1 /* $NetBSD: transited.c,v 1.1.1.1 2011/04/13 18:15:39 elric Exp $ */ 2 3 /* 4 * Copyright (c) 1997 - 2001, 2003 Kungliga Tekniska Högskolan 5 * (Royal Institute of Technology, Stockholm, Sweden). 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * 3. Neither the name of the Institute nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include "krb5_locl.h" 37 38 /* this is an attempt at one of the most horrible `compression' 39 schemes that has ever been invented; it's so amazingly brain-dead 40 that words can not describe it, and all this just to save a few 41 silly bytes */ 42 43 struct tr_realm { 44 char *realm; 45 unsigned leading_space:1; 46 unsigned leading_slash:1; 47 unsigned trailing_dot:1; 48 struct tr_realm *next; 49 }; 50 51 static void 52 free_realms(struct tr_realm *r) 53 { 54 struct tr_realm *p; 55 while(r){ 56 p = r; 57 r = r->next; 58 free(p->realm); 59 free(p); 60 } 61 } 62 63 static int 64 make_path(krb5_context context, struct tr_realm *r, 65 const char *from, const char *to) 66 { 67 struct tr_realm *tmp; 68 const char *p; 69 70 if(strlen(from) < strlen(to)){ 71 const char *str; 72 str = from; 73 from = to; 74 to = str; 75 } 76 77 if(strcmp(from + strlen(from) - strlen(to), to) == 0){ 78 p = from; 79 while(1){ 80 p = strchr(p, '.'); 81 if(p == NULL) { 82 krb5_clear_error_message (context); 83 return KRB5KDC_ERR_POLICY; 84 } 85 p++; 86 if(strcmp(p, to) == 0) 87 break; 88 tmp = calloc(1, sizeof(*tmp)); 89 if(tmp == NULL){ 90 krb5_set_error_message(context, ENOMEM, 91 N_("malloc: out of memory", "")); 92 return ENOMEM; 93 } 94 tmp->next = r->next; 95 r->next = tmp; 96 tmp->realm = strdup(p); 97 if(tmp->realm == NULL){ 98 r->next = tmp->next; 99 free(tmp); 100 krb5_set_error_message(context, ENOMEM, 101 N_("malloc: out of memory", "")); 102 return ENOMEM;; 103 } 104 } 105 }else if(strncmp(from, to, strlen(to)) == 0){ 106 p = from + strlen(from); 107 while(1){ 108 while(p >= from && *p != '/') p--; 109 if(p == from) 110 return KRB5KDC_ERR_POLICY; 111 112 if(strncmp(to, from, p - from) == 0) 113 break; 114 tmp = calloc(1, sizeof(*tmp)); 115 if(tmp == NULL){ 116 krb5_set_error_message(context, ENOMEM, 117 N_("malloc: out of memory", "")); 118 return ENOMEM; 119 } 120 tmp->next = r->next; 121 r->next = tmp; 122 tmp->realm = malloc(p - from + 1); 123 if(tmp->realm == NULL){ 124 r->next = tmp->next; 125 free(tmp); 126 krb5_set_error_message(context, ENOMEM, 127 N_("malloc: out of memory", "")); 128 return ENOMEM; 129 } 130 memcpy(tmp->realm, from, p - from); 131 tmp->realm[p - from] = '\0'; 132 p--; 133 } 134 } else { 135 krb5_clear_error_message (context); 136 return KRB5KDC_ERR_POLICY; 137 } 138 139 return 0; 140 } 141 142 static int 143 make_paths(krb5_context context, 144 struct tr_realm *realms, const char *client_realm, 145 const char *server_realm) 146 { 147 struct tr_realm *r; 148 int ret; 149 const char *prev_realm = client_realm; 150 const char *next_realm = NULL; 151 for(r = realms; r; r = r->next){ 152 /* it *might* be that you can have more than one empty 153 component in a row, at least that's how I interpret the 154 "," exception in 1510 */ 155 if(r->realm[0] == '\0'){ 156 while(r->next && r->next->realm[0] == '\0') 157 r = r->next; 158 if(r->next) 159 next_realm = r->next->realm; 160 else 161 next_realm = server_realm; 162 ret = make_path(context, r, prev_realm, next_realm); 163 if(ret){ 164 free_realms(realms); 165 return ret; 166 } 167 } 168 prev_realm = r->realm; 169 } 170 return 0; 171 } 172 173 static int 174 expand_realms(krb5_context context, 175 struct tr_realm *realms, const char *client_realm) 176 { 177 struct tr_realm *r; 178 const char *prev_realm = NULL; 179 for(r = realms; r; r = r->next){ 180 if(r->trailing_dot){ 181 char *tmp; 182 size_t len; 183 184 if(prev_realm == NULL) 185 prev_realm = client_realm; 186 187 len = strlen(r->realm) + strlen(prev_realm) + 1; 188 189 tmp = realloc(r->realm, len); 190 if(tmp == NULL){ 191 free_realms(realms); 192 krb5_set_error_message(context, ENOMEM, 193 N_("malloc: out of memory", "")); 194 return ENOMEM; 195 } 196 r->realm = tmp; 197 strlcat(r->realm, prev_realm, len); 198 }else if(r->leading_slash && !r->leading_space && prev_realm){ 199 /* yet another exception: if you use x500-names, the 200 leading realm doesn't have to be "quoted" with a space */ 201 char *tmp; 202 size_t len = strlen(r->realm) + strlen(prev_realm) + 1; 203 204 tmp = malloc(len); 205 if(tmp == NULL){ 206 free_realms(realms); 207 krb5_set_error_message(context, ENOMEM, 208 N_("malloc: out of memory", "")); 209 return ENOMEM; 210 } 211 strlcpy(tmp, prev_realm, len); 212 strlcat(tmp, r->realm, len); 213 free(r->realm); 214 r->realm = tmp; 215 } 216 prev_realm = r->realm; 217 } 218 return 0; 219 } 220 221 static struct tr_realm * 222 make_realm(char *realm) 223 { 224 struct tr_realm *r; 225 char *p, *q; 226 int quote = 0; 227 r = calloc(1, sizeof(*r)); 228 if(r == NULL){ 229 free(realm); 230 return NULL; 231 } 232 r->realm = realm; 233 for(p = q = r->realm; *p; p++){ 234 if(p == r->realm && *p == ' '){ 235 r->leading_space = 1; 236 continue; 237 } 238 if(q == r->realm && *p == '/') 239 r->leading_slash = 1; 240 if(quote){ 241 *q++ = *p; 242 quote = 0; 243 continue; 244 } 245 if(*p == '\\'){ 246 quote = 1; 247 continue; 248 } 249 if(p[0] == '.' && p[1] == '\0') 250 r->trailing_dot = 1; 251 *q++ = *p; 252 } 253 *q = '\0'; 254 return r; 255 } 256 257 static struct tr_realm* 258 append_realm(struct tr_realm *head, struct tr_realm *r) 259 { 260 struct tr_realm *p; 261 if(head == NULL){ 262 r->next = NULL; 263 return r; 264 } 265 p = head; 266 while(p->next) p = p->next; 267 p->next = r; 268 return head; 269 } 270 271 static int 272 decode_realms(krb5_context context, 273 const char *tr, int length, struct tr_realm **realms) 274 { 275 struct tr_realm *r = NULL; 276 277 char *tmp; 278 int quote = 0; 279 const char *start = tr; 280 int i; 281 282 for(i = 0; i < length; i++){ 283 if(quote){ 284 quote = 0; 285 continue; 286 } 287 if(tr[i] == '\\'){ 288 quote = 1; 289 continue; 290 } 291 if(tr[i] == ','){ 292 tmp = malloc(tr + i - start + 1); 293 if(tmp == NULL){ 294 krb5_set_error_message(context, ENOMEM, 295 N_("malloc: out of memory", "")); 296 return ENOMEM; 297 } 298 memcpy(tmp, start, tr + i - start); 299 tmp[tr + i - start] = '\0'; 300 r = make_realm(tmp); 301 if(r == NULL){ 302 free_realms(*realms); 303 krb5_set_error_message(context, ENOMEM, 304 N_("malloc: out of memory", "")); 305 return ENOMEM; 306 } 307 *realms = append_realm(*realms, r); 308 start = tr + i + 1; 309 } 310 } 311 tmp = malloc(tr + i - start + 1); 312 if(tmp == NULL){ 313 free(*realms); 314 krb5_set_error_message(context, ENOMEM, 315 N_("malloc: out of memory", "")); 316 return ENOMEM; 317 } 318 memcpy(tmp, start, tr + i - start); 319 tmp[tr + i - start] = '\0'; 320 r = make_realm(tmp); 321 if(r == NULL){ 322 free_realms(*realms); 323 krb5_set_error_message(context, ENOMEM, 324 N_("malloc: out of memory", "")); 325 return ENOMEM; 326 } 327 *realms = append_realm(*realms, r); 328 329 return 0; 330 } 331 332 333 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL 334 krb5_domain_x500_decode(krb5_context context, 335 krb5_data tr, char ***realms, unsigned int *num_realms, 336 const char *client_realm, const char *server_realm) 337 { 338 struct tr_realm *r = NULL; 339 struct tr_realm *p, **q; 340 int ret; 341 342 if(tr.length == 0) { 343 *realms = NULL; 344 *num_realms = 0; 345 return 0; 346 } 347 348 /* split string in components */ 349 ret = decode_realms(context, tr.data, tr.length, &r); 350 if(ret) 351 return ret; 352 353 /* apply prefix rule */ 354 ret = expand_realms(context, r, client_realm); 355 if(ret) 356 return ret; 357 358 ret = make_paths(context, r, client_realm, server_realm); 359 if(ret) 360 return ret; 361 362 /* remove empty components and count realms */ 363 *num_realms = 0; 364 for(q = &r; *q; ){ 365 if((*q)->realm[0] == '\0'){ 366 p = *q; 367 *q = (*q)->next; 368 free(p->realm); 369 free(p); 370 }else{ 371 q = &(*q)->next; 372 (*num_realms)++; 373 } 374 } 375 if (*num_realms < 0 || *num_realms + 1 > UINT_MAX/sizeof(**realms)) 376 return ERANGE; 377 378 { 379 char **R; 380 R = malloc((*num_realms + 1) * sizeof(*R)); 381 if (R == NULL) 382 return ENOMEM; 383 *realms = R; 384 while(r){ 385 *R++ = r->realm; 386 p = r->next; 387 free(r); 388 r = p; 389 } 390 } 391 return 0; 392 } 393 394 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL 395 krb5_domain_x500_encode(char **realms, unsigned int num_realms, 396 krb5_data *encoding) 397 { 398 char *s = NULL; 399 int len = 0; 400 unsigned int i; 401 krb5_data_zero(encoding); 402 if (num_realms == 0) 403 return 0; 404 for(i = 0; i < num_realms; i++){ 405 len += strlen(realms[i]); 406 if(realms[i][0] == '/') 407 len++; 408 } 409 len += num_realms - 1; 410 s = malloc(len + 1); 411 if (s == NULL) 412 return ENOMEM; 413 *s = '\0'; 414 for(i = 0; i < num_realms; i++){ 415 if(i && i < num_realms - 1) 416 strlcat(s, ",", len + 1); 417 if(realms[i][0] == '/') 418 strlcat(s, " ", len + 1); 419 strlcat(s, realms[i], len + 1); 420 } 421 encoding->data = s; 422 encoding->length = strlen(s); 423 return 0; 424 } 425 426 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL 427 krb5_check_transited(krb5_context context, 428 krb5_const_realm client_realm, 429 krb5_const_realm server_realm, 430 krb5_realm *realms, 431 unsigned int num_realms, 432 int *bad_realm) 433 { 434 char **tr_realms; 435 char **p; 436 int i; 437 438 if(num_realms == 0) 439 return 0; 440 441 tr_realms = krb5_config_get_strings(context, NULL, 442 "capaths", 443 client_realm, 444 server_realm, 445 NULL); 446 for(i = 0; i < num_realms; i++) { 447 for(p = tr_realms; p && *p; p++) { 448 if(strcmp(*p, realms[i]) == 0) 449 break; 450 } 451 if(p == NULL || *p == NULL) { 452 krb5_config_free_strings(tr_realms); 453 krb5_set_error_message (context, KRB5KRB_AP_ERR_ILL_CR_TKT, 454 N_("no transit allowed " 455 "through realm %s", ""), 456 realms[i]); 457 if(bad_realm) 458 *bad_realm = i; 459 return KRB5KRB_AP_ERR_ILL_CR_TKT; 460 } 461 } 462 krb5_config_free_strings(tr_realms); 463 return 0; 464 } 465 466 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL 467 krb5_check_transited_realms(krb5_context context, 468 const char *const *realms, 469 unsigned int num_realms, 470 int *bad_realm) 471 { 472 int i; 473 int ret = 0; 474 char **bad_realms = krb5_config_get_strings(context, NULL, 475 "libdefaults", 476 "transited_realms_reject", 477 NULL); 478 if(bad_realms == NULL) 479 return 0; 480 481 for(i = 0; i < num_realms; i++) { 482 char **p; 483 for(p = bad_realms; *p; p++) 484 if(strcmp(*p, realms[i]) == 0) { 485 ret = KRB5KRB_AP_ERR_ILL_CR_TKT; 486 krb5_set_error_message (context, ret, 487 N_("no transit allowed " 488 "through realm %s", ""), 489 *p); 490 if(bad_realm) 491 *bad_realm = i; 492 break; 493 } 494 } 495 krb5_config_free_strings(bad_realms); 496 return ret; 497 } 498 499 #if 0 500 int 501 main(int argc, char **argv) 502 { 503 krb5_data x; 504 char **r; 505 int num, i; 506 x.data = argv[1]; 507 x.length = strlen(x.data); 508 if(domain_expand(x, &r, &num, argv[2], argv[3])) 509 exit(1); 510 for(i = 0; i < num; i++) 511 printf("%s\n", r[i]); 512 return 0; 513 } 514 #endif 515 516