xref: /freebsd/lib/libc/rpc/key_call.c (revision caf6fbd81a21a5bd5fac57a0163582bbc8968920)
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 static thread_key_t key_call_key;
283 static once_t key_call_once = ONCE_INITIALIZER;
284 static int key_call_key_error;
285 
286 static void
287 key_call_destroy(void *vp)
288 {
289 	struct key_call_private *kcp = (struct key_call_private *)vp;
290 
291 	if (kcp) {
292 		if (kcp->client)
293 			clnt_destroy(kcp->client);
294 		free(kcp);
295 	}
296 }
297 
298 static void
299 key_call_init(void)
300 {
301 
302 	key_call_key_error = thr_keycreate(&key_call_key, key_call_destroy);
303 }
304 
305 /*
306  * Keep the handle cached.  This call may be made quite often.
307  */
308 static CLIENT *
309 getkeyserv_handle(vers)
310 int	vers;
311 {
312 	void *localhandle;
313 	struct netconfig *nconf;
314 	struct netconfig *tpconf;
315 	struct key_call_private *kcp;
316 	struct timeval wait_time;
317 	struct utsname u;
318 	int main_thread;
319 	int fd;
320 
321 #define	TOTAL_TIMEOUT	30	/* total timeout talking to keyserver */
322 #define	TOTAL_TRIES	5	/* Number of tries */
323 
324 	if ((main_thread = thr_main())) {
325 		kcp = key_call_private_main;
326 	} else {
327 		if (thr_once(&key_call_once, key_call_init) != 0 ||
328 		    key_call_key_error != 0)
329 			return ((CLIENT *) NULL);
330 		kcp = (struct key_call_private *)thr_getspecific(key_call_key);
331 	}
332 	if (kcp == (struct key_call_private *)NULL) {
333 		kcp = (struct key_call_private *)malloc(sizeof (*kcp));
334 		if (kcp == (struct key_call_private *)NULL) {
335 			return ((CLIENT *) NULL);
336 		}
337                 if (main_thread)
338                         key_call_private_main = kcp;
339                 else
340                         thr_setspecific(key_call_key, (void *) kcp);
341 		kcp->client = NULL;
342 	}
343 
344 	/* if pid has changed, destroy client and rebuild */
345 	if (kcp->client != NULL && kcp->pid != getpid()) {
346 		clnt_destroy(kcp->client);
347 		kcp->client = NULL;
348 	}
349 
350 	if (kcp->client != NULL) {
351 		/* if uid has changed, build client handle again */
352 		if (kcp->uid != geteuid()) {
353 			kcp->uid = geteuid();
354 			auth_destroy(kcp->client->cl_auth);
355 			kcp->client->cl_auth =
356 				authsys_create("", kcp->uid, 0, 0, NULL);
357 			if (kcp->client->cl_auth == NULL) {
358 				clnt_destroy(kcp->client);
359 				kcp->client = NULL;
360 				return ((CLIENT *) NULL);
361 			}
362 		}
363 		/* Change the version number to the new one */
364 		clnt_control(kcp->client, CLSET_VERS, (void *)&vers);
365 		return (kcp->client);
366 	}
367 	if (!(localhandle = setnetconfig())) {
368 		return ((CLIENT *) NULL);
369 	}
370         tpconf = NULL;
371 #if defined(__FreeBSD__)
372 	if (uname(&u) == -1)
373 #else
374 #if defined(i386)
375 	if (_nuname(&u) == -1)
376 #elif defined(sparc)
377 	if (_uname(&u) == -1)
378 #else
379 #error Unknown architecture!
380 #endif
381 #endif
382 	{
383 		endnetconfig(localhandle);
384 		return ((CLIENT *) NULL);
385         }
386 	while ((nconf = getnetconfig(localhandle)) != NULL) {
387 		if (strcmp(nconf->nc_protofmly, NC_LOOPBACK) == 0) {
388 			/*
389 			 * We use COTS_ORD here so that the caller can
390 			 * find out immediately if the server is dead.
391 			 */
392 			if (nconf->nc_semantics == NC_TPI_COTS_ORD) {
393 				kcp->client = clnt_tp_create(u.nodename,
394 					KEY_PROG, vers, nconf);
395 				if (kcp->client)
396 					break;
397 			} else {
398 				tpconf = nconf;
399 			}
400 		}
401 	}
402 	if ((kcp->client == (CLIENT *) NULL) && (tpconf))
403 		/* Now, try the CLTS or COTS loopback transport */
404 		kcp->client = clnt_tp_create(u.nodename,
405 			KEY_PROG, vers, tpconf);
406 	endnetconfig(localhandle);
407 
408 	if (kcp->client == (CLIENT *) NULL) {
409 		return ((CLIENT *) NULL);
410         }
411 	kcp->uid = geteuid();
412 	kcp->pid = getpid();
413 	kcp->client->cl_auth = authsys_create("", kcp->uid, 0, 0, NULL);
414 	if (kcp->client->cl_auth == NULL) {
415 		clnt_destroy(kcp->client);
416 		kcp->client = NULL;
417 		return ((CLIENT *) NULL);
418 	}
419 
420 	wait_time.tv_sec = TOTAL_TIMEOUT/TOTAL_TRIES;
421 	wait_time.tv_usec = 0;
422 	(void) clnt_control(kcp->client, CLSET_RETRY_TIMEOUT,
423 		(char *)&wait_time);
424 	if (clnt_control(kcp->client, CLGET_FD, (char *)&fd))
425 		_fcntl(fd, F_SETFD, 1);	/* make it "close on exec" */
426 
427 	return (kcp->client);
428 }
429 
430 /* returns  0 on failure, 1 on success */
431 
432 static int
433 key_call(proc, xdr_arg, arg, xdr_rslt, rslt)
434 	u_long proc;
435 	xdrproc_t xdr_arg;
436 	void *arg;
437 	xdrproc_t xdr_rslt;
438 	void *rslt;
439 {
440 	CLIENT *clnt;
441 	struct timeval wait_time;
442 
443 	if (proc == KEY_ENCRYPT_PK && __key_encryptsession_pk_LOCAL) {
444 		cryptkeyres *res;
445 		res = (*__key_encryptsession_pk_LOCAL)(geteuid(), arg);
446 		*(cryptkeyres*)rslt = *res;
447 		return (1);
448 	} else if (proc == KEY_DECRYPT_PK && __key_decryptsession_pk_LOCAL) {
449 		cryptkeyres *res;
450 		res = (*__key_decryptsession_pk_LOCAL)(geteuid(), arg);
451 		*(cryptkeyres*)rslt = *res;
452 		return (1);
453 	} else if (proc == KEY_GEN && __key_gendes_LOCAL) {
454 		des_block *res;
455 		res = (*__key_gendes_LOCAL)(geteuid(), 0);
456 		*(des_block*)rslt = *res;
457 		return (1);
458 	}
459 
460 	if ((proc == KEY_ENCRYPT_PK) || (proc == KEY_DECRYPT_PK) ||
461 	    (proc == KEY_NET_GET) || (proc == KEY_NET_PUT) ||
462 	    (proc == KEY_GET_CONV))
463 		clnt = getkeyserv_handle(2); /* talk to version 2 */
464 	else
465 		clnt = getkeyserv_handle(1); /* talk to version 1 */
466 
467 	if (clnt == NULL) {
468 		return (0);
469 	}
470 
471 	wait_time.tv_sec = TOTAL_TIMEOUT;
472 	wait_time.tv_usec = 0;
473 
474 	if (clnt_call(clnt, proc, xdr_arg, arg, xdr_rslt, rslt,
475 		wait_time) == RPC_SUCCESS) {
476 		return (1);
477 	} else {
478 		return (0);
479 	}
480 }
481