xref: /freebsd/crypto/heimdal/lib/krb5/fcache.c (revision 8aac90f18aef7c9eea906c3ff9a001ca7b94f375)
1 /*
2  * Copyright (c) 1997 - 2008 Kungliga Tekniska Högskolan
3  * (Royal Institute of Technology, Stockholm, Sweden).
4  * All rights reserved.
5  *
6  * Portions Copyright (c) 2009 Apple Inc. All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * 3. Neither the name of the Institute nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include "krb5_locl.h"
37 
38 typedef struct krb5_fcache{
39     char *filename;
40     int version;
41 }krb5_fcache;
42 
43 struct fcc_cursor {
44     int fd;
45     krb5_storage *sp;
46 };
47 
48 #define KRB5_FCC_FVNO_1 1
49 #define KRB5_FCC_FVNO_2 2
50 #define KRB5_FCC_FVNO_3 3
51 #define KRB5_FCC_FVNO_4 4
52 
53 #define FCC_TAG_DELTATIME 1
54 
55 #define FCACHE(X) ((krb5_fcache*)(X)->data.data)
56 
57 #define FILENAME(X) (FCACHE(X)->filename)
58 
59 #define FCC_CURSOR(C) ((struct fcc_cursor*)(C))
60 
61 static const char* KRB5_CALLCONV
62 fcc_get_name(krb5_context context,
63 	     krb5_ccache id)
64 {
65     if (FCACHE(id) == NULL)
66         return NULL;
67 
68     return FILENAME(id);
69 }
70 
71 int
72 _krb5_xlock(krb5_context context, int fd, krb5_boolean exclusive,
73 	    const char *filename)
74 {
75     int ret;
76 #ifdef HAVE_FCNTL
77     struct flock l;
78 
79     l.l_start = 0;
80     l.l_len = 0;
81     l.l_type = exclusive ? F_WRLCK : F_RDLCK;
82     l.l_whence = SEEK_SET;
83     ret = fcntl(fd, F_SETLKW, &l);
84 #else
85     ret = flock(fd, exclusive ? LOCK_EX : LOCK_SH);
86 #endif
87     if(ret < 0)
88 	ret = errno;
89     if(ret == EACCES) /* fcntl can return EACCES instead of EAGAIN */
90 	ret = EAGAIN;
91 
92     switch (ret) {
93     case 0:
94 	break;
95     case EINVAL: /* filesystem doesn't support locking, let the user have it */
96 	ret = 0;
97 	break;
98     case EAGAIN:
99 	krb5_set_error_message(context, ret,
100 			       N_("timed out locking cache file %s", "file"),
101 			       filename);
102 	break;
103     default: {
104 	char buf[128];
105 	rk_strerror_r(ret, buf, sizeof(buf));
106 	krb5_set_error_message(context, ret,
107 			       N_("error locking cache file %s: %s",
108 				  "file, error"), filename, buf);
109 	break;
110     }
111     }
112     return ret;
113 }
114 
115 int
116 _krb5_xunlock(krb5_context context, int fd)
117 {
118     int ret;
119 #ifdef HAVE_FCNTL
120     struct flock l;
121     l.l_start = 0;
122     l.l_len = 0;
123     l.l_type = F_UNLCK;
124     l.l_whence = SEEK_SET;
125     ret = fcntl(fd, F_SETLKW, &l);
126 #else
127     ret = flock(fd, LOCK_UN);
128 #endif
129     if (ret < 0)
130 	ret = errno;
131     switch (ret) {
132     case 0:
133 	break;
134     case EINVAL: /* filesystem doesn't support locking, let the user have it */
135 	ret = 0;
136 	break;
137     default: {
138 	char buf[128];
139 	rk_strerror_r(ret, buf, sizeof(buf));
140 	krb5_set_error_message(context, ret,
141 			       N_("Failed to unlock file: %s", ""), buf);
142 	break;
143     }
144     }
145     return ret;
146 }
147 
148 static krb5_error_code
149 write_storage(krb5_context context, krb5_storage *sp, int fd)
150 {
151     krb5_error_code ret;
152     krb5_data data;
153     ssize_t sret;
154 
155     ret = krb5_storage_to_data(sp, &data);
156     if (ret) {
157 	krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
158 	return ret;
159     }
160     sret = write(fd, data.data, data.length);
161     ret = (sret != (ssize_t)data.length);
162     krb5_data_free(&data);
163     if (ret) {
164 	ret = errno;
165 	krb5_set_error_message(context, ret,
166 			       N_("Failed to write FILE credential data", ""));
167 	return ret;
168     }
169     return 0;
170 }
171 
172 
173 static krb5_error_code KRB5_CALLCONV
174 fcc_lock(krb5_context context, krb5_ccache id,
175 	 int fd, krb5_boolean exclusive)
176 {
177     return _krb5_xlock(context, fd, exclusive, fcc_get_name(context, id));
178 }
179 
180 static krb5_error_code KRB5_CALLCONV
181 fcc_unlock(krb5_context context, int fd)
182 {
183     return _krb5_xunlock(context, fd);
184 }
185 
186 static krb5_error_code KRB5_CALLCONV
187 fcc_resolve(krb5_context context, krb5_ccache *id, const char *res)
188 {
189     krb5_fcache *f;
190     f = malloc(sizeof(*f));
191     if(f == NULL) {
192 	krb5_set_error_message(context, KRB5_CC_NOMEM,
193 			       N_("malloc: out of memory", ""));
194 	return KRB5_CC_NOMEM;
195     }
196     f->filename = strdup(res);
197     if(f->filename == NULL){
198 	free(f);
199 	krb5_set_error_message(context, KRB5_CC_NOMEM,
200 			       N_("malloc: out of memory", ""));
201 	return KRB5_CC_NOMEM;
202     }
203     f->version = 0;
204     (*id)->data.data = f;
205     (*id)->data.length = sizeof(*f);
206     return 0;
207 }
208 
209 /*
210  * Try to scrub the contents of `filename' safely.
211  */
212 
213 static int
214 scrub_file (int fd)
215 {
216     off_t pos;
217     char buf[128];
218 
219     pos = lseek(fd, 0, SEEK_END);
220     if (pos < 0)
221         return errno;
222     if (lseek(fd, 0, SEEK_SET) < 0)
223         return errno;
224     memset(buf, 0, sizeof(buf));
225     while(pos > 0) {
226         ssize_t tmp = write(fd, buf, min((off_t)sizeof(buf), pos));
227 
228 	if (tmp < 0)
229 	    return errno;
230 	pos -= tmp;
231     }
232 #ifdef _MSC_VER
233     _commit (fd);
234 #else
235     fsync (fd);
236 #endif
237     return 0;
238 }
239 
240 /*
241  * Erase `filename' if it exists, trying to remove the contents if
242  * it's `safe'.  We always try to remove the file, it it exists.  It's
243  * only overwritten if it's a regular file (not a symlink and not a
244  * hardlink)
245  */
246 
247 krb5_error_code
248 _krb5_erase_file(krb5_context context, const char *filename)
249 {
250     int fd;
251     struct stat sb1, sb2;
252     int ret;
253 
254     ret = lstat (filename, &sb1);
255     if (ret < 0)
256 	return errno;
257 
258     fd = open(filename, O_RDWR | O_BINARY);
259     if(fd < 0) {
260 	if(errno == ENOENT)
261 	    return 0;
262 	else
263 	    return errno;
264     }
265     rk_cloexec(fd);
266     ret = _krb5_xlock(context, fd, 1, filename);
267     if (ret) {
268 	close(fd);
269 	return ret;
270     }
271     if (unlink(filename) < 0) {
272 	_krb5_xunlock(context, fd);
273         close (fd);
274         return errno;
275     }
276     ret = fstat (fd, &sb2);
277     if (ret < 0) {
278 	_krb5_xunlock(context, fd);
279 	close (fd);
280 	return errno;
281     }
282 
283     /* check if someone was playing with symlinks */
284 
285     if (sb1.st_dev != sb2.st_dev || sb1.st_ino != sb2.st_ino) {
286 	_krb5_xunlock(context, fd);
287 	close (fd);
288 	return EPERM;
289     }
290 
291     /* there are still hard links to this file */
292 
293     if (sb2.st_nlink != 0) {
294 	_krb5_xunlock(context, fd);
295         close (fd);
296         return 0;
297     }
298 
299     ret = scrub_file (fd);
300     if (ret) {
301 	_krb5_xunlock(context, fd);
302 	close(fd);
303 	return ret;
304     }
305     ret = _krb5_xunlock(context, fd);
306     close (fd);
307     return ret;
308 }
309 
310 static krb5_error_code KRB5_CALLCONV
311 fcc_gen_new(krb5_context context, krb5_ccache *id)
312 {
313     char *file = NULL, *exp_file = NULL;
314     krb5_error_code ret;
315     krb5_fcache *f;
316     int fd;
317 
318     f = malloc(sizeof(*f));
319     if(f == NULL) {
320 	krb5_set_error_message(context, KRB5_CC_NOMEM,
321 			       N_("malloc: out of memory", ""));
322 	return KRB5_CC_NOMEM;
323     }
324     ret = asprintf (&file, "%sXXXXXX", KRB5_DEFAULT_CCFILE_ROOT);
325     if(ret < 0 || file == NULL) {
326 	free(f);
327 	krb5_set_error_message(context, KRB5_CC_NOMEM,
328 			       N_("malloc: out of memory", ""));
329 	return KRB5_CC_NOMEM;
330     }
331     ret = _krb5_expand_path_tokens(context, file, &exp_file);
332     free(file);
333     if (ret)
334 	return ret;
335 
336     file = exp_file;
337 
338     fd = mkstemp(exp_file);
339     if(fd < 0) {
340 	int xret = errno;
341 	krb5_set_error_message(context, xret, N_("mkstemp %s failed", ""), exp_file);
342 	free(f);
343 	free(exp_file);
344 	return xret;
345     }
346     close(fd);
347     f->filename = exp_file;
348     f->version = 0;
349     (*id)->data.data = f;
350     (*id)->data.length = sizeof(*f);
351     return 0;
352 }
353 
354 static void
355 storage_set_flags(krb5_context context, krb5_storage *sp, int vno)
356 {
357     int flags = 0;
358     switch(vno) {
359     case KRB5_FCC_FVNO_1:
360 	flags |= KRB5_STORAGE_PRINCIPAL_WRONG_NUM_COMPONENTS;
361 	flags |= KRB5_STORAGE_PRINCIPAL_NO_NAME_TYPE;
362 	flags |= KRB5_STORAGE_HOST_BYTEORDER;
363 	break;
364     case KRB5_FCC_FVNO_2:
365 	flags |= KRB5_STORAGE_HOST_BYTEORDER;
366 	break;
367     case KRB5_FCC_FVNO_3:
368 	flags |= KRB5_STORAGE_KEYBLOCK_KEYTYPE_TWICE;
369 	break;
370     case KRB5_FCC_FVNO_4:
371 	break;
372     default:
373 	krb5_abortx(context,
374 		    "storage_set_flags called with bad vno (%x)", vno);
375     }
376     krb5_storage_set_flags(sp, flags);
377 }
378 
379 static krb5_error_code KRB5_CALLCONV
380 fcc_open(krb5_context context,
381 	 krb5_ccache id,
382 	 int *fd_ret,
383 	 int flags,
384 	 mode_t mode)
385 {
386     krb5_boolean exclusive = ((flags | O_WRONLY) == flags ||
387 			      (flags | O_RDWR) == flags);
388     krb5_error_code ret;
389     const char *filename;
390     int fd;
391 
392     if (FCACHE(id) == NULL)
393         return krb5_einval(context, 2);
394 
395     filename = FILENAME(id);
396 
397     fd = open(filename, flags, mode);
398     if(fd < 0) {
399 	char buf[128];
400 	ret = errno;
401 	rk_strerror_r(ret, buf, sizeof(buf));
402 	krb5_set_error_message(context, ret, N_("open(%s): %s", "file, error"),
403 			       filename, buf);
404 	return ret;
405     }
406     rk_cloexec(fd);
407 
408     if((ret = fcc_lock(context, id, fd, exclusive)) != 0) {
409 	close(fd);
410 	return ret;
411     }
412     *fd_ret = fd;
413     return 0;
414 }
415 
416 static krb5_error_code KRB5_CALLCONV
417 fcc_initialize(krb5_context context,
418 	       krb5_ccache id,
419 	       krb5_principal primary_principal)
420 {
421     krb5_fcache *f = FCACHE(id);
422     int ret = 0;
423     int fd;
424 
425     if (f == NULL)
426         return krb5_einval(context, 2);
427 
428     unlink (f->filename);
429 
430     ret = fcc_open(context, id, &fd, O_RDWR | O_CREAT | O_EXCL | O_BINARY | O_CLOEXEC, 0600);
431     if(ret)
432 	return ret;
433     {
434 	krb5_storage *sp;
435 	sp = krb5_storage_emem();
436 	krb5_storage_set_eof_code(sp, KRB5_CC_END);
437 	if(context->fcache_vno != 0)
438 	    f->version = context->fcache_vno;
439 	else
440 	    f->version = KRB5_FCC_FVNO_4;
441 	ret |= krb5_store_int8(sp, 5);
442 	ret |= krb5_store_int8(sp, f->version);
443 	storage_set_flags(context, sp, f->version);
444 	if(f->version == KRB5_FCC_FVNO_4 && ret == 0) {
445 	    /* V4 stuff */
446 	    if (context->kdc_sec_offset) {
447 		ret |= krb5_store_int16 (sp, 12); /* length */
448 		ret |= krb5_store_int16 (sp, FCC_TAG_DELTATIME); /* Tag */
449 		ret |= krb5_store_int16 (sp, 8); /* length of data */
450 		ret |= krb5_store_int32 (sp, context->kdc_sec_offset);
451 		ret |= krb5_store_int32 (sp, context->kdc_usec_offset);
452 	    } else {
453 		ret |= krb5_store_int16 (sp, 0);
454 	    }
455 	}
456 	ret |= krb5_store_principal(sp, primary_principal);
457 
458 	ret |= write_storage(context, sp, fd);
459 
460 	krb5_storage_free(sp);
461     }
462     fcc_unlock(context, fd);
463     if (close(fd) < 0)
464 	if (ret == 0) {
465 	    char buf[128];
466 	    ret = errno;
467 	    rk_strerror_r(ret, buf, sizeof(buf));
468 	    krb5_set_error_message (context, ret, N_("close %s: %s", ""),
469 				    FILENAME(id), buf);
470 	}
471     return ret;
472 }
473 
474 static krb5_error_code KRB5_CALLCONV
475 fcc_close(krb5_context context,
476 	  krb5_ccache id)
477 {
478     if (FCACHE(id) == NULL)
479         return krb5_einval(context, 2);
480 
481     free (FILENAME(id));
482     krb5_data_free(&id->data);
483     return 0;
484 }
485 
486 static krb5_error_code KRB5_CALLCONV
487 fcc_destroy(krb5_context context,
488 	    krb5_ccache id)
489 {
490     if (FCACHE(id) == NULL)
491         return krb5_einval(context, 2);
492 
493     _krb5_erase_file(context, FILENAME(id));
494     return 0;
495 }
496 
497 static krb5_error_code KRB5_CALLCONV
498 fcc_store_cred(krb5_context context,
499 	       krb5_ccache id,
500 	       krb5_creds *creds)
501 {
502     int ret;
503     int fd;
504 
505     ret = fcc_open(context, id, &fd, O_WRONLY | O_APPEND | O_BINARY | O_CLOEXEC, 0);
506     if(ret)
507 	return ret;
508     {
509 	krb5_storage *sp;
510 
511 	sp = krb5_storage_emem();
512 	krb5_storage_set_eof_code(sp, KRB5_CC_END);
513 	storage_set_flags(context, sp, FCACHE(id)->version);
514 	if (!krb5_config_get_bool_default(context, NULL, TRUE,
515 					  "libdefaults",
516 					  "fcc-mit-ticketflags",
517 					  NULL))
518 	    krb5_storage_set_flags(sp, KRB5_STORAGE_CREDS_FLAGS_WRONG_BITORDER);
519 	ret = krb5_store_creds(sp, creds);
520 	if (ret == 0)
521 	    ret = write_storage(context, sp, fd);
522 	krb5_storage_free(sp);
523     }
524     fcc_unlock(context, fd);
525     if (close(fd) < 0) {
526 	if (ret == 0) {
527 	    char buf[128];
528 	    rk_strerror_r(ret, buf, sizeof(buf));
529 	    ret = errno;
530 	    krb5_set_error_message (context, ret, N_("close %s: %s", ""),
531 				    FILENAME(id), buf);
532 	}
533     }
534     return ret;
535 }
536 
537 static krb5_error_code
538 init_fcc (krb5_context context,
539 	  krb5_ccache id,
540 	  krb5_storage **ret_sp,
541 	  int *ret_fd,
542 	  krb5_deltat *kdc_offset)
543 {
544     int fd;
545     int8_t pvno, tag;
546     krb5_storage *sp;
547     krb5_error_code ret;
548 
549     if (kdc_offset)
550 	*kdc_offset = 0;
551 
552     ret = fcc_open(context, id, &fd, O_RDONLY | O_BINARY | O_CLOEXEC, 0);
553     if(ret)
554 	return ret;
555 
556     sp = krb5_storage_from_fd(fd);
557     if(sp == NULL) {
558 	krb5_clear_error_message(context);
559 	ret = ENOMEM;
560 	goto out;
561     }
562     krb5_storage_set_eof_code(sp, KRB5_CC_END);
563     ret = krb5_ret_int8(sp, &pvno);
564     if(ret != 0) {
565 	if(ret == KRB5_CC_END) {
566 	    ret = ENOENT;
567 	    krb5_set_error_message(context, ret,
568 				   N_("Empty credential cache file: %s", ""),
569 				   FILENAME(id));
570 	} else
571 	    krb5_set_error_message(context, ret, N_("Error reading pvno "
572 						    "in cache file: %s", ""),
573 				   FILENAME(id));
574 	goto out;
575     }
576     if(pvno != 5) {
577 	ret = KRB5_CCACHE_BADVNO;
578 	krb5_set_error_message(context, ret, N_("Bad version number in credential "
579 						"cache file: %s", ""),
580 			       FILENAME(id));
581 	goto out;
582     }
583     ret = krb5_ret_int8(sp, &tag); /* should not be host byte order */
584     if(ret != 0) {
585 	ret = KRB5_CC_FORMAT;
586 	krb5_set_error_message(context, ret, "Error reading tag in "
587 			      "cache file: %s", FILENAME(id));
588 	goto out;
589     }
590     FCACHE(id)->version = tag;
591     storage_set_flags(context, sp, FCACHE(id)->version);
592     switch (tag) {
593     case KRB5_FCC_FVNO_4: {
594 	int16_t length;
595 
596 	ret = krb5_ret_int16 (sp, &length);
597 	if(ret) {
598 	    ret = KRB5_CC_FORMAT;
599 	    krb5_set_error_message(context, ret,
600 				   N_("Error reading tag length in "
601 				      "cache file: %s", ""), FILENAME(id));
602 	    goto out;
603 	}
604 	while(length > 0) {
605 	    int16_t dtag, data_len;
606 	    int i;
607 	    int8_t dummy;
608 
609 	    ret = krb5_ret_int16 (sp, &dtag);
610 	    if(ret) {
611 		ret = KRB5_CC_FORMAT;
612 		krb5_set_error_message(context, ret, N_("Error reading dtag in "
613 							"cache file: %s", ""),
614 				       FILENAME(id));
615 		goto out;
616 	    }
617 	    ret = krb5_ret_int16 (sp, &data_len);
618 	    if(ret) {
619 		ret = KRB5_CC_FORMAT;
620 		krb5_set_error_message(context, ret,
621 				       N_("Error reading dlength "
622 					  "in cache file: %s",""),
623 				       FILENAME(id));
624 		goto out;
625 	    }
626 	    switch (dtag) {
627 	    case FCC_TAG_DELTATIME : {
628 		int32_t offset;
629 
630 		ret = krb5_ret_int32 (sp, &offset);
631 		ret |= krb5_ret_int32 (sp, &context->kdc_usec_offset);
632 		if(ret) {
633 		    ret = KRB5_CC_FORMAT;
634 		    krb5_set_error_message(context, ret,
635 					   N_("Error reading kdc_sec in "
636 					      "cache file: %s", ""),
637 					   FILENAME(id));
638 		    goto out;
639 		}
640 		context->kdc_sec_offset = offset;
641 		if (kdc_offset)
642 		    *kdc_offset = offset;
643 		break;
644 	    }
645 	    default :
646 		for (i = 0; i < data_len; ++i) {
647 		    ret = krb5_ret_int8 (sp, &dummy);
648 		    if(ret) {
649 			ret = KRB5_CC_FORMAT;
650 			krb5_set_error_message(context, ret,
651 					       N_("Error reading unknown "
652 						  "tag in cache file: %s", ""),
653 					       FILENAME(id));
654 			goto out;
655 		    }
656 		}
657 		break;
658 	    }
659 	    length -= 4 + data_len;
660 	}
661 	break;
662     }
663     case KRB5_FCC_FVNO_3:
664     case KRB5_FCC_FVNO_2:
665     case KRB5_FCC_FVNO_1:
666 	break;
667     default :
668 	ret = KRB5_CCACHE_BADVNO;
669 	krb5_set_error_message(context, ret,
670 			       N_("Unknown version number (%d) in "
671 				  "credential cache file: %s", ""),
672 			       (int)tag, FILENAME(id));
673 	goto out;
674     }
675     *ret_sp = sp;
676     *ret_fd = fd;
677 
678     return 0;
679   out:
680     if(sp != NULL)
681 	krb5_storage_free(sp);
682     fcc_unlock(context, fd);
683     close(fd);
684     return ret;
685 }
686 
687 static krb5_error_code KRB5_CALLCONV
688 fcc_get_principal(krb5_context context,
689 		  krb5_ccache id,
690 		  krb5_principal *principal)
691 {
692     krb5_error_code ret;
693     int fd;
694     krb5_storage *sp;
695 
696     ret = init_fcc (context, id, &sp, &fd, NULL);
697     if (ret)
698 	return ret;
699     ret = krb5_ret_principal(sp, principal);
700     if (ret)
701 	krb5_clear_error_message(context);
702     krb5_storage_free(sp);
703     fcc_unlock(context, fd);
704     close(fd);
705     return ret;
706 }
707 
708 static krb5_error_code KRB5_CALLCONV
709 fcc_end_get (krb5_context context,
710 	     krb5_ccache id,
711 	     krb5_cc_cursor *cursor);
712 
713 static krb5_error_code KRB5_CALLCONV
714 fcc_get_first (krb5_context context,
715 	       krb5_ccache id,
716 	       krb5_cc_cursor *cursor)
717 {
718     krb5_error_code ret;
719     krb5_principal principal;
720 
721     if (FCACHE(id) == NULL)
722         return krb5_einval(context, 2);
723 
724     *cursor = malloc(sizeof(struct fcc_cursor));
725     if (*cursor == NULL) {
726         krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
727 	return ENOMEM;
728     }
729     memset(*cursor, 0, sizeof(struct fcc_cursor));
730 
731     ret = init_fcc (context, id, &FCC_CURSOR(*cursor)->sp,
732 		    &FCC_CURSOR(*cursor)->fd, NULL);
733     if (ret) {
734 	free(*cursor);
735 	*cursor = NULL;
736 	return ret;
737     }
738     ret = krb5_ret_principal (FCC_CURSOR(*cursor)->sp, &principal);
739     if(ret) {
740 	krb5_clear_error_message(context);
741 	fcc_end_get(context, id, cursor);
742 	return ret;
743     }
744     krb5_free_principal (context, principal);
745     fcc_unlock(context, FCC_CURSOR(*cursor)->fd);
746     return 0;
747 }
748 
749 static krb5_error_code KRB5_CALLCONV
750 fcc_get_next (krb5_context context,
751 	      krb5_ccache id,
752 	      krb5_cc_cursor *cursor,
753 	      krb5_creds *creds)
754 {
755     krb5_error_code ret;
756 
757     if (FCACHE(id) == NULL)
758         return krb5_einval(context, 2);
759 
760     if (FCC_CURSOR(*cursor) == NULL)
761         return krb5_einval(context, 3);
762 
763     if((ret = fcc_lock(context, id, FCC_CURSOR(*cursor)->fd, FALSE)) != 0)
764 	return ret;
765 
766     ret = krb5_ret_creds(FCC_CURSOR(*cursor)->sp, creds);
767     if (ret)
768 	krb5_clear_error_message(context);
769 
770     fcc_unlock(context, FCC_CURSOR(*cursor)->fd);
771     return ret;
772 }
773 
774 static krb5_error_code KRB5_CALLCONV
775 fcc_end_get (krb5_context context,
776 	     krb5_ccache id,
777 	     krb5_cc_cursor *cursor)
778 {
779 
780     if (FCACHE(id) == NULL)
781         return krb5_einval(context, 2);
782 
783     if (FCC_CURSOR(*cursor) == NULL)
784         return krb5_einval(context, 3);
785 
786     krb5_storage_free(FCC_CURSOR(*cursor)->sp);
787     close (FCC_CURSOR(*cursor)->fd);
788     free(*cursor);
789     *cursor = NULL;
790     return 0;
791 }
792 
793 static krb5_error_code KRB5_CALLCONV
794 fcc_remove_cred(krb5_context context,
795 		 krb5_ccache id,
796 		 krb5_flags which,
797 		 krb5_creds *cred)
798 {
799     krb5_error_code ret;
800     krb5_ccache copy, newfile;
801     char *newname = NULL;
802     int fd;
803 
804     if (FCACHE(id) == NULL)
805         return krb5_einval(context, 2);
806 
807     ret = krb5_cc_new_unique(context, krb5_cc_type_memory, NULL, &copy);
808     if (ret)
809 	return ret;
810 
811     ret = krb5_cc_copy_cache(context, id, copy);
812     if (ret) {
813 	krb5_cc_destroy(context, copy);
814 	return ret;
815     }
816 
817     ret = krb5_cc_remove_cred(context, copy, which, cred);
818     if (ret) {
819 	krb5_cc_destroy(context, copy);
820 	return ret;
821     }
822 
823     ret = asprintf(&newname, "FILE:%s.XXXXXX", FILENAME(id));
824     if (ret < 0 || newname == NULL) {
825 	krb5_cc_destroy(context, copy);
826 	return ENOMEM;
827     }
828 
829     fd = mkstemp(&newname[5]);
830     if (fd < 0) {
831 	ret = errno;
832 	krb5_cc_destroy(context, copy);
833 	return ret;
834     }
835     close(fd);
836 
837     ret = krb5_cc_resolve(context, newname, &newfile);
838     if (ret) {
839 	unlink(&newname[5]);
840 	free(newname);
841 	krb5_cc_destroy(context, copy);
842 	return ret;
843     }
844 
845     ret = krb5_cc_copy_cache(context, copy, newfile);
846     krb5_cc_destroy(context, copy);
847     if (ret) {
848 	free(newname);
849 	krb5_cc_destroy(context, newfile);
850 	return ret;
851     }
852 
853     ret = rk_rename(&newname[5], FILENAME(id));
854     if (ret)
855 	ret = errno;
856     free(newname);
857     krb5_cc_close(context, newfile);
858 
859     return ret;
860 }
861 
862 static krb5_error_code KRB5_CALLCONV
863 fcc_set_flags(krb5_context context,
864 	      krb5_ccache id,
865 	      krb5_flags flags)
866 {
867     if (FCACHE(id) == NULL)
868         return krb5_einval(context, 2);
869 
870     return 0; /* XXX */
871 }
872 
873 static int KRB5_CALLCONV
874 fcc_get_version(krb5_context context,
875 		krb5_ccache id)
876 {
877     if (FCACHE(id) == NULL)
878         return -1;
879 
880     return FCACHE(id)->version;
881 }
882 
883 struct fcache_iter {
884     int first;
885 };
886 
887 static krb5_error_code KRB5_CALLCONV
888 fcc_get_cache_first(krb5_context context, krb5_cc_cursor *cursor)
889 {
890     struct fcache_iter *iter;
891 
892     iter = calloc(1, sizeof(*iter));
893     if (iter == NULL) {
894 	krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
895 	return ENOMEM;
896     }
897     iter->first = 1;
898     *cursor = iter;
899     return 0;
900 }
901 
902 static krb5_error_code KRB5_CALLCONV
903 fcc_get_cache_next(krb5_context context, krb5_cc_cursor cursor, krb5_ccache *id)
904 {
905     struct fcache_iter *iter = cursor;
906     krb5_error_code ret;
907     const char *fn;
908     char *expandedfn = NULL;
909 
910     if (iter == NULL)
911         return krb5_einval(context, 2);
912 
913     if (!iter->first) {
914 	krb5_clear_error_message(context);
915 	return KRB5_CC_END;
916     }
917     iter->first = 0;
918 
919     fn = krb5_cc_default_name(context);
920     if (fn == NULL || strncasecmp(fn, "FILE:", 5) != 0) {
921 	ret = _krb5_expand_default_cc_name(context,
922 					   KRB5_DEFAULT_CCNAME_FILE,
923 					   &expandedfn);
924 	if (ret)
925 	    return ret;
926 	fn = expandedfn;
927     }
928     /* check if file exists, don't return a non existant "next" */
929     if (strncasecmp(fn, "FILE:", 5) == 0) {
930 	struct stat sb;
931 	ret = stat(fn + 5, &sb);
932 	if (ret) {
933 	    ret = KRB5_CC_END;
934 	    goto out;
935 	}
936     }
937     ret = krb5_cc_resolve(context, fn, id);
938  out:
939     if (expandedfn)
940 	free(expandedfn);
941 
942     return ret;
943 }
944 
945 static krb5_error_code KRB5_CALLCONV
946 fcc_end_cache_get(krb5_context context, krb5_cc_cursor cursor)
947 {
948     struct fcache_iter *iter = cursor;
949 
950     if (iter == NULL)
951         return krb5_einval(context, 2);
952 
953     free(iter);
954     return 0;
955 }
956 
957 static krb5_error_code KRB5_CALLCONV
958 fcc_move(krb5_context context, krb5_ccache from, krb5_ccache to)
959 {
960     krb5_error_code ret = 0;
961 
962     ret = rk_rename(FILENAME(from), FILENAME(to));
963 
964     if (ret && errno != EXDEV) {
965 	char buf[128];
966 	ret = errno;
967 	rk_strerror_r(ret, buf, sizeof(buf));
968 	krb5_set_error_message(context, ret,
969 			       N_("Rename of file from %s "
970 				  "to %s failed: %s", ""),
971 			       FILENAME(from), FILENAME(to), buf);
972 	return ret;
973     } else if (ret && errno == EXDEV) {
974 	/* make a copy and delete the orignal */
975 	krb5_ssize_t sz1, sz2;
976 	int fd1, fd2;
977 	char buf[BUFSIZ];
978 
979 	ret = fcc_open(context, from, &fd1, O_RDONLY | O_BINARY | O_CLOEXEC, 0);
980 	if(ret)
981 	    return ret;
982 
983 	unlink(FILENAME(to));
984 
985 	ret = fcc_open(context, to, &fd2,
986 		       O_WRONLY | O_CREAT | O_EXCL | O_BINARY | O_CLOEXEC, 0600);
987 	if(ret)
988 	    goto out1;
989 
990 	while((sz1 = read(fd1, buf, sizeof(buf))) > 0) {
991 	    sz2 = write(fd2, buf, sz1);
992 	    if (sz1 != sz2) {
993 		ret = EIO;
994 		krb5_set_error_message(context, ret,
995 				       N_("Failed to write data from one file "
996 					  "credential cache to the other", ""));
997 		goto out2;
998 	    }
999 	}
1000 	if (sz1 < 0) {
1001 	    ret = EIO;
1002 	    krb5_set_error_message(context, ret,
1003 				   N_("Failed to read data from one file "
1004 				      "credential cache to the other", ""));
1005 	    goto out2;
1006 	}
1007     out2:
1008 	fcc_unlock(context, fd2);
1009 	close(fd2);
1010 
1011     out1:
1012 	fcc_unlock(context, fd1);
1013 	close(fd1);
1014 
1015 	_krb5_erase_file(context, FILENAME(from));
1016 
1017 	if (ret) {
1018 	    _krb5_erase_file(context, FILENAME(to));
1019 	    return ret;
1020 	}
1021     }
1022 
1023     /* make sure ->version is uptodate */
1024     {
1025 	krb5_storage *sp;
1026 	int fd;
1027 	if ((ret = init_fcc (context, to, &sp, &fd, NULL)) == 0) {
1028 	    if (sp)
1029 		krb5_storage_free(sp);
1030 	    fcc_unlock(context, fd);
1031 	    close(fd);
1032 	}
1033     }
1034 
1035     fcc_close(context, from);
1036 
1037     return ret;
1038 }
1039 
1040 static krb5_error_code KRB5_CALLCONV
1041 fcc_get_default_name(krb5_context context, char **str)
1042 {
1043     return _krb5_expand_default_cc_name(context,
1044 					KRB5_DEFAULT_CCNAME_FILE,
1045 					str);
1046 }
1047 
1048 static krb5_error_code KRB5_CALLCONV
1049 fcc_lastchange(krb5_context context, krb5_ccache id, krb5_timestamp *mtime)
1050 {
1051     krb5_error_code ret;
1052     struct stat sb;
1053     int fd;
1054 
1055     ret = fcc_open(context, id, &fd, O_RDONLY | O_BINARY | O_CLOEXEC, 0);
1056     if(ret)
1057 	return ret;
1058     ret = fstat(fd, &sb);
1059     close(fd);
1060     if (ret) {
1061 	ret = errno;
1062 	krb5_set_error_message(context, ret, N_("Failed to stat cache file", ""));
1063 	return ret;
1064     }
1065     *mtime = sb.st_mtime;
1066     return 0;
1067 }
1068 
1069 static krb5_error_code KRB5_CALLCONV
1070 fcc_set_kdc_offset(krb5_context context, krb5_ccache id, krb5_deltat kdc_offset)
1071 {
1072     return 0;
1073 }
1074 
1075 static krb5_error_code KRB5_CALLCONV
1076 fcc_get_kdc_offset(krb5_context context, krb5_ccache id, krb5_deltat *kdc_offset)
1077 {
1078     krb5_error_code ret;
1079     krb5_storage *sp = NULL;
1080     int fd;
1081     ret = init_fcc(context, id, &sp, &fd, kdc_offset);
1082     if (sp)
1083 	krb5_storage_free(sp);
1084     fcc_unlock(context, fd);
1085     close(fd);
1086 
1087     return ret;
1088 }
1089 
1090 
1091 /**
1092  * Variable containing the FILE based credential cache implemention.
1093  *
1094  * @ingroup krb5_ccache
1095  */
1096 
1097 KRB5_LIB_VARIABLE const krb5_cc_ops krb5_fcc_ops = {
1098     KRB5_CC_OPS_VERSION,
1099     "FILE",
1100     fcc_get_name,
1101     fcc_resolve,
1102     fcc_gen_new,
1103     fcc_initialize,
1104     fcc_destroy,
1105     fcc_close,
1106     fcc_store_cred,
1107     NULL, /* fcc_retrieve */
1108     fcc_get_principal,
1109     fcc_get_first,
1110     fcc_get_next,
1111     fcc_end_get,
1112     fcc_remove_cred,
1113     fcc_set_flags,
1114     fcc_get_version,
1115     fcc_get_cache_first,
1116     fcc_get_cache_next,
1117     fcc_end_cache_get,
1118     fcc_move,
1119     fcc_get_default_name,
1120     NULL,
1121     fcc_lastchange,
1122     fcc_set_kdc_offset,
1123     fcc_get_kdc_offset
1124 };
1125