xref: /freebsd/lib/libc/rpc/key_call.c (revision 4cf49a43559ed9fdad601bdcccd2c55963008675)
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 
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 <stdio.h>
45 #include <stdlib.h>
46 #include <unistd.h>
47 #include <errno.h>
48 #include <rpc/rpc.h>
49 #include <rpc/auth.h>
50 #include <rpc/auth_unix.h>
51 #include <rpc/key_prot.h>
52 #include <string.h>
53 #include <sys/utsname.h>
54 #include <stdlib.h>
55 #include <signal.h>
56 #include <sys/wait.h>
57 #include <sys/fcntl.h>
58 
59 
60 #define	KEY_TIMEOUT	5	/* per-try timeout in seconds */
61 #define	KEY_NRETRY	12	/* number of retries */
62 
63 #ifdef DEBUG
64 #define	debug(msg)	(void) fprintf(stderr, "%s\n", msg);
65 #else
66 #define	debug(msg)
67 #endif /* DEBUG */
68 
69 /*
70  * Hack to allow the keyserver to use AUTH_DES (for authenticated
71  * NIS+ calls, for example).  The only functions that get called
72  * are key_encryptsession_pk, key_decryptsession_pk, and key_gendes.
73  *
74  * The approach is to have the keyserver fill in pointers to local
75  * implementations of these functions, and to call those in key_call().
76  */
77 
78 cryptkeyres *(*__key_encryptsession_pk_LOCAL)() = 0;
79 cryptkeyres *(*__key_decryptsession_pk_LOCAL)() = 0;
80 des_block *(*__key_gendes_LOCAL)() = 0;
81 
82 static int key_call __P(( u_long, xdrproc_t, char *, xdrproc_t, char * ));
83 
84 int
85 key_setsecret(secretkey)
86 	const char *secretkey;
87 {
88 	keystatus status;
89 
90 	if (!key_call((u_long) KEY_SET, xdr_keybuf, (char *) secretkey,
91 			xdr_keystatus, (char *)&status)) {
92 		return (-1);
93 	}
94 	if (status != KEY_SUCCESS) {
95 		debug("set status is nonzero");
96 		return (-1);
97 	}
98 	return (0);
99 }
100 
101 
102 /* key_secretkey_is_set() returns 1 if the keyserver has a secret key
103  * stored for the caller's effective uid; it returns 0 otherwise
104  *
105  * N.B.:  The KEY_NET_GET key call is undocumented.  Applications shouldn't
106  * be using it, because it allows them to get the user's secret key.
107  */
108 
109 int
110 key_secretkey_is_set(void)
111 {
112 	struct key_netstres 	kres;
113 
114 	memset((void*)&kres, 0, sizeof (kres));
115 	if (key_call((u_long) KEY_NET_GET, xdr_void, (char *)NULL,
116 			xdr_key_netstres, (char *) &kres) &&
117 	    (kres.status == KEY_SUCCESS) &&
118 	    (kres.key_netstres_u.knet.st_priv_key[0] != 0)) {
119 		/* avoid leaving secret key in memory */
120 		memset(kres.key_netstres_u.knet.st_priv_key, 0, HEXKEYBYTES);
121 		return (1);
122 	}
123 	return (0);
124 }
125 
126 int
127 key_encryptsession_pk(remotename, remotekey, deskey)
128 	char *remotename;
129 	netobj *remotekey;
130 	des_block *deskey;
131 {
132 	cryptkeyarg2 arg;
133 	cryptkeyres res;
134 
135 	arg.remotename = remotename;
136 	arg.remotekey = *remotekey;
137 	arg.deskey = *deskey;
138 	if (!key_call((u_long)KEY_ENCRYPT_PK, xdr_cryptkeyarg2, (char *)&arg,
139 			xdr_cryptkeyres, (char *)&res)) {
140 		return (-1);
141 	}
142 	if (res.status != KEY_SUCCESS) {
143 		debug("encrypt status is nonzero");
144 		return (-1);
145 	}
146 	*deskey = res.cryptkeyres_u.deskey;
147 	return (0);
148 }
149 
150 int
151 key_decryptsession_pk(remotename, remotekey, deskey)
152 	char *remotename;
153 	netobj *remotekey;
154 	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, xdr_cryptkeyarg2, (char *)&arg,
163 			xdr_cryptkeyres, (char *)&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(remotename, deskey)
176 	const char *remotename;
177 	des_block *deskey;
178 {
179 	cryptkeyarg arg;
180 	cryptkeyres res;
181 
182 	arg.remotename = (char *) remotename;
183 	arg.deskey = *deskey;
184 	if (!key_call((u_long)KEY_ENCRYPT, xdr_cryptkeyarg, (char *)&arg,
185 			xdr_cryptkeyres, (char *)&res)) {
186 		return (-1);
187 	}
188 	if (res.status != KEY_SUCCESS) {
189 		debug("encrypt status is nonzero");
190 		return (-1);
191 	}
192 	*deskey = res.cryptkeyres_u.deskey;
193 	return (0);
194 }
195 
196 int
197 key_decryptsession(remotename, deskey)
198 	const char *remotename;
199 	des_block *deskey;
200 {
201 	cryptkeyarg arg;
202 	cryptkeyres res;
203 
204 	arg.remotename = (char *) remotename;
205 	arg.deskey = *deskey;
206 	if (!key_call((u_long)KEY_DECRYPT, xdr_cryptkeyarg, (char *)&arg,
207 			xdr_cryptkeyres, (char *)&res)) {
208 		return (-1);
209 	}
210 	if (res.status != KEY_SUCCESS) {
211 		debug("decrypt status is nonzero");
212 		return (-1);
213 	}
214 	*deskey = res.cryptkeyres_u.deskey;
215 	return (0);
216 }
217 
218 int
219 key_gendes(key)
220 	des_block *key;
221 {
222 	if (!key_call((u_long)KEY_GEN, xdr_void, (char *)NULL,
223 			xdr_des_block, (char *)key)) {
224 		return (-1);
225 	}
226 	return (0);
227 }
228 
229 int
230 key_setnet(arg)
231 struct netstarg *arg;
232 {
233 	keystatus status;
234 
235 
236 	if (!key_call((u_long) KEY_NET_PUT, xdr_key_netstarg, (char *) arg,
237 		xdr_keystatus, (char *) &status)){
238 		return (-1);
239 	}
240 
241 	if (status != KEY_SUCCESS) {
242 		debug("key_setnet status is nonzero");
243 		return (-1);
244 	}
245 	return (1);
246 }
247 
248 
249 int
250 key_get_conv(pkey, deskey)
251 	char *pkey;
252 	des_block *deskey;
253 {
254 	cryptkeyres res;
255 
256 	if (!key_call((u_long) KEY_GET_CONV, xdr_keybuf, pkey,
257 		xdr_cryptkeyres, (char *)&res)) {
258 		return (-1);
259 	}
260 	if (res.status != KEY_SUCCESS) {
261 		debug("get_conv status is nonzero");
262 		return (-1);
263 	}
264 	*deskey = res.cryptkeyres_u.deskey;
265 	return (0);
266 }
267 
268 struct  key_call_private {
269 	CLIENT	*client;	/* Client handle */
270 	pid_t	pid;		/* process-id at moment of creation */
271 	uid_t	uid;		/* user-id at last authorization */
272 };
273 static struct key_call_private *key_call_private_main = NULL;
274 
275 #ifdef foo
276 static void
277 key_call_destroy(void *vp)
278 {
279 	register struct key_call_private *kcp = (struct key_call_private *)vp;
280 
281 	if (kcp) {
282 		if (kcp->client)
283 			clnt_destroy(kcp->client);
284 		free(kcp);
285 	}
286 }
287 #endif
288 
289 /*
290  * Keep the handle cached.  This call may be made quite often.
291  */
292 static CLIENT *
293 getkeyserv_handle(vers)
294 int	vers;
295 {
296 	struct key_call_private *kcp = key_call_private_main;
297 	struct timeval wait_time;
298 	int fd;
299 	struct sockaddr_un name;
300 	int namelen = sizeof(struct sockaddr_un);
301 
302 #define	TOTAL_TIMEOUT	30	/* total timeout talking to keyserver */
303 #define	TOTAL_TRIES	5	/* Number of tries */
304 
305 	if (kcp == (struct key_call_private *)NULL) {
306 		kcp = (struct key_call_private *)malloc(sizeof (*kcp));
307 		if (kcp == (struct key_call_private *)NULL) {
308 			return ((CLIENT *) NULL);
309 		}
310 		key_call_private_main = kcp;
311 		kcp->client = NULL;
312 	}
313 
314 	/* if pid has changed, destroy client and rebuild */
315 	if (kcp->client != NULL && kcp->pid != getpid()) {
316 		clnt_destroy(kcp->client);
317 		kcp->client = NULL;
318 	}
319 
320 	if (kcp->client != NULL) {
321 		/* if other side closed socket, build handle again */
322 		clnt_control(kcp->client, CLGET_FD, (char *)&fd);
323 		if (getpeername(fd,(struct sockaddr *)&name,&namelen) == -1) {
324 			auth_destroy(kcp->client->cl_auth);
325 			clnt_destroy(kcp->client);
326 			kcp->client = NULL;
327 		}
328 	}
329 
330 	if (kcp->client != NULL) {
331 		/* if uid has changed, build client handle again */
332 		if (kcp->uid != geteuid()) {
333 			kcp->uid = geteuid();
334 			auth_destroy(kcp->client->cl_auth);
335 			kcp->client->cl_auth =
336 				authsys_create("", kcp->uid, 0, 0, NULL);
337 			if (kcp->client->cl_auth == NULL) {
338 				clnt_destroy(kcp->client);
339 				kcp->client = NULL;
340 				return ((CLIENT *) NULL);
341 			}
342 		}
343 		/* Change the version number to the new one */
344 		clnt_control(kcp->client, CLSET_VERS, (void *)&vers);
345 		return (kcp->client);
346 	}
347 
348 	if ((kcp->client == (CLIENT *) NULL))
349 		/* Use the AF_UNIX transport */
350 		kcp->client = clnt_create("/var/run/keyservsock", KEY_PROG,
351 							vers, "unix");
352 
353 	if (kcp->client == (CLIENT *) NULL) {
354 		return ((CLIENT *) NULL);
355 	}
356 	kcp->uid = geteuid();
357 	kcp->pid = getpid();
358 	kcp->client->cl_auth = authsys_create("", kcp->uid, 0, 0, NULL);
359 	if (kcp->client->cl_auth == NULL) {
360 		clnt_destroy(kcp->client);
361 		kcp->client = NULL;
362 		return ((CLIENT *) NULL);
363 	}
364 
365 	wait_time.tv_sec = TOTAL_TIMEOUT/TOTAL_TRIES;
366 	wait_time.tv_usec = 0;
367 	(void) clnt_control(kcp->client, CLSET_RETRY_TIMEOUT,
368 		(char *)&wait_time);
369 	if (clnt_control(kcp->client, CLGET_FD, (char *)&fd))
370 		fcntl(fd, F_SETFD, 1);	/* make it "close on exec" */
371 
372 	return (kcp->client);
373 }
374 
375 /* returns  0 on failure, 1 on success */
376 
377 static int
378 key_call(proc, xdr_arg, arg, xdr_rslt, rslt)
379 	u_long proc;
380 	xdrproc_t xdr_arg;
381 	char *arg;
382 	xdrproc_t xdr_rslt;
383 	char *rslt;
384 {
385 	CLIENT *clnt;
386 	struct timeval wait_time;
387 
388 	if (proc == KEY_ENCRYPT_PK && __key_encryptsession_pk_LOCAL) {
389 		cryptkeyres *res;
390 		res = (*__key_encryptsession_pk_LOCAL)(geteuid(), arg);
391 		*(cryptkeyres*)rslt = *res;
392 		return (1);
393 	} else if (proc == KEY_DECRYPT_PK && __key_decryptsession_pk_LOCAL) {
394 		cryptkeyres *res;
395 		res = (*__key_decryptsession_pk_LOCAL)(geteuid(), arg);
396 		*(cryptkeyres*)rslt = *res;
397 		return (1);
398 	} else if (proc == KEY_GEN && __key_gendes_LOCAL) {
399 		des_block *res;
400 		res = (*__key_gendes_LOCAL)(geteuid(), 0);
401 		*(des_block*)rslt = *res;
402 		return (1);
403 	}
404 
405 	if ((proc == KEY_ENCRYPT_PK) || (proc == KEY_DECRYPT_PK) ||
406 	    (proc == KEY_NET_GET) || (proc == KEY_NET_PUT) ||
407 	    (proc == KEY_GET_CONV))
408 		clnt = getkeyserv_handle(2); /* talk to version 2 */
409 	else
410 		clnt = getkeyserv_handle(1); /* talk to version 1 */
411 
412 	if (clnt == NULL) {
413 		return (0);
414 	}
415 
416 	wait_time.tv_sec = TOTAL_TIMEOUT;
417 	wait_time.tv_usec = 0;
418 
419 	if (clnt_call(clnt, proc, xdr_arg, arg, xdr_rslt, rslt,
420 		wait_time) == RPC_SUCCESS) {
421 		return (1);
422 	} else {
423 		return (0);
424 	}
425 }
426