1/* 2 * Copyright (c) 1997 - 2001, 2003 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/* this is an attempt at one of the most horrible `compression' 37 schemes that has ever been invented; it's so amazingly brain-dead 38 that words can not describe it, and all this just to save a few 39 silly bytes */ 40 41struct tr_realm { 42 char *realm; 43 unsigned leading_space:1; 44 unsigned leading_slash:1; 45 unsigned trailing_dot:1; 46 struct tr_realm *next; 47}; 48 49static void 50free_realms(struct tr_realm *r) 51{ 52 struct tr_realm *p; 53 while(r){ 54 p = r; 55 r = r->next; 56 free(p->realm); 57 free(p); 58 } 59} 60 61static int 62make_path(krb5_context context, struct tr_realm *r, 63 const char *from, const char *to) 64{ 65 struct tr_realm *tmp; 66 const char *p; 67 68 if(strlen(from) < strlen(to)){ 69 const char *str; 70 str = from; 71 from = to; 72 to = str; 73 } 74 75 if(strcmp(from + strlen(from) - strlen(to), to) == 0){ 76 p = from; 77 while(1){ 78 p = strchr(p, '.'); 79 if(p == NULL) { 80 krb5_clear_error_message (context); 81 return KRB5KDC_ERR_POLICY; 82 } 83 p++; 84 if(strcmp(p, to) == 0) 85 break; 86 tmp = calloc(1, sizeof(*tmp)); 87 if(tmp == NULL){ 88 krb5_set_error_message(context, ENOMEM, 89 N_("malloc: out of memory", "")); 90 return ENOMEM; 91 } 92 tmp->next = r->next; 93 r->next = tmp; 94 tmp->realm = strdup(p); 95 if(tmp->realm == NULL){ 96 r->next = tmp->next; 97 free(tmp); 98 krb5_set_error_message(context, ENOMEM, 99 N_("malloc: out of memory", "")); 100 return ENOMEM;; 101 } 102 } 103 }else if(strncmp(from, to, strlen(to)) == 0){ 104 p = from + strlen(from); 105 while(1){ 106 while(p >= from && *p != '/') p--; 107 if(p == from) 108 return KRB5KDC_ERR_POLICY; 109 110 if(strncmp(to, from, p - from) == 0) 111 break; 112 tmp = calloc(1, sizeof(*tmp)); 113 if(tmp == NULL){ 114 krb5_set_error_message(context, ENOMEM, 115 N_("malloc: out of memory", "")); 116 return ENOMEM; 117 } 118 tmp->next = r->next; 119 r->next = tmp; 120 tmp->realm = malloc(p - from + 1); 121 if(tmp->realm == NULL){ 122 r->next = tmp->next; 123 free(tmp); 124 krb5_set_error_message(context, ENOMEM, 125 N_("malloc: out of memory", "")); 126 return ENOMEM; 127 } 128 memcpy(tmp->realm, from, p - from); 129 tmp->realm[p - from] = '\0'; 130 p--; 131 } 132 } else { 133 krb5_clear_error_message (context); 134 return KRB5KDC_ERR_POLICY; 135 } 136 137 return 0; 138} 139 140static int 141make_paths(krb5_context context, 142 struct tr_realm *realms, const char *client_realm, 143 const char *server_realm) 144{ 145 struct tr_realm *r; 146 int ret; 147 const char *prev_realm = client_realm; 148 const char *next_realm = NULL; 149 for(r = realms; r; r = r->next){ 150 /* it *might* be that you can have more than one empty 151 component in a row, at least that's how I interpret the 152 "," exception in 1510 */ 153 if(r->realm[0] == '\0'){ 154 while(r->next && r->next->realm[0] == '\0') 155 r = r->next; 156 if(r->next) 157 next_realm = r->next->realm; 158 else 159 next_realm = server_realm; 160 ret = make_path(context, r, prev_realm, next_realm); 161 if(ret){ 162 free_realms(realms); 163 return ret; 164 } 165 } 166 prev_realm = r->realm; 167 } 168 return 0; 169} 170 171static int 172expand_realms(krb5_context context, 173 struct tr_realm *realms, const char *client_realm) 174{ 175 struct tr_realm *r; 176 const char *prev_realm = NULL; 177 for(r = realms; r; r = r->next){ 178 if(r->trailing_dot){ 179 char *tmp; 180 size_t len; 181 182 if(prev_realm == NULL) 183 prev_realm = client_realm; 184 185 len = strlen(r->realm) + strlen(prev_realm) + 1; 186 187 tmp = realloc(r->realm, len); 188 if(tmp == NULL){ 189 free_realms(realms); 190 krb5_set_error_message(context, ENOMEM, 191 N_("malloc: out of memory", "")); 192 return ENOMEM; 193 } 194 r->realm = tmp; 195 strlcat(r->realm, prev_realm, len); 196 }else if(r->leading_slash && !r->leading_space && prev_realm){ 197 /* yet another exception: if you use x500-names, the 198 leading realm doesn't have to be "quoted" with a space */ 199 char *tmp; 200 size_t len = strlen(r->realm) + strlen(prev_realm) + 1; 201 202 tmp = malloc(len); 203 if(tmp == NULL){ 204 free_realms(realms); 205 krb5_set_error_message(context, ENOMEM, 206 N_("malloc: out of memory", "")); 207 return ENOMEM; 208 } 209 strlcpy(tmp, prev_realm, len); 210 strlcat(tmp, r->realm, len); 211 free(r->realm); 212 r->realm = tmp; 213 } 214 prev_realm = r->realm; 215 } 216 return 0; 217} 218 219static struct tr_realm * 220make_realm(char *realm) 221{ 222 struct tr_realm *r; 223 char *p, *q; 224 int quote = 0; 225 r = calloc(1, sizeof(*r)); 226 if(r == NULL){ 227 free(realm); 228 return NULL; 229 } 230 r->realm = realm; 231 for(p = q = r->realm; *p; p++){ 232 if(p == r->realm && *p == ' '){ 233 r->leading_space = 1; 234 continue; 235 } 236 if(q == r->realm && *p == '/') 237 r->leading_slash = 1; 238 if(quote){ 239 *q++ = *p; 240 quote = 0; 241 continue; 242 } 243 if(*p == '\\'){ 244 quote = 1; 245 continue; 246 } 247 if(p[0] == '.' && p[1] == '\0') 248 r->trailing_dot = 1; 249 *q++ = *p; 250 } 251 *q = '\0'; 252 return r; 253} 254 255static struct tr_realm* 256append_realm(struct tr_realm *head, struct tr_realm *r) 257{ 258 struct tr_realm *p; 259 if(head == NULL){ 260 r->next = NULL; 261 return r; 262 } 263 p = head; 264 while(p->next) p = p->next; 265 p->next = r; 266 return head; 267} 268 269static int 270decode_realms(krb5_context context, 271 const char *tr, int length, struct tr_realm **realms) 272{ 273 struct tr_realm *r = NULL; 274 275 char *tmp; 276 int quote = 0; 277 const char *start = tr; 278 int i; 279 280 for(i = 0; i < length; i++){ 281 if(quote){ 282 quote = 0; 283 continue; 284 } 285 if(tr[i] == '\\'){ 286 quote = 1; 287 continue; 288 } 289 if(tr[i] == ','){ 290 tmp = malloc(tr + i - start + 1); 291 if(tmp == NULL){ 292 krb5_set_error_message(context, ENOMEM, 293 N_("malloc: out of memory", "")); 294 return ENOMEM; 295 } 296 memcpy(tmp, start, tr + i - start); 297 tmp[tr + i - start] = '\0'; 298 r = make_realm(tmp); 299 if(r == NULL){ 300 free_realms(*realms); 301 krb5_set_error_message(context, ENOMEM, 302 N_("malloc: out of memory", "")); 303 return ENOMEM; 304 } 305 *realms = append_realm(*realms, r); 306 start = tr + i + 1; 307 } 308 } 309 tmp = malloc(tr + i - start + 1); 310 if(tmp == NULL){ 311 free(*realms); 312 krb5_set_error_message(context, ENOMEM, 313 N_("malloc: out of memory", "")); 314 return ENOMEM; 315 } 316 memcpy(tmp, start, tr + i - start); 317 tmp[tr + i - start] = '\0'; 318 r = make_realm(tmp); 319 if(r == NULL){ 320 free_realms(*realms); 321 krb5_set_error_message(context, ENOMEM, 322 N_("malloc: out of memory", "")); 323 return ENOMEM; 324 } 325 *realms = append_realm(*realms, r); 326 327 return 0; 328} 329 330 331krb5_error_code KRB5_LIB_FUNCTION 332krb5_domain_x500_decode(krb5_context context, 333 krb5_data tr, char ***realms, unsigned int *num_realms, 334 const char *client_realm, const char *server_realm) 335{ 336 struct tr_realm *r = NULL; 337 struct tr_realm *p, **q; 338 int ret; 339 340 if(tr.length == 0) { 341 *realms = NULL; 342 *num_realms = 0; 343 return 0; 344 } 345 346 /* split string in components */ 347 ret = decode_realms(context, tr.data, tr.length, &r); 348 if(ret) 349 return ret; 350 351 /* apply prefix rule */ 352 ret = expand_realms(context, r, client_realm); 353 if(ret) 354 return ret; 355 356 ret = make_paths(context, r, client_realm, server_realm); 357 if(ret) 358 return ret; 359 360 /* remove empty components and count realms */ 361 *num_realms = 0; 362 for(q = &r; *q; ){ 363 if((*q)->realm[0] == '\0'){ 364 p = *q; 365 *q = (*q)->next; 366 free(p->realm); 367 free(p); 368 }else{ 369 q = &(*q)->next; 370 (*num_realms)++; 371 } 372 } 373 if (*num_realms < 0 || *num_realms + 1 > UINT_MAX/sizeof(**realms)) 374 return ERANGE; 375 376 { 377 char **R; 378 R = malloc((*num_realms + 1) * sizeof(*R)); 379 if (R == NULL) 380 return ENOMEM; 381 *realms = R; 382 while(r){ 383 *R++ = r->realm; 384 p = r->next; 385 free(r); 386 r = p; 387 } 388 } 389 return 0; 390} 391 392krb5_error_code KRB5_LIB_FUNCTION 393krb5_domain_x500_encode(char **realms, unsigned int num_realms, 394 krb5_data *encoding) 395{ 396 char *s = NULL; 397 int len = 0; 398 unsigned int i; 399 krb5_data_zero(encoding); 400 if (num_realms == 0) 401 return 0; 402 for(i = 0; i < num_realms; i++){ 403 len += strlen(realms[i]); 404 if(realms[i][0] == '/') 405 len++; 406 } 407 len += num_realms - 1; 408 s = malloc(len + 1); 409 if (s == NULL) 410 return ENOMEM; 411 *s = '\0'; 412 for(i = 0; i < num_realms; i++){ 413 if(i && i < num_realms - 1) 414 strlcat(s, ",", len + 1); 415 if(realms[i][0] == '/') 416 strlcat(s, " ", len + 1); 417 strlcat(s, realms[i], len + 1); 418 } 419 encoding->data = s; 420 encoding->length = strlen(s); 421 return 0; 422} 423 424krb5_error_code KRB5_LIB_FUNCTION 425krb5_check_transited(krb5_context context, 426 krb5_const_realm client_realm, 427 krb5_const_realm server_realm, 428 krb5_realm *realms, 429 unsigned int num_realms, 430 int *bad_realm) 431{ 432 char **tr_realms; 433 char **p; 434 int i; 435 436 if(num_realms == 0) 437 return 0; 438 439 tr_realms = krb5_config_get_strings(context, NULL, 440 "capaths", 441 client_realm, 442 server_realm, 443 NULL); 444 for(i = 0; i < num_realms; i++) { 445 for(p = tr_realms; p && *p; p++) { 446 if(strcmp(*p, realms[i]) == 0) 447 break; 448 } 449 if(p == NULL || *p == NULL) { 450 krb5_config_free_strings(tr_realms); 451 krb5_set_error_message (context, KRB5KRB_AP_ERR_ILL_CR_TKT, 452 N_("no transit allowed " 453 "through realm %s", ""), 454 realms[i]); 455 if(bad_realm) 456 *bad_realm = i; 457 return KRB5KRB_AP_ERR_ILL_CR_TKT; 458 } 459 } 460 krb5_config_free_strings(tr_realms); 461 return 0; 462} 463 464krb5_error_code KRB5_LIB_FUNCTION 465krb5_check_transited_realms(krb5_context context, 466 const char *const *realms, 467 unsigned int num_realms, 468 int *bad_realm) 469{ 470 int i; 471 int ret = 0; 472 char **bad_realms = krb5_config_get_strings(context, NULL, 473 "libdefaults", 474 "transited_realms_reject", 475 NULL); 476 if(bad_realms == NULL) 477 return 0; 478 479 for(i = 0; i < num_realms; i++) { 480 char **p; 481 for(p = bad_realms; *p; p++) 482 if(strcmp(*p, realms[i]) == 0) { 483 ret = KRB5KRB_AP_ERR_ILL_CR_TKT; 484 krb5_set_error_message (context, ret, 485 N_("no transit allowed " 486 "through realm %s", ""), 487 *p); 488 if(bad_realm) 489 *bad_realm = i; 490 break; 491 } 492 } 493 krb5_config_free_strings(bad_realms); 494 return ret; 495} 496 497#if 0 498int 499main(int argc, char **argv) 500{ 501 krb5_data x; 502 char **r; 503 int num, i; 504 x.data = argv[1]; 505 x.length = strlen(x.data); 506 if(domain_expand(x, &r, &num, argv[2], argv[3])) 507 exit(1); 508 for(i = 0; i < num; i++) 509 printf("%s\n", r[i]); 510 return 0; 511} 512#endif 513 514