source: heimdal/trunk/lib/krb5/keytab_keyfile.c

Last change on this file was 1, checked in by Paul Smedley, 10 years ago

Initial commit of Heimdal 1.5.3
File size: 10.7 KB
Line 
1/*
2 * Copyright (c) 1997 - 2007 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include "krb5_locl.h"
35
36#ifndef HEIMDAL_SMALLER
37
38/* afs keyfile operations --------------------------------------- */
39
40/*
41 * Minimum tools to handle the AFS KeyFile.
42 *
43 * Format of the KeyFile is:
44 * <int32_t numkeys> {[<int32_t kvno> <char[8] deskey>] * numkeys}
45 *
46 * It just adds to the end of the keyfile, deleting isn't implemented.
47 * Use your favorite text/hex editor to delete keys.
48 *
49 */
50
51#define AFS_SERVERTHISCELL "/usr/afs/etc/ThisCell"
52#define AFS_SERVERMAGICKRBCONF "/usr/afs/etc/krb.conf"
53
54struct akf_data {
55 uint32_t num_entries;
56 char *filename;
57 char *cell;
58 char *realm;
59};
60
61/*
62 * set `d->cell' and `d->realm'
63 */
64
65static int
66get_cell_and_realm (krb5_context context, struct akf_data *d)
67{
68 FILE *f;
69 char buf[BUFSIZ], *cp;
70 int ret;
71
72 f = fopen (AFS_SERVERTHISCELL, "r");
73 if (f == NULL) {
74 ret = errno;
75 krb5_set_error_message (context, ret,
76 N_("Open ThisCell %s: %s", ""),
77 AFS_SERVERTHISCELL,
78 strerror(ret));
79 return ret;
80 }
81 if (fgets (buf, sizeof(buf), f) == NULL) {
82 fclose (f);
83 krb5_set_error_message (context, EINVAL,
84 N_("No cell in ThisCell file %s", ""),
85 AFS_SERVERTHISCELL);
86 return EINVAL;
87 }
88 buf[strcspn(buf, "\n")] = '\0';
89 fclose(f);
90
91 d->cell = strdup (buf);
92 if (d->cell == NULL) {
93 krb5_set_error_message(context, ENOMEM,
94 N_("malloc: out of memory", ""));
95 return ENOMEM;
96 }
97
98 f = fopen (AFS_SERVERMAGICKRBCONF, "r");
99 if (f != NULL) {
100 if (fgets (buf, sizeof(buf), f) == NULL) {
101 free (d->cell);
102 d->cell = NULL;
103 fclose (f);
104 krb5_set_error_message (context, EINVAL,
105 N_("No realm in ThisCell file %s", ""),
106 AFS_SERVERMAGICKRBCONF);
107 return EINVAL;
108 }
109 buf[strcspn(buf, "\n")] = '\0';
110 fclose(f);
111 }
112 /* uppercase */
113 for (cp = buf; *cp != '\0'; cp++)
114 *cp = toupper((unsigned char)*cp);
115
116 d->realm = strdup (buf);
117 if (d->realm == NULL) {
118 free (d->cell);
119 d->cell = NULL;
120 krb5_set_error_message(context, ENOMEM,
121 N_("malloc: out of memory", ""));
122 return ENOMEM;
123 }
124 return 0;
125}
126
127/*
128 * init and get filename
129 */
130
131static krb5_error_code KRB5_CALLCONV
132akf_resolve(krb5_context context, const char *name, krb5_keytab id)
133{
134 int ret;
135 struct akf_data *d = malloc(sizeof (struct akf_data));
136
137 if (d == NULL) {
138 krb5_set_error_message(context, ENOMEM,
139 N_("malloc: out of memory", ""));
140 return ENOMEM;
141 }
142
143 d->num_entries = 0;
144 ret = get_cell_and_realm (context, d);
145 if (ret) {
146 free (d);
147 return ret;
148 }
149 d->filename = strdup (name);
150 if (d->filename == NULL) {
151 free (d->cell);
152 free (d->realm);
153 free (d);
154 krb5_set_error_message(context, ENOMEM,
155 N_("malloc: out of memory", ""));
156 return ENOMEM;
157 }
158 id->data = d;
159
160 return 0;
161}
162
163/*
164 * cleanup
165 */
166
167static krb5_error_code KRB5_CALLCONV
168akf_close(krb5_context context, krb5_keytab id)
169{
170 struct akf_data *d = id->data;
171
172 free (d->filename);
173 free (d->cell);
174 free (d);
175 return 0;
176}
177
178/*
179 * Return filename
180 */
181
182static krb5_error_code KRB5_CALLCONV
183akf_get_name(krb5_context context,
184 krb5_keytab id,
185 char *name,
186 size_t name_sz)
187{
188 struct akf_data *d = id->data;
189
190 strlcpy (name, d->filename, name_sz);
191 return 0;
192}
193
194/*
195 * Init
196 */
197
198static krb5_error_code KRB5_CALLCONV
199akf_start_seq_get(krb5_context context,
200 krb5_keytab id,
201 krb5_kt_cursor *c)
202{
203 int32_t ret;
204 struct akf_data *d = id->data;
205
206 c->fd = open (d->filename, O_RDONLY | O_BINARY | O_CLOEXEC, 0600);
207 if (c->fd < 0) {
208 ret = errno;
209 krb5_set_error_message(context, ret,
210 N_("keytab afs keyfile open %s failed: %s", ""),
211 d->filename, strerror(ret));
212 return ret;
213 }
214
215 c->data = NULL;
216 c->sp = krb5_storage_from_fd(c->fd);
217 if (c->sp == NULL) {
218 close(c->fd);
219 krb5_clear_error_message (context);
220 return KRB5_KT_NOTFOUND;
221 }
222 krb5_storage_set_eof_code(c->sp, KRB5_KT_END);
223
224 ret = krb5_ret_uint32(c->sp, &d->num_entries);
225 if(ret || d->num_entries > INT_MAX / 8) {
226 krb5_storage_free(c->sp);
227 close(c->fd);
228 krb5_clear_error_message (context);
229 if(ret == KRB5_KT_END)
230 return KRB5_KT_NOTFOUND;
231 return ret;
232 }
233
234 return 0;
235}
236
237static krb5_error_code KRB5_CALLCONV
238akf_next_entry(krb5_context context,
239 krb5_keytab id,
240 krb5_keytab_entry *entry,
241 krb5_kt_cursor *cursor)
242{
243 struct akf_data *d = id->data;
244 int32_t kvno;
245 off_t pos;
246 int ret;
247
248 pos = krb5_storage_seek(cursor->sp, 0, SEEK_CUR);
249
250 if ((pos - 4) / (4 + 8) >= d->num_entries)
251 return KRB5_KT_END;
252
253 ret = krb5_make_principal (context, &entry->principal,
254 d->realm, "afs", d->cell, NULL);
255 if (ret)
256 goto out;
257
258 ret = krb5_ret_int32(cursor->sp, &kvno);
259 if (ret) {
260 krb5_free_principal (context, entry->principal);
261 goto out;
262 }
263
264 entry->vno = kvno;
265
266 if (cursor->data)
267 entry->keyblock.keytype = ETYPE_DES_CBC_MD5;
268 else
269 entry->keyblock.keytype = ETYPE_DES_CBC_CRC;
270 entry->keyblock.keyvalue.length = 8;
271 entry->keyblock.keyvalue.data = malloc (8);
272 if (entry->keyblock.keyvalue.data == NULL) {
273 krb5_free_principal (context, entry->principal);
274 krb5_set_error_message(context, ENOMEM,
275 N_("malloc: out of memory", ""));
276 ret = ENOMEM;
277 goto out;
278 }
279
280 ret = krb5_storage_read(cursor->sp, entry->keyblock.keyvalue.data, 8);
281 if(ret != 8)
282 ret = (ret < 0) ? errno : KRB5_KT_END;
283 else
284 ret = 0;
285
286 entry->timestamp = time(NULL);
287 entry->flags = 0;
288 entry->aliases = NULL;
289
290 out:
291 if (cursor->data) {
292 krb5_storage_seek(cursor->sp, pos + 4 + 8, SEEK_SET);
293 cursor->data = NULL;
294 } else
295 cursor->data = cursor;
296 return ret;
297}
298
299static krb5_error_code KRB5_CALLCONV
300akf_end_seq_get(krb5_context context,
301 krb5_keytab id,
302 krb5_kt_cursor *cursor)
303{
304 krb5_storage_free(cursor->sp);
305 close(cursor->fd);
306 cursor->data = NULL;
307 return 0;
308}
309
310static krb5_error_code KRB5_CALLCONV
311akf_add_entry(krb5_context context,
312 krb5_keytab id,
313 krb5_keytab_entry *entry)
314{
315 struct akf_data *d = id->data;
316 int fd, created = 0;
317 krb5_error_code ret;
318 int32_t len;
319 krb5_storage *sp;
320
321
322 if (entry->keyblock.keyvalue.length != 8)
323 return 0;
324 switch(entry->keyblock.keytype) {
325 case ETYPE_DES_CBC_CRC:
326 case ETYPE_DES_CBC_MD4:
327 case ETYPE_DES_CBC_MD5:
328 break;
329 default:
330 return 0;
331 }
332
333 fd = open (d->filename, O_RDWR | O_BINARY | O_CLOEXEC);
334 if (fd < 0) {
335 fd = open (d->filename,
336 O_RDWR | O_BINARY | O_CREAT | O_EXCL | O_CLOEXEC, 0600);
337 if (fd < 0) {
338 ret = errno;
339 krb5_set_error_message(context, ret,
340 N_("open keyfile(%s): %s", ""),
341 d->filename,
342 strerror(ret));
343 return ret;
344 }
345 created = 1;
346 }
347
348 sp = krb5_storage_from_fd(fd);
349 if(sp == NULL) {
350 close(fd);
351 krb5_set_error_message(context, ENOMEM,
352 N_("malloc: out of memory", ""));
353 return ENOMEM;
354 }
355 if (created)
356 len = 0;
357 else {
358 if(krb5_storage_seek(sp, 0, SEEK_SET) < 0) {
359 ret = errno;
360 krb5_storage_free(sp);
361 close(fd);
362 krb5_set_error_message(context, ret,
363 N_("seeking in keyfile: %s", ""),
364 strerror(ret));
365 return ret;
366 }
367
368 ret = krb5_ret_int32(sp, &len);
369 if(ret) {
370 krb5_storage_free(sp);
371 close(fd);
372 return ret;
373 }
374 }
375
376 /*
377 * Make sure we don't add the entry twice, assumes the DES
378 * encryption types are all the same key.
379 */
380 if (len > 0) {
381 int32_t kvno;
382 int i;
383
384 for (i = 0; i < len; i++) {
385 ret = krb5_ret_int32(sp, &kvno);
386 if (ret) {
387 krb5_set_error_message (context, ret,
388 N_("Failed getting kvno from keyfile", ""));
389 goto out;
390 }
391 if(krb5_storage_seek(sp, 8, SEEK_CUR) < 0) {
392 ret = errno;
393 krb5_set_error_message (context, ret,
394 N_("Failed seeing in keyfile: %s", ""),
395 strerror(ret));
396 goto out;
397 }
398 if (kvno == entry->vno) {
399 ret = 0;
400 goto out;
401 }
402 }
403 }
404
405 len++;
406
407 if(krb5_storage_seek(sp, 0, SEEK_SET) < 0) {
408 ret = errno;
409 krb5_set_error_message (context, ret,
410 N_("Failed seeing in keyfile: %s", ""),
411 strerror(ret));
412 goto out;
413 }
414
415 ret = krb5_store_int32(sp, len);
416 if(ret) {
417 ret = errno;
418 krb5_set_error_message (context, ret,
419 N_("keytab keyfile failed new length", ""));
420 return ret;
421 }
422
423 if(krb5_storage_seek(sp, (len - 1) * (8 + 4), SEEK_CUR) < 0) {
424 ret = errno;
425 krb5_set_error_message (context, ret,
426 N_("seek to end: %s", ""), strerror(ret));
427 goto out;
428 }
429
430 ret = krb5_store_int32(sp, entry->vno);
431 if(ret) {
432 krb5_set_error_message(context, ret,
433 N_("keytab keyfile failed store kvno", ""));
434 goto out;
435 }
436 ret = krb5_storage_write(sp, entry->keyblock.keyvalue.data,
437 entry->keyblock.keyvalue.length);
438 if(ret != entry->keyblock.keyvalue.length) {
439 if (ret < 0)
440 ret = errno;
441 else
442 ret = ENOTTY;
443 krb5_set_error_message(context, ret,
444 N_("keytab keyfile failed to add key", ""));
445 goto out;
446 }
447 ret = 0;
448out:
449 krb5_storage_free(sp);
450 close (fd);
451 return ret;
452}
453
454const krb5_kt_ops krb5_akf_ops = {
455 "AFSKEYFILE",
456 akf_resolve,
457 akf_get_name,
458 akf_close,
459 NULL, /* destroy */
460 NULL, /* get */
461 akf_start_seq_get,
462 akf_next_entry,
463 akf_end_seq_get,
464 akf_add_entry,
465 NULL /* remove */
466};
467
468#endif /* HEIMDAL_SMALLER */
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