1 /* 2 * Copyright (c) 1997 - 2001, 2003 Kungliga Tekniska H�gskolan 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 RCSID("$Id: transited.c,v 1.10.2.3 2003/10/22 06:07:41 lha Exp $"); 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 const char *p; 68 struct tr_realm *path = r->next; 69 struct tr_realm *tmp; 70 71 if(strlen(from) < strlen(to)){ 72 const char *tmp; 73 tmp = from; 74 from = to; 75 to = tmp; 76 } 77 78 if(strcmp(from + strlen(from) - strlen(to), to) == 0){ 79 p = from; 80 while(1){ 81 p = strchr(p, '.'); 82 if(p == NULL) { 83 krb5_clear_error_string (context); 84 return KRB5KDC_ERR_POLICY; 85 } 86 p++; 87 if(strcmp(p, to) == 0) 88 break; 89 tmp = calloc(1, sizeof(*tmp)); 90 tmp->next = path; 91 path = tmp; 92 path->realm = strdup(p); 93 if(path->realm == NULL){ 94 r->next = path; /* XXX */ 95 krb5_set_error_string (context, "malloc: out of memory"); 96 return ENOMEM;; 97 } 98 } 99 }else if(strncmp(from, to, strlen(to)) == 0){ 100 p = from + strlen(from); 101 while(1){ 102 while(p >= from && *p != '/') p--; 103 if(p == from) 104 return KRB5KDC_ERR_POLICY; 105 if(strncmp(to, from, p - from) == 0) 106 break; 107 tmp = calloc(1, sizeof(*tmp)); 108 tmp->next = path; 109 path = tmp; 110 path->realm = malloc(p - from + 1); 111 if(path->realm == NULL){ 112 r->next = path; /* XXX */ 113 krb5_set_error_string (context, "malloc: out of memory"); 114 return ENOMEM; 115 } 116 memcpy(path->realm, from, p - from); 117 path->realm[p - from] = '\0'; 118 p--; 119 } 120 } else { 121 krb5_clear_error_string (context); 122 return KRB5KDC_ERR_POLICY; 123 } 124 r->next = path; 125 126 return 0; 127 } 128 129 static int 130 make_paths(krb5_context context, 131 struct tr_realm *realms, const char *client_realm, 132 const char *server_realm) 133 { 134 struct tr_realm *r; 135 int ret; 136 const char *prev_realm = client_realm; 137 const char *next_realm = NULL; 138 for(r = realms; r; r = r->next){ 139 /* it *might* be that you can have more than one empty 140 component in a row, at least that's how I interpret the 141 "," exception in 1510 */ 142 if(r->realm[0] == '\0'){ 143 while(r->next && r->next->realm[0] == '\0') 144 r = r->next; 145 if(r->next) 146 next_realm = r->next->realm; 147 else 148 next_realm = server_realm; 149 ret = make_path(context, r, prev_realm, next_realm); 150 if(ret){ 151 free_realms(realms); 152 return ret; 153 } 154 } 155 prev_realm = r->realm; 156 } 157 return 0; 158 } 159 160 static int 161 expand_realms(krb5_context context, 162 struct tr_realm *realms, const char *client_realm) 163 { 164 struct tr_realm *r; 165 const char *prev_realm = NULL; 166 for(r = realms; r; r = r->next){ 167 if(r->trailing_dot){ 168 char *tmp; 169 size_t len = strlen(r->realm) + strlen(prev_realm) + 1; 170 171 if(prev_realm == NULL) 172 prev_realm = client_realm; 173 tmp = realloc(r->realm, len); 174 if(tmp == NULL){ 175 free_realms(realms); 176 krb5_set_error_string (context, "malloc: out of memory"); 177 return ENOMEM; 178 } 179 r->realm = tmp; 180 strlcat(r->realm, prev_realm, len); 181 }else if(r->leading_slash && !r->leading_space && prev_realm){ 182 /* yet another exception: if you use x500-names, the 183 leading realm doesn't have to be "quoted" with a space */ 184 char *tmp; 185 size_t len = strlen(r->realm) + strlen(prev_realm) + 1; 186 187 tmp = malloc(len); 188 if(tmp == NULL){ 189 free_realms(realms); 190 krb5_set_error_string (context, "malloc: out of memory"); 191 return ENOMEM; 192 } 193 strlcpy(tmp, prev_realm, len); 194 strlcat(tmp, r->realm, len); 195 free(r->realm); 196 r->realm = tmp; 197 } 198 prev_realm = r->realm; 199 } 200 return 0; 201 } 202 203 static struct tr_realm * 204 make_realm(char *realm) 205 { 206 struct tr_realm *r; 207 char *p, *q; 208 int quote = 0; 209 r = calloc(1, sizeof(*r)); 210 if(r == NULL){ 211 free(realm); 212 return NULL; 213 } 214 r->realm = realm; 215 for(p = q = r->realm; *p; p++){ 216 if(p == r->realm && *p == ' '){ 217 r->leading_space = 1; 218 continue; 219 } 220 if(q == r->realm && *p == '/') 221 r->leading_slash = 1; 222 if(quote){ 223 *q++ = *p; 224 quote = 0; 225 continue; 226 } 227 if(*p == '\\'){ 228 quote = 1; 229 continue; 230 } 231 if(p[0] == '.' && p[1] == '\0') 232 r->trailing_dot = 1; 233 *q++ = *p; 234 } 235 *q = '\0'; 236 return r; 237 } 238 239 static struct tr_realm* 240 append_realm(struct tr_realm *head, struct tr_realm *r) 241 { 242 struct tr_realm *p; 243 if(head == NULL){ 244 r->next = NULL; 245 return r; 246 } 247 p = head; 248 while(p->next) p = p->next; 249 p->next = r; 250 return head; 251 } 252 253 static int 254 decode_realms(krb5_context context, 255 const char *tr, int length, struct tr_realm **realms) 256 { 257 struct tr_realm *r = NULL; 258 259 char *tmp; 260 int quote = 0; 261 const char *start = tr; 262 int i; 263 264 for(i = 0; i < length; i++){ 265 if(quote){ 266 quote = 0; 267 continue; 268 } 269 if(tr[i] == '\\'){ 270 quote = 1; 271 continue; 272 } 273 if(tr[i] == ','){ 274 tmp = malloc(tr + i - start + 1); 275 memcpy(tmp, start, tr + i - start); 276 tmp[tr + i - start] = '\0'; 277 r = make_realm(tmp); 278 if(r == NULL){ 279 free_realms(*realms); 280 krb5_set_error_string (context, "malloc: out of memory"); 281 return ENOMEM; 282 } 283 *realms = append_realm(*realms, r); 284 start = tr + i + 1; 285 } 286 } 287 tmp = malloc(tr + i - start + 1); 288 memcpy(tmp, start, tr + i - start); 289 tmp[tr + i - start] = '\0'; 290 r = make_realm(tmp); 291 if(r == NULL){ 292 free_realms(*realms); 293 krb5_set_error_string (context, "malloc: out of memory"); 294 return ENOMEM; 295 } 296 *realms = append_realm(*realms, r); 297 298 return 0; 299 } 300 301 302 krb5_error_code 303 krb5_domain_x500_decode(krb5_context context, 304 krb5_data tr, char ***realms, int *num_realms, 305 const char *client_realm, const char *server_realm) 306 { 307 struct tr_realm *r = NULL; 308 struct tr_realm *p, **q; 309 int ret; 310 311 if(tr.length == 0) { 312 *realms = NULL; 313 *num_realms = 0; 314 return 0; 315 } 316 317 /* split string in components */ 318 ret = decode_realms(context, tr.data, tr.length, &r); 319 if(ret) 320 return ret; 321 322 /* apply prefix rule */ 323 ret = expand_realms(context, r, client_realm); 324 if(ret) 325 return ret; 326 327 ret = make_paths(context, r, client_realm, server_realm); 328 if(ret) 329 return ret; 330 331 /* remove empty components and count realms */ 332 q = &r; 333 *num_realms = 0; 334 for(p = r; p; ){ 335 if(p->realm[0] == '\0'){ 336 free(p->realm); 337 *q = p->next; 338 free(p); 339 p = *q; 340 }else{ 341 q = &p->next; 342 p = p->next; 343 (*num_realms)++; 344 } 345 } 346 if (*num_realms < 0 || *num_realms + 1 > UINT_MAX/sizeof(**realms)) 347 return ERANGE; 348 349 { 350 char **R; 351 R = malloc((*num_realms + 1) * sizeof(*R)); 352 if (R == NULL) 353 return ENOMEM; 354 *realms = R; 355 while(r){ 356 *R++ = r->realm; 357 p = r->next; 358 free(r); 359 r = p; 360 } 361 } 362 return 0; 363 } 364 365 krb5_error_code 366 krb5_domain_x500_encode(char **realms, int num_realms, krb5_data *encoding) 367 { 368 char *s = NULL; 369 int len = 0; 370 int i; 371 krb5_data_zero(encoding); 372 if (num_realms == 0) 373 return 0; 374 for(i = 0; i < num_realms; i++){ 375 len += strlen(realms[i]); 376 if(realms[i][0] == '/') 377 len++; 378 } 379 len += num_realms - 1; 380 s = malloc(len + 1); 381 if (s == NULL) 382 return ENOMEM; 383 *s = '\0'; 384 for(i = 0; i < num_realms; i++){ 385 if(i && i < num_realms - 1) 386 strlcat(s, ",", len + 1); 387 if(realms[i][0] == '/') 388 strlcat(s, " ", len + 1); 389 strlcat(s, realms[i], len + 1); 390 } 391 encoding->data = s; 392 encoding->length = strlen(s); 393 return 0; 394 } 395 396 krb5_error_code 397 krb5_check_transited(krb5_context context, 398 krb5_const_realm client_realm, 399 krb5_const_realm server_realm, 400 krb5_realm *realms, 401 int num_realms, 402 int *bad_realm) 403 { 404 char **tr_realms; 405 char **p; 406 int i; 407 408 if(num_realms == 0) 409 return 0; 410 411 tr_realms = krb5_config_get_strings(context, NULL, 412 "capaths", 413 client_realm, 414 server_realm, 415 NULL); 416 for(i = 0; i < num_realms; i++) { 417 for(p = tr_realms; p && *p; p++) { 418 if(strcmp(*p, realms[i]) == 0) 419 break; 420 } 421 if(p == NULL || *p == NULL) { 422 krb5_config_free_strings(tr_realms); 423 krb5_set_error_string (context, "no transit through realm %s", 424 realms[i]); 425 if(bad_realm) 426 *bad_realm = i; 427 return KRB5KRB_AP_ERR_ILL_CR_TKT; 428 } 429 } 430 krb5_config_free_strings(tr_realms); 431 return 0; 432 } 433 434 krb5_error_code 435 krb5_check_transited_realms(krb5_context context, 436 const char *const *realms, 437 int num_realms, 438 int *bad_realm) 439 { 440 int i; 441 int ret = 0; 442 char **bad_realms = krb5_config_get_strings(context, NULL, 443 "libdefaults", 444 "transited_realms_reject", 445 NULL); 446 if(bad_realms == NULL) 447 return 0; 448 449 for(i = 0; i < num_realms; i++) { 450 char **p; 451 for(p = bad_realms; *p; p++) 452 if(strcmp(*p, realms[i]) == 0) { 453 krb5_set_error_string (context, "no transit through realm %s", 454 *p); 455 ret = KRB5KRB_AP_ERR_ILL_CR_TKT; 456 if(bad_realm) 457 *bad_realm = i; 458 break; 459 } 460 } 461 krb5_config_free_strings(bad_realms); 462 return ret; 463 } 464 465 #if 0 466 int 467 main(int argc, char **argv) 468 { 469 krb5_data x; 470 char **r; 471 int num, i; 472 x.data = argv[1]; 473 x.length = strlen(x.data); 474 if(domain_expand(x, &r, &num, argv[2], argv[3])) 475 exit(1); 476 for(i = 0; i < num; i++) 477 printf("%s\n", r[i]); 478 return 0; 479 } 480 #endif 481 482