xref: /freebsd/lib/libc/rpc/key_call.c (revision 38f0b757fd84d17d0fc24739a7cda160c4516d81)
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) 1986-1991 by Sun Microsystems Inc.
30  */
31 
32 #ident	"@(#)key_call.c	1.25	94/04/24 SMI"
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 /*
37  * key_call.c, Interface to keyserver
38  *
39  * setsecretkey(key) - set your secret key
40  * encryptsessionkey(agent, deskey) - encrypt a session key to talk to agent
41  * decryptsessionkey(agent, deskey) - decrypt ditto
42  * gendeskey(deskey) - generate a secure des key
43  */
44 
45 #include "namespace.h"
46 #include "reentrant.h"
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <unistd.h>
50 #include <errno.h>
51 #include <rpc/rpc.h>
52 #include <rpc/auth.h>
53 #include <rpc/auth_unix.h>
54 #include <rpc/key_prot.h>
55 #include <string.h>
56 #include <netconfig.h>
57 #include <sys/utsname.h>
58 #include <stdlib.h>
59 #include <signal.h>
60 #include <sys/wait.h>
61 #include <sys/fcntl.h>
62 #include "un-namespace.h"
63 #include "mt_misc.h"
64 
65 
66 #define	KEY_TIMEOUT	5	/* per-try timeout in seconds */
67 #define	KEY_NRETRY	12	/* number of retries */
68 
69 #ifdef DEBUG
70 #define	debug(msg)	(void) fprintf(stderr, "%s\n", msg);
71 #else
72 #define	debug(msg)
73 #endif /* DEBUG */
74 
75 /*
76  * Hack to allow the keyserver to use AUTH_DES (for authenticated
77  * NIS+ calls, for example).  The only functions that get called
78  * are key_encryptsession_pk, key_decryptsession_pk, and key_gendes.
79  *
80  * The approach is to have the keyserver fill in pointers to local
81  * implementations of these functions, and to call those in key_call().
82  */
83 
84 cryptkeyres *(*__key_encryptsession_pk_LOCAL)() = 0;
85 cryptkeyres *(*__key_decryptsession_pk_LOCAL)() = 0;
86 des_block *(*__key_gendes_LOCAL)() = 0;
87 
88 static int key_call( u_long, xdrproc_t, void *, xdrproc_t, void *);
89 
90 int
91 key_setsecret(secretkey)
92 	const char *secretkey;
93 {
94 	keystatus status;
95 
96 	if (!key_call((u_long) KEY_SET, (xdrproc_t)xdr_keybuf,
97 			(void *)secretkey,
98 			(xdrproc_t)xdr_keystatus, &status)) {
99 		return (-1);
100 	}
101 	if (status != KEY_SUCCESS) {
102 		debug("set status is nonzero");
103 		return (-1);
104 	}
105 	return (0);
106 }
107 
108 
109 /* key_secretkey_is_set() returns 1 if the keyserver has a secret key
110  * stored for the caller's effective uid; it returns 0 otherwise
111  *
112  * N.B.:  The KEY_NET_GET key call is undocumented.  Applications shouldn't
113  * be using it, because it allows them to get the user's secret key.
114  */
115 
116 int
117 key_secretkey_is_set(void)
118 {
119 	struct key_netstres 	kres;
120 
121 	memset((void*)&kres, 0, sizeof (kres));
122 	if (key_call((u_long) KEY_NET_GET, (xdrproc_t)xdr_void, NULL,
123 			(xdrproc_t)xdr_key_netstres, &kres) &&
124 	    (kres.status == KEY_SUCCESS) &&
125 	    (kres.key_netstres_u.knet.st_priv_key[0] != 0)) {
126 		/* avoid leaving secret key in memory */
127 		memset(kres.key_netstres_u.knet.st_priv_key, 0, HEXKEYBYTES);
128 		return (1);
129 	}
130 	return (0);
131 }
132 
133 int
134 key_encryptsession_pk(remotename, remotekey, deskey)
135 	char *remotename;
136 	netobj *remotekey;
137 	des_block *deskey;
138 {
139 	cryptkeyarg2 arg;
140 	cryptkeyres res;
141 
142 	arg.remotename = remotename;
143 	arg.remotekey = *remotekey;
144 	arg.deskey = *deskey;
145 	if (!key_call((u_long)KEY_ENCRYPT_PK, (xdrproc_t)xdr_cryptkeyarg2, &arg,
146 			(xdrproc_t)xdr_cryptkeyres, &res)) {
147 		return (-1);
148 	}
149 	if (res.status != KEY_SUCCESS) {
150 		debug("encrypt status is nonzero");
151 		return (-1);
152 	}
153 	*deskey = res.cryptkeyres_u.deskey;
154 	return (0);
155 }
156 
157 int
158 key_decryptsession_pk(remotename, remotekey, deskey)
159 	char *remotename;
160 	netobj *remotekey;
161 	des_block *deskey;
162 {
163 	cryptkeyarg2 arg;
164 	cryptkeyres res;
165 
166 	arg.remotename = remotename;
167 	arg.remotekey = *remotekey;
168 	arg.deskey = *deskey;
169 	if (!key_call((u_long)KEY_DECRYPT_PK, (xdrproc_t)xdr_cryptkeyarg2, &arg,
170 			(xdrproc_t)xdr_cryptkeyres, &res)) {
171 		return (-1);
172 	}
173 	if (res.status != KEY_SUCCESS) {
174 		debug("decrypt status is nonzero");
175 		return (-1);
176 	}
177 	*deskey = res.cryptkeyres_u.deskey;
178 	return (0);
179 }
180 
181 int
182 key_encryptsession(remotename, deskey)
183 	const char *remotename;
184 	des_block *deskey;
185 {
186 	cryptkeyarg arg;
187 	cryptkeyres res;
188 
189 	arg.remotename = (char *) remotename;
190 	arg.deskey = *deskey;
191 	if (!key_call((u_long)KEY_ENCRYPT, (xdrproc_t)xdr_cryptkeyarg, &arg,
192 			(xdrproc_t)xdr_cryptkeyres, &res)) {
193 		return (-1);
194 	}
195 	if (res.status != KEY_SUCCESS) {
196 		debug("encrypt status is nonzero");
197 		return (-1);
198 	}
199 	*deskey = res.cryptkeyres_u.deskey;
200 	return (0);
201 }
202 
203 int
204 key_decryptsession(remotename, deskey)
205 	const char *remotename;
206 	des_block *deskey;
207 {
208 	cryptkeyarg arg;
209 	cryptkeyres res;
210 
211 	arg.remotename = (char *) remotename;
212 	arg.deskey = *deskey;
213 	if (!key_call((u_long)KEY_DECRYPT, (xdrproc_t)xdr_cryptkeyarg, &arg,
214 			(xdrproc_t)xdr_cryptkeyres, &res)) {
215 		return (-1);
216 	}
217 	if (res.status != KEY_SUCCESS) {
218 		debug("decrypt status is nonzero");
219 		return (-1);
220 	}
221 	*deskey = res.cryptkeyres_u.deskey;
222 	return (0);
223 }
224 
225 int
226 key_gendes(key)
227 	des_block *key;
228 {
229 	if (!key_call((u_long)KEY_GEN, (xdrproc_t)xdr_void, NULL,
230 			(xdrproc_t)xdr_des_block, key)) {
231 		return (-1);
232 	}
233 	return (0);
234 }
235 
236 int
237 key_setnet(arg)
238 struct key_netstarg *arg;
239 {
240 	keystatus status;
241 
242 
243 	if (!key_call((u_long) KEY_NET_PUT, (xdrproc_t)xdr_key_netstarg, arg,
244 			(xdrproc_t)xdr_keystatus, &status)){
245 		return (-1);
246 	}
247 
248 	if (status != KEY_SUCCESS) {
249 		debug("key_setnet status is nonzero");
250 		return (-1);
251 	}
252 	return (1);
253 }
254 
255 
256 int
257 key_get_conv(pkey, deskey)
258 	char *pkey;
259 	des_block *deskey;
260 {
261 	cryptkeyres res;
262 
263 	if (!key_call((u_long) KEY_GET_CONV, (xdrproc_t)xdr_keybuf, pkey,
264 			(xdrproc_t)xdr_cryptkeyres, &res)) {
265 		return (-1);
266 	}
267 	if (res.status != KEY_SUCCESS) {
268 		debug("get_conv status is nonzero");
269 		return (-1);
270 	}
271 	*deskey = res.cryptkeyres_u.deskey;
272 	return (0);
273 }
274 
275 struct  key_call_private {
276 	CLIENT	*client;	/* Client handle */
277 	pid_t	pid;		/* process-id at moment of creation */
278 	uid_t	uid;		/* user-id at last authorization */
279 };
280 static struct key_call_private *key_call_private_main = NULL;
281 static thread_key_t key_call_key;
282 static once_t key_call_once = ONCE_INITIALIZER;
283 static int key_call_key_error;
284 
285 static void
286 key_call_destroy(void *vp)
287 {
288 	struct key_call_private *kcp = (struct key_call_private *)vp;
289 
290 	if (kcp) {
291 		if (kcp->client)
292 			clnt_destroy(kcp->client);
293 		free(kcp);
294 	}
295 }
296 
297 static void
298 key_call_init(void)
299 {
300 
301 	key_call_key_error = thr_keycreate(&key_call_key, key_call_destroy);
302 }
303 
304 /*
305  * Keep the handle cached.  This call may be made quite often.
306  */
307 static CLIENT *
308 getkeyserv_handle(vers)
309 int	vers;
310 {
311 	void *localhandle;
312 	struct netconfig *nconf;
313 	struct netconfig *tpconf;
314 	struct key_call_private *kcp;
315 	struct timeval wait_time;
316 	struct utsname u;
317 	int main_thread;
318 	int fd;
319 
320 #define	TOTAL_TIMEOUT	30	/* total timeout talking to keyserver */
321 #define	TOTAL_TRIES	5	/* Number of tries */
322 
323 	if ((main_thread = thr_main())) {
324 		kcp = key_call_private_main;
325 	} else {
326 		if (thr_once(&key_call_once, key_call_init) != 0 ||
327 		    key_call_key_error != 0)
328 			return ((CLIENT *) NULL);
329 		kcp = (struct key_call_private *)thr_getspecific(key_call_key);
330 	}
331 	if (kcp == (struct key_call_private *)NULL) {
332 		kcp = (struct key_call_private *)malloc(sizeof (*kcp));
333 		if (kcp == (struct key_call_private *)NULL) {
334 			return ((CLIENT *) NULL);
335 		}
336                 if (main_thread)
337                         key_call_private_main = kcp;
338                 else
339                         thr_setspecific(key_call_key, (void *) kcp);
340 		kcp->client = NULL;
341 	}
342 
343 	/* if pid has changed, destroy client and rebuild */
344 	if (kcp->client != NULL && kcp->pid != getpid()) {
345 		clnt_destroy(kcp->client);
346 		kcp->client = NULL;
347 	}
348 
349 	if (kcp->client != NULL) {
350 		/* if uid has changed, build client handle again */
351 		if (kcp->uid != geteuid()) {
352 			kcp->uid = geteuid();
353 			auth_destroy(kcp->client->cl_auth);
354 			kcp->client->cl_auth =
355 				authsys_create("", kcp->uid, 0, 0, NULL);
356 			if (kcp->client->cl_auth == NULL) {
357 				clnt_destroy(kcp->client);
358 				kcp->client = NULL;
359 				return ((CLIENT *) NULL);
360 			}
361 		}
362 		/* Change the version number to the new one */
363 		clnt_control(kcp->client, CLSET_VERS, (void *)&vers);
364 		return (kcp->client);
365 	}
366 	if (!(localhandle = setnetconfig())) {
367 		return ((CLIENT *) NULL);
368 	}
369         tpconf = NULL;
370 #if defined(__FreeBSD__)
371 	if (uname(&u) == -1)
372 #else
373 #if defined(i386)
374 	if (_nuname(&u) == -1)
375 #elif defined(sparc)
376 	if (_uname(&u) == -1)
377 #else
378 #error Unknown architecture!
379 #endif
380 #endif
381 	{
382 		endnetconfig(localhandle);
383 		return ((CLIENT *) NULL);
384         }
385 	while ((nconf = getnetconfig(localhandle)) != NULL) {
386 		if (strcmp(nconf->nc_protofmly, NC_LOOPBACK) == 0) {
387 			/*
388 			 * We use COTS_ORD here so that the caller can
389 			 * find out immediately if the server is dead.
390 			 */
391 			if (nconf->nc_semantics == NC_TPI_COTS_ORD) {
392 				kcp->client = clnt_tp_create(u.nodename,
393 					KEY_PROG, vers, nconf);
394 				if (kcp->client)
395 					break;
396 			} else {
397 				tpconf = nconf;
398 			}
399 		}
400 	}
401 	if ((kcp->client == (CLIENT *) NULL) && (tpconf))
402 		/* Now, try the CLTS or COTS loopback transport */
403 		kcp->client = clnt_tp_create(u.nodename,
404 			KEY_PROG, vers, tpconf);
405 	endnetconfig(localhandle);
406 
407 	if (kcp->client == (CLIENT *) NULL) {
408 		return ((CLIENT *) NULL);
409         }
410 	kcp->uid = geteuid();
411 	kcp->pid = getpid();
412 	kcp->client->cl_auth = authsys_create("", kcp->uid, 0, 0, NULL);
413 	if (kcp->client->cl_auth == NULL) {
414 		clnt_destroy(kcp->client);
415 		kcp->client = NULL;
416 		return ((CLIENT *) NULL);
417 	}
418 
419 	wait_time.tv_sec = TOTAL_TIMEOUT/TOTAL_TRIES;
420 	wait_time.tv_usec = 0;
421 	(void) clnt_control(kcp->client, CLSET_RETRY_TIMEOUT,
422 		(char *)&wait_time);
423 	if (clnt_control(kcp->client, CLGET_FD, (char *)&fd))
424 		_fcntl(fd, F_SETFD, 1);	/* make it "close on exec" */
425 
426 	return (kcp->client);
427 }
428 
429 /* returns  0 on failure, 1 on success */
430 
431 static int
432 key_call(proc, xdr_arg, arg, xdr_rslt, rslt)
433 	u_long proc;
434 	xdrproc_t xdr_arg;
435 	void *arg;
436 	xdrproc_t xdr_rslt;
437 	void *rslt;
438 {
439 	CLIENT *clnt;
440 	struct timeval wait_time;
441 
442 	if (proc == KEY_ENCRYPT_PK && __key_encryptsession_pk_LOCAL) {
443 		cryptkeyres *res;
444 		res = (*__key_encryptsession_pk_LOCAL)(geteuid(), arg);
445 		*(cryptkeyres*)rslt = *res;
446 		return (1);
447 	} else if (proc == KEY_DECRYPT_PK && __key_decryptsession_pk_LOCAL) {
448 		cryptkeyres *res;
449 		res = (*__key_decryptsession_pk_LOCAL)(geteuid(), arg);
450 		*(cryptkeyres*)rslt = *res;
451 		return (1);
452 	} else if (proc == KEY_GEN && __key_gendes_LOCAL) {
453 		des_block *res;
454 		res = (*__key_gendes_LOCAL)(geteuid(), 0);
455 		*(des_block*)rslt = *res;
456 		return (1);
457 	}
458 
459 	if ((proc == KEY_ENCRYPT_PK) || (proc == KEY_DECRYPT_PK) ||
460 	    (proc == KEY_NET_GET) || (proc == KEY_NET_PUT) ||
461 	    (proc == KEY_GET_CONV))
462 		clnt = getkeyserv_handle(2); /* talk to version 2 */
463 	else
464 		clnt = getkeyserv_handle(1); /* talk to version 1 */
465 
466 	if (clnt == NULL) {
467 		return (0);
468 	}
469 
470 	wait_time.tv_sec = TOTAL_TIMEOUT;
471 	wait_time.tv_usec = 0;
472 
473 	if (clnt_call(clnt, proc, xdr_arg, arg, xdr_rslt, rslt,
474 		wait_time) == RPC_SUCCESS) {
475 		return (1);
476 	} else {
477 		return (0);
478 	}
479 }
480