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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: key-misc.c,v 1.2 2000/02/12 18:21:02 mdw Exp $ |
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4 | * |
5 | * Simple key management |
6 | * |
7 | * (c) 1999 Straylight/Edgeware |
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-misc.c,v $ |
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33 | * Revision 1.2 2000/02/12 18:21:02 mdw |
34 | * Overhaul of key management (again). |
35 | * |
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36 | * Revision 1.1 1999/12/22 15:47:48 mdw |
37 | * Major key-management revision. |
38 | * |
39 | */ |
40 | |
41 | /*----- Header files ------------------------------------------------------*/ |
42 | |
43 | #include <stdio.h> |
44 | #include <stdlib.h> |
45 | #include <string.h> |
46 | #include <time.h> |
47 | |
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48 | #include <mLib/bits.h> |
49 | #include <mLib/hash.h> |
50 | #include <mLib/sub.h> |
51 | #include <mLib/sym.h> |
52 | |
53 | #include "key.h" |
54 | |
55 | /*----- Useful macros -----------------------------------------------------*/ |
56 | |
57 | #define KEY_WRITE(f) do { \ |
58 | if (!(f)->f & KF_WRITE) \ |
59 | return (KERR_READONLY); \ |
60 | } while (0) |
61 | |
62 | #define KEY_MODIFY(f) do { (f)->f |= KF_MODIFIED; } while (0) |
63 | |
64 | #define KEY_LOAD(n) ((n) * 2) |
65 | |
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66 | /*----- Iteration and iterators -------------------------------------------*/ |
67 | |
68 | /* --- @key_mkiter@ --- * |
69 | * |
70 | * Arguments: @key_iter *i@ = pointer to iterator object |
71 | * @key_file *f@ = pointer to file structure |
72 | * |
73 | * Returns: --- |
74 | * |
75 | * Use: Initializes a key iterator. The keys are returned by |
76 | * @key_next@. |
77 | */ |
78 | |
79 | void key_mkiter(key_iter *i, key_file *f) |
80 | { |
81 | HASH_MKITER(&i->i, &f->byid); |
82 | i->t = time(0); |
83 | } |
84 | |
85 | /* --- @key_next@ --- * |
86 | * |
87 | * Arguments: @key_iter *i@ = pointer to iterator object |
88 | * |
89 | * Returns: Pointer to next key, or null. |
90 | * |
91 | * Use: Returns the next key in some arbitrary sequence. |
92 | */ |
93 | |
94 | key *key_next(key_iter *i) |
95 | { |
96 | hash_base *b; |
97 | key *k; |
98 | do { |
99 | HASH_NEXT(&i->i, b); |
100 | k = (key *)b; |
101 | } while (k && KEY_EXPIRED(i->t, k->exp) && KEY_EXPIRED(i->t, k->del)); |
102 | return (k); |
103 | } |
104 | |
105 | /*----- Lookup ------------------------------------------------------------*/ |
106 | |
107 | /* --- @key_bytype@ --- * |
108 | * |
109 | * Arguments: @key_file *f@ = key file we want a key from |
110 | * @const char *type@ = type string for desired key |
111 | * |
112 | * Returns: Pointer to the best key to use, or null. |
113 | * |
114 | * Use: Looks up a key by its type. Returns the key with the latest |
115 | * expiry time. This function will not return an expired key. |
116 | */ |
117 | |
118 | key *key_bytype(key_file *f, const char *type) |
119 | { |
120 | time_t now = time(0); |
121 | key *k; |
122 | key_ref *kr; |
123 | |
124 | if ((kr = sym_find(&f->bytype, type, -1, 0, 0)) == 0) |
125 | return (0); |
126 | for (k = kr->k; k && KEY_EXPIRED(now, k->exp); k = k->next) |
127 | ; |
128 | return (k); |
129 | } |
130 | |
131 | /* --- @key_byid@ --- * |
132 | * |
133 | * Arguments: @key_file *f@ = key file to find a key from |
134 | * @uint32 id@ = id to look for |
135 | * |
136 | * Returns: Key with matching id. |
137 | * |
138 | * Use: Returns a key given its id. This function will return an |
139 | * expired key, but not a deleted one. |
140 | */ |
141 | |
142 | key *key_byid(key_file *f, uint32 id) |
143 | { |
144 | time_t t = time(0); |
145 | hash_base **bin, *b; |
146 | |
147 | bin = HASH_BIN(&f->byid, id); |
148 | for (b = *bin; b; b = b->next) { |
149 | if (b->hash == id) { |
150 | key *k = (key *)b; |
151 | if (KEY_EXPIRED(t, k->exp) && KEY_EXPIRED(t, k->del)) |
152 | return (0); |
153 | return (k); |
154 | } |
155 | } |
156 | return (0); |
157 | } |
158 | |
159 | /* --- @key_bytag@ --- * |
160 | * |
161 | * Arguments: @key_file *f@ = key file to find a key from |
162 | * @const char *tag@ = pointer to tag string |
163 | * |
164 | * Returns: Key with matching id or tag. |
165 | * |
166 | * Use: Returns a key given its tag or id. This function will return |
167 | * an expired key, but not a deleted one. |
168 | */ |
169 | |
170 | key *key_bytag(key_file *f, const char *tag) |
171 | { |
172 | time_t t = time(0); |
173 | char *p; |
174 | uint32 id; |
175 | key_ref *kr = sym_find(&f->bytag, tag, -1, 0, 0); |
176 | |
177 | if (kr && !(KEY_EXPIRED(t, kr->k->exp) && KEY_EXPIRED(t, kr->k->exp))) |
178 | return (kr->k); |
179 | id = strtoul(tag, &p, 16); |
180 | if (!*p) |
181 | return (key_byid(f, id)); |
182 | return (key_bytype(f, tag)); |
183 | } |
184 | |
185 | /* --- @key_qtag@ --- * |
186 | * |
187 | * Arguments: @key_file *f@ = key file to find a key from |
188 | * @const char *tag@ = pointer to tag string |
189 | * @dstr *d@ = pointer to string for full tag name |
190 | * @key **k@ = where to store the key pointer |
191 | * @key_data **kd@ = where to store the key data pointer |
192 | * |
193 | * Returns: Zero if OK, nonzero if it failed. |
194 | * |
195 | * Use: Performs a full lookup on a qualified tag name. The tag is |
196 | * qualified by the names of subkeys, separated by dots. Hence, |
197 | * a qualified tag is ID|TAG[.TAG...]. The various result |
198 | * pointers can be null to indicate that the result isn't |
199 | * interesting. |
200 | */ |
201 | |
202 | int key_qtag(key_file *f, const char *tag, dstr *d, key **k, key_data **kd) |
203 | { |
204 | dstr dd = DSTR_INIT; |
205 | const char *q; |
206 | key *kk; |
207 | key_data *kkd; |
208 | |
209 | /* --- Find the end of the base tag --- */ |
210 | |
211 | if ((q = strchr(tag, '.')) == 0) |
212 | DPUTS(&dd, tag); |
213 | else { |
214 | DPUTM(&dd, tag, q - tag); |
215 | DPUTZ(&dd); |
216 | q++; |
217 | } |
218 | |
219 | /* --- Look up the key tag --- */ |
220 | |
221 | if ((kk = key_bytag(f, dd.buf)) == 0) { |
222 | dstr_destroy(&dd); |
223 | return (-1); |
224 | } |
225 | |
226 | /* --- Set the various initial bits of result up --- */ |
227 | |
228 | if (d) |
229 | key_fulltag(kk, d); |
230 | if (k) |
231 | *k = kk; |
232 | kkd = &kk->k; |
233 | |
234 | /* --- Now dig through the rest of the tag --- */ |
235 | |
236 | while (q && *q) { |
237 | |
238 | /* --- Stick on the next bit of the fullqtag --- */ |
239 | |
240 | DRESET(&dd); |
241 | while (*q && *q != '.') { |
242 | DPUTC(&dd, *q); |
243 | q++; |
244 | } |
245 | DPUTZ(&dd); |
246 | if (d) { |
247 | DPUTC(d, '.'); |
248 | DPUTD(d, &dd); |
249 | } |
250 | |
251 | /* --- Look up the subkey --- */ |
252 | |
253 | if (kkd->e != KENC_STRUCT) { |
254 | kkd = 0; |
255 | break; |
256 | } |
257 | if ((kkd = key_structfind(kkd, dd.buf)) == 0) |
258 | break; |
259 | } |
260 | |
261 | /* --- Return the results --- */ |
262 | |
263 | if (!kkd) |
264 | return (-1); |
265 | dstr_destroy(&dd); |
266 | if (kd) |
267 | *kd = kkd; |
268 | return (0); |
269 | } |
270 | |
271 | /*----- Miscellaneous functions -------------------------------------------*/ |
272 | |
273 | /* --- @key_delete@ --- * |
274 | * |
275 | * Arguments: @key_file *f@ = pointer to file block |
276 | * @key *k@ = key to delete |
277 | * |
278 | * Returns: Error code (one of the @KERR@ constants). |
279 | * |
280 | * Use: Removes the given key from the list. The key file must be |
281 | * writable. (Due to the horridness of the data structures, |
282 | * deleted keys aren't actually removed, just marked so that |
283 | * they can't be looked up or iterated over. One upshot of |
284 | * this is that they don't get written back to the file when |
285 | * it's closed.) |
286 | */ |
287 | |
288 | int key_delete(key_file *f, key *k) |
289 | { |
290 | KEY_WRITE(f); |
291 | k->exp = KEXP_EXPIRE; |
292 | k->del = KEXP_EXPIRE; |
293 | KEY_MODIFY(f); |
294 | return (0); |
295 | } |
296 | |
297 | /* --- @key_expire@ --- * |
298 | * |
299 | * Arguments: @key_file *f@ = pointer to file block |
300 | * @key *k@ = pointer to key block |
301 | * |
302 | * Returns: Error code (one of the @KERR@ constants). |
303 | * |
304 | * Use: Immediately marks the key as expired. It may be removed |
305 | * immediately, if it is no longer required, and will be removed |
306 | * by a tidy operation when it is no longer required. The key |
307 | * file must be writable. |
308 | */ |
309 | |
310 | int key_expire(key_file *f, key *k) |
311 | { |
312 | KEY_WRITE(f); |
313 | k->exp = KEXP_EXPIRE; |
314 | if (k->del == KEXP_FOREVER) |
315 | k->del = KEXP_EXPIRE; |
316 | KEY_MODIFY(f); |
317 | return (0); |
318 | } |
319 | |
320 | /* --- @key_used@ --- * |
321 | * |
322 | * Arguments: @key_file *f@ = pointer to key file |
323 | * @key *k@ = pointer to key block |
324 | * @time_t t@ = when key can be removed |
325 | * |
326 | * Returns: Zero if OK, nonzero on failure. |
327 | * |
328 | * Use: Marks a key as being required until a given time. Even |
329 | * though the key may expire before then (and won't be returned |
330 | * by type after that time), it will still be available when |
331 | * requested explicitly by id. The key file must be writable. |
332 | * |
333 | * The only (current) reason for failure is attempting to use |
334 | * a key which can expire for something which can't. |
335 | */ |
336 | |
337 | int key_used(key_file *f, key *k, time_t t) |
338 | { |
339 | KEY_WRITE(f); |
340 | if (t == KEXP_FOREVER) { |
341 | if (k->exp != KEXP_FOREVER) |
342 | return (KERR_WILLEXPIRE); |
343 | } else if (k->del >= t) |
344 | return (0); |
345 | |
346 | k->del = t; |
347 | KEY_MODIFY(f); |
348 | return (0); |
349 | } |
350 | |
351 | /*----- That's all, folks -------------------------------------------------*/ |