1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2009, Sun Microsystems, Inc.
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 are met:
9 * - Redistributions of source code must retain the above copyright notice,
10 *   this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright notice,
12 *   this list of conditions and the following disclaimer in the documentation
13 *   and/or other materials provided with the distribution.
14 * - Neither the name of Sun Microsystems, Inc. nor the names of its
15 *   contributors may be used to endorse or promote products derived
16 *   from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30/*
31 * Copyright (c) 1988 by Sun Microsystems, Inc.
32 */
33/*
34 * auth_des.c, client-side implementation of DES authentication
35 */
36
37#include "namespace.h"
38#include "reentrant.h"
39#include <err.h>
40#include <errno.h>
41#include <string.h>
42#include <stdlib.h>
43#include <unistd.h>
44#include <rpc/des_crypt.h>
45#include <syslog.h>
46#include <rpc/types.h>
47#include <rpc/auth.h>
48#include <rpc/auth_des.h>
49#include <rpc/clnt.h>
50#include <rpc/xdr.h>
51#include <sys/socket.h>
52#undef NIS
53#include <rpcsvc/nis.h>
54#include "un-namespace.h"
55#include "mt_misc.h"
56
57#define USEC_PER_SEC		1000000
58#define RTIME_TIMEOUT		5	/* seconds to wait for sync */
59
60#define AUTH_PRIVATE(auth)	(struct ad_private *) auth->ah_private
61#define ALLOC(object_type)	(object_type *) mem_alloc(sizeof(object_type))
62#define FREE(ptr, size)		mem_free((char *)(ptr), (int) size)
63#define ATTEMPT(xdr_op)		if (!(xdr_op)) return (FALSE)
64
65extern bool_t xdr_authdes_cred( XDR *, struct authdes_cred *);
66extern bool_t xdr_authdes_verf( XDR *, struct authdes_verf *);
67extern int key_encryptsession_pk(char *, netobj *, des_block *);
68
69extern bool_t __rpc_get_time_offset(struct timeval *, nis_server *, char *,
70	char **, char **);
71
72/*
73 * DES authenticator operations vector
74 */
75static void	authdes_nextverf(AUTH *);
76static bool_t	authdes_marshal(AUTH *, XDR *);
77static bool_t	authdes_validate(AUTH *, struct opaque_auth *);
78static bool_t	authdes_refresh(AUTH *, void *);
79static void	authdes_destroy(AUTH *);
80
81static struct auth_ops *authdes_ops(void);
82
83/*
84 * This struct is pointed to by the ah_private field of an "AUTH *"
85 */
86struct ad_private {
87	char *ad_fullname; 		/* client's full name */
88	u_int ad_fullnamelen;		/* length of name, rounded up */
89	char *ad_servername; 		/* server's full name */
90	u_int ad_servernamelen;		/* length of name, rounded up */
91	u_int ad_window;	  	/* client specified window */
92	bool_t ad_dosync;		/* synchronize? */
93	struct netbuf ad_syncaddr;	/* remote host to synch with */
94	char *ad_timehost;		/* remote host to synch with */
95	struct timeval ad_timediff;	/* server's time - client's time */
96	u_int ad_nickname;		/* server's nickname for client */
97	struct authdes_cred ad_cred;	/* storage for credential */
98	struct authdes_verf ad_verf;	/* storage for verifier */
99	struct timeval ad_timestamp;	/* timestamp sent */
100	des_block ad_xkey;		/* encrypted conversation key */
101	u_char ad_pkey[1024];		/* Server's actual public key */
102	char *ad_netid;			/* Timehost netid */
103	char *ad_uaddr;			/* Timehost uaddr */
104	nis_server *ad_nis_srvr;	/* NIS+ server struct */
105};
106
107AUTH *authdes_pk_seccreate(const char *, netobj *, u_int, const char *,
108	const des_block *, nis_server *);
109
110/*
111 * documented version of authdes_seccreate
112 */
113/*
114	servername:	network name of server
115	win:		time to live
116	timehost:	optional hostname to sync with
117	ckey:		optional conversation key to use
118*/
119
120AUTH *
121authdes_seccreate(const char *servername, const u_int win,
122	const char *timehost, const des_block *ckey)
123{
124	u_char  pkey_data[1024];
125	netobj  pkey;
126	AUTH    *dummy;
127
128	if (! getpublickey(servername, (char *) pkey_data)) {
129		syslog(LOG_ERR,
130		    "authdes_seccreate: no public key found for %s",
131		    servername);
132		return (NULL);
133	}
134
135	pkey.n_bytes = (char *) pkey_data;
136	pkey.n_len = (u_int)strlen((char *)pkey_data) + 1;
137	dummy = authdes_pk_seccreate(servername, &pkey, win, timehost,
138	    ckey, NULL);
139	return (dummy);
140}
141
142/*
143 * Slightly modified version of authdessec_create which takes the public key
144 * of the server principal as an argument. This spares us a call to
145 * getpublickey() which in the nameserver context can cause a deadlock.
146 */
147AUTH *
148authdes_pk_seccreate(const char *servername, netobj *pkey, u_int window,
149	const char *timehost, const des_block *ckey, nis_server *srvr)
150{
151	AUTH *auth;
152	struct ad_private *ad;
153	char namebuf[MAXNETNAMELEN+1];
154
155	/*
156	 * Allocate everything now
157	 */
158	auth = ALLOC(AUTH);
159	if (auth == NULL) {
160		syslog(LOG_ERR, "authdes_pk_seccreate: out of memory");
161		return (NULL);
162	}
163	ad = ALLOC(struct ad_private);
164	if (ad == NULL) {
165		syslog(LOG_ERR, "authdes_pk_seccreate: out of memory");
166		goto failed;
167	}
168	ad->ad_fullname = ad->ad_servername = NULL; /* Sanity reasons */
169	ad->ad_timehost = NULL;
170	ad->ad_netid = NULL;
171	ad->ad_uaddr = NULL;
172	ad->ad_nis_srvr = NULL;
173	ad->ad_timediff.tv_sec = 0;
174	ad->ad_timediff.tv_usec = 0;
175	memcpy(ad->ad_pkey, pkey->n_bytes, pkey->n_len);
176	if (!getnetname(namebuf))
177		goto failed;
178	ad->ad_fullnamelen = RNDUP((u_int) strlen(namebuf));
179	ad->ad_fullname = (char *)mem_alloc(ad->ad_fullnamelen + 1);
180	ad->ad_servernamelen = strlen(servername);
181	ad->ad_servername = (char *)mem_alloc(ad->ad_servernamelen + 1);
182
183	if (ad->ad_fullname == NULL || ad->ad_servername == NULL) {
184		syslog(LOG_ERR, "authdes_seccreate: out of memory");
185		goto failed;
186	}
187	if (timehost != NULL) {
188		ad->ad_timehost = (char *)mem_alloc(strlen(timehost) + 1);
189		if (ad->ad_timehost == NULL) {
190			syslog(LOG_ERR, "authdes_seccreate: out of memory");
191			goto failed;
192		}
193		memcpy(ad->ad_timehost, timehost, strlen(timehost) + 1);
194		ad->ad_dosync = TRUE;
195	} else if (srvr != NULL) {
196		ad->ad_nis_srvr = srvr;	/* transient */
197		ad->ad_dosync = TRUE;
198	} else {
199		ad->ad_dosync = FALSE;
200	}
201	memcpy(ad->ad_fullname, namebuf, ad->ad_fullnamelen + 1);
202	memcpy(ad->ad_servername, servername, ad->ad_servernamelen + 1);
203	ad->ad_window = window;
204	if (ckey == NULL) {
205		if (key_gendes(&auth->ah_key) < 0) {
206			syslog(LOG_ERR,
207	    "authdes_seccreate: keyserv(1m) is unable to generate session key");
208			goto failed;
209		}
210	} else {
211		auth->ah_key = *ckey;
212	}
213
214	/*
215	 * Set up auth handle
216	 */
217	auth->ah_cred.oa_flavor = AUTH_DES;
218	auth->ah_verf.oa_flavor = AUTH_DES;
219	auth->ah_ops = authdes_ops();
220	auth->ah_private = (caddr_t)ad;
221
222	if (!authdes_refresh(auth, NULL)) {
223		goto failed;
224	}
225	ad->ad_nis_srvr = NULL; /* not needed any longer */
226	return (auth);
227
228failed:
229	if (auth)
230		FREE(auth, sizeof (AUTH));
231	if (ad) {
232		if (ad->ad_fullname)
233			FREE(ad->ad_fullname, ad->ad_fullnamelen + 1);
234		if (ad->ad_servername)
235			FREE(ad->ad_servername, ad->ad_servernamelen + 1);
236		if (ad->ad_timehost)
237			FREE(ad->ad_timehost, strlen(ad->ad_timehost) + 1);
238		if (ad->ad_netid)
239			FREE(ad->ad_netid, strlen(ad->ad_netid) + 1);
240		if (ad->ad_uaddr)
241			FREE(ad->ad_uaddr, strlen(ad->ad_uaddr) + 1);
242		FREE(ad, sizeof (struct ad_private));
243	}
244	return (NULL);
245}
246
247/*
248 * Implement the five authentication operations
249 */
250
251
252/*
253 * 1. Next Verifier
254 */
255/*ARGSUSED*/
256static void
257authdes_nextverf(AUTH *auth __unused)
258{
259	/* what the heck am I supposed to do??? */
260}
261
262
263/*
264 * 2. Marshal
265 */
266static bool_t
267authdes_marshal(AUTH *auth, XDR *xdrs)
268{
269/* LINTED pointer alignment */
270	struct ad_private *ad = AUTH_PRIVATE(auth);
271	struct authdes_cred *cred = &ad->ad_cred;
272	struct authdes_verf *verf = &ad->ad_verf;
273	des_block cryptbuf[2];
274	des_block ivec;
275	int status;
276	int len;
277	rpc_inline_t *ixdr;
278
279	/*
280	 * Figure out the "time", accounting for any time difference
281	 * with the server if necessary.
282	 */
283	(void)gettimeofday(&ad->ad_timestamp, NULL);
284	ad->ad_timestamp.tv_sec += ad->ad_timediff.tv_sec;
285	ad->ad_timestamp.tv_usec += ad->ad_timediff.tv_usec;
286	while (ad->ad_timestamp.tv_usec >= USEC_PER_SEC) {
287		ad->ad_timestamp.tv_usec -= USEC_PER_SEC;
288		ad->ad_timestamp.tv_sec++;
289	}
290
291	/*
292	 * XDR the timestamp and possibly some other things, then
293	 * encrypt them.
294	 */
295	ixdr = (rpc_inline_t *)cryptbuf;
296	IXDR_PUT_INT32(ixdr, ad->ad_timestamp.tv_sec);
297	IXDR_PUT_INT32(ixdr, ad->ad_timestamp.tv_usec);
298	if (ad->ad_cred.adc_namekind == ADN_FULLNAME) {
299		IXDR_PUT_U_INT32(ixdr, ad->ad_window);
300		IXDR_PUT_U_INT32(ixdr, ad->ad_window - 1);
301		ivec.key.high = ivec.key.low = 0;
302		status = cbc_crypt((char *)&auth->ah_key, (char *)cryptbuf,
303			(u_int) 2 * sizeof (des_block),
304			DES_ENCRYPT | DES_HW, (char *)&ivec);
305	} else {
306		status = ecb_crypt((char *)&auth->ah_key, (char *)cryptbuf,
307			(u_int) sizeof (des_block),
308			DES_ENCRYPT | DES_HW);
309	}
310	if (DES_FAILED(status)) {
311		syslog(LOG_ERR, "authdes_marshal: DES encryption failure");
312		return (FALSE);
313	}
314	ad->ad_verf.adv_xtimestamp = cryptbuf[0];
315	if (ad->ad_cred.adc_namekind == ADN_FULLNAME) {
316		ad->ad_cred.adc_fullname.window = cryptbuf[1].key.high;
317		ad->ad_verf.adv_winverf = cryptbuf[1].key.low;
318	} else {
319		ad->ad_cred.adc_nickname = ad->ad_nickname;
320		ad->ad_verf.adv_winverf = 0;
321	}
322
323	/*
324	 * Serialize the credential and verifier into opaque
325	 * authentication data.
326	 */
327	if (ad->ad_cred.adc_namekind == ADN_FULLNAME) {
328		len = ((1 + 1 + 2 + 1)*BYTES_PER_XDR_UNIT + ad->ad_fullnamelen);
329	} else {
330		len = (1 + 1)*BYTES_PER_XDR_UNIT;
331	}
332
333	if ((ixdr = xdr_inline(xdrs, 2*BYTES_PER_XDR_UNIT))) {
334		IXDR_PUT_INT32(ixdr, AUTH_DES);
335		IXDR_PUT_INT32(ixdr, len);
336	} else {
337		ATTEMPT(xdr_putint32(xdrs, (int *)&auth->ah_cred.oa_flavor));
338		ATTEMPT(xdr_putint32(xdrs, &len));
339	}
340	ATTEMPT(xdr_authdes_cred(xdrs, cred));
341
342	len = (2 + 1)*BYTES_PER_XDR_UNIT;
343	if ((ixdr = xdr_inline(xdrs, 2*BYTES_PER_XDR_UNIT))) {
344		IXDR_PUT_INT32(ixdr, AUTH_DES);
345		IXDR_PUT_INT32(ixdr, len);
346	} else {
347		ATTEMPT(xdr_putint32(xdrs, (int *)&auth->ah_verf.oa_flavor));
348		ATTEMPT(xdr_putint32(xdrs, &len));
349	}
350	ATTEMPT(xdr_authdes_verf(xdrs, verf));
351	return (TRUE);
352}
353
354
355/*
356 * 3. Validate
357 */
358static bool_t
359authdes_validate(AUTH *auth, struct opaque_auth *rverf)
360{
361/* LINTED pointer alignment */
362	struct ad_private *ad = AUTH_PRIVATE(auth);
363	struct authdes_verf verf;
364	int status;
365	uint32_t *ixdr;
366	des_block buf;
367
368	if (rverf->oa_length != (2 + 1) * BYTES_PER_XDR_UNIT) {
369		return (FALSE);
370	}
371/* LINTED pointer alignment */
372	ixdr = (uint32_t *)rverf->oa_base;
373	buf.key.high = (uint32_t)*ixdr++;
374	buf.key.low = (uint32_t)*ixdr++;
375	verf.adv_int_u = (uint32_t)*ixdr++;
376
377	/*
378	 * Decrypt the timestamp
379	 */
380	status = ecb_crypt((char *)&auth->ah_key, (char *)&buf,
381		(u_int)sizeof (des_block), DES_DECRYPT | DES_HW);
382
383	if (DES_FAILED(status)) {
384		syslog(LOG_ERR, "authdes_validate: DES decryption failure");
385		return (FALSE);
386	}
387
388	/*
389	 * xdr the decrypted timestamp
390	 */
391/* LINTED pointer alignment */
392	ixdr = (uint32_t *)buf.c;
393	verf.adv_timestamp.tv_sec = IXDR_GET_INT32(ixdr) + 1;
394	verf.adv_timestamp.tv_usec = IXDR_GET_INT32(ixdr);
395
396	/*
397	 * validate
398	 */
399	if (bcmp((char *)&ad->ad_timestamp, (char *)&verf.adv_timestamp,
400		 sizeof(struct timeval)) != 0) {
401		syslog(LOG_DEBUG, "authdes_validate: verifier mismatch");
402		return (FALSE);
403	}
404
405	/*
406	 * We have a nickname now, let's use it
407	 */
408	ad->ad_nickname = verf.adv_nickname;
409	ad->ad_cred.adc_namekind = ADN_NICKNAME;
410	return (TRUE);
411}
412
413/*
414 * 4. Refresh
415 */
416/*ARGSUSED*/
417static bool_t
418authdes_refresh(AUTH *auth, void *dummy __unused)
419{
420/* LINTED pointer alignment */
421	struct ad_private *ad = AUTH_PRIVATE(auth);
422	struct authdes_cred *cred = &ad->ad_cred;
423	int		ok;
424	netobj		pkey;
425
426	if (ad->ad_dosync) {
427                ok = __rpc_get_time_offset(&ad->ad_timediff, ad->ad_nis_srvr,
428		    ad->ad_timehost, &(ad->ad_uaddr),
429		    &(ad->ad_netid));
430		if (! ok) {
431			/*
432			 * Hope the clocks are synced!
433			 */
434			ad->ad_dosync = 0;
435			syslog(LOG_DEBUG,
436			    "authdes_refresh: unable to synchronize clock");
437		 }
438	}
439	ad->ad_xkey = auth->ah_key;
440	pkey.n_bytes = (char *)(ad->ad_pkey);
441	pkey.n_len = (u_int)strlen((char *)ad->ad_pkey) + 1;
442	if (key_encryptsession_pk(ad->ad_servername, &pkey, &ad->ad_xkey) < 0) {
443		syslog(LOG_INFO,
444		    "authdes_refresh: keyserv(1m) is unable to encrypt session key");
445		return (FALSE);
446	}
447	cred->adc_fullname.key = ad->ad_xkey;
448	cred->adc_namekind = ADN_FULLNAME;
449	cred->adc_fullname.name = ad->ad_fullname;
450	return (TRUE);
451}
452
453
454/*
455 * 5. Destroy
456 */
457static void
458authdes_destroy(AUTH *auth)
459{
460/* LINTED pointer alignment */
461	struct ad_private *ad = AUTH_PRIVATE(auth);
462
463	FREE(ad->ad_fullname, ad->ad_fullnamelen + 1);
464	FREE(ad->ad_servername, ad->ad_servernamelen + 1);
465	if (ad->ad_timehost)
466		FREE(ad->ad_timehost, strlen(ad->ad_timehost) + 1);
467	if (ad->ad_netid)
468		FREE(ad->ad_netid, strlen(ad->ad_netid) + 1);
469	if (ad->ad_uaddr)
470		FREE(ad->ad_uaddr, strlen(ad->ad_uaddr) + 1);
471	FREE(ad, sizeof (struct ad_private));
472	FREE(auth, sizeof(AUTH));
473}
474
475static struct auth_ops *
476authdes_ops(void)
477{
478	static struct auth_ops ops;
479
480	/* VARIABLES PROTECTED BY ops_lock: ops */
481
482	mutex_lock(&authdes_ops_lock);
483	if (ops.ah_nextverf == NULL) {
484		ops.ah_nextverf = authdes_nextverf;
485		ops.ah_marshal = authdes_marshal;
486		ops.ah_validate = authdes_validate;
487		ops.ah_refresh = authdes_refresh;
488		ops.ah_destroy = authdes_destroy;
489        }
490	mutex_unlock(&authdes_ops_lock);
491	return (&ops);
492}
493