auth_des.c revision 261046
1/*-
2 * Copyright (c) 2009, Sun Microsystems, Inc.
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 are met:
7 * - Redistributions of source code must retain the above copyright notice,
8 *   this list of conditions and the following disclaimer.
9 * - Redistributions in binary form must reproduce the above copyright notice,
10 *   this list of conditions and the following disclaimer in the documentation
11 *   and/or other materials provided with the distribution.
12 * - Neither the name of Sun Microsystems, Inc. nor the names of its
13 *   contributors may be used to endorse or promote products derived
14 *   from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND 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 COPYRIGHT HOLDER OR CONTRIBUTORS BE
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28/*
29 * Copyright (c) 1988 by Sun Microsystems, Inc.
30 */
31/*
32 * auth_des.c, client-side implementation of DES authentication
33 */
34
35#include "namespace.h"
36#include "reentrant.h"
37#include <err.h>
38#include <errno.h>
39#include <string.h>
40#include <stdlib.h>
41#include <unistd.h>
42#include <sys/cdefs.h>
43#include <rpc/des_crypt.h>
44#include <syslog.h>
45#include <rpc/types.h>
46#include <rpc/auth.h>
47#include <rpc/auth_des.h>
48#include <rpc/clnt.h>
49#include <rpc/xdr.h>
50#include <sys/socket.h>
51#undef NIS
52#include <rpcsvc/nis.h>
53#include "un-namespace.h"
54#include "mt_misc.h"
55
56#if defined(LIBC_SCCS) && !defined(lint)
57static char sccsid[] = 	"@(#)auth_des.c	2.2 88/07/29 4.0 RPCSRC; from 1.9 88/02/08 SMI";
58#endif
59#include <sys/cdefs.h>
60__FBSDID("$FreeBSD: stable/10/lib/libc/rpc/auth_des.c 261046 2014-01-22 23:45:27Z mav $");
61
62#define USEC_PER_SEC		1000000
63#define RTIME_TIMEOUT		5	/* seconds to wait for sync */
64
65#define AUTH_PRIVATE(auth)	(struct ad_private *) auth->ah_private
66#define ALLOC(object_type)	(object_type *) mem_alloc(sizeof(object_type))
67#define FREE(ptr, size)		mem_free((char *)(ptr), (int) size)
68#define ATTEMPT(xdr_op)		if (!(xdr_op)) return (FALSE)
69
70extern bool_t xdr_authdes_cred( XDR *, struct authdes_cred *);
71extern bool_t xdr_authdes_verf( XDR *, struct authdes_verf *);
72extern int key_encryptsession_pk();
73
74extern bool_t __rpc_get_time_offset(struct timeval *, nis_server *, char *,
75	char **, char **);
76
77/*
78 * DES authenticator operations vector
79 */
80static void	authdes_nextverf(AUTH *);
81static bool_t	authdes_marshal(AUTH *, XDR *);
82static bool_t	authdes_validate(AUTH *, struct opaque_auth *);
83static bool_t	authdes_refresh(AUTH *, void *);
84static void	authdes_destroy(AUTH *);
85
86static struct auth_ops *authdes_ops(void);
87
88/*
89 * This struct is pointed to by the ah_private field of an "AUTH *"
90 */
91struct ad_private {
92	char *ad_fullname; 		/* client's full name */
93	u_int ad_fullnamelen;		/* length of name, rounded up */
94	char *ad_servername; 		/* server's full name */
95	u_int ad_servernamelen;		/* length of name, rounded up */
96	u_int ad_window;	  	/* client specified window */
97	bool_t ad_dosync;		/* synchronize? */
98	struct netbuf ad_syncaddr;	/* remote host to synch with */
99	char *ad_timehost;		/* remote host to synch with */
100	struct timeval ad_timediff;	/* server's time - client's time */
101	u_int ad_nickname;		/* server's nickname for client */
102	struct authdes_cred ad_cred;	/* storage for credential */
103	struct authdes_verf ad_verf;	/* storage for verifier */
104	struct timeval ad_timestamp;	/* timestamp sent */
105	des_block ad_xkey;		/* encrypted conversation key */
106	u_char ad_pkey[1024];		/* Server's actual public key */
107	char *ad_netid;			/* Timehost netid */
108	char *ad_uaddr;			/* Timehost uaddr */
109	nis_server *ad_nis_srvr;	/* NIS+ server struct */
110};
111
112AUTH *authdes_pk_seccreate(const char *, netobj *, u_int, const char *,
113	const des_block *, nis_server *);
114
115/*
116 * documented version of authdes_seccreate
117 */
118/*
119	servername:	network name of server
120	win:		time to live
121	timehost:	optional hostname to sync with
122	ckey:		optional conversation key to use
123*/
124
125AUTH *
126authdes_seccreate(const char *servername, const u_int win,
127	const char *timehost, const des_block *ckey)
128{
129	u_char  pkey_data[1024];
130	netobj  pkey;
131	AUTH    *dummy;
132
133	if (! getpublickey(servername, (char *) pkey_data)) {
134		syslog(LOG_ERR,
135		    "authdes_seccreate: no public key found for %s",
136		    servername);
137		return (NULL);
138	}
139
140	pkey.n_bytes = (char *) pkey_data;
141	pkey.n_len = (u_int)strlen((char *)pkey_data) + 1;
142	dummy = authdes_pk_seccreate(servername, &pkey, win, timehost,
143	    ckey, NULL);
144	return (dummy);
145}
146
147/*
148 * Slightly modified version of authdessec_create which takes the public key
149 * of the server principal as an argument. This spares us a call to
150 * getpublickey() which in the nameserver context can cause a deadlock.
151 */
152AUTH *
153authdes_pk_seccreate(const char *servername, netobj *pkey, u_int window,
154	const char *timehost, const des_block *ckey, nis_server *srvr)
155{
156	AUTH *auth;
157	struct ad_private *ad;
158	char namebuf[MAXNETNAMELEN+1];
159
160	/*
161	 * Allocate everything now
162	 */
163	auth = ALLOC(AUTH);
164	if (auth == NULL) {
165		syslog(LOG_ERR, "authdes_pk_seccreate: out of memory");
166		return (NULL);
167	}
168	ad = ALLOC(struct ad_private);
169	if (ad == NULL) {
170		syslog(LOG_ERR, "authdes_pk_seccreate: out of memory");
171		goto failed;
172	}
173	ad->ad_fullname = ad->ad_servername = NULL; /* Sanity reasons */
174	ad->ad_timehost = NULL;
175	ad->ad_netid = NULL;
176	ad->ad_uaddr = NULL;
177	ad->ad_nis_srvr = NULL;
178	ad->ad_timediff.tv_sec = 0;
179	ad->ad_timediff.tv_usec = 0;
180	memcpy(ad->ad_pkey, pkey->n_bytes, pkey->n_len);
181	if (!getnetname(namebuf))
182		goto failed;
183	ad->ad_fullnamelen = RNDUP((u_int) strlen(namebuf));
184	ad->ad_fullname = (char *)mem_alloc(ad->ad_fullnamelen + 1);
185	ad->ad_servernamelen = strlen(servername);
186	ad->ad_servername = (char *)mem_alloc(ad->ad_servernamelen + 1);
187
188	if (ad->ad_fullname == NULL || ad->ad_servername == NULL) {
189		syslog(LOG_ERR, "authdes_seccreate: out of memory");
190		goto failed;
191	}
192	if (timehost != NULL) {
193		ad->ad_timehost = (char *)mem_alloc(strlen(timehost) + 1);
194		if (ad->ad_timehost == NULL) {
195			syslog(LOG_ERR, "authdes_seccreate: out of memory");
196			goto failed;
197		}
198		memcpy(ad->ad_timehost, timehost, strlen(timehost) + 1);
199		ad->ad_dosync = TRUE;
200	} else if (srvr != NULL) {
201		ad->ad_nis_srvr = srvr;	/* transient */
202		ad->ad_dosync = TRUE;
203	} else {
204		ad->ad_dosync = FALSE;
205	}
206	memcpy(ad->ad_fullname, namebuf, ad->ad_fullnamelen + 1);
207	memcpy(ad->ad_servername, servername, ad->ad_servernamelen + 1);
208	ad->ad_window = window;
209	if (ckey == NULL) {
210		if (key_gendes(&auth->ah_key) < 0) {
211			syslog(LOG_ERR,
212	    "authdes_seccreate: keyserv(1m) is unable to generate session key");
213			goto failed;
214		}
215	} else {
216		auth->ah_key = *ckey;
217	}
218
219	/*
220	 * Set up auth handle
221	 */
222	auth->ah_cred.oa_flavor = AUTH_DES;
223	auth->ah_verf.oa_flavor = AUTH_DES;
224	auth->ah_ops = authdes_ops();
225	auth->ah_private = (caddr_t)ad;
226
227	if (!authdes_refresh(auth, NULL)) {
228		goto failed;
229	}
230	ad->ad_nis_srvr = NULL; /* not needed any longer */
231	return (auth);
232
233failed:
234	if (auth)
235		FREE(auth, sizeof (AUTH));
236	if (ad) {
237		if (ad->ad_fullname)
238			FREE(ad->ad_fullname, ad->ad_fullnamelen + 1);
239		if (ad->ad_servername)
240			FREE(ad->ad_servername, ad->ad_servernamelen + 1);
241		if (ad->ad_timehost)
242			FREE(ad->ad_timehost, strlen(ad->ad_timehost) + 1);
243		if (ad->ad_netid)
244			FREE(ad->ad_netid, strlen(ad->ad_netid) + 1);
245		if (ad->ad_uaddr)
246			FREE(ad->ad_uaddr, strlen(ad->ad_uaddr) + 1);
247		FREE(ad, sizeof (struct ad_private));
248	}
249	return (NULL);
250}
251
252/*
253 * Implement the five authentication operations
254 */
255
256
257/*
258 * 1. Next Verifier
259 */
260/*ARGSUSED*/
261static void
262authdes_nextverf(AUTH *auth)
263{
264	/* what the heck am I supposed to do??? */
265}
266
267
268/*
269 * 2. Marshal
270 */
271static bool_t
272authdes_marshal(AUTH *auth, XDR *xdrs)
273{
274/* LINTED pointer alignment */
275	struct ad_private *ad = AUTH_PRIVATE(auth);
276	struct authdes_cred *cred = &ad->ad_cred;
277	struct authdes_verf *verf = &ad->ad_verf;
278	des_block cryptbuf[2];
279	des_block ivec;
280	int status;
281	int len;
282	rpc_inline_t *ixdr;
283
284	/*
285	 * Figure out the "time", accounting for any time difference
286	 * with the server if necessary.
287	 */
288	(void)gettimeofday(&ad->ad_timestamp, NULL);
289	ad->ad_timestamp.tv_sec += ad->ad_timediff.tv_sec;
290	ad->ad_timestamp.tv_usec += ad->ad_timediff.tv_usec;
291	while (ad->ad_timestamp.tv_usec >= USEC_PER_SEC) {
292		ad->ad_timestamp.tv_usec -= USEC_PER_SEC;
293		ad->ad_timestamp.tv_sec++;
294	}
295
296	/*
297	 * XDR the timestamp and possibly some other things, then
298	 * encrypt them.
299	 */
300	ixdr = (rpc_inline_t *)cryptbuf;
301	IXDR_PUT_INT32(ixdr, ad->ad_timestamp.tv_sec);
302	IXDR_PUT_INT32(ixdr, ad->ad_timestamp.tv_usec);
303	if (ad->ad_cred.adc_namekind == ADN_FULLNAME) {
304		IXDR_PUT_U_INT32(ixdr, ad->ad_window);
305		IXDR_PUT_U_INT32(ixdr, ad->ad_window - 1);
306		ivec.key.high = ivec.key.low = 0;
307		status = cbc_crypt((char *)&auth->ah_key, (char *)cryptbuf,
308			(u_int) 2 * sizeof (des_block),
309			DES_ENCRYPT | DES_HW, (char *)&ivec);
310	} else {
311		status = ecb_crypt((char *)&auth->ah_key, (char *)cryptbuf,
312			(u_int) sizeof (des_block),
313			DES_ENCRYPT | DES_HW);
314	}
315	if (DES_FAILED(status)) {
316		syslog(LOG_ERR, "authdes_marshal: DES encryption failure");
317		return (FALSE);
318	}
319	ad->ad_verf.adv_xtimestamp = cryptbuf[0];
320	if (ad->ad_cred.adc_namekind == ADN_FULLNAME) {
321		ad->ad_cred.adc_fullname.window = cryptbuf[1].key.high;
322		ad->ad_verf.adv_winverf = cryptbuf[1].key.low;
323	} else {
324		ad->ad_cred.adc_nickname = ad->ad_nickname;
325		ad->ad_verf.adv_winverf = 0;
326	}
327
328	/*
329	 * Serialize the credential and verifier into opaque
330	 * authentication data.
331	 */
332	if (ad->ad_cred.adc_namekind == ADN_FULLNAME) {
333		len = ((1 + 1 + 2 + 1)*BYTES_PER_XDR_UNIT + ad->ad_fullnamelen);
334	} else {
335		len = (1 + 1)*BYTES_PER_XDR_UNIT;
336	}
337
338	if ((ixdr = xdr_inline(xdrs, 2*BYTES_PER_XDR_UNIT))) {
339		IXDR_PUT_INT32(ixdr, AUTH_DES);
340		IXDR_PUT_INT32(ixdr, len);
341	} else {
342		ATTEMPT(xdr_putint32(xdrs, (int *)&auth->ah_cred.oa_flavor));
343		ATTEMPT(xdr_putint32(xdrs, &len));
344	}
345	ATTEMPT(xdr_authdes_cred(xdrs, cred));
346
347	len = (2 + 1)*BYTES_PER_XDR_UNIT;
348	if ((ixdr = xdr_inline(xdrs, 2*BYTES_PER_XDR_UNIT))) {
349		IXDR_PUT_INT32(ixdr, AUTH_DES);
350		IXDR_PUT_INT32(ixdr, len);
351	} else {
352		ATTEMPT(xdr_putint32(xdrs, (int *)&auth->ah_verf.oa_flavor));
353		ATTEMPT(xdr_putint32(xdrs, &len));
354	}
355	ATTEMPT(xdr_authdes_verf(xdrs, verf));
356	return (TRUE);
357}
358
359
360/*
361 * 3. Validate
362 */
363static bool_t
364authdes_validate(AUTH *auth, struct opaque_auth *rverf)
365{
366/* LINTED pointer alignment */
367	struct ad_private *ad = AUTH_PRIVATE(auth);
368	struct authdes_verf verf;
369	int status;
370	uint32_t *ixdr;
371	des_block buf;
372
373	if (rverf->oa_length != (2 + 1) * BYTES_PER_XDR_UNIT) {
374		return (FALSE);
375	}
376/* LINTED pointer alignment */
377	ixdr = (uint32_t *)rverf->oa_base;
378	buf.key.high = (uint32_t)*ixdr++;
379	buf.key.low = (uint32_t)*ixdr++;
380	verf.adv_int_u = (uint32_t)*ixdr++;
381
382	/*
383	 * Decrypt the timestamp
384	 */
385	status = ecb_crypt((char *)&auth->ah_key, (char *)&buf,
386		(u_int)sizeof (des_block), DES_DECRYPT | DES_HW);
387
388	if (DES_FAILED(status)) {
389		syslog(LOG_ERR, "authdes_validate: DES decryption failure");
390		return (FALSE);
391	}
392
393	/*
394	 * xdr the decrypted timestamp
395	 */
396/* LINTED pointer alignment */
397	ixdr = (uint32_t *)buf.c;
398	verf.adv_timestamp.tv_sec = IXDR_GET_INT32(ixdr) + 1;
399	verf.adv_timestamp.tv_usec = IXDR_GET_INT32(ixdr);
400
401	/*
402	 * validate
403	 */
404	if (bcmp((char *)&ad->ad_timestamp, (char *)&verf.adv_timestamp,
405		 sizeof(struct timeval)) != 0) {
406		syslog(LOG_DEBUG, "authdes_validate: verifier mismatch");
407		return (FALSE);
408	}
409
410	/*
411	 * We have a nickname now, let's use it
412	 */
413	ad->ad_nickname = verf.adv_nickname;
414	ad->ad_cred.adc_namekind = ADN_NICKNAME;
415	return (TRUE);
416}
417
418/*
419 * 4. Refresh
420 */
421/*ARGSUSED*/
422static bool_t
423authdes_refresh(AUTH *auth, void *dummy)
424{
425/* LINTED pointer alignment */
426	struct ad_private *ad = AUTH_PRIVATE(auth);
427	struct authdes_cred *cred = &ad->ad_cred;
428	int		ok;
429	netobj		pkey;
430
431	if (ad->ad_dosync) {
432                ok = __rpc_get_time_offset(&ad->ad_timediff, ad->ad_nis_srvr,
433		    ad->ad_timehost, &(ad->ad_uaddr),
434		    &(ad->ad_netid));
435		if (! ok) {
436			/*
437			 * Hope the clocks are synced!
438			 */
439			ad->ad_dosync = 0;
440			syslog(LOG_DEBUG,
441			    "authdes_refresh: unable to synchronize clock");
442		 }
443	}
444	ad->ad_xkey = auth->ah_key;
445	pkey.n_bytes = (char *)(ad->ad_pkey);
446	pkey.n_len = (u_int)strlen((char *)ad->ad_pkey) + 1;
447	if (key_encryptsession_pk(ad->ad_servername, &pkey, &ad->ad_xkey) < 0) {
448		syslog(LOG_INFO,
449		    "authdes_refresh: keyserv(1m) is unable to encrypt session key");
450		return (FALSE);
451	}
452	cred->adc_fullname.key = ad->ad_xkey;
453	cred->adc_namekind = ADN_FULLNAME;
454	cred->adc_fullname.name = ad->ad_fullname;
455	return (TRUE);
456}
457
458
459/*
460 * 5. Destroy
461 */
462static void
463authdes_destroy(AUTH *auth)
464{
465/* LINTED pointer alignment */
466	struct ad_private *ad = AUTH_PRIVATE(auth);
467
468	FREE(ad->ad_fullname, ad->ad_fullnamelen + 1);
469	FREE(ad->ad_servername, ad->ad_servernamelen + 1);
470	if (ad->ad_timehost)
471		FREE(ad->ad_timehost, strlen(ad->ad_timehost) + 1);
472	if (ad->ad_netid)
473		FREE(ad->ad_netid, strlen(ad->ad_netid) + 1);
474	if (ad->ad_uaddr)
475		FREE(ad->ad_uaddr, strlen(ad->ad_uaddr) + 1);
476	FREE(ad, sizeof (struct ad_private));
477	FREE(auth, sizeof(AUTH));
478}
479
480static struct auth_ops *
481authdes_ops(void)
482{
483	static struct auth_ops ops;
484
485	/* VARIABLES PROTECTED BY ops_lock: ops */
486
487	mutex_lock(&authdes_ops_lock);
488	if (ops.ah_nextverf == NULL) {
489		ops.ah_nextverf = authdes_nextverf;
490		ops.ah_marshal = authdes_marshal;
491		ops.ah_validate = authdes_validate;
492		ops.ah_refresh = authdes_refresh;
493		ops.ah_destroy = authdes_destroy;
494        }
495	mutex_unlock(&authdes_ops_lock);
496	return (&ops);
497}
498