d03ab969 |
1 | /* -*-c-*- |
2 | * |
3 | * $Id: key.c,v 1.1 1999/09/03 08:41:12 mdw Exp $ |
4 | * |
5 | * Simple key management |
6 | * |
7 | * (c) 1999 Mark Wooding |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of Catacomb. |
13 | * |
14 | * Catacomb is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU Library General Public License as |
16 | * published by the Free Software Foundation; either version 2 of the |
17 | * License, or (at your option) any later version. |
18 | * |
19 | * Catacomb is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | * GNU Library General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU Library General Public |
25 | * License along with Catacomb; if not, write to the Free |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
27 | * MA 02111-1307, USA. |
28 | */ |
29 | |
30 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: key.c,v $ |
33 | * Revision 1.1 1999/09/03 08:41:12 mdw |
34 | * Initial import. |
35 | * |
36 | */ |
37 | |
38 | /*----- Header files ------------------------------------------------------*/ |
39 | |
40 | #include <ctype.h> |
41 | #include <errno.h> |
42 | #include <stdio.h> |
43 | #include <stdlib.h> |
44 | #include <string.h> |
45 | #include <time.h> |
46 | |
47 | #include <sys/types.h> |
48 | #include <sys/time.h> |
49 | #include <sys/stat.h> |
50 | #include <unistd.h> |
51 | #include <fcntl.h> |
52 | |
53 | #include <mLib/alloc.h> |
54 | #include <mLib/base64.h> |
55 | #include <mLib/bits.h> |
56 | #include <mLib/crc32.h> |
57 | #include <mLib/dstr.h> |
58 | #include <mLib/hash.h> |
59 | #include <mLib/lock.h> |
60 | #include <mLib/report.h> |
61 | #include <mLib/str.h> |
62 | #include <mLib/sub.h> |
63 | #include <mLib/sym.h> |
64 | #include <mLib/url.h> |
65 | |
66 | #include "key.h" |
67 | |
68 | /*----- Useful macros -----------------------------------------------------*/ |
69 | |
70 | #define KEY_PARANOID |
71 | #define NOTHING |
72 | |
73 | #ifdef KEY_PARANOID |
74 | # define KEY_WRITE(f, func, val) do { \ |
75 | if (!(f)->f & KF_WRITE) { \ |
76 | moan(#func " [caller error]: keyfile is readonly"); \ |
77 | errno = EROFS; \ |
78 | return val; \ |
79 | } \ |
80 | } while (0) |
81 | #else |
82 | # define KEY_WRITE(f, func) do { ; } while (0) |
83 | #endif |
84 | |
85 | #define KEY_MODIFY(f) do { (f)->f |= KF_MODIFIED; } while (0) |
86 | |
87 | #define KEY_LOAD(n) ((n) * 2) |
88 | |
89 | /*----- Sanity checking of values -----------------------------------------*/ |
90 | |
91 | /* --- @key_chktype@ --- * |
92 | * |
93 | * Arguments: @const char *type@ = pointer to a type string |
94 | * |
95 | * Returns: Zero if OK, -1 on error. |
96 | * |
97 | * Use: Checks whether a type string is OK. |
98 | */ |
99 | |
100 | int key_chktype(const char *type) |
101 | { |
102 | if (!type || !*type) |
103 | goto fail; |
104 | while (*type) { |
105 | if (isspace((unsigned char)*type)) |
106 | goto fail; |
107 | type++; |
108 | } |
109 | return (0); |
110 | |
111 | fail: |
112 | errno = EINVAL; |
113 | return (-1); |
114 | } |
115 | |
116 | /* --- @key_chkcomment@ --- * |
117 | * |
118 | * Arguments: @const char *comment@ = pointer to a comment string |
119 | * |
120 | * Returns: Zero if OK, -1 on error. |
121 | * |
122 | * Use: Checks whether a comment string is OK. |
123 | */ |
124 | |
125 | int key_chkcomment(const char *c) |
126 | { |
127 | if (!c) |
128 | return (0); |
129 | if (!*c) |
130 | goto fail; |
131 | while (*c) { |
132 | if (*c == '\n') |
133 | goto fail; |
134 | c++; |
135 | } |
136 | return (0); |
137 | |
138 | fail: |
139 | errno = EINVAL; |
140 | return (-1); |
141 | } |
142 | |
143 | /*----- Low-level fiddling ------------------------------------------------*/ |
144 | |
145 | /* --- @insert@ --- * |
146 | * |
147 | * Arguments: @key_file *f@ = pointer to file structure |
148 | * @const char *type@ = type of key to insert |
149 | * @const void *k@ = pointer to key data |
150 | * @size_t ksz@ = size of key data |
151 | * @time_t exp@ = expiry time for key |
152 | * @time_t del@ = deletion time for key |
153 | * |
154 | * Returns: Pointer to key block to fill in the rest of, or zero. |
155 | * |
156 | * Use: Inserts a key into a key file. |
157 | */ |
158 | |
159 | static key *insert(key_file *f, |
160 | const char *type, |
161 | const void *k, size_t ksz, |
162 | time_t exp, time_t del) |
163 | { |
164 | uint32 id; |
165 | key *kk; |
166 | key_type *t; |
167 | |
168 | /* --- Sanity preservatives --- */ |
169 | |
170 | if (key_chktype(type)) |
171 | return (0); |
172 | |
173 | /* --- Insert into the id table --- */ |
174 | |
175 | { |
176 | hash_base **bin, **b; |
177 | |
178 | CRC32(id, 0, k, ksz); |
179 | bin = HASH_BIN(&f->byid, id); |
180 | for (b = bin; *b; b = &(*b)->next) { |
181 | if ((*b)->hash == id) { |
182 | errno = EEXIST; |
183 | return (0); |
184 | } |
185 | } |
186 | |
187 | kk = CREATE(key); |
188 | kk->_b.next = 0; |
189 | *b = &kk->_b; |
190 | kk->_b.hash = id; |
191 | } |
192 | |
193 | /* --- Extend the table --- */ |
194 | |
195 | if (f->idload > 0) |
196 | f->idload--; |
197 | else if (hash_extend(&f->byid)) |
198 | f->idload = KEY_LOAD(f->byid.mask / 2); |
199 | |
200 | /* --- Initialize the key block --- */ |
201 | |
202 | kk->id = id; |
203 | kk->k = sub_alloc(ksz); |
204 | memcpy(kk->k, k, ksz); |
205 | kk->ksz = ksz; |
206 | kk->type = xstrdup(type); |
207 | kk->exp = exp; |
208 | kk->del = del; |
209 | sym_create(&kk->a); |
210 | kk->c = 0; |
211 | |
212 | /* --- Insert into the type table --- */ |
213 | |
214 | { |
215 | unsigned found; |
216 | t = sym_find(&f->bytype, type, -1, sizeof(*t), &found); |
217 | if (!found) { |
218 | t->k = kk; |
219 | kk->next = 0; |
220 | } else { |
221 | key **p = &t->k; |
222 | if (exp != KEXP_FOREVER) { |
223 | while (*p && (*p)->exp != KEXP_EXPIRE && (*p)->exp > exp) |
224 | p = &(*p)->next; |
225 | } |
226 | kk->next = *p; |
227 | *p = kk; |
228 | } |
229 | } |
230 | |
231 | return (kk); |
232 | } |
233 | |
234 | /*----- Iteration and iterators -------------------------------------------*/ |
235 | |
236 | /* --- @key_mkiter@ --- * |
237 | * |
238 | * Arguments: @key_iter *i@ = pointer to iterator object |
239 | * @key_file *f@ = pointer to file structure |
240 | * |
241 | * Returns: --- |
242 | * |
243 | * Use: Initializes a key iterator. The keys are returned by |
244 | * @key_next@. |
245 | */ |
246 | |
247 | void key_mkiter(key_iter *i, key_file *f) |
248 | { |
249 | HASH_MKITER(&i->i, &f->byid); |
250 | i->t = time(0); |
251 | } |
252 | |
253 | /* --- @key_next@ --- * |
254 | * |
255 | * Arguments: @key_iter *i@ = pointer to iterator object |
256 | * |
257 | * Returns: Pointer to next key, or null. |
258 | * |
259 | * Use: Returns the next key in some arbitrary sequence. |
260 | */ |
261 | |
262 | key *key_next(key_iter *i) |
263 | { |
264 | hash_base *b; |
265 | key *k; |
266 | do { |
267 | HASH_NEXT(&i->i, b); |
268 | k = (key *)b; |
269 | } while (k && KEY_EXPIRED(i->t, k->exp) && KEY_DELETED(i->t, k->del)); |
270 | return (k); |
271 | } |
272 | |
273 | /* --- @key_mkattriter@ --- * |
274 | * |
275 | * Arguments: @key_attriter *i@ = pointer to attribute iterator |
276 | * @key_file *f@ = pointer to key file |
277 | * @key *k@ = pointer to key |
278 | * |
279 | * Returns: --- |
280 | * |
281 | * Use: Initializes an attribute iterator. The attributes are |
282 | * returned by @key_nextattr@. |
283 | */ |
284 | |
285 | void key_mkattriter(key_attriter *i, key_file *f, key *k) |
286 | { |
287 | sym_mkiter(&i->i, &k->a); |
288 | } |
289 | |
290 | /* --- @key_nextattr@ --- * |
291 | * |
292 | * Arguments: @key_attriter *i@ = pointer to attribute iterator |
293 | * @const char **n, **v@ = pointers to name and value |
294 | * |
295 | * Returns: Zero if no attribute available, or nonzero if returned OK. |
296 | * |
297 | * Use: Returns the next attribute. |
298 | */ |
299 | |
300 | int key_nextattr(key_attriter *i, const char **n, const char **v) |
301 | { |
302 | key_attr *a = sym_next(&i->i); |
303 | if (!a) |
304 | return (0); |
305 | *n = SYM_NAME(a); |
306 | *v = a->p; |
307 | return (1); |
308 | } |
309 | |
310 | /*----- Lookup ------------------------------------------------------------*/ |
311 | |
312 | /* --- @key_bytype@ --- * |
313 | * |
314 | * Arguments: @key_file *f@ = key file we want a key from |
315 | * @const char *type@ = type string for desired key |
316 | * |
317 | * Returns: Pointer to the best key to use, or null. |
318 | * |
319 | * Use: Looks up a key by its type. Returns the key with the latest |
320 | * expiry time. This function will not return an expired key. |
321 | */ |
322 | |
323 | key *key_bytype(key_file *f, const char *type) |
324 | { |
325 | time_t now = time(0); |
326 | key *k; |
327 | key_type *t; |
328 | |
329 | if ((t = sym_find(&f->bytype, type, -1, 0, 0)) == 0) |
330 | return (0); |
331 | for (k = t->k; k && KEY_EXPIRED(now, k->exp); k = k->next) |
332 | ; |
333 | return (k); |
334 | } |
335 | |
336 | /* --- @key_byid@ --- * |
337 | * |
338 | * Arguments: @key_file *f@ = key file to find a key from |
339 | * @uint32 id@ = id to look for |
340 | * |
341 | * Returns: Key with matching id. |
342 | * |
343 | * Use: Returns a key given its id. This function will return an |
344 | * expired key, but not a deleted one. |
345 | */ |
346 | |
347 | key *key_byid(key_file *f, uint32 id) |
348 | { |
349 | time_t t = time(0); |
350 | hash_base **bin, *b; |
351 | |
352 | bin = HASH_BIN(&f->byid, id); |
353 | for (b = *bin; b; b = b->next) { |
354 | if (b->hash == id) { |
355 | key *k = (key *)b; |
356 | if (KEY_EXPIRED(t, k->exp) && KEY_DELETED(t, k->del)) |
357 | return (0); |
358 | return (k); |
359 | } |
360 | } |
361 | return (0); |
362 | } |
363 | |
364 | /*----- Attributes --------------------------------------------------------*/ |
365 | |
366 | /* --- @key_getattr@ --- * |
367 | * |
368 | * Arguments: @key_file *f@ = pointer to file |
369 | * @key *k@ = pointer to key |
370 | * @const char *n@ = pointer to attribute name |
371 | * |
372 | * Returns: Pointer to attribute value, or null if not found. |
373 | * |
374 | * Use: Returns the value of a key attribute. |
375 | */ |
376 | |
377 | const char *key_getattr(key_file *f, key *k, const char *n) |
378 | { |
379 | key_attr *a; |
380 | if ((a = sym_find(&k->a, n, -1, 0, 0)) == 0) |
381 | return (0); |
382 | return (a->p); |
383 | } |
384 | |
385 | /* --- @key_putattr@ --- * |
386 | * |
387 | * Arguments: @key_file *f@ = pointer to file |
388 | * @key *k@ = pointer to key |
389 | * @const char *n@ = pointer to attribute name |
390 | * @const char *v@ = pointer to attribute value or null |
391 | * |
392 | * Returns: --- |
393 | * |
394 | * Use: Inserts an attribute on a key. If an attribute with the same |
395 | * name already exists, it is deleted. Setting a null value |
396 | * removes the attribute. |
397 | */ |
398 | |
399 | void key_putattr(key_file *f, key *k, const char *n, const char *v) |
400 | { |
401 | key_attr *a; |
402 | unsigned found; |
403 | |
404 | KEY_WRITE(f, key_putattr, NOTHING); |
405 | |
406 | if (v) { |
407 | a = sym_find(&k->a, n, -1, sizeof(*a), &found); |
408 | if (found) |
409 | free(a->p); |
410 | a->p = xstrdup(v); |
411 | } else if ((a = sym_find(&k->a, n, -1, 0, 0)) != 0) { |
412 | free(a->p); |
413 | sym_remove(&k->a, a); |
414 | } |
415 | |
416 | KEY_MODIFY(f); |
417 | } |
418 | |
419 | /* --- @key_setcomment@ --- * |
420 | * |
421 | * Arguments: @key_file *f@ = pointer to key file block |
422 | * @key *k@ = pointer to key block |
423 | * @const char *c@ = pointer to comment to set, or zero |
424 | * |
425 | * Returns: --- |
426 | * |
427 | * Use: Replaces the key's current comment with a new one. |
428 | */ |
429 | |
430 | void key_setcomment(key_file *f, key *k, const char *c) |
431 | { |
432 | KEY_WRITE(f, key_setcomment, NOTHING); |
433 | if (key_chkcomment(c)) |
434 | return; |
435 | if (k->c) |
436 | free(k->c); |
437 | if (c) |
438 | k->c = xstrdup(c); |
439 | else |
440 | k->c = 0; |
441 | KEY_MODIFY(f); |
442 | } |
443 | |
444 | /*----- Low-level file I/O ------------------------------------------------*/ |
445 | |
446 | /* --- @key_merge@ --- * |
447 | * |
448 | * Arguments: @key_file *f@ = pointer to file structure |
449 | * @const char *file@ = name of file (for error messages) |
450 | * @FILE *fp@ = file handle to read from |
451 | * |
452 | * Returns: --- |
453 | * |
454 | * Use: Reads keys from a file, and inserts them into the file. |
455 | */ |
456 | |
457 | void key_merge(key_file *f, const char *file, FILE *fp) |
458 | { |
459 | int line = 0; |
460 | dstr l = DSTR_INIT; |
461 | dstr d = DSTR_INIT; |
462 | dstr n = DSTR_INIT, v = DSTR_INIT; |
463 | |
464 | KEY_WRITE(f, key_merge, NOTHING); |
465 | |
466 | for (; dstr_putline(&l, fp) != EOF; DRESET(&l)) { |
467 | char *vf[6]; |
468 | char *p = l.buf; |
469 | key *k; |
470 | |
471 | /* --- Skip blank lines and comments --- * |
472 | * |
473 | * Quite what they're doing in what ought to be an automatically- |
474 | * maintained file I don't know. |
475 | */ |
476 | |
477 | line++; |
478 | while (isspace((unsigned char)*p)) |
479 | p++; |
480 | if (!*p || *p == '#') |
481 | continue; |
482 | |
483 | /* --- Break the line into fields --- * |
484 | * |
485 | * There are currently six fields of interest: |
486 | * |
487 | * * The key's type tag. |
488 | * * The actual key data itself. |
489 | * * The key expiry time. |
490 | * * The key deletion time. |
491 | * * The attributes field. |
492 | * * Any further comments. |
493 | * |
494 | * All but the last field can contain no spaces. |
495 | */ |
496 | |
497 | { |
498 | int n = str_split(p, vf, 5, &vf[5]); |
499 | if (n < 4) { |
500 | moan("key file `%s', line %i: too few fields", file, line); |
501 | continue; |
502 | } |
503 | } |
504 | |
505 | /* --- Decode various bits and insert the key --- */ |
506 | |
507 | { |
508 | base64_ctx b; |
509 | time_t exp, del; |
510 | |
511 | base64_init(&b); |
512 | base64_decode(&b, vf[1], strlen(vf[1]), &d); |
513 | base64_decode(&b, 0, 0, &d); |
514 | |
515 | exp = (time_t)atol(vf[2]); |
516 | del = (time_t)atol(vf[3]); |
517 | |
518 | if ((k = insert(f, vf[0], d.buf, d.len, exp, del)) == 0) |
519 | continue; |
520 | DRESET(&d); |
521 | } |
522 | |
523 | /* --- Parse up the attributes, if specified --- */ |
524 | |
525 | if (vf[4]) { |
526 | url_dctx uc; |
527 | for (url_initdec(&uc, vf[4]); url_dec(&uc, &n, &v); ) { |
528 | key_putattr(f, k, n.buf, v.buf); |
529 | DRESET(&n); DRESET(&v); |
530 | } |
531 | } |
532 | |
533 | /* --- Insert the comment --- */ |
534 | |
535 | if (vf[5]) |
536 | k->c = xstrdup(vf[5]); |
537 | } |
538 | |
539 | /* --- Extensive tidying up now required --- */ |
540 | |
541 | dstr_destroy(&l); |
542 | dstr_destroy(&d); |
543 | dstr_destroy(&n); |
544 | dstr_destroy(&v); |
545 | KEY_MODIFY(f); |
546 | } |
547 | |
548 | /* --- @key_extract@ --- * |
549 | * |
550 | * Arguments: @key_file *f@ = pointer to file structure |
551 | * @key *k@ = key to extract |
552 | * @FILE *fp@ = file to write on |
553 | * |
554 | * Returns: Zero if OK, EOF on error. |
555 | * |
556 | * Use: Extracts a key to an ouptut file. |
557 | */ |
558 | |
559 | int key_extract(key_file *f, key *k, FILE *fp) |
560 | { |
561 | dstr d = DSTR_INIT; |
562 | |
563 | /* --- Encode the key and write the easy stuff --- */ |
564 | |
565 | { |
566 | base64_ctx b; |
567 | base64_init(&b); |
568 | b.indent = ""; |
569 | base64_encode(&b, k->k, k->ksz, &d); |
570 | base64_encode(&b, 0, 0, &d); |
571 | DPUTZ(&d); |
572 | fprintf(fp, "%s %s %li %li ", |
573 | k->type, d.buf, (long)k->exp, (long)k->del); |
574 | DRESET(&d); |
575 | } |
576 | |
577 | /* --- Output the attributes --- */ |
578 | |
579 | { |
580 | int none = 1; |
581 | sym_iter i; |
582 | key_attr *a; |
583 | url_ectx uc; |
584 | |
585 | url_initenc(&uc); |
586 | for (sym_mkiter(&i, &k->a); (a = sym_next(&i)) != 0; ) { |
587 | none = 0; |
588 | url_enc(&uc, &d, SYM_NAME(a), a->p); |
589 | } |
590 | if (none) |
591 | DPUTS(&d, "-"); |
592 | DWRITE(&d, fp); |
593 | } |
594 | |
595 | dstr_destroy(&d); |
596 | if (k->c) { |
597 | putc(' ', fp); |
598 | fputs(k->c, fp); |
599 | } |
600 | putc('\n', fp); |
601 | return (ferror(fp) ? EOF : 0); |
602 | } |
603 | |
604 | /* --- @fdcopy@ --- * |
605 | * |
606 | * Arguments: @int source@ = source file descriptor |
607 | * @int dest@ = destination file descriptor |
608 | * |
609 | * Returns: Zero if OK, nonzero otherwise. |
610 | * |
611 | * Use: Copies data from one file descriptor to another. |
612 | */ |
613 | |
614 | static int fdcopy(int source, int dest) |
615 | { |
616 | char buf[4096]; |
617 | |
618 | if (lseek(source, 0, SEEK_SET) < 0|| |
619 | lseek(dest, 0, SEEK_SET) < 0 || |
620 | ftruncate(dest, 0) < 0) |
621 | return (-1); |
622 | for (;;) { |
623 | int n = read(source, buf, sizeof(buf)); |
624 | if (n < 0) |
625 | return (-1); |
626 | else if (n == 0) |
627 | break; |
628 | else if (write(dest, buf, n) < 0) |
629 | return (-1); |
630 | } |
631 | return (0); |
632 | } |
633 | |
634 | /* --- @key_write@ --- * |
635 | * |
636 | * Arguments: @key_file *f@ = pointer to key file block |
637 | * |
638 | * Returns: A @KWRITE_@ code indicating how well it worked. |
639 | * |
640 | * Use: Writes a key file's data back to the actual file. This code |
641 | * is extremely careful about error handling. It should usually |
642 | * be able to back out somewhere sensible, but it can tell when |
643 | * it's got itself into a real pickle and starts leaving well |
644 | * alone. |
645 | * |
646 | * Callers, please make sure that you ring alarm bells when this |
647 | * function returns @KWRITE_BROKEN@. |
648 | */ |
649 | |
650 | int key_write(key_file *f) |
651 | { |
652 | dstr n_older = DSTR_INIT, n_old = DSTR_INIT, n_new = DSTR_INIT; |
653 | int rc = KWRITE_FAIL; |
654 | |
655 | if (!(f->f & KF_MODIFIED)) |
656 | return (KWRITE_OK); |
657 | |
658 | /* --- Write a new key file out --- * |
659 | * |
660 | * Check for an error after each key line. This ought to be enough. |
661 | * Checking after each individual byte write and @fprintf@ isn't much fun. |
662 | */ |
663 | |
664 | dstr_putf(&n_new, "%s.new", f->name); |
665 | |
666 | { |
667 | key *k; |
668 | key_iter i; |
669 | FILE *fp; |
670 | |
671 | if ((fp = fopen(n_new.buf, "w")) == 0) |
672 | goto fail_open; |
673 | |
674 | for (key_mkiter(&i, f); (k = key_next(&i)) != 0; ) { |
675 | if (key_extract(f, k, fp)) { |
676 | fclose(fp); |
677 | goto fail_write; |
678 | } |
679 | } |
680 | |
681 | if (fclose(fp)) |
682 | goto fail_write; |
683 | } |
684 | |
685 | /* --- Set up the other filenames --- */ |
686 | |
687 | dstr_putf(&n_older, "%s.older", f->name); |
688 | dstr_putf(&n_old, "%s.old", f->name); |
689 | |
690 | /* --- Move the current backup on one --- * |
691 | * |
692 | * If the `older' file exists, then we're in need of attention. |
693 | */ |
694 | |
695 | { |
696 | struct stat st; |
697 | if (stat(n_older.buf, &st) == 0 || errno != ENOENT) { |
698 | errno = EEXIST; |
699 | rc = KWRITE_BROKEN; |
700 | goto fail_shift; |
701 | } |
702 | if (rename(n_old.buf, n_older.buf) && errno != ENOENT) |
703 | goto fail_shift; |
704 | } |
705 | |
706 | /* --- Copy the current file to the backup --- */ |
707 | |
708 | { |
709 | int fd; |
710 | if ((fd = open(n_old.buf, O_WRONLY | O_CREAT | O_EXCL, 0600)) < 0) |
711 | goto fail_backup; |
712 | if (fdcopy(f->fd, fd)) { |
713 | close(fd); |
714 | goto fail_backup; |
715 | } |
716 | if (close(fd)) |
717 | goto fail_backup; |
718 | } |
719 | |
720 | /* --- Copy the newly created file to the current one --- * |
721 | * |
722 | * This is the dangerous bit. |
723 | */ |
724 | |
725 | { |
726 | int fd; |
727 | if ((fd = open(n_new.buf, O_RDONLY)) < 0) |
728 | goto fail_update; |
729 | if (fdcopy(fd, f->fd)) { |
730 | close(fd); |
731 | goto fail_update; |
732 | } |
733 | close(fd); |
734 | if (fsync(f->fd)) |
735 | goto fail_update; |
736 | } |
737 | |
738 | /* --- Clean up --- * |
739 | * |
740 | * Remove the `new' file and the `older' backup. Then we're done. |
741 | */ |
742 | |
743 | unlink(n_new.buf); |
744 | unlink(n_older.buf); |
745 | return (KWRITE_OK); |
746 | |
747 | /* --- Failure while writing the new key file --- * |
748 | * |
749 | * I need to copy the backup back. If that fails then I'm really stuffed. |
750 | * If not, then I might as well try to get the backups sorted back out |
751 | * again. |
752 | */ |
753 | |
754 | fail_update: |
755 | { |
756 | int fd; |
757 | int e = errno; |
758 | |
759 | if ((fd = open(n_old.buf, O_RDONLY)) < 0) |
760 | rc = KWRITE_BROKEN; |
761 | else if (fdcopy(fd, f->fd)) { |
762 | close(fd); |
763 | rc = KWRITE_BROKEN; |
764 | } else { |
765 | close(fd); |
766 | if (fsync(f->fd)) |
767 | rc = KWRITE_BROKEN; |
768 | } |
769 | |
770 | errno = e; |
771 | if (rc == KWRITE_BROKEN) |
772 | goto fail_shift; |
773 | } |
774 | /* Now drop through */ |
775 | |
776 | /* --- Failure while writing the new backup --- * |
777 | * |
778 | * The new backup isn't any use. Try to recover the old one. |
779 | */ |
780 | |
781 | fail_backup: |
782 | { |
783 | int e = errno; |
784 | unlink(n_old.buf); |
785 | if (rename(n_older.buf, n_old.buf) && errno != ENOENT) |
786 | rc = KWRITE_BROKEN; |
787 | errno = e; |
788 | } |
789 | /* Now drop through */ |
790 | |
791 | /* --- Failure while demoting the current backup --- * |
792 | * |
793 | * Leave the completed output file there for the operator in case he wants |
794 | * to clean up. |
795 | */ |
796 | |
797 | fail_shift: |
798 | dstr_destroy(&n_new); |
799 | dstr_destroy(&n_old); |
800 | dstr_destroy(&n_older); |
801 | return (rc); |
802 | |
803 | /* --- Failure during write of new data --- * |
804 | * |
805 | * Clean up the new file and return. These errors can never cause |
806 | * breakage. |
807 | */ |
808 | |
809 | fail_write: |
810 | unlink(n_new.buf); |
811 | fail_open: |
812 | dstr_destroy(&n_new); |
813 | return (rc); |
814 | } |
815 | |
816 | /*----- Opening and closing files -----------------------------------------*/ |
817 | |
818 | /* --- @key_open@ --- * |
819 | * |
820 | * Arguments: @key_file *f@ = pointer to file structure to initialize |
821 | * @const char *file@ = pointer to the file name |
822 | * @int how@ = opening options (@KOPEN_*@). |
823 | * |
824 | * Returns: Zero if it worked, nonzero otherwise. |
825 | * |
826 | * Use: Opens a key file, reads its contents, and stores them in a |
827 | * structure. The file is locked appropriately until closed |
828 | * using @key_close@. On an error, everything is cleared away |
829 | * tidily. If the file is opened with @KOPEN_WRITE@, it's |
830 | * created if necessary, with read and write permissions for its |
831 | * owner only. |
832 | */ |
833 | |
834 | int key_open(key_file *f, const char *file, int how) |
835 | { |
836 | FILE *fp; |
837 | |
838 | /* --- Trivial bits of initialization --- */ |
839 | |
840 | f->f = 0; |
841 | f->name = xstrdup(file); |
842 | |
843 | /* --- Open the file and get the lock --- */ |
844 | |
845 | { |
846 | int of, lf; |
847 | const char *ff; |
848 | int fd; |
849 | |
850 | /* --- Lots of things depend on whether we're writing --- */ |
851 | |
852 | switch (how) { |
853 | case KOPEN_READ: |
854 | of = O_RDONLY; |
855 | lf = LOCK_NONEXCL; |
856 | ff = "r"; |
857 | break; |
858 | case KOPEN_WRITE: |
859 | of = O_RDWR | O_CREAT; |
860 | lf = LOCK_EXCL; |
861 | ff = "r+"; |
862 | break; |
863 | default: |
864 | errno = EINVAL; |
865 | return (-1); |
866 | } |
867 | |
868 | if ((fd = open(file, of, 0600)) < 0) |
869 | return (-1); |
870 | if (fcntl(fd, F_SETFD, 1) < 0 || |
871 | lock_file(fd, lf) < 0 || (fp = fdopen(fd, ff)) == 0) { |
872 | close(fd); |
873 | return (-1); |
874 | } |
875 | f->fd = fd; |
876 | } |
877 | |
878 | /* --- Read the file of keys into the table --- */ |
879 | |
880 | hash_create(&f->byid, 64); |
881 | f->idload = KEY_LOAD(64); |
882 | sym_create(&f->bytype); |
883 | f->f |= KF_WRITE; |
884 | key_merge(f, file, fp); |
885 | if (how == KOPEN_READ) |
886 | f->f &= ~(KF_WRITE | KF_MODIFIED); |
887 | else |
888 | f->f &= ~KF_MODIFIED; |
889 | |
890 | /* --- Close the file if only needed for reading --- */ |
891 | |
892 | if (how == KOPEN_READ) { |
893 | f->fp = 0; |
894 | fclose(fp); |
895 | } else |
896 | f->fp = fp; |
897 | |
898 | return (0); |
899 | } |
900 | |
901 | /* --- @key_close@ --- * |
902 | * |
903 | * Arguments: @key_file *f@ = pointer to key file block |
904 | * |
905 | * Returns: A @KWRITE_@ code indicating how it went. |
906 | * |
907 | * Use: Frees all the key data, writes any changes. Make sure that |
908 | * all hell breaks loose if this returns @KWRITE_BROKEN@. |
909 | */ |
910 | |
911 | int key_close(key_file *f) |
912 | { |
913 | int e; |
914 | hash_base *b; |
915 | hash_iter i; |
916 | |
917 | if ((e = key_write(f)) != KWRITE_OK) |
918 | return (e); |
919 | |
920 | /* --- Free all the individual keys --- */ |
921 | |
922 | for (hash_mkiter(&i, &f->byid); (b = hash_next(&i)) != 0; ) { |
923 | sym_iter j; |
924 | key_attr *a; |
925 | key *k = (key *)b; |
926 | |
927 | sub_free(k->k, k->ksz); |
928 | free(k->type); |
929 | if (k->c) |
930 | free(k->c); |
931 | for (sym_mkiter(&j, &k->a); (a = sym_next(&j)) != 0; ) |
932 | free(a->p); |
933 | sym_destroy(&k->a); |
934 | DESTROY(k); |
935 | } |
936 | hash_destroy(&f->byid); |
937 | sym_destroy(&f->bytype); |
938 | |
939 | if (f->fp) |
940 | fclose(f->fp); |
941 | free(f->name); |
942 | return (KWRITE_OK); |
943 | } |
944 | |
945 | /*----- Miscellaneous functions -------------------------------------------*/ |
946 | |
947 | /* --- @key_new@ --- |
948 | * |
949 | * Arguments: @key_file *f@ = pointer to key file |
950 | * @const char *type@ = the type of this key |
951 | * @const void *k@ = pointer to key data |
952 | * @size_t ksz@ = size of key data |
953 | * @time_t exp@ = when the key expires |
954 | * @const char *c@ = textual comment to attach |
955 | * |
956 | * Returns: Key block containing new data, or null if it couldn't be |
957 | * done. |
958 | * |
959 | * Use: Attaches a new key to a key file. You must have a writable |
960 | * key file for this to work. |
961 | * |
962 | * The type is a key type string. This interface doesn't care |
963 | * about how type strings are formatted: it just treats them as |
964 | * opaque gobs of text. Clients are advised to choose some |
965 | * standard for representing key types, though. |
966 | * |
967 | * The key can be any old binary mess. |
968 | * |
969 | * The expiry time should either be a time in the future, or the |
970 | * magic value @KEXP_FOREVER@ which means `never expire this |
971 | * key'. Be careful with `forever' keys. If I were you, I'd |
972 | * use a more sophisticated key management system than this for |
973 | * them. |
974 | * |
975 | * The comment can be any old text not containing newlines or |
976 | * nulls. This interface doesn't impose any length restrictions |
977 | * on comment lengths. |
978 | */ |
979 | |
980 | key *key_new(key_file *f, const char *type, |
981 | const void *k, size_t ksz, |
982 | time_t exp, const char *c) |
983 | { |
984 | key *kk; |
985 | time_t t = time(0); |
986 | |
987 | KEY_WRITE(f, key_new, 0); |
988 | |
989 | if (KEY_EXPIRED(t, exp) || |
990 | key_chktype(type) || key_chkcomment(c) || |
991 | (kk = insert(f, type, k, ksz, exp, KEXP_UNUSED)) == 0) |
992 | return (0); |
993 | if (c) |
994 | kk->c = xstrdup(c); |
995 | KEY_MODIFY(f); |
996 | return (kk); |
997 | } |
998 | |
999 | /* --- @key_delete@ --- * |
1000 | * |
1001 | * Arguments: @key_file *f@ = pointer to file block |
1002 | * @key *k@ = key to delete |
1003 | * |
1004 | * Returns: --- |
1005 | * |
1006 | * Use: Removes the given key from the list. The key file must be |
1007 | * writable. (Due to the horridness of the data structures, |
1008 | * deleted keys aren't actually removed, just marked so that |
1009 | * they can't be looked up or iterated over. One upshot of |
1010 | * this is that they don't get written back to the file when |
1011 | * it's closed.) |
1012 | */ |
1013 | |
1014 | void key_delete(key_file *f, key *k) |
1015 | { |
1016 | KEY_WRITE(f, key_delete, NOTHING); |
1017 | k->exp = KEXP_EXPIRE; |
1018 | k->del = KEXP_UNUSED; |
1019 | KEY_MODIFY(f); |
1020 | } |
1021 | |
1022 | /* --- @key_expire@ --- * |
1023 | * |
1024 | * Arguments: @key_file *f@ = pointer to file block |
1025 | * @key *k@ = pointer to key block |
1026 | * |
1027 | * Returns: --- |
1028 | * |
1029 | * Use: Immediately marks the key as expired. It may be removed |
1030 | * immediately, if it is no longer required, and will be removed |
1031 | * by a tidy operation when it is no longer required. The key |
1032 | * file must be writable. |
1033 | */ |
1034 | |
1035 | void key_expire(key_file *f, key *k) |
1036 | { |
1037 | KEY_WRITE(f, key_expire, NOTHING); |
1038 | k->exp = KEXP_EXPIRE; |
1039 | if (k->del == KEXP_FOREVER) |
1040 | k->del = KEXP_UNUSED; |
1041 | KEY_MODIFY(f); |
1042 | } |
1043 | |
1044 | /* --- @key_used@ --- * |
1045 | * |
1046 | * Arguments: @key_file *f@ = pointer to key file |
1047 | * @key *k@ = pointer to key block |
1048 | * @time_t t@ = when key can be removed |
1049 | * |
1050 | * Returns: Zero if OK, nonzero on failure. |
1051 | * |
1052 | * Use: Marks a key as being required until a given time. Even |
1053 | * though the key may expire before then (and won't be returned |
1054 | * by type after that time), it will still be available when |
1055 | * requested explicitly by id. The key file must be writable. |
1056 | * |
1057 | * The only (current) reason for failure is attempting to use |
1058 | * a key which can expire for something which can't. |
1059 | */ |
1060 | |
1061 | int key_used(key_file *f, key *k, time_t t) |
1062 | { |
1063 | KEY_WRITE(f, key_used, -1); |
1064 | if (t == KEXP_FOREVER) { |
1065 | if (k->exp != KEXP_FOREVER) { |
1066 | errno = EINVAL; |
1067 | return (-1); |
1068 | } |
1069 | } else if (k->del >= t) |
1070 | return (0); |
1071 | |
1072 | k->del = t; |
1073 | KEY_MODIFY(f); |
1074 | return (0); |
1075 | } |
1076 | |
1077 | /*----- That's all, folks -------------------------------------------------*/ |