		m->gm_mech.gm_compat = calloc(1, sizeof(struct gss_mech_compat_desc_struct));
337		if (m->gm_mech.gm_compat == NULL)
338			goto bad;
339
340		major_status = gss_add_oid_set_member(&minor_status,
341		    &m->gm_mech.gm_mech_oid, &_gss_mech_oids);
342		if (GSS_ERROR(major_status))
343			goto bad;
344
345		SYM(acquire_cred);
346		SYM(release_cred);
347		SYM(init_sec_context);
348		SYM(accept_sec_context);
349		SYM(process_context_token);
350		SYM(delete_sec_context);
351		SYM(context_time);
352		SYM(get_mic);
353		SYM(verify_mic);
354		SYM(wrap);
355		SYM(unwrap);
356		SYM(display_status);
357		SYM(indicate_mechs);
358		SYM(compare_name);
359		SYM(display_name);
360		SYM(import_name);
361		SYM(export_name);
362		SYM(release_name);
363		SYM(inquire_cred);
364		SYM(inquire_context);
365		SYM(wrap_size_limit);
366		SYM(add_cred);
367		SYM(inquire_cred_by_mech);
368		SYM(export_sec_context);
369		SYM(import_sec_context);
370		SYM(inquire_names_for_mech);
371		SYM(inquire_mechs_for_name);
372		SYM(canonicalize_name);
373		SYM(duplicate_name);
374		OPTSYM(inquire_cred_by_oid);
375		OPTSYM(inquire_sec_context_by_oid);
376		OPTSYM(set_sec_context_option);
377		OPTSPISYM(set_cred_option);
378		OPTSYM(pseudo_random);
379		OPTSYM(wrap_iov);
380		OPTSYM(unwrap_iov);
381		OPTSYM(wrap_iov_length);
382		OPTSYM(store_cred);
383		OPTSYM(export_cred);
384		OPTSYM(import_cred);
385#if 0
386		OPTSYM(acquire_cred_ext);
387		OPTSYM(iter_creds);
388		OPTSYM(destroy_cred);
389		OPTSYM(cred_hold);
390		OPTSYM(cred_unhold);
391		OPTSYM(cred_label_get);
392		OPTSYM(cred_label_set);
393#endif
394		OPTSYM(display_name_ext);
395		OPTSYM(inquire_name);
396		OPTSYM(get_name_attribute);
397		OPTSYM(set_name_attribute);
398		OPTSYM(delete_name_attribute);
399		OPTSYM(export_name_composite);
400		OPTSYM(pname_to_uid);
401		OPTSPISYM(authorize_localname);
402
403		mi = dlsym(so, "gss_mo_init");
404		if (mi != NULL) {
405			major_status = mi(&minor_status, &mech_oid,
406					  &m->gm_mech.gm_mo, &m->gm_mech.gm_mo_num);
407			if (GSS_ERROR(major_status))
408				goto bad;
409		} else {
410			/* API-as-SPI compatibility */
411			COMPATSYM(inquire_saslname_for_mech);
412			COMPATSYM(inquire_mech_for_saslname);
413			COMPATSYM(inquire_attrs_for_mech);
414			COMPATSPISYM(acquire_cred_with_password);
415		}
416
417		/* pick up the oid sets of names */
418
419		if (m->gm_mech.gm_inquire_names_for_mech)
420			(*m->gm_mech.gm_inquire_names_for_mech)(&minor_status,
421			&m->gm_mech.gm_mech_oid, &m->gm_name_types);
422
423		if (m->gm_name_types == NULL)
424			gss_create_empty_oid_set(&minor_status, &m->gm_name_types);
425
426		HEIM_SLIST_INSERT_HEAD(&_gss_mechs, m, gm_link);
427		continue;
428
429	bad:
430		if (m != NULL) {
431			free(m->gm_mech.gm_compat);
432			free(m->gm_mech.gm_mech_oid.elements);
433			free(m);
434		}
435		dlclose(so);
436		continue;
437	}
438	fclose(fp);
439#endif
440	HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
441}
442
443struct gssapi_mech_interface_desc *
444__gss_get_mechanism(gss_const_OID mech)
445{
446        struct _gss_mech_switch	*m;
447
448	_gss_load_mech();
449	HEIM_SLIST_FOREACH(m, &_gss_mechs, gm_link) {
450		if (gss_oid_equal(&m->gm_mech.gm_mech_oid, mech))
451			return &m->gm_mech;
452	}
453	return NULL;
454}
455