transited.c revision 178825
1139749Simp/* 2116491Sharti * Copyright (c) 1997 - 2001, 2003 Kungliga Tekniska H�gskolan 3116491Sharti * (Royal Institute of Technology, Stockholm, Sweden). 4116491Sharti * All rights reserved. 5116491Sharti * 6116491Sharti * Redistribution and use in source and binary forms, with or without 7116491Sharti * modification, are permitted provided that the following conditions 8116491Sharti * are met: 9116491Sharti * 10116491Sharti * 1. Redistributions of source code must retain the above copyright 11116491Sharti * notice, this list of conditions and the following disclaimer. 12116491Sharti * 13116491Sharti * 2. Redistributions in binary form must reproduce the above copyright 14116491Sharti * notice, this list of conditions and the following disclaimer in the 15116491Sharti * documentation and/or other materials provided with the distribution. 16116491Sharti * 17116491Sharti * 3. Neither the name of the Institute nor the names of its contributors 18116491Sharti * may be used to endorse or promote products derived from this software 19116491Sharti * without specific prior written permission. 20116491Sharti * 21116491Sharti * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 22116491Sharti * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23116491Sharti * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24116491Sharti * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 25116491Sharti * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26116491Sharti * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27116491Sharti * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28116491Sharti * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29116491Sharti * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30116491Sharti * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31116491Sharti * SUCH DAMAGE. 32116491Sharti */ 33116491Sharti 34116519Sharti#include "krb5_locl.h" 35116519Sharti 36116519ShartiRCSID("$Id: transited.c 21745 2007-07-31 16:11:25Z lha $"); 37116491Sharti 38116491Sharti/* this is an attempt at one of the most horrible `compression' 39116491Sharti schemes that has ever been invented; it's so amazingly brain-dead 40116491Sharti that words can not describe it, and all this just to save a few 41116491Sharti silly bytes */ 42116491Sharti 43116491Shartistruct tr_realm { 44116491Sharti char *realm; 45116491Sharti unsigned leading_space:1; 46116491Sharti unsigned leading_slash:1; 47116491Sharti unsigned trailing_dot:1; 48116491Sharti struct tr_realm *next; 49116491Sharti}; 50116491Sharti 51116491Shartistatic void 52116491Shartifree_realms(struct tr_realm *r) 53116491Sharti{ 54116491Sharti struct tr_realm *p; 55116491Sharti while(r){ 56116491Sharti p = r; 57116491Sharti r = r->next; 58116491Sharti free(p->realm); 59116491Sharti free(p); 60257176Sglebius } 61116491Sharti} 62116491Sharti 63116491Shartistatic int 64116491Shartimake_path(krb5_context context, struct tr_realm *r, 65116491Sharti const char *from, const char *to) 66116491Sharti{ 67116491Sharti const char *p; 68116491Sharti struct tr_realm *path = r->next; 69116491Sharti struct tr_realm *tmp; 70116491Sharti 71119280Simp if(strlen(from) < strlen(to)){ 72119280Simp const char *str; 73116491Sharti str = from; 74116491Sharti from = to; 75116491Sharti to = str; 76116491Sharti } 77116491Sharti 78116491Sharti if(strcmp(from + strlen(from) - strlen(to), to) == 0){ 79116491Sharti p = from; 80116491Sharti while(1){ 81116491Sharti p = strchr(p, '.'); 82116491Sharti if(p == NULL) { 83116491Sharti krb5_clear_error_string (context); 84116491Sharti return KRB5KDC_ERR_POLICY; 85116491Sharti } 86116491Sharti p++; 87116491Sharti if(strcmp(p, to) == 0) 88116491Sharti break; 89116491Sharti tmp = calloc(1, sizeof(*tmp)); 90116491Sharti if(tmp == NULL){ 91116491Sharti krb5_set_error_string (context, "malloc: out of memory"); 92116491Sharti return ENOMEM; 93116491Sharti } 94116491Sharti tmp->next = path; 95116491Sharti path = tmp; 96116491Sharti path->realm = strdup(p); 97116491Sharti if(path->realm == NULL){ 98116491Sharti r->next = path; /* XXX */ 99116491Sharti krb5_set_error_string (context, "malloc: out of memory"); 100116491Sharti return ENOMEM;; 101116491Sharti } 102116491Sharti } 103116491Sharti }else if(strncmp(from, to, strlen(to)) == 0){ 104116491Sharti p = from + strlen(from); 105116491Sharti while(1){ 106116491Sharti while(p >= from && *p != '/') p--; 107116491Sharti if(p == from) { 108116491Sharti r->next = path; /* XXX */ 109116491Sharti return KRB5KDC_ERR_POLICY; 110116491Sharti } 111116491Sharti if(strncmp(to, from, p - from) == 0) 112116491Sharti break; 113116491Sharti tmp = calloc(1, sizeof(*tmp)); 114116491Sharti if(tmp == NULL){ 115116491Sharti krb5_set_error_string (context, "malloc: out of memory"); 116116491Sharti return ENOMEM; 117116491Sharti } 118116491Sharti tmp->next = path; 119116491Sharti path = tmp; 120148887Srwatson path->realm = malloc(p - from + 1); 121116491Sharti if(path->realm == NULL){ 122116491Sharti r->next = path; /* XXX */ 123116491Sharti krb5_set_error_string (context, "malloc: out of memory"); 124116491Sharti return ENOMEM; 125116491Sharti } 126116491Sharti memcpy(path->realm, from, p - from); 127116491Sharti path->realm[p - from] = '\0'; 128116491Sharti p--; 129116491Sharti } 130116491Sharti } else { 131116491Sharti krb5_clear_error_string (context); 132116491Sharti return KRB5KDC_ERR_POLICY; 133116491Sharti } 134116491Sharti r->next = path; 135116491Sharti 136116491Sharti return 0; 137116491Sharti} 138116491Sharti 139116491Shartistatic int 140116491Shartimake_paths(krb5_context context, 141116491Sharti struct tr_realm *realms, const char *client_realm, 142116491Sharti const char *server_realm) 143116491Sharti{ 144116491Sharti struct tr_realm *r; 145116491Sharti int ret; 146116491Sharti const char *prev_realm = client_realm; 147116491Sharti const char *next_realm = NULL; 148116491Sharti for(r = realms; r; r = r->next){ 149116491Sharti /* it *might* be that you can have more than one empty 150116491Sharti component in a row, at least that's how I interpret the 151116491Sharti "," exception in 1510 */ 152116491Sharti if(r->realm[0] == '\0'){ 153116491Sharti while(r->next && r->next->realm[0] == '\0') 154116491Sharti r = r->next; 155116491Sharti if(r->next) 156116491Sharti next_realm = r->next->realm; 157116491Sharti else 158116491Sharti next_realm = server_realm; 159116491Sharti ret = make_path(context, r, prev_realm, next_realm); 160116491Sharti if(ret){ 161116491Sharti free_realms(realms); 162116491Sharti return ret; 163118598Sharti } 164116491Sharti } 165116491Sharti prev_realm = r->realm; 166116491Sharti } 167116491Sharti return 0; 168116491Sharti} 169116491Sharti 170116491Shartistatic int 171116491Shartiexpand_realms(krb5_context context, 172116491Sharti struct tr_realm *realms, const char *client_realm) 173116491Sharti{ 174116491Sharti struct tr_realm *r; 175116491Sharti const char *prev_realm = NULL; 176118598Sharti for(r = realms; r; r = r->next){ 177118598Sharti if(r->trailing_dot){ 178118598Sharti char *tmp; 179118598Sharti size_t len; 180118598Sharti 181118598Sharti if(prev_realm == NULL) 182118598Sharti prev_realm = client_realm; 183118598Sharti 184118598Sharti len = strlen(r->realm) + strlen(prev_realm) + 1; 185118598Sharti 186118598Sharti tmp = realloc(r->realm, len); 187118598Sharti if(tmp == NULL){ 188118598Sharti free_realms(realms); 189118598Sharti krb5_set_error_string (context, "malloc: out of memory"); 190118598Sharti return ENOMEM; 191118598Sharti } 192147256Sbrooks r->realm = tmp; 193118598Sharti strlcat(r->realm, prev_realm, len); 194118598Sharti }else if(r->leading_slash && !r->leading_space && prev_realm){ 195118598Sharti /* yet another exception: if you use x500-names, the 196116491Sharti leading realm doesn't have to be "quoted" with a space */ 197116491Sharti char *tmp; 198116491Sharti size_t len = strlen(r->realm) + strlen(prev_realm) + 1; 199116491Sharti 200116491Sharti tmp = malloc(len); 201116491Sharti if(tmp == NULL){ 202116491Sharti free_realms(realms); 203116491Sharti krb5_set_error_string (context, "malloc: out of memory"); 204116491Sharti return ENOMEM; 205116491Sharti } 206116491Sharti strlcpy(tmp, prev_realm, len); 207147256Sbrooks strlcat(tmp, r->realm, len); 208116491Sharti free(r->realm); 209116491Sharti r->realm = tmp; 210116491Sharti } 211116491Sharti prev_realm = r->realm; 212116491Sharti } 213116491Sharti return 0; 214116491Sharti} 215116491Sharti 216116491Shartistatic struct tr_realm * 217116491Shartimake_realm(char *realm) 218116491Sharti{ 219116491Sharti struct tr_realm *r; 220116491Sharti char *p, *q; 221116491Sharti int quote = 0; 222116491Sharti r = calloc(1, sizeof(*r)); 223116491Sharti if(r == NULL){ 224116491Sharti free(realm); 225116491Sharti return NULL; 226116491Sharti } 227116491Sharti r->realm = realm; 228116491Sharti for(p = q = r->realm; *p; p++){ 229116491Sharti if(p == r->realm && *p == ' '){ 230116491Sharti r->leading_space = 1; 231116491Sharti continue; 232116491Sharti } 233116491Sharti if(q == r->realm && *p == '/') 234148887Srwatson r->leading_slash = 1; 235116491Sharti if(quote){ 236116491Sharti *q++ = *p; 237116491Sharti quote = 0; 238116491Sharti continue; 239116491Sharti } 240116491Sharti if(*p == '\\'){ 241116491Sharti quote = 1; 242116491Sharti continue; 243116491Sharti } 244116491Sharti if(p[0] == '.' && p[1] == '\0') 245116491Sharti r->trailing_dot = 1; 246116491Sharti *q++ = *p; 247116491Sharti } 248116491Sharti *q = '\0'; 249118540Sharti return r; 250116491Sharti} 251116491Sharti 252148887Srwatsonstatic struct tr_realm* 253116491Shartiappend_realm(struct tr_realm *head, struct tr_realm *r) 254116491Sharti{ 255116491Sharti struct tr_realm *p; 256148887Srwatson if(head == NULL){ 257116491Sharti r->next = NULL; 258116491Sharti return r; 259116491Sharti } 260116491Sharti p = head; 261116491Sharti while(p->next) p = p->next; 262116491Sharti p->next = r; 263116491Sharti return head; 264116491Sharti} 265116491Sharti 266116491Shartistatic int 267116491Shartidecode_realms(krb5_context context, 268116491Sharti const char *tr, int length, struct tr_realm **realms) 269116491Sharti{ 270116491Sharti struct tr_realm *r = NULL; 271116491Sharti 272116491Sharti char *tmp; 273116491Sharti int quote = 0; 274116491Sharti const char *start = tr; 275116491Sharti int i; 276116491Sharti 277116491Sharti for(i = 0; i < length; i++){ 278116491Sharti if(quote){ 279147721Sharti quote = 0; 280116491Sharti continue; 281116491Sharti } 282116491Sharti if(tr[i] == '\\'){ 283116491Sharti quote = 1; 284116491Sharti continue; 285116491Sharti } 286116491Sharti if(tr[i] == ','){ 287116491Sharti tmp = malloc(tr + i - start + 1); 288148887Srwatson if(tmp == NULL){ 289116491Sharti krb5_set_error_string (context, "malloc: out of memory"); 290116491Sharti return ENOMEM; 291116491Sharti } 292116491Sharti memcpy(tmp, start, tr + i - start); 293116491Sharti tmp[tr + i - start] = '\0'; 294116491Sharti r = make_realm(tmp); 295116491Sharti if(r == NULL){ 296116491Sharti free_realms(*realms); 297116491Sharti krb5_set_error_string (context, "malloc: out of memory"); 298116491Sharti return ENOMEM; 299116491Sharti } 300116491Sharti *realms = append_realm(*realms, r); 301116491Sharti start = tr + i + 1; 302116491Sharti } 303116491Sharti } 304116491Sharti tmp = malloc(tr + i - start + 1); 305116491Sharti if(tmp == NULL){ 306116491Sharti free(*realms); 307148887Srwatson krb5_set_error_string (context, "malloc: out of memory"); 308116491Sharti return ENOMEM; 309116491Sharti } 310116491Sharti memcpy(tmp, start, tr + i - start); 311148887Srwatson tmp[tr + i - start] = '\0'; 312116491Sharti r = make_realm(tmp); 313116491Sharti if(r == NULL){ 314116491Sharti free_realms(*realms); 315116491Sharti krb5_set_error_string (context, "malloc: out of memory"); 316116491Sharti return ENOMEM; 317116491Sharti } 318116491Sharti *realms = append_realm(*realms, r); 319116491Sharti 320116491Sharti return 0; 321116491Sharti} 322116491Sharti 323116491Sharti 324116491Shartikrb5_error_code KRB5_LIB_FUNCTION 325116491Shartikrb5_domain_x500_decode(krb5_context context, 326116491Sharti krb5_data tr, char ***realms, int *num_realms, 327116491Sharti const char *client_realm, const char *server_realm) 328116491Sharti{ 329116491Sharti struct tr_realm *r = NULL; 330116491Sharti struct tr_realm *p, **q; 331116491Sharti int ret; 332116491Sharti 333116491Sharti if(tr.length == 0) { 334116491Sharti *realms = NULL; 335118205Sharti *num_realms = 0; 336118205Sharti return 0; 337332288Sbrooks } 338116491Sharti 339116491Sharti /* split string in components */ 340116491Sharti ret = decode_realms(context, tr.data, tr.length, &r); 341116491Sharti if(ret) 342116491Sharti return ret; 343118205Sharti 344118205Sharti /* apply prefix rule */ 345118205Sharti ret = expand_realms(context, r, client_realm); 346116491Sharti if(ret) 347116491Sharti return ret; 348116491Sharti 349116491Sharti ret = make_paths(context, r, client_realm, server_realm); 350116491Sharti if(ret) 351116491Sharti return ret; 352118548Sharti 353116491Sharti /* remove empty components and count realms */ 354116491Sharti q = &r; 355116491Sharti *num_realms = 0; 356118548Sharti for(p = r; p; ){ 357116491Sharti if(p->realm[0] == '\0'){ 358116491Sharti free(p->realm); 359116491Sharti *q = p->next; 360116491Sharti free(p); 361116491Sharti p = *q; 362116491Sharti }else{ 363116491Sharti q = &p->next; 364116491Sharti p = p->next; 365116491Sharti (*num_realms)++; 366116491Sharti } 367116491Sharti } 368116491Sharti if (*num_realms < 0 || *num_realms + 1 > UINT_MAX/sizeof(**realms)) 369116491Sharti return ERANGE; 370116491Sharti 371116491Sharti { 372116491Sharti char **R; 373116491Sharti R = malloc((*num_realms + 1) * sizeof(*R)); 374116491Sharti if (R == NULL) 375116491Sharti return ENOMEM; 376116491Sharti *realms = R; 377116491Sharti while(r){ 378116491Sharti *R++ = r->realm; 379116491Sharti p = r->next; 380116491Sharti free(r); 381116491Sharti r = p; 382116491Sharti } 383116491Sharti } 384116491Sharti return 0; 385116491Sharti} 386 387krb5_error_code KRB5_LIB_FUNCTION 388krb5_domain_x500_encode(char **realms, int num_realms, krb5_data *encoding) 389{ 390 char *s = NULL; 391 int len = 0; 392 int i; 393 krb5_data_zero(encoding); 394 if (num_realms == 0) 395 return 0; 396 for(i = 0; i < num_realms; i++){ 397 len += strlen(realms[i]); 398 if(realms[i][0] == '/') 399 len++; 400 } 401 len += num_realms - 1; 402 s = malloc(len + 1); 403 if (s == NULL) 404 return ENOMEM; 405 *s = '\0'; 406 for(i = 0; i < num_realms; i++){ 407 if(i && i < num_realms - 1) 408 strlcat(s, ",", len + 1); 409 if(realms[i][0] == '/') 410 strlcat(s, " ", len + 1); 411 strlcat(s, realms[i], len + 1); 412 } 413 encoding->data = s; 414 encoding->length = strlen(s); 415 return 0; 416} 417 418krb5_error_code KRB5_LIB_FUNCTION 419krb5_check_transited(krb5_context context, 420 krb5_const_realm client_realm, 421 krb5_const_realm server_realm, 422 krb5_realm *realms, 423 int num_realms, 424 int *bad_realm) 425{ 426 char **tr_realms; 427 char **p; 428 int i; 429 430 if(num_realms == 0) 431 return 0; 432 433 tr_realms = krb5_config_get_strings(context, NULL, 434 "capaths", 435 client_realm, 436 server_realm, 437 NULL); 438 for(i = 0; i < num_realms; i++) { 439 for(p = tr_realms; p && *p; p++) { 440 if(strcmp(*p, realms[i]) == 0) 441 break; 442 } 443 if(p == NULL || *p == NULL) { 444 krb5_config_free_strings(tr_realms); 445 krb5_set_error_string (context, "no transit through realm %s", 446 realms[i]); 447 if(bad_realm) 448 *bad_realm = i; 449 return KRB5KRB_AP_ERR_ILL_CR_TKT; 450 } 451 } 452 krb5_config_free_strings(tr_realms); 453 return 0; 454} 455 456krb5_error_code KRB5_LIB_FUNCTION 457krb5_check_transited_realms(krb5_context context, 458 const char *const *realms, 459 int num_realms, 460 int *bad_realm) 461{ 462 int i; 463 int ret = 0; 464 char **bad_realms = krb5_config_get_strings(context, NULL, 465 "libdefaults", 466 "transited_realms_reject", 467 NULL); 468 if(bad_realms == NULL) 469 return 0; 470 471 for(i = 0; i < num_realms; i++) { 472 char **p; 473 for(p = bad_realms; *p; p++) 474 if(strcmp(*p, realms[i]) == 0) { 475 krb5_set_error_string (context, "no transit through realm %s", 476 *p); 477 ret = KRB5KRB_AP_ERR_ILL_CR_TKT; 478 if(bad_realm) 479 *bad_realm = i; 480 break; 481 } 482 } 483 krb5_config_free_strings(bad_realms); 484 return ret; 485} 486 487#if 0 488int 489main(int argc, char **argv) 490{ 491 krb5_data x; 492 char **r; 493 int num, i; 494 x.data = argv[1]; 495 x.length = strlen(x.data); 496 if(domain_expand(x, &r, &num, argv[2], argv[3])) 497 exit(1); 498 for(i = 0; i < num; i++) 499 printf("%s\n", r[i]); 500 return 0; 501} 502#endif 503 504