xref: /freebsd/crypto/heimdal/kcm/cache.c (revision 33644623554bb0fc57ed3c7d874193a498679b22)
1 /*
2  * Copyright (c) 2005, PADL Software Pty Ltd.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  *
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * 3. Neither the name of PADL Software nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY PADL SOFTWARE AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL PADL SOFTWARE OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include "kcm_locl.h"
34 
35 RCSID("$Id: cache.c 14566 2005-02-06 01:22:49Z lukeh $");
36 
37 static HEIMDAL_MUTEX ccache_mutex = HEIMDAL_MUTEX_INITIALIZER;
38 static kcm_ccache_data *ccache_head = NULL;
39 static unsigned int ccache_nextid = 0;
40 
41 char *kcm_ccache_nextid(pid_t pid, uid_t uid, gid_t gid)
42 {
43     unsigned n;
44     char *name;
45 
46     HEIMDAL_MUTEX_lock(&ccache_mutex);
47     n = ++ccache_nextid;
48     HEIMDAL_MUTEX_unlock(&ccache_mutex);
49 
50     asprintf(&name, "%d:%u", uid, n);
51 
52     return name;
53 }
54 
55 static krb5_error_code
56 kcm_ccache_resolve_internal(krb5_context context,
57 			    const char *name,
58 			    kcm_ccache *ccache)
59 {
60     kcm_ccache p;
61     krb5_error_code ret;
62 
63     *ccache = NULL;
64 
65     ret = KRB5_FCC_NOFILE;
66 
67     HEIMDAL_MUTEX_lock(&ccache_mutex);
68 
69     for (p = ccache_head; p != NULL; p = p->next) {
70 	if ((p->flags & KCM_FLAGS_VALID) == 0)
71 	    continue;
72 	if (strcmp(p->name, name) == 0) {
73 	    ret = 0;
74 	    break;
75 	}
76     }
77 
78     if (ret == 0) {
79 	kcm_retain_ccache(context, p);
80 	*ccache = p;
81     }
82 
83     HEIMDAL_MUTEX_unlock(&ccache_mutex);
84 
85     return ret;
86 }
87 
88 krb5_error_code kcm_debug_ccache(krb5_context context)
89 {
90     kcm_ccache p;
91 
92     for (p = ccache_head; p != NULL; p = p->next) {
93 	char *cpn = NULL, *spn = NULL;
94 	int ncreds = 0;
95 	struct kcm_creds *k;
96 
97 	if ((p->flags & KCM_FLAGS_VALID) == 0) {
98 	    kcm_log(7, "cache %08x: empty slot");
99 	    continue;
100 	}
101 
102 	KCM_ASSERT_VALID(p);
103 
104 	for (k = p->creds; k != NULL; k = k->next)
105 	    ncreds++;
106 
107 	if (p->client != NULL)
108 	    krb5_unparse_name(context, p->client, &cpn);
109 	if (p->server != NULL)
110 	    krb5_unparse_name(context, p->server, &spn);
111 
112 	kcm_log(7, "cache %08x: name %s refcnt %d flags %04x mode %04o "
113 		"uid %d gid %d client %s server %s ncreds %d",
114 		p, p->name, p->refcnt, p->flags, p->mode, p->uid, p->gid,
115 		(cpn == NULL) ? "<none>" : cpn,
116 		(spn == NULL) ? "<none>" : spn,
117 		ncreds);
118 
119 	if (cpn != NULL)
120 	    free(cpn);
121 	if (spn != NULL)
122 	    free(spn);
123     }
124 
125     return 0;
126 }
127 
128 static krb5_error_code
129 kcm_ccache_destroy_internal(krb5_context context, const char *name)
130 {
131     kcm_ccache *p;
132     krb5_error_code ret;
133 
134     ret = KRB5_FCC_NOFILE;
135 
136     HEIMDAL_MUTEX_lock(&ccache_mutex);
137     for (p = &ccache_head; *p != NULL; p = &(*p)->next) {
138 	if (((*p)->flags & KCM_FLAGS_VALID) == 0)
139 	    continue;
140 	if (strcmp((*p)->name, name) == 0) {
141 	    ret = 0;
142 	    break;
143 	}
144     }
145 
146     if (ret)
147 	goto out;
148 
149     kcm_release_ccache(context, p);
150 
151 out:
152     HEIMDAL_MUTEX_unlock(&ccache_mutex);
153 
154     return ret;
155 }
156 
157 static krb5_error_code
158 kcm_ccache_alloc(krb5_context context,
159 		 const char *name,
160 		 kcm_ccache *ccache)
161 {
162     kcm_ccache slot = NULL, p;
163     krb5_error_code ret;
164     int new_slot = 0;
165 
166     *ccache = NULL;
167 
168     /* First, check for duplicates */
169     HEIMDAL_MUTEX_lock(&ccache_mutex);
170     ret = 0;
171     for (p = ccache_head; p != NULL; p = p->next) {
172 	if (p->flags & KCM_FLAGS_VALID) {
173 	    if (strcmp(p->name, name) == 0) {
174 		ret = KRB5_CC_WRITE;
175 		break;
176 	    }
177 	} else if (slot == NULL)
178 	    slot = p;
179     }
180 
181     if (ret)
182 	goto out;
183 
184     /*
185      * Then try and find an empty slot
186      * XXX we need to recycle slots for this to actually do anything
187      */
188     if (slot == NULL) {
189 	for (; p != NULL; p = p->next) {
190 	    if ((p->flags & KCM_FLAGS_VALID) == 0) {
191 		slot = p;
192 		break;
193 	    }
194 	}
195 
196 	if (slot == NULL) {
197 	    slot = (kcm_ccache_data *)malloc(sizeof(*slot));
198 	    if (slot == NULL) {
199 		ret = KRB5_CC_NOMEM;
200 		goto out;
201 	    }
202 	    slot->next = ccache_head;
203 	    HEIMDAL_MUTEX_init(&slot->mutex);
204 	    new_slot = 1;
205 	}
206     }
207 
208     slot->name = strdup(name);
209     if (slot->name == NULL) {
210 	ret = KRB5_CC_NOMEM;
211 	goto out;
212     }
213 
214     slot->refcnt = 1;
215     slot->flags = KCM_FLAGS_VALID;
216     slot->mode = S_IRUSR | S_IWUSR;
217     slot->uid = -1;
218     slot->gid = -1;
219     slot->client = NULL;
220     slot->server = NULL;
221     slot->creds = NULL;
222     slot->n_cursor = 0;
223     slot->cursors = NULL;
224     slot->key.keytab = NULL;
225     slot->tkt_life = 0;
226     slot->renew_life = 0;
227 
228     if (new_slot)
229 	ccache_head = slot;
230 
231     *ccache = slot;
232 
233     HEIMDAL_MUTEX_unlock(&ccache_mutex);
234     return 0;
235 
236 out:
237     HEIMDAL_MUTEX_unlock(&ccache_mutex);
238     if (new_slot && slot != NULL) {
239 	HEIMDAL_MUTEX_destroy(&slot->mutex);
240 	free(slot);
241     }
242     return ret;
243 }
244 
245 krb5_error_code
246 kcm_ccache_remove_creds_internal(krb5_context context,
247 				 kcm_ccache ccache)
248 {
249     struct kcm_creds *k;
250     struct kcm_cursor *c;
251 
252     k = ccache->creds;
253     while (k != NULL) {
254 	struct kcm_creds *old;
255 
256 	krb5_free_cred_contents(context, &k->cred);
257 	old = k;
258 	k = k->next;
259 	free(old);
260     }
261     ccache->creds = NULL;
262 
263     /* remove anything that would have pointed into the creds too */
264 
265     ccache->n_cursor = 0;
266 
267     c = ccache->cursors;
268     while (c != NULL) {
269 	struct kcm_cursor *old;
270 
271 	old = c;
272 	c = c->next;
273 	free(old);
274     }
275     ccache->cursors = NULL;
276 
277     return 0;
278 }
279 
280 krb5_error_code
281 kcm_ccache_remove_creds(krb5_context context,
282 			kcm_ccache ccache)
283 {
284     krb5_error_code ret;
285 
286     KCM_ASSERT_VALID(ccache);
287 
288     HEIMDAL_MUTEX_lock(&ccache->mutex);
289     ret = kcm_ccache_remove_creds_internal(context, ccache);
290     HEIMDAL_MUTEX_unlock(&ccache->mutex);
291 
292     return ret;
293 }
294 
295 krb5_error_code
296 kcm_zero_ccache_data_internal(krb5_context context,
297 			      kcm_ccache_data *cache)
298 {
299     if (cache->client != NULL) {
300 	krb5_free_principal(context, cache->client);
301 	cache->client = NULL;
302     }
303 
304     if (cache->server != NULL) {
305 	krb5_free_principal(context, cache->server);
306 	cache->server = NULL;
307     }
308 
309     kcm_ccache_remove_creds_internal(context, cache);
310 
311     return 0;
312 }
313 
314 krb5_error_code
315 kcm_zero_ccache_data(krb5_context context,
316 		     kcm_ccache cache)
317 {
318     krb5_error_code ret;
319 
320     KCM_ASSERT_VALID(cache);
321 
322     HEIMDAL_MUTEX_lock(&cache->mutex);
323     ret = kcm_zero_ccache_data_internal(context, cache);
324     HEIMDAL_MUTEX_unlock(&cache->mutex);
325 
326     return ret;
327 }
328 
329 static krb5_error_code
330 kcm_free_ccache_data_internal(krb5_context context,
331 			      kcm_ccache_data *cache)
332 {
333     KCM_ASSERT_VALID(cache);
334 
335     if (cache->name != NULL) {
336 	free(cache->name);
337 	cache->name = NULL;
338     }
339 
340     if (cache->flags & KCM_FLAGS_USE_KEYTAB) {
341 	krb5_kt_close(context, cache->key.keytab);
342 	cache->key.keytab = NULL;
343     } else if (cache->flags & KCM_FLAGS_USE_CACHED_KEY) {
344 	krb5_free_keyblock_contents(context, &cache->key.keyblock);
345 	krb5_keyblock_zero(&cache->key.keyblock);
346     }
347 
348     cache->flags = 0;
349     cache->mode = 0;
350     cache->uid = -1;
351     cache->gid = -1;
352 
353     kcm_zero_ccache_data_internal(context, cache);
354 
355     cache->tkt_life = 0;
356     cache->renew_life = 0;
357 
358     cache->next = NULL;
359     cache->refcnt = 0;
360 
361     HEIMDAL_MUTEX_unlock(&cache->mutex);
362     HEIMDAL_MUTEX_destroy(&cache->mutex);
363 
364     return 0;
365 }
366 
367 krb5_error_code
368 kcm_retain_ccache(krb5_context context,
369 		  kcm_ccache ccache)
370 {
371     KCM_ASSERT_VALID(ccache);
372 
373     HEIMDAL_MUTEX_lock(&ccache->mutex);
374     ccache->refcnt++;
375     HEIMDAL_MUTEX_unlock(&ccache->mutex);
376 
377     return 0;
378 }
379 
380 krb5_error_code
381 kcm_release_ccache(krb5_context context,
382 		   kcm_ccache *ccache)
383 {
384     kcm_ccache c = *ccache;
385     krb5_error_code ret = 0;
386 
387     KCM_ASSERT_VALID(c);
388 
389     HEIMDAL_MUTEX_lock(&c->mutex);
390     if (c->refcnt == 1) {
391 	ret = kcm_free_ccache_data_internal(context, c);
392 	if (ret == 0)
393 	    free(c);
394     } else {
395 	c->refcnt--;
396 	HEIMDAL_MUTEX_unlock(&c->mutex);
397     }
398 
399     *ccache = NULL;
400 
401     return ret;
402 }
403 
404 krb5_error_code
405 kcm_ccache_gen_new(krb5_context context,
406 		   pid_t pid,
407 		   uid_t uid,
408 		   gid_t gid,
409 		   kcm_ccache *ccache)
410 {
411     krb5_error_code ret;
412     char *name;
413 
414     name = kcm_ccache_nextid(pid, uid, gid);
415     if (name == NULL) {
416 	return KRB5_CC_NOMEM;
417     }
418 
419     ret = kcm_ccache_new(context, name, ccache);
420 
421     free(name);
422     return ret;
423 }
424 
425 krb5_error_code
426 kcm_ccache_new(krb5_context context,
427 	       const char *name,
428 	       kcm_ccache *ccache)
429 {
430     krb5_error_code ret;
431 
432     ret = kcm_ccache_alloc(context, name, ccache);
433     if (ret == 0) {
434 	/*
435 	 * one reference is held by the linked list,
436 	 * one by the caller
437 	 */
438 	kcm_retain_ccache(context, *ccache);
439     }
440 
441     return ret;
442 }
443 
444 krb5_error_code
445 kcm_ccache_resolve(krb5_context context,
446 		   const char *name,
447 		   kcm_ccache *ccache)
448 {
449     krb5_error_code ret;
450 
451     ret = kcm_ccache_resolve_internal(context, name, ccache);
452 
453     return ret;
454 }
455 
456 krb5_error_code
457 kcm_ccache_destroy(krb5_context context,
458 		   const char *name)
459 {
460     krb5_error_code ret;
461 
462     ret = kcm_ccache_destroy_internal(context, name);
463 
464     return ret;
465 }
466 
467 krb5_error_code
468 kcm_ccache_destroy_if_empty(krb5_context context,
469 			    kcm_ccache ccache)
470 {
471     krb5_error_code ret;
472 
473     KCM_ASSERT_VALID(ccache);
474 
475     if (ccache->creds == NULL) {
476 	ret = kcm_ccache_destroy_internal(context, ccache->name);
477     } else
478 	ret = 0;
479 
480     return ret;
481 }
482 
483 krb5_error_code
484 kcm_ccache_store_cred(krb5_context context,
485 		      kcm_ccache ccache,
486 		      krb5_creds *creds,
487 		      int copy)
488 {
489     krb5_error_code ret;
490     krb5_creds *tmp;
491 
492     KCM_ASSERT_VALID(ccache);
493 
494     HEIMDAL_MUTEX_lock(&ccache->mutex);
495     ret = kcm_ccache_store_cred_internal(context, ccache, creds, copy, &tmp);
496     HEIMDAL_MUTEX_unlock(&ccache->mutex);
497 
498     return ret;
499 }
500 
501 krb5_error_code
502 kcm_ccache_store_cred_internal(krb5_context context,
503 			       kcm_ccache ccache,
504 			       krb5_creds *creds,
505 			       int copy,
506 			       krb5_creds **credp)
507 {
508     struct kcm_creds **c;
509     krb5_error_code ret;
510 
511     for (c = &ccache->creds; *c != NULL; c = &(*c)->next)
512 	;
513 
514     *c = (struct kcm_creds *)malloc(sizeof(struct kcm_creds));
515     if (*c == NULL) {
516 	return KRB5_CC_NOMEM;
517     }
518 
519     *credp = &(*c)->cred;
520 
521     if (copy) {
522 	ret = krb5_copy_creds_contents(context, creds, *credp);
523 	if (ret) {
524 	    free(*c);
525 	    *c = NULL;
526 	}
527     } else {
528 	**credp = *creds;
529 	ret = 0;
530     }
531 
532     (*c)->next = NULL;
533 
534     return ret;
535 }
536 
537 static void
538 remove_cred(krb5_context context,
539 	    struct kcm_creds **c)
540 {
541     struct kcm_creds *cred;
542 
543     cred = *c;
544 
545     *c = cred->next;
546 
547     krb5_free_cred_contents(context, &cred->cred);
548     free(cred);
549 }
550 
551 krb5_error_code
552 kcm_ccache_remove_cred_internal(krb5_context context,
553 				kcm_ccache ccache,
554 				krb5_flags whichfields,
555 				const krb5_creds *mcreds)
556 {
557     krb5_error_code ret;
558     struct kcm_creds **c;
559 
560     ret = KRB5_CC_NOTFOUND;
561 
562     for (c = &ccache->creds; *c != NULL; c = &(*c)->next) {
563 	if (krb5_compare_creds(context, whichfields, mcreds, &(*c)->cred)) {
564 	    remove_cred(context, c);
565 	    ret = 0;
566 	}
567     }
568 
569     return ret;
570 }
571 
572 krb5_error_code
573 kcm_ccache_remove_cred(krb5_context context,
574 		       kcm_ccache ccache,
575 		       krb5_flags whichfields,
576 		       const krb5_creds *mcreds)
577 {
578     krb5_error_code ret;
579 
580     KCM_ASSERT_VALID(ccache);
581 
582     HEIMDAL_MUTEX_lock(&ccache->mutex);
583     ret = kcm_ccache_remove_cred_internal(context, ccache, whichfields, mcreds);
584     HEIMDAL_MUTEX_unlock(&ccache->mutex);
585 
586     return ret;
587 }
588 
589 krb5_error_code
590 kcm_ccache_retrieve_cred_internal(krb5_context context,
591 			 	  kcm_ccache ccache,
592 			 	  krb5_flags whichfields,
593 			 	  const krb5_creds *mcreds,
594 			 	  krb5_creds **creds)
595 {
596     krb5_boolean match;
597     struct kcm_creds *c;
598     krb5_error_code ret;
599 
600     memset(creds, 0, sizeof(*creds));
601 
602     ret = KRB5_CC_END;
603 
604     match = FALSE;
605     for (c = ccache->creds; c != NULL; c = c->next) {
606 	match = krb5_compare_creds(context, whichfields, mcreds, &c->cred);
607 	if (match)
608 	    break;
609     }
610 
611     if (match) {
612 	ret = 0;
613 	*creds = &c->cred;
614     }
615 
616     return ret;
617 }
618 
619 krb5_error_code
620 kcm_ccache_retrieve_cred(krb5_context context,
621 			 kcm_ccache ccache,
622 			 krb5_flags whichfields,
623 			 const krb5_creds *mcreds,
624 			 krb5_creds **credp)
625 {
626     krb5_error_code ret;
627 
628     KCM_ASSERT_VALID(ccache);
629 
630     HEIMDAL_MUTEX_lock(&ccache->mutex);
631     ret = kcm_ccache_retrieve_cred_internal(context, ccache,
632 					    whichfields, mcreds, credp);
633     HEIMDAL_MUTEX_unlock(&ccache->mutex);
634 
635     return ret;
636 }
637