xref: /freebsd/lib/libc/rpc/key_call.c (revision 2008043f386721d58158e37e0d7e50df8095942d)
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) 1986-1991 by Sun Microsystems Inc.
32  */
33 
34 #ident	"@(#)key_call.c	1.25	94/04/24 SMI"
35 /*
36  * key_call.c, Interface to keyserver
37  *
38  * setsecretkey(key) - set your secret key
39  * encryptsessionkey(agent, deskey) - encrypt a session key to talk to agent
40  * decryptsessionkey(agent, deskey) - decrypt ditto
41  * gendeskey(deskey) - generate a secure des key
42  */
43 
44 #include "namespace.h"
45 #include "reentrant.h"
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <unistd.h>
49 #include <errno.h>
50 #include <rpc/rpc.h>
51 #include <rpc/auth.h>
52 #include <rpc/auth_unix.h>
53 #include <rpc/key_prot.h>
54 #include <string.h>
55 #include <netconfig.h>
56 #include <sys/utsname.h>
57 #include <stdlib.h>
58 #include <signal.h>
59 #include <sys/wait.h>
60 #include <sys/fcntl.h>
61 #include "un-namespace.h"
62 #include "mt_misc.h"
63 
64 
65 #define	KEY_TIMEOUT	5	/* per-try timeout in seconds */
66 #define	KEY_NRETRY	12	/* number of retries */
67 
68 #ifdef DEBUG
69 #define	debug(msg)	(void) fprintf(stderr, "%s\n", msg);
70 #else
71 #define	debug(msg)
72 #endif /* DEBUG */
73 
74 /*
75  * Hack to allow the keyserver to use AUTH_DES (for authenticated
76  * NIS+ calls, for example).  The only functions that get called
77  * are key_encryptsession_pk, key_decryptsession_pk, and key_gendes.
78  *
79  * The approach is to have the keyserver fill in pointers to local
80  * implementations of these functions, and to call those in key_call().
81  */
82 
83 cryptkeyres *(*__key_encryptsession_pk_LOCAL)(uid_t, void *arg) = 0;
84 cryptkeyres *(*__key_decryptsession_pk_LOCAL)(uid_t, void *arg) = 0;
85 des_block *(*__key_gendes_LOCAL)(uid_t, void *) = 0;
86 
87 static int key_call( u_long, xdrproc_t, void *, xdrproc_t, void *);
88 
89 int
90 key_setsecret(const char *secretkey)
91 {
92 	keystatus status;
93 
94 	if (!key_call((u_long) KEY_SET, (xdrproc_t)xdr_keybuf,
95 			(void *)secretkey,
96 			(xdrproc_t)xdr_keystatus, &status)) {
97 		return (-1);
98 	}
99 	if (status != KEY_SUCCESS) {
100 		debug("set status is nonzero");
101 		return (-1);
102 	}
103 	return (0);
104 }
105 
106 
107 /* key_secretkey_is_set() returns 1 if the keyserver has a secret key
108  * stored for the caller's effective uid; it returns 0 otherwise
109  *
110  * N.B.:  The KEY_NET_GET key call is undocumented.  Applications shouldn't
111  * be using it, because it allows them to get the user's secret key.
112  */
113 
114 int
115 key_secretkey_is_set(void)
116 {
117 	struct key_netstres 	kres;
118 
119 	memset((void*)&kres, 0, sizeof (kres));
120 	if (key_call((u_long) KEY_NET_GET, (xdrproc_t)xdr_void, NULL,
121 			(xdrproc_t)xdr_key_netstres, &kres) &&
122 	    (kres.status == KEY_SUCCESS) &&
123 	    (kres.key_netstres_u.knet.st_priv_key[0] != 0)) {
124 		/* avoid leaving secret key in memory */
125 		memset(kres.key_netstres_u.knet.st_priv_key, 0, HEXKEYBYTES);
126 		return (1);
127 	}
128 	return (0);
129 }
130 
131 int
132 key_encryptsession_pk(char *remotename, netobj *remotekey, des_block *deskey)
133 {
134 	cryptkeyarg2 arg;
135 	cryptkeyres res;
136 
137 	arg.remotename = remotename;
138 	arg.remotekey = *remotekey;
139 	arg.deskey = *deskey;
140 	if (!key_call((u_long)KEY_ENCRYPT_PK, (xdrproc_t)xdr_cryptkeyarg2, &arg,
141 			(xdrproc_t)xdr_cryptkeyres, &res)) {
142 		return (-1);
143 	}
144 	if (res.status != KEY_SUCCESS) {
145 		debug("encrypt status is nonzero");
146 		return (-1);
147 	}
148 	*deskey = res.cryptkeyres_u.deskey;
149 	return (0);
150 }
151 
152 int
153 key_decryptsession_pk(char *remotename, netobj *remotekey, des_block *deskey)
154 {
155 	cryptkeyarg2 arg;
156 	cryptkeyres res;
157 
158 	arg.remotename = remotename;
159 	arg.remotekey = *remotekey;
160 	arg.deskey = *deskey;
161 	if (!key_call((u_long)KEY_DECRYPT_PK, (xdrproc_t)xdr_cryptkeyarg2, &arg,
162 			(xdrproc_t)xdr_cryptkeyres, &res)) {
163 		return (-1);
164 	}
165 	if (res.status != KEY_SUCCESS) {
166 		debug("decrypt status is nonzero");
167 		return (-1);
168 	}
169 	*deskey = res.cryptkeyres_u.deskey;
170 	return (0);
171 }
172 
173 int
174 key_encryptsession(const char *remotename, des_block *deskey)
175 {
176 	cryptkeyarg arg;
177 	cryptkeyres res;
178 
179 	arg.remotename = (char *) remotename;
180 	arg.deskey = *deskey;
181 	if (!key_call((u_long)KEY_ENCRYPT, (xdrproc_t)xdr_cryptkeyarg, &arg,
182 			(xdrproc_t)xdr_cryptkeyres, &res)) {
183 		return (-1);
184 	}
185 	if (res.status != KEY_SUCCESS) {
186 		debug("encrypt status is nonzero");
187 		return (-1);
188 	}
189 	*deskey = res.cryptkeyres_u.deskey;
190 	return (0);
191 }
192 
193 int
194 key_decryptsession(const char *remotename, des_block *deskey)
195 {
196 	cryptkeyarg arg;
197 	cryptkeyres res;
198 
199 	arg.remotename = (char *) remotename;
200 	arg.deskey = *deskey;
201 	if (!key_call((u_long)KEY_DECRYPT, (xdrproc_t)xdr_cryptkeyarg, &arg,
202 			(xdrproc_t)xdr_cryptkeyres, &res)) {
203 		return (-1);
204 	}
205 	if (res.status != KEY_SUCCESS) {
206 		debug("decrypt status is nonzero");
207 		return (-1);
208 	}
209 	*deskey = res.cryptkeyres_u.deskey;
210 	return (0);
211 }
212 
213 int
214 key_gendes(des_block *key)
215 {
216 	if (!key_call((u_long)KEY_GEN, (xdrproc_t)xdr_void, NULL,
217 			(xdrproc_t)xdr_des_block, key)) {
218 		return (-1);
219 	}
220 	return (0);
221 }
222 
223 int
224 key_setnet(struct key_netstarg *arg)
225 {
226 	keystatus status;
227 
228 
229 	if (!key_call((u_long) KEY_NET_PUT, (xdrproc_t)xdr_key_netstarg, arg,
230 			(xdrproc_t)xdr_keystatus, &status)){
231 		return (-1);
232 	}
233 
234 	if (status != KEY_SUCCESS) {
235 		debug("key_setnet status is nonzero");
236 		return (-1);
237 	}
238 	return (1);
239 }
240 
241 
242 int
243 key_get_conv(char *pkey, des_block *deskey)
244 {
245 	cryptkeyres res;
246 
247 	if (!key_call((u_long) KEY_GET_CONV, (xdrproc_t)xdr_keybuf, pkey,
248 			(xdrproc_t)xdr_cryptkeyres, &res)) {
249 		return (-1);
250 	}
251 	if (res.status != KEY_SUCCESS) {
252 		debug("get_conv status is nonzero");
253 		return (-1);
254 	}
255 	*deskey = res.cryptkeyres_u.deskey;
256 	return (0);
257 }
258 
259 struct  key_call_private {
260 	CLIENT	*client;	/* Client handle */
261 	pid_t	pid;		/* process-id at moment of creation */
262 	uid_t	uid;		/* user-id at last authorization */
263 };
264 static struct key_call_private *key_call_private_main = NULL;
265 static thread_key_t key_call_key;
266 static once_t key_call_once = ONCE_INITIALIZER;
267 static int key_call_key_error;
268 
269 static void
270 key_call_destroy(void *vp)
271 {
272 	struct key_call_private *kcp = (struct key_call_private *)vp;
273 
274 	if (kcp) {
275 		if (kcp->client)
276 			clnt_destroy(kcp->client);
277 		free(kcp);
278 	}
279 }
280 
281 static void
282 key_call_init(void)
283 {
284 
285 	key_call_key_error = thr_keycreate(&key_call_key, key_call_destroy);
286 }
287 
288 /*
289  * Keep the handle cached.  This call may be made quite often.
290  */
291 static CLIENT *
292 getkeyserv_handle(int vers)
293 {
294 	void *localhandle;
295 	struct netconfig *nconf;
296 	struct netconfig *tpconf;
297 	struct key_call_private *kcp;
298 	struct timeval wait_time;
299 	struct utsname u;
300 	int main_thread;
301 	int fd;
302 
303 #define	TOTAL_TIMEOUT	30	/* total timeout talking to keyserver */
304 #define	TOTAL_TRIES	5	/* Number of tries */
305 
306 	if ((main_thread = thr_main())) {
307 		kcp = key_call_private_main;
308 	} else {
309 		if (thr_once(&key_call_once, key_call_init) != 0 ||
310 		    key_call_key_error != 0)
311 			return ((CLIENT *) NULL);
312 		kcp = (struct key_call_private *)thr_getspecific(key_call_key);
313 	}
314 	if (kcp == (struct key_call_private *)NULL) {
315 		kcp = (struct key_call_private *)malloc(sizeof (*kcp));
316 		if (kcp == (struct key_call_private *)NULL) {
317 			return ((CLIENT *) NULL);
318 		}
319                 if (main_thread)
320                         key_call_private_main = kcp;
321                 else
322                         thr_setspecific(key_call_key, (void *) kcp);
323 		kcp->client = NULL;
324 	}
325 
326 	/* if pid has changed, destroy client and rebuild */
327 	if (kcp->client != NULL && kcp->pid != getpid()) {
328 		clnt_destroy(kcp->client);
329 		kcp->client = NULL;
330 	}
331 
332 	if (kcp->client != NULL) {
333 		/* if uid has changed, build client handle again */
334 		if (kcp->uid != geteuid()) {
335 			kcp->uid = geteuid();
336 			auth_destroy(kcp->client->cl_auth);
337 			kcp->client->cl_auth =
338 				authsys_create("", kcp->uid, 0, 0, NULL);
339 			if (kcp->client->cl_auth == NULL) {
340 				clnt_destroy(kcp->client);
341 				kcp->client = NULL;
342 				return ((CLIENT *) NULL);
343 			}
344 		}
345 		/* Change the version number to the new one */
346 		clnt_control(kcp->client, CLSET_VERS, (void *)&vers);
347 		return (kcp->client);
348 	}
349 	if (!(localhandle = setnetconfig())) {
350 		return ((CLIENT *) NULL);
351 	}
352         tpconf = NULL;
353 #if defined(__FreeBSD__)
354 	if (uname(&u) == -1)
355 #else
356 #if defined(i386)
357 	if (_nuname(&u) == -1)
358 #elif defined(sparc)
359 	if (_uname(&u) == -1)
360 #else
361 #error Unknown architecture!
362 #endif
363 #endif
364 	{
365 		endnetconfig(localhandle);
366 		return ((CLIENT *) NULL);
367         }
368 	while ((nconf = getnetconfig(localhandle)) != NULL) {
369 		if (strcmp(nconf->nc_protofmly, NC_LOOPBACK) == 0) {
370 			/*
371 			 * We use COTS_ORD here so that the caller can
372 			 * find out immediately if the server is dead.
373 			 */
374 			if (nconf->nc_semantics == NC_TPI_COTS_ORD) {
375 				kcp->client = clnt_tp_create(u.nodename,
376 					KEY_PROG, vers, nconf);
377 				if (kcp->client)
378 					break;
379 			} else {
380 				tpconf = nconf;
381 			}
382 		}
383 	}
384 	if ((kcp->client == (CLIENT *) NULL) && (tpconf))
385 		/* Now, try the CLTS or COTS loopback transport */
386 		kcp->client = clnt_tp_create(u.nodename,
387 			KEY_PROG, vers, tpconf);
388 	endnetconfig(localhandle);
389 
390 	if (kcp->client == (CLIENT *) NULL) {
391 		return ((CLIENT *) NULL);
392         }
393 	kcp->uid = geteuid();
394 	kcp->pid = getpid();
395 	kcp->client->cl_auth = authsys_create("", kcp->uid, 0, 0, NULL);
396 	if (kcp->client->cl_auth == NULL) {
397 		clnt_destroy(kcp->client);
398 		kcp->client = NULL;
399 		return ((CLIENT *) NULL);
400 	}
401 
402 	wait_time.tv_sec = TOTAL_TIMEOUT/TOTAL_TRIES;
403 	wait_time.tv_usec = 0;
404 	(void) clnt_control(kcp->client, CLSET_RETRY_TIMEOUT,
405 		(char *)&wait_time);
406 	if (clnt_control(kcp->client, CLGET_FD, (char *)&fd))
407 		_fcntl(fd, F_SETFD, 1);	/* make it "close on exec" */
408 
409 	return (kcp->client);
410 }
411 
412 /* returns  0 on failure, 1 on success */
413 
414 static int
415 key_call(u_long proc, xdrproc_t xdr_arg, void *arg, xdrproc_t xdr_rslt,
416     void *rslt)
417 {
418 	CLIENT *clnt;
419 	struct timeval wait_time;
420 
421 	if (proc == KEY_ENCRYPT_PK && __key_encryptsession_pk_LOCAL) {
422 		cryptkeyres *res;
423 		res = (*__key_encryptsession_pk_LOCAL)(geteuid(), arg);
424 		*(cryptkeyres*)rslt = *res;
425 		return (1);
426 	} else if (proc == KEY_DECRYPT_PK && __key_decryptsession_pk_LOCAL) {
427 		cryptkeyres *res;
428 		res = (*__key_decryptsession_pk_LOCAL)(geteuid(), arg);
429 		*(cryptkeyres*)rslt = *res;
430 		return (1);
431 	} else if (proc == KEY_GEN && __key_gendes_LOCAL) {
432 		des_block *res;
433 		res = (*__key_gendes_LOCAL)(geteuid(), 0);
434 		*(des_block*)rslt = *res;
435 		return (1);
436 	}
437 
438 	if ((proc == KEY_ENCRYPT_PK) || (proc == KEY_DECRYPT_PK) ||
439 	    (proc == KEY_NET_GET) || (proc == KEY_NET_PUT) ||
440 	    (proc == KEY_GET_CONV))
441 		clnt = getkeyserv_handle(2); /* talk to version 2 */
442 	else
443 		clnt = getkeyserv_handle(1); /* talk to version 1 */
444 
445 	if (clnt == NULL) {
446 		return (0);
447 	}
448 
449 	wait_time.tv_sec = TOTAL_TIMEOUT;
450 	wait_time.tv_usec = 0;
451 
452 	if (clnt_call(clnt, proc, xdr_arg, arg, xdr_rslt, rslt,
453 		wait_time) == RPC_SUCCESS) {
454 		return (1);
455 	} else {
456 		return (0);
457 	}
458 }
459