xref: /freebsd/lib/libc/rpc/auth_des.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
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 <sys/cdefs.h>
45 #include <rpc/des_crypt.h>
46 #include <syslog.h>
47 #include <rpc/types.h>
48 #include <rpc/auth.h>
49 #include <rpc/auth_des.h>
50 #include <rpc/clnt.h>
51 #include <rpc/xdr.h>
52 #include <sys/socket.h>
53 #undef NIS
54 #include <rpcsvc/nis.h>
55 #include "un-namespace.h"
56 #include "mt_misc.h"
57 
58 #if defined(LIBC_SCCS) && !defined(lint)
59 static char sccsid[] = 	"@(#)auth_des.c	2.2 88/07/29 4.0 RPCSRC; from 1.9 88/02/08 SMI";
60 #endif
61 #include <sys/cdefs.h>
62 __FBSDID("$FreeBSD$");
63 
64 #define USEC_PER_SEC		1000000
65 #define RTIME_TIMEOUT		5	/* seconds to wait for sync */
66 
67 #define AUTH_PRIVATE(auth)	(struct ad_private *) auth->ah_private
68 #define ALLOC(object_type)	(object_type *) mem_alloc(sizeof(object_type))
69 #define FREE(ptr, size)		mem_free((char *)(ptr), (int) size)
70 #define ATTEMPT(xdr_op)		if (!(xdr_op)) return (FALSE)
71 
72 extern bool_t xdr_authdes_cred( XDR *, struct authdes_cred *);
73 extern bool_t xdr_authdes_verf( XDR *, struct authdes_verf *);
74 extern int key_encryptsession_pk(char *, netobj *, des_block *);
75 
76 extern bool_t __rpc_get_time_offset(struct timeval *, nis_server *, char *,
77 	char **, char **);
78 
79 /*
80  * DES authenticator operations vector
81  */
82 static void	authdes_nextverf(AUTH *);
83 static bool_t	authdes_marshal(AUTH *, XDR *);
84 static bool_t	authdes_validate(AUTH *, struct opaque_auth *);
85 static bool_t	authdes_refresh(AUTH *, void *);
86 static void	authdes_destroy(AUTH *);
87 
88 static struct auth_ops *authdes_ops(void);
89 
90 /*
91  * This struct is pointed to by the ah_private field of an "AUTH *"
92  */
93 struct ad_private {
94 	char *ad_fullname; 		/* client's full name */
95 	u_int ad_fullnamelen;		/* length of name, rounded up */
96 	char *ad_servername; 		/* server's full name */
97 	u_int ad_servernamelen;		/* length of name, rounded up */
98 	u_int ad_window;	  	/* client specified window */
99 	bool_t ad_dosync;		/* synchronize? */
100 	struct netbuf ad_syncaddr;	/* remote host to synch with */
101 	char *ad_timehost;		/* remote host to synch with */
102 	struct timeval ad_timediff;	/* server's time - client's time */
103 	u_int ad_nickname;		/* server's nickname for client */
104 	struct authdes_cred ad_cred;	/* storage for credential */
105 	struct authdes_verf ad_verf;	/* storage for verifier */
106 	struct timeval ad_timestamp;	/* timestamp sent */
107 	des_block ad_xkey;		/* encrypted conversation key */
108 	u_char ad_pkey[1024];		/* Server's actual public key */
109 	char *ad_netid;			/* Timehost netid */
110 	char *ad_uaddr;			/* Timehost uaddr */
111 	nis_server *ad_nis_srvr;	/* NIS+ server struct */
112 };
113 
114 AUTH *authdes_pk_seccreate(const char *, netobj *, u_int, const char *,
115 	const des_block *, nis_server *);
116 
117 /*
118  * documented version of authdes_seccreate
119  */
120 /*
121 	servername:	network name of server
122 	win:		time to live
123 	timehost:	optional hostname to sync with
124 	ckey:		optional conversation key to use
125 */
126 
127 AUTH *
128 authdes_seccreate(const char *servername, const u_int win,
129 	const char *timehost, const des_block *ckey)
130 {
131 	u_char  pkey_data[1024];
132 	netobj  pkey;
133 	AUTH    *dummy;
134 
135 	if (! getpublickey(servername, (char *) pkey_data)) {
136 		syslog(LOG_ERR,
137 		    "authdes_seccreate: no public key found for %s",
138 		    servername);
139 		return (NULL);
140 	}
141 
142 	pkey.n_bytes = (char *) pkey_data;
143 	pkey.n_len = (u_int)strlen((char *)pkey_data) + 1;
144 	dummy = authdes_pk_seccreate(servername, &pkey, win, timehost,
145 	    ckey, NULL);
146 	return (dummy);
147 }
148 
149 /*
150  * Slightly modified version of authdessec_create which takes the public key
151  * of the server principal as an argument. This spares us a call to
152  * getpublickey() which in the nameserver context can cause a deadlock.
153  */
154 AUTH *
155 authdes_pk_seccreate(const char *servername, netobj *pkey, u_int window,
156 	const char *timehost, const des_block *ckey, nis_server *srvr)
157 {
158 	AUTH *auth;
159 	struct ad_private *ad;
160 	char namebuf[MAXNETNAMELEN+1];
161 
162 	/*
163 	 * Allocate everything now
164 	 */
165 	auth = ALLOC(AUTH);
166 	if (auth == NULL) {
167 		syslog(LOG_ERR, "authdes_pk_seccreate: out of memory");
168 		return (NULL);
169 	}
170 	ad = ALLOC(struct ad_private);
171 	if (ad == NULL) {
172 		syslog(LOG_ERR, "authdes_pk_seccreate: out of memory");
173 		goto failed;
174 	}
175 	ad->ad_fullname = ad->ad_servername = NULL; /* Sanity reasons */
176 	ad->ad_timehost = NULL;
177 	ad->ad_netid = NULL;
178 	ad->ad_uaddr = NULL;
179 	ad->ad_nis_srvr = NULL;
180 	ad->ad_timediff.tv_sec = 0;
181 	ad->ad_timediff.tv_usec = 0;
182 	memcpy(ad->ad_pkey, pkey->n_bytes, pkey->n_len);
183 	if (!getnetname(namebuf))
184 		goto failed;
185 	ad->ad_fullnamelen = RNDUP((u_int) strlen(namebuf));
186 	ad->ad_fullname = (char *)mem_alloc(ad->ad_fullnamelen + 1);
187 	ad->ad_servernamelen = strlen(servername);
188 	ad->ad_servername = (char *)mem_alloc(ad->ad_servernamelen + 1);
189 
190 	if (ad->ad_fullname == NULL || ad->ad_servername == NULL) {
191 		syslog(LOG_ERR, "authdes_seccreate: out of memory");
192 		goto failed;
193 	}
194 	if (timehost != NULL) {
195 		ad->ad_timehost = (char *)mem_alloc(strlen(timehost) + 1);
196 		if (ad->ad_timehost == NULL) {
197 			syslog(LOG_ERR, "authdes_seccreate: out of memory");
198 			goto failed;
199 		}
200 		memcpy(ad->ad_timehost, timehost, strlen(timehost) + 1);
201 		ad->ad_dosync = TRUE;
202 	} else if (srvr != NULL) {
203 		ad->ad_nis_srvr = srvr;	/* transient */
204 		ad->ad_dosync = TRUE;
205 	} else {
206 		ad->ad_dosync = FALSE;
207 	}
208 	memcpy(ad->ad_fullname, namebuf, ad->ad_fullnamelen + 1);
209 	memcpy(ad->ad_servername, servername, ad->ad_servernamelen + 1);
210 	ad->ad_window = window;
211 	if (ckey == NULL) {
212 		if (key_gendes(&auth->ah_key) < 0) {
213 			syslog(LOG_ERR,
214 	    "authdes_seccreate: keyserv(1m) is unable to generate session key");
215 			goto failed;
216 		}
217 	} else {
218 		auth->ah_key = *ckey;
219 	}
220 
221 	/*
222 	 * Set up auth handle
223 	 */
224 	auth->ah_cred.oa_flavor = AUTH_DES;
225 	auth->ah_verf.oa_flavor = AUTH_DES;
226 	auth->ah_ops = authdes_ops();
227 	auth->ah_private = (caddr_t)ad;
228 
229 	if (!authdes_refresh(auth, NULL)) {
230 		goto failed;
231 	}
232 	ad->ad_nis_srvr = NULL; /* not needed any longer */
233 	return (auth);
234 
235 failed:
236 	if (auth)
237 		FREE(auth, sizeof (AUTH));
238 	if (ad) {
239 		if (ad->ad_fullname)
240 			FREE(ad->ad_fullname, ad->ad_fullnamelen + 1);
241 		if (ad->ad_servername)
242 			FREE(ad->ad_servername, ad->ad_servernamelen + 1);
243 		if (ad->ad_timehost)
244 			FREE(ad->ad_timehost, strlen(ad->ad_timehost) + 1);
245 		if (ad->ad_netid)
246 			FREE(ad->ad_netid, strlen(ad->ad_netid) + 1);
247 		if (ad->ad_uaddr)
248 			FREE(ad->ad_uaddr, strlen(ad->ad_uaddr) + 1);
249 		FREE(ad, sizeof (struct ad_private));
250 	}
251 	return (NULL);
252 }
253 
254 /*
255  * Implement the five authentication operations
256  */
257 
258 
259 /*
260  * 1. Next Verifier
261  */
262 /*ARGSUSED*/
263 static void
264 authdes_nextverf(AUTH *auth __unused)
265 {
266 	/* what the heck am I supposed to do??? */
267 }
268 
269 
270 /*
271  * 2. Marshal
272  */
273 static bool_t
274 authdes_marshal(AUTH *auth, XDR *xdrs)
275 {
276 /* LINTED pointer alignment */
277 	struct ad_private *ad = AUTH_PRIVATE(auth);
278 	struct authdes_cred *cred = &ad->ad_cred;
279 	struct authdes_verf *verf = &ad->ad_verf;
280 	des_block cryptbuf[2];
281 	des_block ivec;
282 	int status;
283 	int len;
284 	rpc_inline_t *ixdr;
285 
286 	/*
287 	 * Figure out the "time", accounting for any time difference
288 	 * with the server if necessary.
289 	 */
290 	(void)gettimeofday(&ad->ad_timestamp, NULL);
291 	ad->ad_timestamp.tv_sec += ad->ad_timediff.tv_sec;
292 	ad->ad_timestamp.tv_usec += ad->ad_timediff.tv_usec;
293 	while (ad->ad_timestamp.tv_usec >= USEC_PER_SEC) {
294 		ad->ad_timestamp.tv_usec -= USEC_PER_SEC;
295 		ad->ad_timestamp.tv_sec++;
296 	}
297 
298 	/*
299 	 * XDR the timestamp and possibly some other things, then
300 	 * encrypt them.
301 	 */
302 	ixdr = (rpc_inline_t *)cryptbuf;
303 	IXDR_PUT_INT32(ixdr, ad->ad_timestamp.tv_sec);
304 	IXDR_PUT_INT32(ixdr, ad->ad_timestamp.tv_usec);
305 	if (ad->ad_cred.adc_namekind == ADN_FULLNAME) {
306 		IXDR_PUT_U_INT32(ixdr, ad->ad_window);
307 		IXDR_PUT_U_INT32(ixdr, ad->ad_window - 1);
308 		ivec.key.high = ivec.key.low = 0;
309 		status = cbc_crypt((char *)&auth->ah_key, (char *)cryptbuf,
310 			(u_int) 2 * sizeof (des_block),
311 			DES_ENCRYPT | DES_HW, (char *)&ivec);
312 	} else {
313 		status = ecb_crypt((char *)&auth->ah_key, (char *)cryptbuf,
314 			(u_int) sizeof (des_block),
315 			DES_ENCRYPT | DES_HW);
316 	}
317 	if (DES_FAILED(status)) {
318 		syslog(LOG_ERR, "authdes_marshal: DES encryption failure");
319 		return (FALSE);
320 	}
321 	ad->ad_verf.adv_xtimestamp = cryptbuf[0];
322 	if (ad->ad_cred.adc_namekind == ADN_FULLNAME) {
323 		ad->ad_cred.adc_fullname.window = cryptbuf[1].key.high;
324 		ad->ad_verf.adv_winverf = cryptbuf[1].key.low;
325 	} else {
326 		ad->ad_cred.adc_nickname = ad->ad_nickname;
327 		ad->ad_verf.adv_winverf = 0;
328 	}
329 
330 	/*
331 	 * Serialize the credential and verifier into opaque
332 	 * authentication data.
333 	 */
334 	if (ad->ad_cred.adc_namekind == ADN_FULLNAME) {
335 		len = ((1 + 1 + 2 + 1)*BYTES_PER_XDR_UNIT + ad->ad_fullnamelen);
336 	} else {
337 		len = (1 + 1)*BYTES_PER_XDR_UNIT;
338 	}
339 
340 	if ((ixdr = xdr_inline(xdrs, 2*BYTES_PER_XDR_UNIT))) {
341 		IXDR_PUT_INT32(ixdr, AUTH_DES);
342 		IXDR_PUT_INT32(ixdr, len);
343 	} else {
344 		ATTEMPT(xdr_putint32(xdrs, (int *)&auth->ah_cred.oa_flavor));
345 		ATTEMPT(xdr_putint32(xdrs, &len));
346 	}
347 	ATTEMPT(xdr_authdes_cred(xdrs, cred));
348 
349 	len = (2 + 1)*BYTES_PER_XDR_UNIT;
350 	if ((ixdr = xdr_inline(xdrs, 2*BYTES_PER_XDR_UNIT))) {
351 		IXDR_PUT_INT32(ixdr, AUTH_DES);
352 		IXDR_PUT_INT32(ixdr, len);
353 	} else {
354 		ATTEMPT(xdr_putint32(xdrs, (int *)&auth->ah_verf.oa_flavor));
355 		ATTEMPT(xdr_putint32(xdrs, &len));
356 	}
357 	ATTEMPT(xdr_authdes_verf(xdrs, verf));
358 	return (TRUE);
359 }
360 
361 
362 /*
363  * 3. Validate
364  */
365 static bool_t
366 authdes_validate(AUTH *auth, struct opaque_auth *rverf)
367 {
368 /* LINTED pointer alignment */
369 	struct ad_private *ad = AUTH_PRIVATE(auth);
370 	struct authdes_verf verf;
371 	int status;
372 	uint32_t *ixdr;
373 	des_block buf;
374 
375 	if (rverf->oa_length != (2 + 1) * BYTES_PER_XDR_UNIT) {
376 		return (FALSE);
377 	}
378 /* LINTED pointer alignment */
379 	ixdr = (uint32_t *)rverf->oa_base;
380 	buf.key.high = (uint32_t)*ixdr++;
381 	buf.key.low = (uint32_t)*ixdr++;
382 	verf.adv_int_u = (uint32_t)*ixdr++;
383 
384 	/*
385 	 * Decrypt the timestamp
386 	 */
387 	status = ecb_crypt((char *)&auth->ah_key, (char *)&buf,
388 		(u_int)sizeof (des_block), DES_DECRYPT | DES_HW);
389 
390 	if (DES_FAILED(status)) {
391 		syslog(LOG_ERR, "authdes_validate: DES decryption failure");
392 		return (FALSE);
393 	}
394 
395 	/*
396 	 * xdr the decrypted timestamp
397 	 */
398 /* LINTED pointer alignment */
399 	ixdr = (uint32_t *)buf.c;
400 	verf.adv_timestamp.tv_sec = IXDR_GET_INT32(ixdr) + 1;
401 	verf.adv_timestamp.tv_usec = IXDR_GET_INT32(ixdr);
402 
403 	/*
404 	 * validate
405 	 */
406 	if (bcmp((char *)&ad->ad_timestamp, (char *)&verf.adv_timestamp,
407 		 sizeof(struct timeval)) != 0) {
408 		syslog(LOG_DEBUG, "authdes_validate: verifier mismatch");
409 		return (FALSE);
410 	}
411 
412 	/*
413 	 * We have a nickname now, let's use it
414 	 */
415 	ad->ad_nickname = verf.adv_nickname;
416 	ad->ad_cred.adc_namekind = ADN_NICKNAME;
417 	return (TRUE);
418 }
419 
420 /*
421  * 4. Refresh
422  */
423 /*ARGSUSED*/
424 static bool_t
425 authdes_refresh(AUTH *auth, void *dummy __unused)
426 {
427 /* LINTED pointer alignment */
428 	struct ad_private *ad = AUTH_PRIVATE(auth);
429 	struct authdes_cred *cred = &ad->ad_cred;
430 	int		ok;
431 	netobj		pkey;
432 
433 	if (ad->ad_dosync) {
434                 ok = __rpc_get_time_offset(&ad->ad_timediff, ad->ad_nis_srvr,
435 		    ad->ad_timehost, &(ad->ad_uaddr),
436 		    &(ad->ad_netid));
437 		if (! ok) {
438 			/*
439 			 * Hope the clocks are synced!
440 			 */
441 			ad->ad_dosync = 0;
442 			syslog(LOG_DEBUG,
443 			    "authdes_refresh: unable to synchronize clock");
444 		 }
445 	}
446 	ad->ad_xkey = auth->ah_key;
447 	pkey.n_bytes = (char *)(ad->ad_pkey);
448 	pkey.n_len = (u_int)strlen((char *)ad->ad_pkey) + 1;
449 	if (key_encryptsession_pk(ad->ad_servername, &pkey, &ad->ad_xkey) < 0) {
450 		syslog(LOG_INFO,
451 		    "authdes_refresh: keyserv(1m) is unable to encrypt session key");
452 		return (FALSE);
453 	}
454 	cred->adc_fullname.key = ad->ad_xkey;
455 	cred->adc_namekind = ADN_FULLNAME;
456 	cred->adc_fullname.name = ad->ad_fullname;
457 	return (TRUE);
458 }
459 
460 
461 /*
462  * 5. Destroy
463  */
464 static void
465 authdes_destroy(AUTH *auth)
466 {
467 /* LINTED pointer alignment */
468 	struct ad_private *ad = AUTH_PRIVATE(auth);
469 
470 	FREE(ad->ad_fullname, ad->ad_fullnamelen + 1);
471 	FREE(ad->ad_servername, ad->ad_servernamelen + 1);
472 	if (ad->ad_timehost)
473 		FREE(ad->ad_timehost, strlen(ad->ad_timehost) + 1);
474 	if (ad->ad_netid)
475 		FREE(ad->ad_netid, strlen(ad->ad_netid) + 1);
476 	if (ad->ad_uaddr)
477 		FREE(ad->ad_uaddr, strlen(ad->ad_uaddr) + 1);
478 	FREE(ad, sizeof (struct ad_private));
479 	FREE(auth, sizeof(AUTH));
480 }
481 
482 static struct auth_ops *
483 authdes_ops(void)
484 {
485 	static struct auth_ops ops;
486 
487 	/* VARIABLES PROTECTED BY ops_lock: ops */
488 
489 	mutex_lock(&authdes_ops_lock);
490 	if (ops.ah_nextverf == NULL) {
491 		ops.ah_nextverf = authdes_nextverf;
492 		ops.ah_marshal = authdes_marshal;
493 		ops.ah_validate = authdes_validate;
494 		ops.ah_refresh = authdes_refresh;
495 		ops.ah_destroy = authdes_destroy;
496         }
497 	mutex_unlock(&authdes_ops_lock);
498 	return (&ops);
499 }
500