xref: /freebsd/usr.sbin/gssd/gssd.c (revision 298cf604ccf133b101c6fad42d1a078a1fac58ca)
1 /*-
2  * Copyright (c) 2008 Isilon Inc http://www.isilon.com/
3  * Authors: Doug Rabson <dfr@rabson.org>
4  * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/param.h>
32 #include <sys/stat.h>
33 #include <sys/linker.h>
34 #include <sys/module.h>
35 #include <sys/queue.h>
36 #include <sys/syslog.h>
37 #include <ctype.h>
38 #include <err.h>
39 #include <pwd.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <unistd.h>
44 #include <gssapi/gssapi.h>
45 #include <rpc/rpc.h>
46 #include <rpc/rpc_com.h>
47 
48 #include "gssd.h"
49 
50 #ifndef _PATH_GSS_MECH
51 #define _PATH_GSS_MECH	"/etc/gss/mech"
52 #endif
53 #ifndef _PATH_GSSDSOCK
54 #define _PATH_GSSDSOCK	"/var/run/gssd.sock"
55 #endif
56 
57 struct gss_resource {
58 	LIST_ENTRY(gss_resource) gr_link;
59 	uint64_t	gr_id;	/* indentifier exported to kernel */
60 	void*		gr_res;	/* GSS-API resource pointer */
61 };
62 LIST_HEAD(gss_resource_list, gss_resource) gss_resources;
63 int gss_resource_count;
64 uint32_t gss_next_id;
65 uint32_t gss_start_time;
66 int debug_level;
67 
68 static void gssd_load_mech(void);
69 
70 extern void gssd_1(struct svc_req *rqstp, SVCXPRT *transp);
71 extern int gssd_syscall(char *path);
72 
73 int
74 main(int argc, char **argv)
75 {
76 	/*
77 	 * We provide an RPC service on a local-domain socket. The
78 	 * kernel's GSS-API code will pass what it can't handle
79 	 * directly to us.
80 	 */
81 	struct sockaddr_un sun;
82 	int fd, oldmask, ch, debug;
83 	SVCXPRT *xprt;
84 
85 	debug = 0;
86 	while ((ch = getopt(argc, argv, "d")) != -1) {
87 		switch (ch) {
88 		case 'd':
89 			debug_level++;
90 			break;
91 		default:
92 			fprintf(stderr, "usage: %s [-d]\n", argv[0]);
93 			exit(1);
94 			break;
95 		}
96 	}
97 
98 	gssd_load_mech();
99 
100 	if (!debug_level)
101 		daemon(0, 0);
102 
103 	memset(&sun, 0, sizeof sun);
104 	sun.sun_family = AF_LOCAL;
105 	unlink(_PATH_GSSDSOCK);
106 	strcpy(sun.sun_path, _PATH_GSSDSOCK);
107 	sun.sun_len = SUN_LEN(&sun);
108 	fd = socket(AF_LOCAL, SOCK_STREAM, 0);
109 	if (!fd) {
110 		if (debug_level == 0) {
111 			syslog(LOG_ERR, "Can't create local gssd socket");
112 			exit(1);
113 		}
114 		err(1, "Can't create local gssd socket");
115 	}
116 	oldmask = umask(S_IXUSR|S_IRWXG|S_IRWXO);
117 	if (bind(fd, (struct sockaddr *) &sun, sun.sun_len) < 0) {
118 		if (debug_level == 0) {
119 			syslog(LOG_ERR, "Can't bind local gssd socket");
120 			exit(1);
121 		}
122 		err(1, "Can't bind local gssd socket");
123 	}
124 	umask(oldmask);
125 	if (listen(fd, SOMAXCONN) < 0) {
126 		if (debug_level == 0) {
127 			syslog(LOG_ERR, "Can't listen on local gssd socket");
128 			exit(1);
129 		}
130 		err(1, "Can't listen on local gssd socket");
131 	}
132 	xprt = svc_vc_create(fd, RPC_MAXDATASIZE, RPC_MAXDATASIZE);
133 	if (!xprt) {
134 		if (debug_level == 0) {
135 			syslog(LOG_ERR,
136 			    "Can't create transport for local gssd socket");
137 			exit(1);
138 		}
139 		err(1, "Can't create transport for local gssd socket");
140 	}
141 	if (!svc_reg(xprt, GSSD, GSSDVERS, gssd_1, NULL)) {
142 		if (debug_level == 0) {
143 			syslog(LOG_ERR,
144 			    "Can't register service for local gssd socket");
145 			exit(1);
146 		}
147 		err(1, "Can't register service for local gssd socket");
148 	}
149 
150 	LIST_INIT(&gss_resources);
151 	gss_next_id = 1;
152 	gss_start_time = time(0);
153 
154 	gssd_syscall(_PATH_GSSDSOCK);
155 	svc_run();
156 
157 	return (0);
158 }
159 
160 static void
161 gssd_load_mech(void)
162 {
163 	FILE		*fp;
164 	char		buf[256];
165 	char		*p;
166 	char		*name, *oid, *lib, *kobj;
167 
168 	fp = fopen(_PATH_GSS_MECH, "r");
169 	if (!fp)
170 		return;
171 
172 	while (fgets(buf, sizeof(buf), fp)) {
173 		if (*buf == '#')
174 			continue;
175 		p = buf;
176 		name = strsep(&p, "\t\n ");
177 		if (p) while (isspace(*p)) p++;
178 		oid = strsep(&p, "\t\n ");
179 		if (p) while (isspace(*p)) p++;
180 		lib = strsep(&p, "\t\n ");
181 		if (p) while (isspace(*p)) p++;
182 		kobj = strsep(&p, "\t\n ");
183 		if (!name || !oid || !lib || !kobj)
184 			continue;
185 
186 		if (strcmp(kobj, "-")) {
187 			/*
188 			 * Attempt to load the kernel module if its
189 			 * not already present.
190 			 */
191 			if (modfind(kobj) < 0) {
192 				if (kldload(kobj) < 0) {
193 					fprintf(stderr,
194 			"%s: can't find or load kernel module %s for %s\n",
195 					    getprogname(), kobj, name);
196 				}
197 			}
198 		}
199 	}
200 	fclose(fp);
201 }
202 
203 static void *
204 gssd_find_resource(uint64_t id)
205 {
206 	struct gss_resource *gr;
207 
208 	if (!id)
209 		return (NULL);
210 
211 	LIST_FOREACH(gr, &gss_resources, gr_link)
212 		if (gr->gr_id == id)
213 			return (gr->gr_res);
214 
215 	return (NULL);
216 }
217 
218 static uint64_t
219 gssd_make_resource(void *res)
220 {
221 	struct gss_resource *gr;
222 
223 	if (!res)
224 		return (0);
225 
226 	gr = malloc(sizeof(struct gss_resource));
227 	if (!gr)
228 		return (0);
229 	gr->gr_id = (gss_next_id++) + ((uint64_t) gss_start_time << 32);
230 	gr->gr_res = res;
231 	LIST_INSERT_HEAD(&gss_resources, gr, gr_link);
232 	gss_resource_count++;
233 	if (debug_level > 1)
234 		printf("%d resources allocated\n", gss_resource_count);
235 
236 	return (gr->gr_id);
237 }
238 
239 static void
240 gssd_delete_resource(uint64_t id)
241 {
242 	struct gss_resource *gr;
243 
244 	LIST_FOREACH(gr, &gss_resources, gr_link) {
245 		if (gr->gr_id == id) {
246 			LIST_REMOVE(gr, gr_link);
247 			free(gr);
248 			gss_resource_count--;
249 			if (debug_level > 1)
250 				printf("%d resources allocated\n",
251 				    gss_resource_count);
252 			return;
253 		}
254 	}
255 }
256 
257 bool_t
258 gssd_null_1_svc(void *argp, void *result, struct svc_req *rqstp)
259 {
260 
261 	return (TRUE);
262 }
263 
264 bool_t
265 gssd_init_sec_context_1_svc(init_sec_context_args *argp, init_sec_context_res *result, struct svc_req *rqstp)
266 {
267 	gss_cred_id_t cred = GSS_C_NO_CREDENTIAL;
268 	gss_ctx_id_t ctx = GSS_C_NO_CONTEXT;
269 	gss_name_t name = GSS_C_NO_NAME;
270 	char ccname[strlen("FILE:/tmp/krb5cc_") + 6 + 1];
271 
272 	snprintf(ccname, sizeof(ccname), "FILE:/tmp/krb5cc_%d",
273 	    (int) argp->uid);
274 	setenv("KRB5CCNAME", ccname, TRUE);
275 
276 	memset(result, 0, sizeof(*result));
277 	if (argp->cred) {
278 		cred = gssd_find_resource(argp->cred);
279 		if (!cred) {
280 			result->major_status = GSS_S_CREDENTIALS_EXPIRED;
281 			return (TRUE);
282 		}
283 	}
284 	if (argp->ctx) {
285 		ctx = gssd_find_resource(argp->ctx);
286 		if (!ctx) {
287 			result->major_status = GSS_S_CONTEXT_EXPIRED;
288 			return (TRUE);
289 		}
290 	}
291 	if (argp->name) {
292 		name = gssd_find_resource(argp->name);
293 		if (!name) {
294 			result->major_status = GSS_S_BAD_NAME;
295 			return (TRUE);
296 		}
297 	}
298 
299 	memset(result, 0, sizeof(*result));
300 	result->major_status = gss_init_sec_context(&result->minor_status,
301 	    cred, &ctx, name, argp->mech_type,
302 	    argp->req_flags, argp->time_req, argp->input_chan_bindings,
303 	    &argp->input_token, &result->actual_mech_type,
304 	    &result->output_token, &result->ret_flags, &result->time_rec);
305 
306 	if (result->major_status == GSS_S_COMPLETE
307 	    || result->major_status == GSS_S_CONTINUE_NEEDED) {
308 		if (argp->ctx)
309 			result->ctx = argp->ctx;
310 		else
311 			result->ctx = gssd_make_resource(ctx);
312 	}
313 
314 	return (TRUE);
315 }
316 
317 bool_t
318 gssd_accept_sec_context_1_svc(accept_sec_context_args *argp, accept_sec_context_res *result, struct svc_req *rqstp)
319 {
320 	gss_ctx_id_t ctx = GSS_C_NO_CONTEXT;
321 	gss_cred_id_t cred = GSS_C_NO_CREDENTIAL;
322 	gss_name_t src_name;
323 	gss_cred_id_t delegated_cred_handle;
324 
325 	memset(result, 0, sizeof(*result));
326 	if (argp->ctx) {
327 		ctx = gssd_find_resource(argp->ctx);
328 		if (!ctx) {
329 			result->major_status = GSS_S_CONTEXT_EXPIRED;
330 			return (TRUE);
331 		}
332 	}
333 	if (argp->cred) {
334 		cred = gssd_find_resource(argp->cred);
335 		if (!cred) {
336 			result->major_status = GSS_S_CREDENTIALS_EXPIRED;
337 			return (TRUE);
338 		}
339 	}
340 
341 	memset(result, 0, sizeof(*result));
342 	result->major_status = gss_accept_sec_context(&result->minor_status,
343 	    &ctx, cred, &argp->input_token, argp->input_chan_bindings,
344 	    &src_name, &result->mech_type, &result->output_token,
345 	    &result->ret_flags, &result->time_rec,
346 	    &delegated_cred_handle);
347 
348 	if (result->major_status == GSS_S_COMPLETE
349 	    || result->major_status == GSS_S_CONTINUE_NEEDED) {
350 		if (argp->ctx)
351 			result->ctx = argp->ctx;
352 		else
353 			result->ctx = gssd_make_resource(ctx);
354 		result->src_name = gssd_make_resource(src_name);
355 		result->delegated_cred_handle =
356 			gssd_make_resource(delegated_cred_handle);
357 	}
358 
359 	return (TRUE);
360 }
361 
362 bool_t
363 gssd_delete_sec_context_1_svc(delete_sec_context_args *argp, delete_sec_context_res *result, struct svc_req *rqstp)
364 {
365 	gss_ctx_id_t ctx = gssd_find_resource(argp->ctx);
366 
367 	if (ctx) {
368 		result->major_status = gss_delete_sec_context(
369 			&result->minor_status, &ctx, &result->output_token);
370 		gssd_delete_resource(argp->ctx);
371 	} else {
372 		result->major_status = GSS_S_COMPLETE;
373 		result->minor_status = 0;
374 	}
375 
376 	return (TRUE);
377 }
378 
379 bool_t
380 gssd_export_sec_context_1_svc(export_sec_context_args *argp, export_sec_context_res *result, struct svc_req *rqstp)
381 {
382 	gss_ctx_id_t ctx = gssd_find_resource(argp->ctx);
383 
384 	if (ctx) {
385 		result->major_status = gss_export_sec_context(
386 			&result->minor_status, &ctx,
387 			&result->interprocess_token);
388 		result->format = KGSS_HEIMDAL_1_1;
389 		gssd_delete_resource(argp->ctx);
390 	} else {
391 		result->major_status = GSS_S_FAILURE;
392 		result->minor_status = 0;
393 		result->interprocess_token.length = 0;
394 		result->interprocess_token.value = NULL;
395 	}
396 
397 	return (TRUE);
398 }
399 
400 bool_t
401 gssd_import_name_1_svc(import_name_args *argp, import_name_res *result, struct svc_req *rqstp)
402 {
403 	gss_name_t name;
404 
405 	result->major_status = gss_import_name(&result->minor_status,
406 	    &argp->input_name_buffer, argp->input_name_type, &name);
407 
408 	if (result->major_status == GSS_S_COMPLETE)
409 		result->output_name = gssd_make_resource(name);
410 	else
411 		result->output_name = 0;
412 
413 	return (TRUE);
414 }
415 
416 bool_t
417 gssd_canonicalize_name_1_svc(canonicalize_name_args *argp, canonicalize_name_res *result, struct svc_req *rqstp)
418 {
419 	gss_name_t name = gssd_find_resource(argp->input_name);
420 	gss_name_t output_name;
421 
422 	memset(result, 0, sizeof(*result));
423 	if (!name) {
424 		result->major_status = GSS_S_BAD_NAME;
425 		return (TRUE);
426 	}
427 
428 	result->major_status = gss_canonicalize_name(&result->minor_status,
429 	    name, argp->mech_type, &output_name);
430 
431 	if (result->major_status == GSS_S_COMPLETE)
432 		result->output_name = gssd_make_resource(output_name);
433 	else
434 		result->output_name = 0;
435 
436 	return (TRUE);
437 }
438 
439 bool_t
440 gssd_export_name_1_svc(export_name_args *argp, export_name_res *result, struct svc_req *rqstp)
441 {
442 	gss_name_t name = gssd_find_resource(argp->input_name);
443 
444 	memset(result, 0, sizeof(*result));
445 	if (!name) {
446 		result->major_status = GSS_S_BAD_NAME;
447 		return (TRUE);
448 	}
449 
450 	result->major_status = gss_export_name(&result->minor_status,
451 	    name, &result->exported_name);
452 
453 	return (TRUE);
454 }
455 
456 bool_t
457 gssd_release_name_1_svc(release_name_args *argp, release_name_res *result, struct svc_req *rqstp)
458 {
459 	gss_name_t name = gssd_find_resource(argp->input_name);
460 
461 	if (name) {
462 		result->major_status = gss_release_name(&result->minor_status,
463 		    &name);
464 		gssd_delete_resource(argp->input_name);
465 	} else {
466 		result->major_status = GSS_S_COMPLETE;
467 		result->minor_status = 0;
468 	}
469 
470 	return (TRUE);
471 }
472 
473 bool_t
474 gssd_pname_to_uid_1_svc(pname_to_uid_args *argp, pname_to_uid_res *result, struct svc_req *rqstp)
475 {
476 	gss_name_t name = gssd_find_resource(argp->pname);
477 	uid_t uid;
478 	char buf[128];
479 	struct passwd pwd, *pw;
480 
481 	memset(result, 0, sizeof(*result));
482 	if (name) {
483 		result->major_status =
484 			gss_pname_to_uid(&result->minor_status,
485 			    name, argp->mech, &uid);
486 		if (result->major_status == GSS_S_COMPLETE) {
487 			result->uid = uid;
488 			getpwuid_r(uid, &pwd, buf, sizeof(buf), &pw);
489 			if (pw) {
490 				int len = NGRPS;
491 				int groups[NGRPS];
492 				result->gid = pw->pw_gid;
493 				getgrouplist(pw->pw_name, pw->pw_gid,
494 				    groups, &len);
495 				result->gidlist.gidlist_len = len;
496 				result->gidlist.gidlist_val =
497 					mem_alloc(len * sizeof(int));
498 				memcpy(result->gidlist.gidlist_val, groups,
499 				    len * sizeof(int));
500 			} else {
501 				result->gid = 65534;
502 				result->gidlist.gidlist_len = 0;
503 				result->gidlist.gidlist_val = NULL;
504 			}
505 		}
506 	} else {
507 		result->major_status = GSS_S_BAD_NAME;
508 		result->minor_status = 0;
509 	}
510 
511 	return (TRUE);
512 }
513 
514 bool_t
515 gssd_acquire_cred_1_svc(acquire_cred_args *argp, acquire_cred_res *result, struct svc_req *rqstp)
516 {
517 	gss_name_t desired_name = GSS_C_NO_NAME;
518 	gss_cred_id_t cred;
519 	char ccname[strlen("FILE:/tmp/krb5cc_") + 6 + 1];
520 
521 	snprintf(ccname, sizeof(ccname), "FILE:/tmp/krb5cc_%d",
522 	    (int) argp->uid);
523 	setenv("KRB5CCNAME", ccname, TRUE);
524 
525 	memset(result, 0, sizeof(*result));
526 	if (argp->desired_name) {
527 		desired_name = gssd_find_resource(argp->desired_name);
528 		if (!desired_name) {
529 			result->major_status = GSS_S_BAD_NAME;
530 			return (TRUE);
531 		}
532 	}
533 
534 	result->major_status = gss_acquire_cred(&result->minor_status,
535 	    desired_name, argp->time_req, argp->desired_mechs,
536 	    argp->cred_usage, &cred, &result->actual_mechs, &result->time_rec);
537 
538 	if (result->major_status == GSS_S_COMPLETE)
539 		result->output_cred = gssd_make_resource(cred);
540 	else
541 		result->output_cred = 0;
542 
543 	return (TRUE);
544 }
545 
546 bool_t
547 gssd_set_cred_option_1_svc(set_cred_option_args *argp, set_cred_option_res *result, struct svc_req *rqstp)
548 {
549 	gss_cred_id_t cred = gssd_find_resource(argp->cred);
550 
551 	memset(result, 0, sizeof(*result));
552 	if (!cred) {
553 		result->major_status = GSS_S_CREDENTIALS_EXPIRED;
554 		return (TRUE);
555 	}
556 
557 	result->major_status = gss_set_cred_option(&result->minor_status,
558 	    &cred, argp->option_name, &argp->option_value);
559 
560 	return (TRUE);
561 }
562 
563 bool_t
564 gssd_release_cred_1_svc(release_cred_args *argp, release_cred_res *result, struct svc_req *rqstp)
565 {
566 	gss_cred_id_t cred = gssd_find_resource(argp->cred);
567 
568 	if (cred) {
569 		result->major_status = gss_release_cred(&result->minor_status,
570 		    &cred);
571 		gssd_delete_resource(argp->cred);
572 	} else {
573 		result->major_status = GSS_S_COMPLETE;
574 		result->minor_status = 0;
575 	}
576 
577 	return (TRUE);
578 }
579 
580 bool_t
581 gssd_display_status_1_svc(display_status_args *argp, display_status_res *result, struct svc_req *rqstp)
582 {
583 
584 	result->message_context = argp->message_context;
585 	result->major_status = gss_display_status(&result->minor_status,
586 	    argp->status_value, argp->status_type, argp->mech_type,
587 	    &result->message_context, &result->status_string);
588 
589 	return (TRUE);
590 }
591 
592 int
593 gssd_1_freeresult(SVCXPRT *transp, xdrproc_t xdr_result, caddr_t result)
594 {
595 	/*
596 	 * We don't use XDR to free the results - anything which was
597 	 * allocated came from GSS-API. We use xdr_result to figure
598 	 * out what to do.
599 	 */
600 	OM_uint32 junk;
601 
602 	if (xdr_result == (xdrproc_t) xdr_init_sec_context_res) {
603 		init_sec_context_res *p = (init_sec_context_res *) result;
604 		gss_release_buffer(&junk, &p->output_token);
605 	} else if (xdr_result == (xdrproc_t) xdr_accept_sec_context_res) {
606 		accept_sec_context_res *p = (accept_sec_context_res *) result;
607 		gss_release_buffer(&junk, &p->output_token);
608 	} else if (xdr_result == (xdrproc_t) xdr_delete_sec_context_res) {
609 		delete_sec_context_res *p = (delete_sec_context_res *) result;
610 		gss_release_buffer(&junk, &p->output_token);
611 	} else if (xdr_result == (xdrproc_t) xdr_export_sec_context_res) {
612 		export_sec_context_res *p = (export_sec_context_res *) result;
613 		if (p->interprocess_token.length)
614 			memset(p->interprocess_token.value, 0,
615 			    p->interprocess_token.length);
616 		gss_release_buffer(&junk, &p->interprocess_token);
617 	} else if (xdr_result == (xdrproc_t) xdr_export_name_res) {
618 		export_name_res *p = (export_name_res *) result;
619 		gss_release_buffer(&junk, &p->exported_name);
620 	} else if (xdr_result == (xdrproc_t) xdr_acquire_cred_res) {
621 		acquire_cred_res *p = (acquire_cred_res *) result;
622 		gss_release_oid_set(&junk, &p->actual_mechs);
623 	} else if (xdr_result == (xdrproc_t) xdr_pname_to_uid_res) {
624 		pname_to_uid_res *p = (pname_to_uid_res *) result;
625 		if (p->gidlist.gidlist_val)
626 			free(p->gidlist.gidlist_val);
627 	} else if (xdr_result == (xdrproc_t) xdr_display_status_res) {
628 		display_status_res *p = (display_status_res *) result;
629 		gss_release_buffer(&junk, &p->status_string);
630 	}
631 
632 	return (TRUE);
633 }
634