xref: /netbsd-src/crypto/external/bsd/heimdal/dist/kcm/cache.c (revision afab4e300d3a9fb07dd8c80daf53d0feb3345706)
1 /*	$NetBSD: cache.c,v 1.6 2023/06/19 21:41:41 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 2005, PADL Software Pty Ltd.
5  * All rights reserved.
6  *
7  * Portions Copyright (c) 2009 Apple Inc. All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  *
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * 3. Neither the name of PADL Software nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY PADL SOFTWARE AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL PADL SOFTWARE OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #include "kcm_locl.h"
38 
39 HEIMDAL_MUTEX ccache_mutex = HEIMDAL_MUTEX_INITIALIZER;
40 kcm_ccache_data *ccache_head = NULL;
41 static unsigned int ccache_nextid = 0;
42 
kcm_ccache_nextid(pid_t pid,uid_t uid,gid_t gid)43 char *kcm_ccache_nextid(pid_t pid, uid_t uid, gid_t gid)
44 {
45     unsigned n;
46     char *name;
47     int ret;
48 
49     HEIMDAL_MUTEX_lock(&ccache_mutex);
50     n = ++ccache_nextid;
51     HEIMDAL_MUTEX_unlock(&ccache_mutex);
52 
53     ret = asprintf(&name, "%ld:%u", (long)uid, n);
54     if (ret == -1)
55 	return NULL;
56 
57     return name;
58 }
59 
60 krb5_error_code
kcm_ccache_resolve(krb5_context context,const char * name,kcm_ccache * ccache)61 kcm_ccache_resolve(krb5_context context,
62 		   const char *name,
63 		   kcm_ccache *ccache)
64 {
65     kcm_ccache p;
66     krb5_error_code ret;
67 
68     *ccache = NULL;
69 
70     ret = KRB5_FCC_NOFILE;
71 
72     HEIMDAL_MUTEX_lock(&ccache_mutex);
73 
74     for (p = ccache_head; p != NULL; p = p->next) {
75 	if ((p->flags & KCM_FLAGS_VALID) == 0)
76 	    continue;
77 	if (strcmp(p->name, name) == 0) {
78 	    ret = 0;
79 	    break;
80 	}
81     }
82 
83     if (ret == 0) {
84 	kcm_retain_ccache(context, p);
85 	*ccache = p;
86     }
87 
88     HEIMDAL_MUTEX_unlock(&ccache_mutex);
89 
90     return ret;
91 }
92 
93 krb5_error_code
kcm_ccache_resolve_by_uuid(krb5_context context,kcmuuid_t uuid,kcm_ccache * ccache)94 kcm_ccache_resolve_by_uuid(krb5_context context,
95 			   kcmuuid_t uuid,
96 			   kcm_ccache *ccache)
97 {
98     kcm_ccache p;
99     krb5_error_code ret;
100 
101     *ccache = NULL;
102 
103     ret = KRB5_FCC_NOFILE;
104 
105     HEIMDAL_MUTEX_lock(&ccache_mutex);
106 
107     for (p = ccache_head; p != NULL; p = p->next) {
108 	if ((p->flags & KCM_FLAGS_VALID) == 0)
109 	    continue;
110 	if (memcmp(p->uuid, uuid, sizeof(kcmuuid_t)) == 0) {
111 	    ret = 0;
112 	    break;
113 	}
114     }
115 
116     if (ret == 0) {
117 	kcm_retain_ccache(context, p);
118 	*ccache = p;
119     }
120 
121     HEIMDAL_MUTEX_unlock(&ccache_mutex);
122 
123     return ret;
124 }
125 
126 krb5_error_code
kcm_ccache_get_uuids(krb5_context context,kcm_client * client,kcm_operation opcode,krb5_storage * sp)127 kcm_ccache_get_uuids(krb5_context context, kcm_client *client, kcm_operation opcode, krb5_storage *sp)
128 {
129     krb5_error_code ret;
130     kcm_ccache p;
131 
132     ret = KRB5_FCC_NOFILE;
133 
134     HEIMDAL_MUTEX_lock(&ccache_mutex);
135 
136     for (p = ccache_head; p != NULL; p = p->next) {
137 	if ((p->flags & KCM_FLAGS_VALID) == 0)
138 	    continue;
139 	ret = kcm_access(context, client, opcode, p);
140 	if (ret) {
141 	    ret = 0;
142 	    continue;
143 	}
144 	krb5_storage_write(sp, p->uuid, sizeof(p->uuid));
145     }
146 
147     HEIMDAL_MUTEX_unlock(&ccache_mutex);
148 
149     return ret;
150 }
151 
152 
kcm_debug_ccache(krb5_context context)153 krb5_error_code kcm_debug_ccache(krb5_context context)
154 {
155     kcm_ccache p;
156 
157     for (p = ccache_head; p != NULL; p = p->next) {
158 	char *cpn = NULL, *spn = NULL;
159 	int ncreds = 0;
160 	struct kcm_creds *k;
161 
162 	if ((p->flags & KCM_FLAGS_VALID) == 0) {
163 	    kcm_log(7, "cache %08x: empty slot");
164 	    continue;
165 	}
166 
167 	KCM_ASSERT_VALID(p);
168 
169 	for (k = p->creds; k != NULL; k = k->next)
170 	    ncreds++;
171 
172 	if (p->client != NULL)
173 	    krb5_unparse_name(context, p->client, &cpn);
174 	if (p->server != NULL)
175 	    krb5_unparse_name(context, p->server, &spn);
176 
177 	kcm_log(7, "cache %08x: name %s refcnt %d flags %04x mode %04o "
178 		"uid %d gid %d client %s server %s ncreds %d",
179 		p, p->name, p->refcnt, p->flags, p->mode, p->uid, p->gid,
180 		(cpn == NULL) ? "<none>" : cpn,
181 		(spn == NULL) ? "<none>" : spn,
182 		ncreds);
183 
184 	if (cpn != NULL)
185 	    free(cpn);
186 	if (spn != NULL)
187 	    free(spn);
188     }
189 
190     return 0;
191 }
192 
193 static void
kcm_free_ccache_data_internal(krb5_context context,kcm_ccache_data * cache)194 kcm_free_ccache_data_internal(krb5_context context,
195 			      kcm_ccache_data *cache)
196 {
197     KCM_ASSERT_VALID(cache);
198 
199     if (cache->name != NULL) {
200 	free(cache->name);
201 	cache->name = NULL;
202     }
203 
204     if (cache->flags & KCM_FLAGS_USE_KEYTAB) {
205 	krb5_kt_close(context, cache->key.keytab);
206 	cache->key.keytab = NULL;
207     } else if (cache->flags & KCM_FLAGS_USE_CACHED_KEY) {
208 	krb5_free_keyblock_contents(context, &cache->key.keyblock);
209 	krb5_keyblock_zero(&cache->key.keyblock);
210     }
211 
212     cache->flags = 0;
213     cache->mode = 0;
214     cache->uid = -1;
215     cache->gid = -1;
216     cache->session = -1;
217 
218     kcm_zero_ccache_data_internal(context, cache);
219 
220     cache->tkt_life = 0;
221     cache->renew_life = 0;
222 
223     cache->next = NULL;
224     cache->refcnt = 0;
225 
226     HEIMDAL_MUTEX_unlock(&cache->mutex);
227     HEIMDAL_MUTEX_destroy(&cache->mutex);
228 }
229 
230 
231 krb5_error_code
kcm_ccache_destroy(krb5_context context,const char * name)232 kcm_ccache_destroy(krb5_context context, const char *name)
233 {
234     kcm_ccache *p, ccache;
235     krb5_error_code ret;
236 
237     ret = KRB5_FCC_NOFILE;
238 
239     HEIMDAL_MUTEX_lock(&ccache_mutex);
240     for (p = &ccache_head; *p != NULL; p = &(*p)->next) {
241 	if (((*p)->flags & KCM_FLAGS_VALID) == 0)
242 	    continue;
243 	if (strcmp((*p)->name, name) == 0) {
244 	    ret = 0;
245 	    break;
246 	}
247     }
248     if (ret)
249 	goto out;
250 
251     if ((*p)->refcnt != 1) {
252 	ret = EAGAIN;
253 	goto out;
254     }
255 
256     ccache = *p;
257     *p = (*p)->next;
258     kcm_free_ccache_data_internal(context, ccache);
259     free(ccache);
260 
261 out:
262     HEIMDAL_MUTEX_unlock(&ccache_mutex);
263 
264     return ret;
265 }
266 
267 static krb5_error_code
kcm_ccache_alloc(krb5_context context,const char * name,kcm_ccache * ccache)268 kcm_ccache_alloc(krb5_context context,
269 		 const char *name,
270 		 kcm_ccache *ccache)
271 {
272     kcm_ccache slot = NULL, p;
273     krb5_error_code ret;
274     int new_slot = 0;
275 
276     *ccache = NULL;
277 
278     /* First, check for duplicates */
279     HEIMDAL_MUTEX_lock(&ccache_mutex);
280     ret = 0;
281     for (p = ccache_head; p != NULL; p = p->next) {
282 	if (p->flags & KCM_FLAGS_VALID) {
283 	    if (strcmp(p->name, name) == 0) {
284 		ret = KRB5_CC_WRITE;
285 		break;
286 	    }
287 	} else if (slot == NULL)
288 	    slot = p;
289     }
290 
291     if (ret)
292 	goto out;
293 
294     /*
295      * Create an enpty slot for us.
296      */
297     if (slot == NULL) {
298 	slot = (kcm_ccache_data *)malloc(sizeof(*slot));
299 	if (slot == NULL) {
300 	    ret = KRB5_CC_NOMEM;
301 	    goto out;
302 	}
303 	slot->next = ccache_head;
304 	HEIMDAL_MUTEX_init(&slot->mutex);
305 	new_slot = 1;
306     }
307 
308     RAND_bytes(slot->uuid, sizeof(slot->uuid));
309 
310     slot->name = strdup(name);
311     if (slot->name == NULL) {
312 	ret = KRB5_CC_NOMEM;
313 	goto out;
314     }
315 
316     slot->refcnt = 1;
317     slot->flags = KCM_FLAGS_VALID;
318     slot->mode = S_IRUSR | S_IWUSR;
319     slot->uid = -1;
320     slot->gid = -1;
321     slot->client = NULL;
322     slot->server = NULL;
323     slot->creds = NULL;
324     slot->key.keytab = NULL;
325     slot->tkt_life = 0;
326     slot->renew_life = 0;
327     slot->kdc_offset = 0;
328 
329     if (new_slot)
330 	ccache_head = slot;
331 
332     *ccache = slot;
333 
334     HEIMDAL_MUTEX_unlock(&ccache_mutex);
335     return 0;
336 
337 out:
338     HEIMDAL_MUTEX_unlock(&ccache_mutex);
339     if (new_slot && slot != NULL) {
340 	HEIMDAL_MUTEX_destroy(&slot->mutex);
341 	free(slot);
342     }
343     return ret;
344 }
345 
346 krb5_error_code
kcm_ccache_remove_creds_internal(krb5_context context,kcm_ccache ccache)347 kcm_ccache_remove_creds_internal(krb5_context context,
348 				 kcm_ccache ccache)
349 {
350     struct kcm_creds *k;
351 
352     k = ccache->creds;
353     while (k != NULL) {
354 	struct kcm_creds *old;
355 
356 	krb5_free_cred_contents(context, &k->cred);
357 	old = k;
358 	k = k->next;
359 	free(old);
360     }
361     ccache->creds = NULL;
362 
363     return 0;
364 }
365 
366 krb5_error_code
kcm_ccache_remove_creds(krb5_context context,kcm_ccache ccache)367 kcm_ccache_remove_creds(krb5_context context,
368 			kcm_ccache ccache)
369 {
370     krb5_error_code ret;
371 
372     KCM_ASSERT_VALID(ccache);
373 
374     HEIMDAL_MUTEX_lock(&ccache->mutex);
375     ret = kcm_ccache_remove_creds_internal(context, ccache);
376     HEIMDAL_MUTEX_unlock(&ccache->mutex);
377 
378     return ret;
379 }
380 
381 krb5_error_code
kcm_zero_ccache_data_internal(krb5_context context,kcm_ccache_data * cache)382 kcm_zero_ccache_data_internal(krb5_context context,
383 			      kcm_ccache_data *cache)
384 {
385     if (cache->client != NULL) {
386 	krb5_free_principal(context, cache->client);
387 	cache->client = NULL;
388     }
389 
390     if (cache->server != NULL) {
391 	krb5_free_principal(context, cache->server);
392 	cache->server = NULL;
393     }
394 
395     kcm_ccache_remove_creds_internal(context, cache);
396 
397     return 0;
398 }
399 
400 krb5_error_code
kcm_zero_ccache_data(krb5_context context,kcm_ccache cache)401 kcm_zero_ccache_data(krb5_context context,
402 		     kcm_ccache cache)
403 {
404     krb5_error_code ret;
405 
406     KCM_ASSERT_VALID(cache);
407 
408     HEIMDAL_MUTEX_lock(&cache->mutex);
409     ret = kcm_zero_ccache_data_internal(context, cache);
410     HEIMDAL_MUTEX_unlock(&cache->mutex);
411 
412     return ret;
413 }
414 
415 krb5_error_code
kcm_retain_ccache(krb5_context context,kcm_ccache ccache)416 kcm_retain_ccache(krb5_context context,
417 		  kcm_ccache ccache)
418 {
419     KCM_ASSERT_VALID(ccache);
420 
421     HEIMDAL_MUTEX_lock(&ccache->mutex);
422     ccache->refcnt++;
423     HEIMDAL_MUTEX_unlock(&ccache->mutex);
424 
425     return 0;
426 }
427 
428 krb5_error_code
kcm_release_ccache(krb5_context context,kcm_ccache c)429 kcm_release_ccache(krb5_context context, kcm_ccache c)
430 {
431     krb5_error_code ret = 0;
432 
433     KCM_ASSERT_VALID(c);
434 
435     HEIMDAL_MUTEX_lock(&c->mutex);
436     if (c->refcnt == 1) {
437 	kcm_free_ccache_data_internal(context, c);
438 	free(c);
439     } else {
440 	c->refcnt--;
441 	HEIMDAL_MUTEX_unlock(&c->mutex);
442     }
443 
444     return ret;
445 }
446 
447 krb5_error_code
kcm_ccache_gen_new(krb5_context context,pid_t pid,uid_t uid,gid_t gid,kcm_ccache * ccache)448 kcm_ccache_gen_new(krb5_context context,
449 		   pid_t pid,
450 		   uid_t uid,
451 		   gid_t gid,
452 		   kcm_ccache *ccache)
453 {
454     krb5_error_code ret;
455     char *name;
456 
457     name = kcm_ccache_nextid(pid, uid, gid);
458     if (name == NULL) {
459 	return KRB5_CC_NOMEM;
460     }
461 
462     ret = kcm_ccache_new(context, name, ccache);
463 
464     free(name);
465     return ret;
466 }
467 
468 krb5_error_code
kcm_ccache_new(krb5_context context,const char * name,kcm_ccache * ccache)469 kcm_ccache_new(krb5_context context,
470 	       const char *name,
471 	       kcm_ccache *ccache)
472 {
473     krb5_error_code ret;
474 
475     ret = kcm_ccache_alloc(context, name, ccache);
476     if (ret == 0) {
477 	/*
478 	 * one reference is held by the linked list,
479 	 * one by the caller
480 	 */
481 	kcm_retain_ccache(context, *ccache);
482     }
483 
484     return ret;
485 }
486 
487 krb5_error_code
kcm_ccache_destroy_if_empty(krb5_context context,kcm_ccache ccache)488 kcm_ccache_destroy_if_empty(krb5_context context,
489 			    kcm_ccache ccache)
490 {
491     krb5_error_code ret;
492 
493     KCM_ASSERT_VALID(ccache);
494 
495     if (ccache->creds == NULL) {
496 	ret = kcm_ccache_destroy(context, ccache->name);
497     } else
498 	ret = 0;
499 
500     return ret;
501 }
502 
503 krb5_error_code
kcm_ccache_store_cred(krb5_context context,kcm_ccache ccache,krb5_creds * creds,int copy)504 kcm_ccache_store_cred(krb5_context context,
505 		      kcm_ccache ccache,
506 		      krb5_creds *creds,
507 		      int copy)
508 {
509     krb5_error_code ret;
510     krb5_creds *tmp;
511 
512     KCM_ASSERT_VALID(ccache);
513 
514     HEIMDAL_MUTEX_lock(&ccache->mutex);
515     ret = kcm_ccache_store_cred_internal(context, ccache, creds, copy, &tmp);
516     HEIMDAL_MUTEX_unlock(&ccache->mutex);
517 
518     return ret;
519 }
520 
521 struct kcm_creds *
kcm_ccache_find_cred_uuid(krb5_context context,kcm_ccache ccache,kcmuuid_t uuid)522 kcm_ccache_find_cred_uuid(krb5_context context,
523 			  kcm_ccache ccache,
524 			  kcmuuid_t uuid)
525 {
526     struct kcm_creds *c;
527 
528     for (c = ccache->creds; c != NULL; c = c->next)
529 	if (memcmp(c->uuid, uuid, sizeof(c->uuid)) == 0)
530 	    return c;
531 
532     return NULL;
533 }
534 
535 
536 
537 krb5_error_code
kcm_ccache_store_cred_internal(krb5_context context,kcm_ccache ccache,krb5_creds * creds,int copy,krb5_creds ** credp)538 kcm_ccache_store_cred_internal(krb5_context context,
539 			       kcm_ccache ccache,
540 			       krb5_creds *creds,
541 			       int copy,
542 			       krb5_creds **credp)
543 {
544     struct kcm_creds **c;
545     krb5_error_code ret;
546 
547     for (c = &ccache->creds; *c != NULL; c = &(*c)->next)
548 	;
549 
550     *c = (struct kcm_creds *)calloc(1, sizeof(**c));
551     if (*c == NULL)
552 	return KRB5_CC_NOMEM;
553 
554     RAND_bytes((*c)->uuid, sizeof((*c)->uuid));
555 
556     *credp = &(*c)->cred;
557 
558     if (copy) {
559 	ret = krb5_copy_creds_contents(context, creds, *credp);
560 	if (ret) {
561 	    free(*c);
562 	    *c = NULL;
563 	}
564     } else {
565 	**credp = *creds;
566 	ret = 0;
567     }
568 
569     return ret;
570 }
571 
572 krb5_error_code
kcm_ccache_remove_cred_internal(krb5_context context,kcm_ccache ccache,krb5_flags whichfields,const krb5_creds * mcreds)573 kcm_ccache_remove_cred_internal(krb5_context context,
574 				kcm_ccache ccache,
575 				krb5_flags whichfields,
576 				const krb5_creds *mcreds)
577 {
578     krb5_error_code ret;
579     struct kcm_creds **c;
580 
581     ret = KRB5_CC_NOTFOUND;
582 
583     for (c = &ccache->creds; *c != NULL; c = &(*c)->next) {
584 	if (krb5_compare_creds(context, whichfields, mcreds, &(*c)->cred)) {
585 	    struct kcm_creds *cred = *c;
586 
587 	    *c = cred->next;
588 	    krb5_free_cred_contents(context, &cred->cred);
589 	    free(cred);
590 	    ret = 0;
591 	    if (*c == NULL)
592 		break;
593 	}
594     }
595 
596     return ret;
597 }
598 
599 krb5_error_code
kcm_ccache_remove_cred(krb5_context context,kcm_ccache ccache,krb5_flags whichfields,const krb5_creds * mcreds)600 kcm_ccache_remove_cred(krb5_context context,
601 		       kcm_ccache ccache,
602 		       krb5_flags whichfields,
603 		       const krb5_creds *mcreds)
604 {
605     krb5_error_code ret;
606 
607     KCM_ASSERT_VALID(ccache);
608 
609     HEIMDAL_MUTEX_lock(&ccache->mutex);
610     ret = kcm_ccache_remove_cred_internal(context, ccache, whichfields, mcreds);
611     HEIMDAL_MUTEX_unlock(&ccache->mutex);
612 
613     return ret;
614 }
615 
616 krb5_error_code
kcm_ccache_retrieve_cred_internal(krb5_context context,kcm_ccache ccache,krb5_flags whichfields,const krb5_creds * mcreds,krb5_creds ** creds)617 kcm_ccache_retrieve_cred_internal(krb5_context context,
618 			 	  kcm_ccache ccache,
619 			 	  krb5_flags whichfields,
620 			 	  const krb5_creds *mcreds,
621 			 	  krb5_creds **creds)
622 {
623     krb5_boolean match;
624     struct kcm_creds *c;
625     krb5_error_code ret;
626 
627     memset(creds, 0, sizeof(*creds));
628 
629     ret = KRB5_CC_END;
630 
631     match = FALSE;
632     for (c = ccache->creds; c != NULL; c = c->next) {
633 	match = krb5_compare_creds(context, whichfields, mcreds, &c->cred);
634 	if (match)
635 	    break;
636     }
637 
638     if (match) {
639 	ret = 0;
640 	*creds = &c->cred;
641     }
642 
643     return ret;
644 }
645 
646 krb5_error_code
kcm_ccache_retrieve_cred(krb5_context context,kcm_ccache ccache,krb5_flags whichfields,const krb5_creds * mcreds,krb5_creds ** credp)647 kcm_ccache_retrieve_cred(krb5_context context,
648 			 kcm_ccache ccache,
649 			 krb5_flags whichfields,
650 			 const krb5_creds *mcreds,
651 			 krb5_creds **credp)
652 {
653     krb5_error_code ret;
654 
655     KCM_ASSERT_VALID(ccache);
656 
657     HEIMDAL_MUTEX_lock(&ccache->mutex);
658     ret = kcm_ccache_retrieve_cred_internal(context, ccache,
659 					    whichfields, mcreds, credp);
660     HEIMDAL_MUTEX_unlock(&ccache->mutex);
661 
662     return ret;
663 }
664 
665 char *
kcm_ccache_first_name(kcm_client * client)666 kcm_ccache_first_name(kcm_client *client)
667 {
668     kcm_ccache p;
669     char *name = NULL;
670 
671     HEIMDAL_MUTEX_lock(&ccache_mutex);
672 
673     for (p = ccache_head; p != NULL; p = p->next) {
674 	if (kcm_is_same_session(client, p->uid, p->session))
675 	    break;
676     }
677     if (p)
678 	name = strdup(p->name);
679     HEIMDAL_MUTEX_unlock(&ccache_mutex);
680     return name;
681 }
682