source: heimdal/vendor/current/lib/hdb/keys.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: 10.4 KB
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1
2/*
3 * Copyright (c) 1997 - 2001, 2003 - 2004 Kungliga Tekniska Högskolan
4 * (Royal Institute of Technology, Stockholm, Sweden).
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 *
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * 3. Neither the name of the Institute nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#include "hdb_locl.h"
36
37/*
38 * free all the memory used by (len, keys)
39 */
40
41void
42hdb_free_keys (krb5_context context, int len, Key *keys)
43{
44 int i;
45
46 for (i = 0; i < len; i++) {
47 free(keys[i].mkvno);
48 keys[i].mkvno = NULL;
49 if (keys[i].salt != NULL) {
50 free_Salt(keys[i].salt);
51 free(keys[i].salt);
52 keys[i].salt = NULL;
53 }
54 krb5_free_keyblock_contents(context, &keys[i].key);
55 }
56 free (keys);
57}
58
59/*
60 * for each entry in `default_keys' try to parse it as a sequence
61 * of etype:salttype:salt, syntax of this if something like:
62 * [(des|des3|etype):](pw-salt|afs3)[:string], if etype is omitted it
63 * means all etypes, and if string is omitted is means the default
64 * string (for that principal). Additional special values:
65 * v5 == pw-salt, and
66 * v4 == des:pw-salt:
67 * afs or afs3 == des:afs3-salt
68 */
69
70static const krb5_enctype des_etypes[] = {
71 ETYPE_DES_CBC_MD5,
72 ETYPE_DES_CBC_MD4,
73 ETYPE_DES_CBC_CRC
74};
75
76static const krb5_enctype all_etypes[] = {
77 ETYPE_AES256_CTS_HMAC_SHA1_96,
78 ETYPE_ARCFOUR_HMAC_MD5,
79 ETYPE_DES3_CBC_SHA1
80};
81
82static krb5_error_code
83parse_key_set(krb5_context context, const char *key,
84 krb5_enctype **ret_enctypes, size_t *ret_num_enctypes,
85 krb5_salt *salt, krb5_principal principal)
86{
87 const char *p;
88 char buf[3][256];
89 int num_buf = 0;
90 int i, num_enctypes = 0;
91 krb5_enctype e;
92 const krb5_enctype *enctypes = NULL;
93 krb5_error_code ret;
94
95 p = key;
96
97 *ret_enctypes = NULL;
98 *ret_num_enctypes = 0;
99
100 /* split p in a list of :-separated strings */
101 for(num_buf = 0; num_buf < 3; num_buf++)
102 if(strsep_copy(&p, ":", buf[num_buf], sizeof(buf[num_buf])) == -1)
103 break;
104
105 salt->saltvalue.data = NULL;
106 salt->saltvalue.length = 0;
107
108 for(i = 0; i < num_buf; i++) {
109 if(enctypes == NULL && num_buf > 1) {
110 /* this might be a etype specifier */
111 /* XXX there should be a string_to_etypes handling
112 special cases like `des' and `all' */
113 if(strcmp(buf[i], "des") == 0) {
114 enctypes = des_etypes;
115 num_enctypes = sizeof(des_etypes)/sizeof(des_etypes[0]);
116 } else if(strcmp(buf[i], "des3") == 0) {
117 e = ETYPE_DES3_CBC_SHA1;
118 enctypes = &e;
119 num_enctypes = 1;
120 } else {
121 ret = krb5_string_to_enctype(context, buf[i], &e);
122 if (ret == 0) {
123 enctypes = &e;
124 num_enctypes = 1;
125 } else
126 return ret;
127 }
128 continue;
129 }
130 if(salt->salttype == 0) {
131 /* interpret string as a salt specifier, if no etype
132 is set, this sets default values */
133 /* XXX should perhaps use string_to_salttype, but that
134 interface sucks */
135 if(strcmp(buf[i], "pw-salt") == 0) {
136 if(enctypes == NULL) {
137 enctypes = all_etypes;
138 num_enctypes = sizeof(all_etypes)/sizeof(all_etypes[0]);
139 }
140 salt->salttype = KRB5_PW_SALT;
141 } else if(strcmp(buf[i], "afs3-salt") == 0) {
142 if(enctypes == NULL) {
143 enctypes = des_etypes;
144 num_enctypes = sizeof(des_etypes)/sizeof(des_etypes[0]);
145 }
146 salt->salttype = KRB5_AFS3_SALT;
147 }
148 continue;
149 }
150
151 {
152 /* if there is a final string, use it as the string to
153 salt with, this is mostly useful with null salt for
154 v4 compat, and a cell name for afs compat */
155 salt->saltvalue.data = strdup(buf[i]);
156 if (salt->saltvalue.data == NULL) {
157 krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
158 return ENOMEM;
159 }
160 salt->saltvalue.length = strlen(buf[i]);
161 }
162 }
163
164 if(enctypes == NULL || salt->salttype == 0) {
165 krb5_set_error_message(context, EINVAL, "bad value for default_keys `%s'", key);
166 return EINVAL;
167 }
168
169 /* if no salt was specified make up default salt */
170 if(salt->saltvalue.data == NULL) {
171 if(salt->salttype == KRB5_PW_SALT)
172 ret = krb5_get_pw_salt(context, principal, salt);
173 else if(salt->salttype == KRB5_AFS3_SALT) {
174 krb5_const_realm realm = krb5_principal_get_realm(context, principal);
175 salt->saltvalue.data = strdup(realm);
176 if(salt->saltvalue.data == NULL) {
177 krb5_set_error_message(context, ENOMEM,
178 "out of memory while "
179 "parsing salt specifiers");
180 return ENOMEM;
181 }
182 strlwr(salt->saltvalue.data);
183 salt->saltvalue.length = strlen(realm);
184 }
185 }
186
187 *ret_enctypes = malloc(sizeof(enctypes[0]) * num_enctypes);
188 if (*ret_enctypes == NULL) {
189 krb5_free_salt(context, *salt);
190 krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
191 return ENOMEM;
192 }
193 memcpy(*ret_enctypes, enctypes, sizeof(enctypes[0]) * num_enctypes);
194 *ret_num_enctypes = num_enctypes;
195
196 return 0;
197}
198
199static krb5_error_code
200add_enctype_to_key_set(Key **key_set, size_t *nkeyset,
201 krb5_enctype enctype, krb5_salt *salt)
202{
203 krb5_error_code ret;
204 Key key, *tmp;
205
206 memset(&key, 0, sizeof(key));
207
208 tmp = realloc(*key_set, (*nkeyset + 1) * sizeof((*key_set)[0]));
209 if (tmp == NULL)
210 return ENOMEM;
211
212 *key_set = tmp;
213
214 key.key.keytype = enctype;
215 key.key.keyvalue.length = 0;
216 key.key.keyvalue.data = NULL;
217
218 if (salt) {
219 key.salt = calloc(1, sizeof(*key.salt));
220 if (key.salt == NULL) {
221 free_Key(&key);
222 return ENOMEM;
223 }
224
225 key.salt->type = salt->salttype;
226 krb5_data_zero (&key.salt->salt);
227
228 ret = krb5_data_copy(&key.salt->salt,
229 salt->saltvalue.data,
230 salt->saltvalue.length);
231 if (ret) {
232 free_Key(&key);
233 return ret;
234 }
235 } else
236 key.salt = NULL;
237
238 (*key_set)[*nkeyset] = key;
239
240 *nkeyset += 1;
241
242 return 0;
243}
244
245
246/*
247 * Generate the `key_set' from the [kadmin]default_keys statement. If
248 * `no_salt' is set, salt is not important (and will not be set) since
249 * it's random keys that is going to be created.
250 */
251
252krb5_error_code
253hdb_generate_key_set(krb5_context context, krb5_principal principal,
254 Key **ret_key_set, size_t *nkeyset, int no_salt)
255{
256 char **ktypes, **kp;
257 krb5_error_code ret;
258 Key *k, *key_set;
259 size_t i, j;
260 static const char *default_keytypes[] = {
261 "aes256-cts-hmac-sha1-96:pw-salt",
262 "des3-cbc-sha1:pw-salt",
263 "arcfour-hmac-md5:pw-salt",
264 NULL
265 };
266
267 ktypes = krb5_config_get_strings(context, NULL, "kadmin",
268 "default_keys", NULL);
269 if (ktypes == NULL)
270 ktypes = (char **)(intptr_t)default_keytypes;
271
272 *ret_key_set = key_set = NULL;
273 *nkeyset = 0;
274
275 ret = 0;
276
277 for(kp = ktypes; kp && *kp; kp++) {
278 const char *p;
279 krb5_salt salt;
280 krb5_enctype *enctypes;
281 size_t num_enctypes;
282
283 p = *kp;
284 /* check alias */
285 if(strcmp(p, "v5") == 0)
286 p = "pw-salt";
287 else if(strcmp(p, "v4") == 0)
288 p = "des:pw-salt:";
289 else if(strcmp(p, "afs") == 0 || strcmp(p, "afs3") == 0)
290 p = "des:afs3-salt";
291 else if (strcmp(p, "arcfour-hmac-md5") == 0)
292 p = "arcfour-hmac-md5:pw-salt";
293
294 memset(&salt, 0, sizeof(salt));
295
296 ret = parse_key_set(context, p,
297 &enctypes, &num_enctypes, &salt, principal);
298 if (ret) {
299 krb5_warn(context, ret, "bad value for default_keys `%s'", *kp);
300 ret = 0;
301 continue;
302 }
303
304 for (i = 0; i < num_enctypes; i++) {
305 /* find duplicates */
306 for (j = 0; j < *nkeyset; j++) {
307
308 k = &key_set[j];
309
310 if (k->key.keytype == enctypes[i]) {
311 if (no_salt)
312 break;
313 if (k->salt == NULL && salt.salttype == KRB5_PW_SALT)
314 break;
315 if (k->salt->type == salt.salttype &&
316 k->salt->salt.length == salt.saltvalue.length &&
317 memcmp(k->salt->salt.data, salt.saltvalue.data,
318 salt.saltvalue.length) == 0)
319 break;
320 }
321 }
322 /* not a duplicate, lets add it */
323 if (j == *nkeyset) {
324 ret = add_enctype_to_key_set(&key_set, nkeyset, enctypes[i],
325 no_salt ? NULL : &salt);
326 if (ret) {
327 free(enctypes);
328 krb5_free_salt(context, salt);
329 goto out;
330 }
331 }
332 }
333 free(enctypes);
334 krb5_free_salt(context, salt);
335 }
336
337 *ret_key_set = key_set;
338
339 out:
340 if (ktypes != (char **)(intptr_t)default_keytypes)
341 krb5_config_free_strings(ktypes);
342
343 if (ret) {
344 krb5_warn(context, ret,
345 "failed to parse the [kadmin]default_keys values");
346
347 for (i = 0; i < *nkeyset; i++)
348 free_Key(&key_set[i]);
349 free(key_set);
350 } else if (*nkeyset == 0) {
351 krb5_warnx(context,
352 "failed to parse any of the [kadmin]default_keys values");
353 ret = EINVAL; /* XXX */
354 }
355
356 return ret;
357}
358
359
360krb5_error_code
361hdb_generate_key_set_password(krb5_context context,
362 krb5_principal principal,
363 const char *password,
364 Key **keys, size_t *num_keys)
365{
366 krb5_error_code ret;
367 size_t i;
368
369 ret = hdb_generate_key_set(context, principal,
370 keys, num_keys, 0);
371 if (ret)
372 return ret;
373
374 for (i = 0; i < (*num_keys); i++) {
375 krb5_salt salt;
376
377 salt.salttype = (*keys)[i].salt->type;
378 salt.saltvalue.length = (*keys)[i].salt->salt.length;
379 salt.saltvalue.data = (*keys)[i].salt->salt.data;
380
381 ret = krb5_string_to_key_salt (context,
382 (*keys)[i].key.keytype,
383 password,
384 salt,
385 &(*keys)[i].key);
386
387 if(ret)
388 break;
389 }
390
391 if(ret) {
392 hdb_free_keys (context, *num_keys, *keys);
393 return ret;
394 }
395 return ret;
396}
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