xref: /freebsd/lib/libc/rpc/key_call.c (revision b6de9e91bd2c47efaeec72a08642f8fd99cc7b20)
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 
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 
282 static void
283 key_call_destroy(void *vp)
284 {
285 	struct key_call_private *kcp = (struct key_call_private *)vp;
286 
287 	if (kcp) {
288 		if (kcp->client)
289 			clnt_destroy(kcp->client);
290 		free(kcp);
291 	}
292 }
293 
294 /*
295  * Keep the handle cached.  This call may be made quite often.
296  */
297 static CLIENT *
298 getkeyserv_handle(vers)
299 int	vers;
300 {
301 	void *localhandle;
302 	struct netconfig *nconf;
303 	struct netconfig *tpconf;
304 	struct key_call_private *kcp = key_call_private_main;
305 	struct timeval wait_time;
306 	struct utsname u;
307 	int main_thread;
308 	int fd;
309 	static thread_key_t key_call_key;
310 	extern mutex_t tsd_lock;
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