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 41 void 42 hdb_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 70 static const krb5_enctype des_etypes[] = { 71 ETYPE_DES_CBC_MD5, 72 ETYPE_DES_CBC_MD4, 73 ETYPE_DES_CBC_CRC 74 }; 75 76 static const krb5_enctype all_etypes[] = { 77 ETYPE_AES256_CTS_HMAC_SHA1_96, 78 ETYPE_ARCFOUR_HMAC_MD5, 79 ETYPE_DES3_CBC_SHA1 80 }; 81 82 static krb5_error_code 83 parse_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 } 198 199 static krb5_error_code 200 add_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 */ 251 252 krb5_error_code 253 hdb_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 } 358 359 360 krb5_error_code 361 hdb_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 } 397