1 /* 2 * Copyright (c) 1997 - 2001 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 1.9 2002/09/09 14:03:03 nectar 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 if(prev_realm == NULL) 170 prev_realm = client_realm; 171 tmp = realloc(r->realm, strlen(r->realm) + strlen(prev_realm) + 1); 172 if(tmp == NULL){ 173 free_realms(realms); 174 krb5_set_error_string (context, "malloc: out of memory"); 175 return ENOMEM; 176 } 177 r->realm = tmp; 178 strcat(r->realm, prev_realm); 179 }else if(r->leading_slash && !r->leading_space && prev_realm){ 180 /* yet another exception: if you use x500-names, the 181 leading realm doesn't have to be "quoted" with a space */ 182 char *tmp; 183 tmp = malloc(strlen(r->realm) + strlen(prev_realm) + 1); 184 if(tmp == NULL){ 185 free_realms(realms); 186 krb5_set_error_string (context, "malloc: out of memory"); 187 return ENOMEM; 188 } 189 strcpy(tmp, prev_realm); 190 strcat(tmp, r->realm); 191 free(r->realm); 192 r->realm = tmp; 193 } 194 prev_realm = r->realm; 195 } 196 return 0; 197 } 198 199 static struct tr_realm * 200 make_realm(char *realm) 201 { 202 struct tr_realm *r; 203 char *p, *q; 204 int quote = 0; 205 r = calloc(1, sizeof(*r)); 206 if(r == NULL){ 207 free(realm); 208 return NULL; 209 } 210 r->realm = realm; 211 for(p = q = r->realm; *p; p++){ 212 if(p == r->realm && *p == ' '){ 213 r->leading_space = 1; 214 continue; 215 } 216 if(q == r->realm && *p == '/') 217 r->leading_slash = 1; 218 if(quote){ 219 *q++ = *p; 220 quote = 0; 221 continue; 222 } 223 if(*p == '\\'){ 224 quote = 1; 225 continue; 226 } 227 if(p[0] == '.' && p[1] == '\0') 228 r->trailing_dot = 1; 229 *q++ = *p; 230 } 231 *q = '\0'; 232 return r; 233 } 234 235 static struct tr_realm* 236 append_realm(struct tr_realm *head, struct tr_realm *r) 237 { 238 struct tr_realm *p; 239 if(head == NULL){ 240 r->next = NULL; 241 return r; 242 } 243 p = head; 244 while(p->next) p = p->next; 245 p->next = r; 246 return head; 247 } 248 249 static int 250 decode_realms(krb5_context context, 251 const char *tr, int length, struct tr_realm **realms) 252 { 253 struct tr_realm *r = NULL; 254 255 char *tmp; 256 int quote = 0; 257 const char *start = tr; 258 int i; 259 260 for(i = 0; i < length; i++){ 261 if(quote){ 262 quote = 0; 263 continue; 264 } 265 if(tr[i] == '\\'){ 266 quote = 1; 267 continue; 268 } 269 if(tr[i] == ','){ 270 tmp = malloc(tr + i - start + 1); 271 memcpy(tmp, start, tr + i - start); 272 tmp[tr + i - start] = '\0'; 273 r = make_realm(tmp); 274 if(r == NULL){ 275 free_realms(*realms); 276 krb5_set_error_string (context, "malloc: out of memory"); 277 return ENOMEM; 278 } 279 *realms = append_realm(*realms, r); 280 start = tr + i + 1; 281 } 282 } 283 tmp = malloc(tr + i - start + 1); 284 memcpy(tmp, start, tr + i - start); 285 tmp[tr + i - start] = '\0'; 286 r = make_realm(tmp); 287 if(r == NULL){ 288 free_realms(*realms); 289 krb5_set_error_string (context, "malloc: out of memory"); 290 return ENOMEM; 291 } 292 *realms = append_realm(*realms, r); 293 294 return 0; 295 } 296 297 298 krb5_error_code 299 krb5_domain_x500_decode(krb5_context context, 300 krb5_data tr, char ***realms, int *num_realms, 301 const char *client_realm, const char *server_realm) 302 { 303 struct tr_realm *r = NULL; 304 struct tr_realm *p, **q; 305 int ret; 306 307 /* split string in components */ 308 ret = decode_realms(context, tr.data, tr.length, &r); 309 if(ret) 310 return ret; 311 312 /* apply prefix rule */ 313 ret = expand_realms(context, r, client_realm); 314 if(ret) 315 return ret; 316 317 ret = make_paths(context, r, client_realm, server_realm); 318 if(ret) 319 return ret; 320 321 /* remove empty components and count realms */ 322 q = &r; 323 *num_realms = 0; 324 for(p = r; p; ){ 325 if(p->realm[0] == '\0'){ 326 free(p->realm); 327 *q = p->next; 328 free(p); 329 p = *q; 330 }else{ 331 q = &p->next; 332 p = p->next; 333 (*num_realms)++; 334 } 335 } 336 if (*num_realms < 0 || *num_realms + 1 > UINT_MAX/sizeof(**realms)) 337 return ERANGE; 338 339 { 340 char **R; 341 R = malloc((*num_realms + 1) * sizeof(*R)); 342 if (R == NULL) 343 return ENOMEM; 344 *realms = R; 345 while(r){ 346 *R++ = r->realm; 347 p = r->next; 348 free(r); 349 r = p; 350 } 351 } 352 return 0; 353 } 354 355 krb5_error_code 356 krb5_domain_x500_encode(char **realms, int num_realms, krb5_data *encoding) 357 { 358 char *s = NULL; 359 int len = 0; 360 int i; 361 for(i = 0; i < num_realms; i++){ 362 len += strlen(realms[i]); 363 if(realms[i][0] == '/') 364 len++; 365 } 366 len += num_realms - 1; 367 s = malloc(len + 1); 368 *s = '\0'; 369 for(i = 0; i < num_realms; i++){ 370 if(i && i < num_realms - 1) 371 strcat(s, ","); 372 if(realms[i][0] == '/') 373 strcat(s, " "); 374 strcat(s, realms[i]); 375 } 376 encoding->data = s; 377 encoding->length = strlen(s); 378 return 0; 379 } 380 381 krb5_error_code 382 krb5_check_transited_realms(krb5_context context, 383 const char *const *realms, 384 int num_realms, 385 int *bad_realm) 386 { 387 int i; 388 int ret = 0; 389 char **bad_realms = krb5_config_get_strings(context, NULL, 390 "libdefaults", 391 "transited_realms_reject", 392 NULL); 393 if(bad_realms == NULL) 394 return 0; 395 396 for(i = 0; i < num_realms; i++) { 397 char **p; 398 for(p = bad_realms; *p; p++) 399 if(strcmp(*p, realms[i]) == 0) { 400 krb5_set_error_string (context, "no transit through realm %s", 401 *p); 402 ret = KRB5KRB_AP_ERR_ILL_CR_TKT; 403 if(bad_realm) 404 *bad_realm = i; 405 break; 406 } 407 } 408 krb5_config_free_strings(bad_realms); 409 return ret; 410 } 411 412 #if 0 413 int 414 main(int argc, char **argv) 415 { 416 krb5_data x; 417 char **r; 418 int num, i; 419 x.data = argv[1]; 420 x.length = strlen(x.data); 421 if(domain_expand(x, &r, &num, argv[2], argv[3])) 422 exit(1); 423 for(i = 0; i < num; i++) 424 printf("%s\n", r[i]); 425 return 0; 426 } 427 #endif 428 429