xref: /freebsd/lib/libc/rpc/key_call.c (revision 39beb93c3f8bdbf72a61fda42300b5ebed7390c8)
1 /*
2  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
3  * unrestricted use provided that this legend is included on all tape
4  * media and as a part of the software program in whole or part.  Users
5  * may copy or modify Sun RPC without charge, but are not authorized
6  * to license or distribute it to anyone else except as part of a product or
7  * program developed by the user.
8  *
9  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
10  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
11  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
12  *
13  * Sun RPC is provided with no support and without any obligation on the
14  * part of Sun Microsystems, Inc. to assist in its use, correction,
15  * modification or enhancement.
16  *
17  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
18  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
19  * OR ANY PART THEREOF.
20  *
21  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
22  * or profits or other special, indirect and consequential damages, even if
23  * Sun has been advised of the possibility of such damages.
24  *
25  * Sun Microsystems, Inc.
26  * 2550 Garcia Avenue
27  * Mountain View, California  94043
28  */
29 /*
30  * Copyright (c) 1986-1991 by Sun Microsystems Inc.
31  */
32 
33 #ident	"@(#)key_call.c	1.25	94/04/24 SMI"
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 /*
38  * key_call.c, Interface to keyserver
39  *
40  * setsecretkey(key) - set your secret key
41  * encryptsessionkey(agent, deskey) - encrypt a session key to talk to agent
42  * decryptsessionkey(agent, deskey) - decrypt ditto
43  * gendeskey(deskey) - generate a secure des key
44  */
45 
46 #include "namespace.h"
47 #include "reentrant.h"
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <unistd.h>
51 #include <errno.h>
52 #include <rpc/rpc.h>
53 #include <rpc/auth.h>
54 #include <rpc/auth_unix.h>
55 #include <rpc/key_prot.h>
56 #include <string.h>
57 #include <netconfig.h>
58 #include <sys/utsname.h>
59 #include <stdlib.h>
60 #include <signal.h>
61 #include <sys/wait.h>
62 #include <sys/fcntl.h>
63 #include "un-namespace.h"
64 #include "mt_misc.h"
65 
66 
67 #define	KEY_TIMEOUT	5	/* per-try timeout in seconds */
68 #define	KEY_NRETRY	12	/* number of retries */
69 
70 #ifdef DEBUG
71 #define	debug(msg)	(void) fprintf(stderr, "%s\n", msg);
72 #else
73 #define	debug(msg)
74 #endif /* DEBUG */
75 
76 /*
77  * Hack to allow the keyserver to use AUTH_DES (for authenticated
78  * NIS+ calls, for example).  The only functions that get called
79  * are key_encryptsession_pk, key_decryptsession_pk, and key_gendes.
80  *
81  * The approach is to have the keyserver fill in pointers to local
82  * implementations of these functions, and to call those in key_call().
83  */
84 
85 cryptkeyres *(*__key_encryptsession_pk_LOCAL)() = 0;
86 cryptkeyres *(*__key_decryptsession_pk_LOCAL)() = 0;
87 des_block *(*__key_gendes_LOCAL)() = 0;
88 
89 static int key_call( u_long, xdrproc_t, void *, xdrproc_t, void *);
90 
91 int
92 key_setsecret(secretkey)
93 	const char *secretkey;
94 {
95 	keystatus status;
96 
97 	if (!key_call((u_long) KEY_SET, (xdrproc_t)xdr_keybuf,
98 			(void *)secretkey,
99 			(xdrproc_t)xdr_keystatus, &status)) {
100 		return (-1);
101 	}
102 	if (status != KEY_SUCCESS) {
103 		debug("set status is nonzero");
104 		return (-1);
105 	}
106 	return (0);
107 }
108 
109 
110 /* key_secretkey_is_set() returns 1 if the keyserver has a secret key
111  * stored for the caller's effective uid; it returns 0 otherwise
112  *
113  * N.B.:  The KEY_NET_GET key call is undocumented.  Applications shouldn't
114  * be using it, because it allows them to get the user's secret key.
115  */
116 
117 int
118 key_secretkey_is_set(void)
119 {
120 	struct key_netstres 	kres;
121 
122 	memset((void*)&kres, 0, sizeof (kres));
123 	if (key_call((u_long) KEY_NET_GET, (xdrproc_t)xdr_void, NULL,
124 			(xdrproc_t)xdr_key_netstres, &kres) &&
125 	    (kres.status == KEY_SUCCESS) &&
126 	    (kres.key_netstres_u.knet.st_priv_key[0] != 0)) {
127 		/* avoid leaving secret key in memory */
128 		memset(kres.key_netstres_u.knet.st_priv_key, 0, HEXKEYBYTES);
129 		return (1);
130 	}
131 	return (0);
132 }
133 
134 int
135 key_encryptsession_pk(remotename, remotekey, deskey)
136 	char *remotename;
137 	netobj *remotekey;
138 	des_block *deskey;
139 {
140 	cryptkeyarg2 arg;
141 	cryptkeyres res;
142 
143 	arg.remotename = remotename;
144 	arg.remotekey = *remotekey;
145 	arg.deskey = *deskey;
146 	if (!key_call((u_long)KEY_ENCRYPT_PK, (xdrproc_t)xdr_cryptkeyarg2, &arg,
147 			(xdrproc_t)xdr_cryptkeyres, &res)) {
148 		return (-1);
149 	}
150 	if (res.status != KEY_SUCCESS) {
151 		debug("encrypt status is nonzero");
152 		return (-1);
153 	}
154 	*deskey = res.cryptkeyres_u.deskey;
155 	return (0);
156 }
157 
158 int
159 key_decryptsession_pk(remotename, remotekey, deskey)
160 	char *remotename;
161 	netobj *remotekey;
162 	des_block *deskey;
163 {
164 	cryptkeyarg2 arg;
165 	cryptkeyres res;
166 
167 	arg.remotename = remotename;
168 	arg.remotekey = *remotekey;
169 	arg.deskey = *deskey;
170 	if (!key_call((u_long)KEY_DECRYPT_PK, (xdrproc_t)xdr_cryptkeyarg2, &arg,
171 			(xdrproc_t)xdr_cryptkeyres, &res)) {
172 		return (-1);
173 	}
174 	if (res.status != KEY_SUCCESS) {
175 		debug("decrypt status is nonzero");
176 		return (-1);
177 	}
178 	*deskey = res.cryptkeyres_u.deskey;
179 	return (0);
180 }
181 
182 int
183 key_encryptsession(remotename, deskey)
184 	const char *remotename;
185 	des_block *deskey;
186 {
187 	cryptkeyarg arg;
188 	cryptkeyres res;
189 
190 	arg.remotename = (char *) remotename;
191 	arg.deskey = *deskey;
192 	if (!key_call((u_long)KEY_ENCRYPT, (xdrproc_t)xdr_cryptkeyarg, &arg,
193 			(xdrproc_t)xdr_cryptkeyres, &res)) {
194 		return (-1);
195 	}
196 	if (res.status != KEY_SUCCESS) {
197 		debug("encrypt status is nonzero");
198 		return (-1);
199 	}
200 	*deskey = res.cryptkeyres_u.deskey;
201 	return (0);
202 }
203 
204 int
205 key_decryptsession(remotename, deskey)
206 	const char *remotename;
207 	des_block *deskey;
208 {
209 	cryptkeyarg arg;
210 	cryptkeyres res;
211 
212 	arg.remotename = (char *) remotename;
213 	arg.deskey = *deskey;
214 	if (!key_call((u_long)KEY_DECRYPT, (xdrproc_t)xdr_cryptkeyarg, &arg,
215 			(xdrproc_t)xdr_cryptkeyres, &res)) {
216 		return (-1);
217 	}
218 	if (res.status != KEY_SUCCESS) {
219 		debug("decrypt status is nonzero");
220 		return (-1);
221 	}
222 	*deskey = res.cryptkeyres_u.deskey;
223 	return (0);
224 }
225 
226 int
227 key_gendes(key)
228 	des_block *key;
229 {
230 	if (!key_call((u_long)KEY_GEN, (xdrproc_t)xdr_void, NULL,
231 			(xdrproc_t)xdr_des_block, key)) {
232 		return (-1);
233 	}
234 	return (0);
235 }
236 
237 int
238 key_setnet(arg)
239 struct key_netstarg *arg;
240 {
241 	keystatus status;
242 
243 
244 	if (!key_call((u_long) KEY_NET_PUT, (xdrproc_t)xdr_key_netstarg, arg,
245 			(xdrproc_t)xdr_keystatus, &status)){
246 		return (-1);
247 	}
248 
249 	if (status != KEY_SUCCESS) {
250 		debug("key_setnet status is nonzero");
251 		return (-1);
252 	}
253 	return (1);
254 }
255 
256 
257 int
258 key_get_conv(pkey, deskey)
259 	char *pkey;
260 	des_block *deskey;
261 {
262 	cryptkeyres res;
263 
264 	if (!key_call((u_long) KEY_GET_CONV, (xdrproc_t)xdr_keybuf, pkey,
265 			(xdrproc_t)xdr_cryptkeyres, &res)) {
266 		return (-1);
267 	}
268 	if (res.status != KEY_SUCCESS) {
269 		debug("get_conv status is nonzero");
270 		return (-1);
271 	}
272 	*deskey = res.cryptkeyres_u.deskey;
273 	return (0);
274 }
275 
276 struct  key_call_private {
277 	CLIENT	*client;	/* Client handle */
278 	pid_t	pid;		/* process-id at moment of creation */
279 	uid_t	uid;		/* user-id at last authorization */
280 };
281 static struct key_call_private *key_call_private_main = NULL;
282 
283 static void
284 key_call_destroy(void *vp)
285 {
286 	struct key_call_private *kcp = (struct key_call_private *)vp;
287 
288 	if (kcp) {
289 		if (kcp->client)
290 			clnt_destroy(kcp->client);
291 		free(kcp);
292 	}
293 }
294 
295 /*
296  * Keep the handle cached.  This call may be made quite often.
297  */
298 static CLIENT *
299 getkeyserv_handle(vers)
300 int	vers;
301 {
302 	void *localhandle;
303 	struct netconfig *nconf;
304 	struct netconfig *tpconf;
305 	struct key_call_private *kcp = key_call_private_main;
306 	struct timeval wait_time;
307 	struct utsname u;
308 	int main_thread;
309 	int fd;
310 	static thread_key_t key_call_key;
311 
312 #define	TOTAL_TIMEOUT	30	/* total timeout talking to keyserver */
313 #define	TOTAL_TRIES	5	/* Number of tries */
314 
315 	if ((main_thread = thr_main())) {
316 		kcp = key_call_private_main;
317 	} else {
318 		if (key_call_key == 0) {
319 			mutex_lock(&tsd_lock);
320 			if (key_call_key == 0)
321 				thr_keycreate(&key_call_key, key_call_destroy);
322 			mutex_unlock(&tsd_lock);
323 		}
324 		kcp = (struct key_call_private *)thr_getspecific(key_call_key);
325 	}
326 	if (kcp == (struct key_call_private *)NULL) {
327 		kcp = (struct key_call_private *)malloc(sizeof (*kcp));
328 		if (kcp == (struct key_call_private *)NULL) {
329 			return ((CLIENT *) NULL);
330 		}
331                 if (main_thread)
332                         key_call_private_main = kcp;
333                 else
334                         thr_setspecific(key_call_key, (void *) kcp);
335 		kcp->client = NULL;
336 	}
337 
338 	/* if pid has changed, destroy client and rebuild */
339 	if (kcp->client != NULL && kcp->pid != getpid()) {
340 		clnt_destroy(kcp->client);
341 		kcp->client = NULL;
342 	}
343 
344 	if (kcp->client != NULL) {
345 		/* if uid has changed, build client handle again */
346 		if (kcp->uid != geteuid()) {
347 			kcp->uid = geteuid();
348 			auth_destroy(kcp->client->cl_auth);
349 			kcp->client->cl_auth =
350 				authsys_create("", kcp->uid, 0, 0, NULL);
351 			if (kcp->client->cl_auth == NULL) {
352 				clnt_destroy(kcp->client);
353 				kcp->client = NULL;
354 				return ((CLIENT *) NULL);
355 			}
356 		}
357 		/* Change the version number to the new one */
358 		clnt_control(kcp->client, CLSET_VERS, (void *)&vers);
359 		return (kcp->client);
360 	}
361 	if (!(localhandle = setnetconfig())) {
362 		return ((CLIENT *) NULL);
363 	}
364         tpconf = NULL;
365 #if defined(__FreeBSD__)
366 	if (uname(&u) == -1)
367 #else
368 #if defined(i386)
369 	if (_nuname(&u) == -1)
370 #elif defined(sparc)
371 	if (_uname(&u) == -1)
372 #else
373 #error Unknown architecture!
374 #endif
375 #endif
376 	{
377 		endnetconfig(localhandle);
378 		return ((CLIENT *) NULL);
379         }
380 	while ((nconf = getnetconfig(localhandle)) != NULL) {
381 		if (strcmp(nconf->nc_protofmly, NC_LOOPBACK) == 0) {
382 			/*
383 			 * We use COTS_ORD here so that the caller can
384 			 * find out immediately if the server is dead.
385 			 */
386 			if (nconf->nc_semantics == NC_TPI_COTS_ORD) {
387 				kcp->client = clnt_tp_create(u.nodename,
388 					KEY_PROG, vers, nconf);
389 				if (kcp->client)
390 					break;
391 			} else {
392 				tpconf = nconf;
393 			}
394 		}
395 	}
396 	if ((kcp->client == (CLIENT *) NULL) && (tpconf))
397 		/* Now, try the CLTS or COTS loopback transport */
398 		kcp->client = clnt_tp_create(u.nodename,
399 			KEY_PROG, vers, tpconf);
400 	endnetconfig(localhandle);
401 
402 	if (kcp->client == (CLIENT *) NULL) {
403 		return ((CLIENT *) NULL);
404         }
405 	kcp->uid = geteuid();
406 	kcp->pid = getpid();
407 	kcp->client->cl_auth = authsys_create("", kcp->uid, 0, 0, NULL);
408 	if (kcp->client->cl_auth == NULL) {
409 		clnt_destroy(kcp->client);
410 		kcp->client = NULL;
411 		return ((CLIENT *) NULL);
412 	}
413 
414 	wait_time.tv_sec = TOTAL_TIMEOUT/TOTAL_TRIES;
415 	wait_time.tv_usec = 0;
416 	(void) clnt_control(kcp->client, CLSET_RETRY_TIMEOUT,
417 		(char *)&wait_time);
418 	if (clnt_control(kcp->client, CLGET_FD, (char *)&fd))
419 		_fcntl(fd, F_SETFD, 1);	/* make it "close on exec" */
420 
421 	return (kcp->client);
422 }
423 
424 /* returns  0 on failure, 1 on success */
425 
426 static int
427 key_call(proc, xdr_arg, arg, xdr_rslt, rslt)
428 	u_long proc;
429 	xdrproc_t xdr_arg;
430 	void *arg;
431 	xdrproc_t xdr_rslt;
432 	void *rslt;
433 {
434 	CLIENT *clnt;
435 	struct timeval wait_time;
436 
437 	if (proc == KEY_ENCRYPT_PK && __key_encryptsession_pk_LOCAL) {
438 		cryptkeyres *res;
439 		res = (*__key_encryptsession_pk_LOCAL)(geteuid(), arg);
440 		*(cryptkeyres*)rslt = *res;
441 		return (1);
442 	} else if (proc == KEY_DECRYPT_PK && __key_decryptsession_pk_LOCAL) {
443 		cryptkeyres *res;
444 		res = (*__key_decryptsession_pk_LOCAL)(geteuid(), arg);
445 		*(cryptkeyres*)rslt = *res;
446 		return (1);
447 	} else if (proc == KEY_GEN && __key_gendes_LOCAL) {
448 		des_block *res;
449 		res = (*__key_gendes_LOCAL)(geteuid(), 0);
450 		*(des_block*)rslt = *res;
451 		return (1);
452 	}
453 
454 	if ((proc == KEY_ENCRYPT_PK) || (proc == KEY_DECRYPT_PK) ||
455 	    (proc == KEY_NET_GET) || (proc == KEY_NET_PUT) ||
456 	    (proc == KEY_GET_CONV))
457 		clnt = getkeyserv_handle(2); /* talk to version 2 */
458 	else
459 		clnt = getkeyserv_handle(1); /* talk to version 1 */
460 
461 	if (clnt == NULL) {
462 		return (0);
463 	}
464 
465 	wait_time.tv_sec = TOTAL_TIMEOUT;
466 	wait_time.tv_usec = 0;
467 
468 	if (clnt_call(clnt, proc, xdr_arg, arg, xdr_rslt, rslt,
469 		wait_time) == RPC_SUCCESS) {
470 		return (1);
471 	} else {
472 		return (0);
473 	}
474 }
475