xref: /freebsd/lib/libc/rpc/key_call.c (revision 22cf89c938886d14f5796fc49f9f020c23ea8eaf)
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 #include <sys/cdefs.h>
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)(uid_t, void *arg) = 0;
85 cryptkeyres *(*__key_decryptsession_pk_LOCAL)(uid_t, void *arg) = 0;
86 des_block *(*__key_gendes_LOCAL)(uid_t, void *) = 0;
87 
88 static int key_call( u_long, xdrproc_t, void *, xdrproc_t, void *);
89 
90 int
91 key_setsecret(const char *secretkey)
92 {
93 	keystatus status;
94 
95 	if (!key_call((u_long) KEY_SET, (xdrproc_t)xdr_keybuf,
96 			(void *)secretkey,
97 			(xdrproc_t)xdr_keystatus, &status)) {
98 		return (-1);
99 	}
100 	if (status != KEY_SUCCESS) {
101 		debug("set status is nonzero");
102 		return (-1);
103 	}
104 	return (0);
105 }
106 
107 
108 /* key_secretkey_is_set() returns 1 if the keyserver has a secret key
109  * stored for the caller's effective uid; it returns 0 otherwise
110  *
111  * N.B.:  The KEY_NET_GET key call is undocumented.  Applications shouldn't
112  * be using it, because it allows them to get the user's secret key.
113  */
114 
115 int
116 key_secretkey_is_set(void)
117 {
118 	struct key_netstres 	kres;
119 
120 	memset((void*)&kres, 0, sizeof (kres));
121 	if (key_call((u_long) KEY_NET_GET, (xdrproc_t)xdr_void, NULL,
122 			(xdrproc_t)xdr_key_netstres, &kres) &&
123 	    (kres.status == KEY_SUCCESS) &&
124 	    (kres.key_netstres_u.knet.st_priv_key[0] != 0)) {
125 		/* avoid leaving secret key in memory */
126 		memset(kres.key_netstres_u.knet.st_priv_key, 0, HEXKEYBYTES);
127 		return (1);
128 	}
129 	return (0);
130 }
131 
132 int
133 key_encryptsession_pk(char *remotename, netobj *remotekey, des_block *deskey)
134 {
135 	cryptkeyarg2 arg;
136 	cryptkeyres res;
137 
138 	arg.remotename = remotename;
139 	arg.remotekey = *remotekey;
140 	arg.deskey = *deskey;
141 	if (!key_call((u_long)KEY_ENCRYPT_PK, (xdrproc_t)xdr_cryptkeyarg2, &arg,
142 			(xdrproc_t)xdr_cryptkeyres, &res)) {
143 		return (-1);
144 	}
145 	if (res.status != KEY_SUCCESS) {
146 		debug("encrypt status is nonzero");
147 		return (-1);
148 	}
149 	*deskey = res.cryptkeyres_u.deskey;
150 	return (0);
151 }
152 
153 int
154 key_decryptsession_pk(char *remotename, netobj *remotekey, des_block *deskey)
155 {
156 	cryptkeyarg2 arg;
157 	cryptkeyres res;
158 
159 	arg.remotename = remotename;
160 	arg.remotekey = *remotekey;
161 	arg.deskey = *deskey;
162 	if (!key_call((u_long)KEY_DECRYPT_PK, (xdrproc_t)xdr_cryptkeyarg2, &arg,
163 			(xdrproc_t)xdr_cryptkeyres, &res)) {
164 		return (-1);
165 	}
166 	if (res.status != KEY_SUCCESS) {
167 		debug("decrypt status is nonzero");
168 		return (-1);
169 	}
170 	*deskey = res.cryptkeyres_u.deskey;
171 	return (0);
172 }
173 
174 int
175 key_encryptsession(const char *remotename, des_block *deskey)
176 {
177 	cryptkeyarg arg;
178 	cryptkeyres res;
179 
180 	arg.remotename = (char *) remotename;
181 	arg.deskey = *deskey;
182 	if (!key_call((u_long)KEY_ENCRYPT, (xdrproc_t)xdr_cryptkeyarg, &arg,
183 			(xdrproc_t)xdr_cryptkeyres, &res)) {
184 		return (-1);
185 	}
186 	if (res.status != KEY_SUCCESS) {
187 		debug("encrypt status is nonzero");
188 		return (-1);
189 	}
190 	*deskey = res.cryptkeyres_u.deskey;
191 	return (0);
192 }
193 
194 int
195 key_decryptsession(const char *remotename, des_block *deskey)
196 {
197 	cryptkeyarg arg;
198 	cryptkeyres res;
199 
200 	arg.remotename = (char *) remotename;
201 	arg.deskey = *deskey;
202 	if (!key_call((u_long)KEY_DECRYPT, (xdrproc_t)xdr_cryptkeyarg, &arg,
203 			(xdrproc_t)xdr_cryptkeyres, &res)) {
204 		return (-1);
205 	}
206 	if (res.status != KEY_SUCCESS) {
207 		debug("decrypt status is nonzero");
208 		return (-1);
209 	}
210 	*deskey = res.cryptkeyres_u.deskey;
211 	return (0);
212 }
213 
214 int
215 key_gendes(des_block *key)
216 {
217 	if (!key_call((u_long)KEY_GEN, (xdrproc_t)xdr_void, NULL,
218 			(xdrproc_t)xdr_des_block, key)) {
219 		return (-1);
220 	}
221 	return (0);
222 }
223 
224 int
225 key_setnet(struct key_netstarg *arg)
226 {
227 	keystatus status;
228 
229 
230 	if (!key_call((u_long) KEY_NET_PUT, (xdrproc_t)xdr_key_netstarg, arg,
231 			(xdrproc_t)xdr_keystatus, &status)){
232 		return (-1);
233 	}
234 
235 	if (status != KEY_SUCCESS) {
236 		debug("key_setnet status is nonzero");
237 		return (-1);
238 	}
239 	return (1);
240 }
241 
242 
243 int
244 key_get_conv(char *pkey, des_block *deskey)
245 {
246 	cryptkeyres res;
247 
248 	if (!key_call((u_long) KEY_GET_CONV, (xdrproc_t)xdr_keybuf, pkey,
249 			(xdrproc_t)xdr_cryptkeyres, &res)) {
250 		return (-1);
251 	}
252 	if (res.status != KEY_SUCCESS) {
253 		debug("get_conv status is nonzero");
254 		return (-1);
255 	}
256 	*deskey = res.cryptkeyres_u.deskey;
257 	return (0);
258 }
259 
260 struct  key_call_private {
261 	CLIENT	*client;	/* Client handle */
262 	pid_t	pid;		/* process-id at moment of creation */
263 	uid_t	uid;		/* user-id at last authorization */
264 };
265 static struct key_call_private *key_call_private_main = NULL;
266 static thread_key_t key_call_key;
267 static once_t key_call_once = ONCE_INITIALIZER;
268 static int key_call_key_error;
269 
270 static void
271 key_call_destroy(void *vp)
272 {
273 	struct key_call_private *kcp = (struct key_call_private *)vp;
274 
275 	if (kcp) {
276 		if (kcp->client)
277 			clnt_destroy(kcp->client);
278 		free(kcp);
279 	}
280 }
281 
282 static void
283 key_call_init(void)
284 {
285 
286 	key_call_key_error = thr_keycreate(&key_call_key, key_call_destroy);
287 }
288 
289 /*
290  * Keep the handle cached.  This call may be made quite often.
291  */
292 static CLIENT *
293 getkeyserv_handle(int vers)
294 {
295 	void *localhandle;
296 	struct netconfig *nconf;
297 	struct netconfig *tpconf;
298 	struct key_call_private *kcp;
299 	struct timeval wait_time;
300 	struct utsname u;
301 	int main_thread;
302 	int fd;
303 
304 #define	TOTAL_TIMEOUT	30	/* total timeout talking to keyserver */
305 #define	TOTAL_TRIES	5	/* Number of tries */
306 
307 	if ((main_thread = thr_main())) {
308 		kcp = key_call_private_main;
309 	} else {
310 		if (thr_once(&key_call_once, key_call_init) != 0 ||
311 		    key_call_key_error != 0)
312 			return ((CLIENT *) NULL);
313 		kcp = (struct key_call_private *)thr_getspecific(key_call_key);
314 	}
315 	if (kcp == (struct key_call_private *)NULL) {
316 		kcp = (struct key_call_private *)malloc(sizeof (*kcp));
317 		if (kcp == (struct key_call_private *)NULL) {
318 			return ((CLIENT *) NULL);
319 		}
320                 if (main_thread)
321                         key_call_private_main = kcp;
322                 else
323                         thr_setspecific(key_call_key, (void *) kcp);
324 		kcp->client = NULL;
325 	}
326 
327 	/* if pid has changed, destroy client and rebuild */
328 	if (kcp->client != NULL && kcp->pid != getpid()) {
329 		clnt_destroy(kcp->client);
330 		kcp->client = NULL;
331 	}
332 
333 	if (kcp->client != NULL) {
334 		/* if uid has changed, build client handle again */
335 		if (kcp->uid != geteuid()) {
336 			kcp->uid = geteuid();
337 			auth_destroy(kcp->client->cl_auth);
338 			kcp->client->cl_auth =
339 				authsys_create("", kcp->uid, 0, 0, NULL);
340 			if (kcp->client->cl_auth == NULL) {
341 				clnt_destroy(kcp->client);
342 				kcp->client = NULL;
343 				return ((CLIENT *) NULL);
344 			}
345 		}
346 		/* Change the version number to the new one */
347 		clnt_control(kcp->client, CLSET_VERS, (void *)&vers);
348 		return (kcp->client);
349 	}
350 	if (!(localhandle = setnetconfig())) {
351 		return ((CLIENT *) NULL);
352 	}
353         tpconf = NULL;
354 #if defined(__FreeBSD__)
355 	if (uname(&u) == -1)
356 #else
357 #if defined(i386)
358 	if (_nuname(&u) == -1)
359 #elif defined(sparc)
360 	if (_uname(&u) == -1)
361 #else
362 #error Unknown architecture!
363 #endif
364 #endif
365 	{
366 		endnetconfig(localhandle);
367 		return ((CLIENT *) NULL);
368         }
369 	while ((nconf = getnetconfig(localhandle)) != NULL) {
370 		if (strcmp(nconf->nc_protofmly, NC_LOOPBACK) == 0) {
371 			/*
372 			 * We use COTS_ORD here so that the caller can
373 			 * find out immediately if the server is dead.
374 			 */
375 			if (nconf->nc_semantics == NC_TPI_COTS_ORD) {
376 				kcp->client = clnt_tp_create(u.nodename,
377 					KEY_PROG, vers, nconf);
378 				if (kcp->client)
379 					break;
380 			} else {
381 				tpconf = nconf;
382 			}
383 		}
384 	}
385 	if ((kcp->client == (CLIENT *) NULL) && (tpconf))
386 		/* Now, try the CLTS or COTS loopback transport */
387 		kcp->client = clnt_tp_create(u.nodename,
388 			KEY_PROG, vers, tpconf);
389 	endnetconfig(localhandle);
390 
391 	if (kcp->client == (CLIENT *) NULL) {
392 		return ((CLIENT *) NULL);
393         }
394 	kcp->uid = geteuid();
395 	kcp->pid = getpid();
396 	kcp->client->cl_auth = authsys_create("", kcp->uid, 0, 0, NULL);
397 	if (kcp->client->cl_auth == NULL) {
398 		clnt_destroy(kcp->client);
399 		kcp->client = NULL;
400 		return ((CLIENT *) NULL);
401 	}
402 
403 	wait_time.tv_sec = TOTAL_TIMEOUT/TOTAL_TRIES;
404 	wait_time.tv_usec = 0;
405 	(void) clnt_control(kcp->client, CLSET_RETRY_TIMEOUT,
406 		(char *)&wait_time);
407 	if (clnt_control(kcp->client, CLGET_FD, (char *)&fd))
408 		_fcntl(fd, F_SETFD, 1);	/* make it "close on exec" */
409 
410 	return (kcp->client);
411 }
412 
413 /* returns  0 on failure, 1 on success */
414 
415 static int
416 key_call(u_long proc, xdrproc_t xdr_arg, void *arg, xdrproc_t xdr_rslt,
417     void *rslt)
418 {
419 	CLIENT *clnt;
420 	struct timeval wait_time;
421 
422 	if (proc == KEY_ENCRYPT_PK && __key_encryptsession_pk_LOCAL) {
423 		cryptkeyres *res;
424 		res = (*__key_encryptsession_pk_LOCAL)(geteuid(), arg);
425 		*(cryptkeyres*)rslt = *res;
426 		return (1);
427 	} else if (proc == KEY_DECRYPT_PK && __key_decryptsession_pk_LOCAL) {
428 		cryptkeyres *res;
429 		res = (*__key_decryptsession_pk_LOCAL)(geteuid(), arg);
430 		*(cryptkeyres*)rslt = *res;
431 		return (1);
432 	} else if (proc == KEY_GEN && __key_gendes_LOCAL) {
433 		des_block *res;
434 		res = (*__key_gendes_LOCAL)(geteuid(), 0);
435 		*(des_block*)rslt = *res;
436 		return (1);
437 	}
438 
439 	if ((proc == KEY_ENCRYPT_PK) || (proc == KEY_DECRYPT_PK) ||
440 	    (proc == KEY_NET_GET) || (proc == KEY_NET_PUT) ||
441 	    (proc == KEY_GET_CONV))
442 		clnt = getkeyserv_handle(2); /* talk to version 2 */
443 	else
444 		clnt = getkeyserv_handle(1); /* talk to version 1 */
445 
446 	if (clnt == NULL) {
447 		return (0);
448 	}
449 
450 	wait_time.tv_sec = TOTAL_TIMEOUT;
451 	wait_time.tv_usec = 0;
452 
453 	if (clnt_call(clnt, proc, xdr_arg, arg, xdr_rslt, rslt,
454 		wait_time) == RPC_SUCCESS) {
455 		return (1);
456 	} else {
457 		return (0);
458 	}
459 }
460