xref: /dragonfly/lib/libc/rpc/key_call.c (revision 279dd846)
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  * @(#)key_call.c	1.25	94/04/24 SMI
32  * $FreeBSD: src/lib/libc/rpc/key_call.c,v 1.16 2006/02/27 22:10:59 deischen Exp $
33  */
34 
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 <signal.h>
58 #include <sys/wait.h>
59 #include <sys/fcntl.h>
60 #include "un-namespace.h"
61 #include "mt_misc.h"
62 
63 
64 #define	KEY_TIMEOUT	5	/* per-try timeout in seconds */
65 #define	KEY_NRETRY	12	/* number of retries */
66 
67 #ifdef DEBUG
68 #define	debug(msg)	fprintf(stderr, "%s\n", msg);
69 #else
70 #define	debug(msg)
71 #endif /* DEBUG */
72 
73 /*
74  * Hack to allow the keyserver to use AUTH_DES (for authenticated
75  * NIS+ calls, for example).  The only functions that get called
76  * are key_encryptsession_pk, key_decryptsession_pk, and key_gendes.
77  *
78  * The approach is to have the keyserver fill in pointers to local
79  * implementations of these functions, and to call those in key_call().
80  */
81 
82 cryptkeyres *(*__key_encryptsession_pk_LOCAL)() = NULL;
83 cryptkeyres *(*__key_decryptsession_pk_LOCAL)() = NULL;
84 des_block *(*__key_gendes_LOCAL)() = NULL;
85 
86 static int key_call( u_long, xdrproc_t, void *, xdrproc_t, void *);
87 
88 int
89 key_setsecret(const char *secretkey)
90 {
91 	keystatus status;
92 
93 	if (!key_call((u_long) KEY_SET, (xdrproc_t)xdr_keybuf,
94 			(void *)secretkey,
95 			(xdrproc_t)xdr_keystatus, &status)) {
96 		return (-1);
97 	}
98 	if (status != KEY_SUCCESS) {
99 		debug("set status is nonzero");
100 		return (-1);
101 	}
102 	return (0);
103 }
104 
105 
106 /* key_secretkey_is_set() returns 1 if the keyserver has a secret key
107  * stored for the caller's effective uid; it returns 0 otherwise
108  *
109  * N.B.:  The KEY_NET_GET key call is undocumented.  Applications shouldn't
110  * be using it, because it allows them to get the user's secret key.
111  */
112 
113 int
114 key_secretkey_is_set(void)
115 {
116 	struct key_netstres 	kres;
117 
118 	memset((void*)&kres, 0, sizeof (kres));
119 	if (key_call((u_long) KEY_NET_GET, (xdrproc_t)xdr_void, NULL,
120 			(xdrproc_t)xdr_key_netstres, &kres) &&
121 	    (kres.status == KEY_SUCCESS) &&
122 	    (kres.key_netstres_u.knet.st_priv_key[0] != 0)) {
123 		/* avoid leaving secret key in memory */
124 		memset(kres.key_netstres_u.knet.st_priv_key, 0, HEXKEYBYTES);
125 		return (1);
126 	}
127 	return (0);
128 }
129 
130 int
131 key_encryptsession_pk(char *remotename, netobj *remotekey, des_block *deskey)
132 {
133 	cryptkeyarg2 arg;
134 	cryptkeyres res;
135 
136 	arg.remotename = remotename;
137 	arg.remotekey = *remotekey;
138 	arg.deskey = *deskey;
139 	if (!key_call((u_long)KEY_ENCRYPT_PK, (xdrproc_t)xdr_cryptkeyarg2, &arg,
140 			(xdrproc_t)xdr_cryptkeyres, &res)) {
141 		return (-1);
142 	}
143 	if (res.status != KEY_SUCCESS) {
144 		debug("encrypt status is nonzero");
145 		return (-1);
146 	}
147 	*deskey = res.cryptkeyres_u.deskey;
148 	return (0);
149 }
150 
151 int
152 key_decryptsession_pk(char *remotename, netobj *remotekey, des_block *deskey)
153 {
154 	cryptkeyarg2 arg;
155 	cryptkeyres res;
156 
157 	arg.remotename = remotename;
158 	arg.remotekey = *remotekey;
159 	arg.deskey = *deskey;
160 	if (!key_call((u_long)KEY_DECRYPT_PK, (xdrproc_t)xdr_cryptkeyarg2, &arg,
161 			(xdrproc_t)xdr_cryptkeyres, &res)) {
162 		return (-1);
163 	}
164 	if (res.status != KEY_SUCCESS) {
165 		debug("decrypt status is nonzero");
166 		return (-1);
167 	}
168 	*deskey = res.cryptkeyres_u.deskey;
169 	return (0);
170 }
171 
172 int
173 key_encryptsession(const char *remotename, des_block *deskey)
174 {
175 	cryptkeyarg arg;
176 	cryptkeyres res;
177 
178 	arg.remotename = (char *) remotename;
179 	arg.deskey = *deskey;
180 	if (!key_call((u_long)KEY_ENCRYPT, (xdrproc_t)xdr_cryptkeyarg, &arg,
181 			(xdrproc_t)xdr_cryptkeyres, &res)) {
182 		return (-1);
183 	}
184 	if (res.status != KEY_SUCCESS) {
185 		debug("encrypt status is nonzero");
186 		return (-1);
187 	}
188 	*deskey = res.cryptkeyres_u.deskey;
189 	return (0);
190 }
191 
192 int
193 key_decryptsession(const char *remotename, des_block *deskey)
194 {
195 	cryptkeyarg arg;
196 	cryptkeyres res;
197 
198 	arg.remotename = (char *) remotename;
199 	arg.deskey = *deskey;
200 	if (!key_call((u_long)KEY_DECRYPT, (xdrproc_t)xdr_cryptkeyarg, &arg,
201 			(xdrproc_t)xdr_cryptkeyres, &res)) {
202 		return (-1);
203 	}
204 	if (res.status != KEY_SUCCESS) {
205 		debug("decrypt status is nonzero");
206 		return (-1);
207 	}
208 	*deskey = res.cryptkeyres_u.deskey;
209 	return (0);
210 }
211 
212 int
213 key_gendes(des_block *key)
214 {
215 	if (!key_call((u_long)KEY_GEN, (xdrproc_t)xdr_void, NULL,
216 			(xdrproc_t)xdr_des_block, key)) {
217 		return (-1);
218 	}
219 	return (0);
220 }
221 
222 int
223 key_setnet(struct key_netstarg *arg)
224 {
225 	keystatus status;
226 
227 
228 	if (!key_call((u_long) KEY_NET_PUT, (xdrproc_t)xdr_key_netstarg, arg,
229 			(xdrproc_t)xdr_keystatus, &status)){
230 		return (-1);
231 	}
232 
233 	if (status != KEY_SUCCESS) {
234 		debug("key_setnet status is nonzero");
235 		return (-1);
236 	}
237 	return (1);
238 }
239 
240 
241 int
242 key_get_conv(char *pkey, des_block *deskey)
243 {
244 	cryptkeyres res;
245 
246 	if (!key_call((u_long) KEY_GET_CONV, (xdrproc_t)xdr_keybuf, pkey,
247 			(xdrproc_t)xdr_cryptkeyres, &res)) {
248 		return (-1);
249 	}
250 	if (res.status != KEY_SUCCESS) {
251 		debug("get_conv status is nonzero");
252 		return (-1);
253 	}
254 	*deskey = res.cryptkeyres_u.deskey;
255 	return (0);
256 }
257 
258 struct  key_call_private {
259 	CLIENT	*client;	/* Client handle */
260 	pid_t	pid;		/* process-id at moment of creation */
261 	uid_t	uid;		/* user-id at last authorization */
262 };
263 static struct key_call_private *key_call_private_main = NULL;
264 
265 static void
266 key_call_destroy(void *vp)
267 {
268 	struct key_call_private *kcp = (struct key_call_private *)vp;
269 
270 	if (kcp) {
271 		if (kcp->client)
272 			clnt_destroy(kcp->client);
273 		free(kcp);
274 	}
275 }
276 
277 /*
278  * Keep the handle cached.  This call may be made quite often.
279  */
280 static CLIENT *
281 getkeyserv_handle(int vers)
282 {
283 	void *localhandle;
284 	struct netconfig *nconf;
285 	struct netconfig *tpconf;
286 	struct key_call_private *kcp = key_call_private_main;
287 	struct timeval wait_time;
288 	struct utsname u;
289 	int main_thread;
290 	int fd;
291 	static thread_key_t key_call_key;
292 
293 #define	TOTAL_TIMEOUT	30	/* total timeout talking to keyserver */
294 #define	TOTAL_TRIES	5	/* Number of tries */
295 
296 	if ((main_thread = thr_main())) {
297 		kcp = key_call_private_main;
298 	} else {
299 		if (key_call_key == 0) {
300 			mutex_lock(&tsd_lock);
301 			if (key_call_key == 0)
302 				thr_keycreate(&key_call_key, key_call_destroy);
303 			mutex_unlock(&tsd_lock);
304 		}
305 		kcp = (struct key_call_private *)thr_getspecific(key_call_key);
306 	}
307 	if (kcp == NULL) {
308 		kcp = (struct key_call_private *)malloc(sizeof (*kcp));
309 		if (kcp == NULL) {
310 			return (NULL);
311 		}
312 		if (main_thread)
313 			key_call_private_main = kcp;
314 		else
315 			thr_setspecific(key_call_key, (void *) kcp);
316 		kcp->client = NULL;
317 	}
318 
319 	/* if pid has changed, destroy client and rebuild */
320 	if (kcp->client != NULL && kcp->pid != getpid()) {
321 		clnt_destroy(kcp->client);
322 		kcp->client = NULL;
323 	}
324 
325 	if (kcp->client != NULL) {
326 		/* if uid has changed, build client handle again */
327 		if (kcp->uid != geteuid()) {
328 			kcp->uid = geteuid();
329 			auth_destroy(kcp->client->cl_auth);
330 			kcp->client->cl_auth =
331 				authsys_create("", kcp->uid, 0, 0, NULL);
332 			if (kcp->client->cl_auth == NULL) {
333 				clnt_destroy(kcp->client);
334 				kcp->client = NULL;
335 				return (NULL);
336 			}
337 		}
338 		/* Change the version number to the new one */
339 		clnt_control(kcp->client, CLSET_VERS, (void *)&vers);
340 		return (kcp->client);
341 	}
342 	if (!(localhandle = setnetconfig())) {
343 		return (NULL);
344 	}
345 	tpconf = NULL;
346 	if (uname(&u) == -1)
347 	{
348 		endnetconfig(localhandle);
349 		return (NULL);
350 	}
351 	while ((nconf = getnetconfig(localhandle)) != NULL) {
352 		if (strcmp(nconf->nc_protofmly, NC_LOOPBACK) == 0) {
353 			/*
354 			 * We use COTS_ORD here so that the caller can
355 			 * find out immediately if the server is dead.
356 			 */
357 			if (nconf->nc_semantics == NC_TPI_COTS_ORD) {
358 				kcp->client = clnt_tp_create(u.nodename,
359 					KEY_PROG, vers, nconf);
360 				if (kcp->client)
361 					break;
362 			} else {
363 				tpconf = nconf;
364 			}
365 		}
366 	}
367 	if ((kcp->client == NULL) && (tpconf))
368 		/* Now, try the CLTS or COTS loopback transport */
369 		kcp->client = clnt_tp_create(u.nodename,
370 			KEY_PROG, vers, tpconf);
371 	endnetconfig(localhandle);
372 
373 	if (kcp->client == NULL) {
374 		return (NULL);
375 	}
376 	kcp->uid = geteuid();
377 	kcp->pid = getpid();
378 	kcp->client->cl_auth = authsys_create("", kcp->uid, 0, 0, NULL);
379 	if (kcp->client->cl_auth == NULL) {
380 		clnt_destroy(kcp->client);
381 		kcp->client = NULL;
382 		return (NULL);
383 	}
384 
385 	wait_time.tv_sec = TOTAL_TIMEOUT/TOTAL_TRIES;
386 	wait_time.tv_usec = 0;
387 	clnt_control(kcp->client, CLSET_RETRY_TIMEOUT,
388 		(char *)&wait_time);
389 	if (clnt_control(kcp->client, CLGET_FD, (char *)&fd))
390 		_fcntl(fd, F_SETFD, 1);	/* make it "close on exec" */
391 
392 	return (kcp->client);
393 }
394 
395 /* returns  0 on failure, 1 on success */
396 
397 static int
398 key_call(u_long proc, xdrproc_t xdr_arg, void *arg, xdrproc_t xdr_rslt,
399 	 void *rslt)
400 {
401 	CLIENT *clnt;
402 	struct timeval wait_time;
403 
404 	if (proc == KEY_ENCRYPT_PK && __key_encryptsession_pk_LOCAL) {
405 		cryptkeyres *res;
406 		res = (*__key_encryptsession_pk_LOCAL)(geteuid(), arg);
407 		*(cryptkeyres*)rslt = *res;
408 		return (1);
409 	} else if (proc == KEY_DECRYPT_PK && __key_decryptsession_pk_LOCAL) {
410 		cryptkeyres *res;
411 		res = (*__key_decryptsession_pk_LOCAL)(geteuid(), arg);
412 		*(cryptkeyres*)rslt = *res;
413 		return (1);
414 	} else if (proc == KEY_GEN && __key_gendes_LOCAL) {
415 		des_block *res;
416 		res = (*__key_gendes_LOCAL)(geteuid(), 0);
417 		*(des_block*)rslt = *res;
418 		return (1);
419 	}
420 
421 	if ((proc == KEY_ENCRYPT_PK) || (proc == KEY_DECRYPT_PK) ||
422 	    (proc == KEY_NET_GET) || (proc == KEY_NET_PUT) ||
423 	    (proc == KEY_GET_CONV))
424 		clnt = getkeyserv_handle(2); /* talk to version 2 */
425 	else
426 		clnt = getkeyserv_handle(1); /* talk to version 1 */
427 
428 	if (clnt == NULL) {
429 		return (0);
430 	}
431 
432 	wait_time.tv_sec = TOTAL_TIMEOUT;
433 	wait_time.tv_usec = 0;
434 
435 	if (clnt_call(clnt, proc, xdr_arg, arg, xdr_rslt, rslt,
436 		wait_time) == RPC_SUCCESS) {
437 		return (1);
438 	} else {
439 		return (0);
440 	}
441 }
442