1 /*- 2 * Copyright (c) 2001-2003 Networks Associates Technology, Inc. 3 * Copyright (c) 2004-2015 Dag-Erling Smørgrav 4 * All rights reserved. 5 * 6 * This software was developed for the FreeBSD Project by ThinkSec AS and 7 * Network Associates Laboratories, the Security Research Division of 8 * Network Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 9 * ("CBOSS"), as part of the DARPA CHATS research program. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. The name of the author may not be used to endorse or promote 20 * products derived from this software without specific prior written 21 * permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 #ifdef HAVE_CONFIG_H 37 # include "config.h" 38 #endif 39 40 #include <sys/param.h> 41 42 #include <errno.h> 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <string.h> 46 47 #include <security/pam_appl.h> 48 49 #include "openpam_impl.h" 50 #include "openpam_ctype.h" 51 #include "openpam_strlcat.h" 52 #include "openpam_strlcpy.h" 53 54 static int openpam_load_chain(pam_handle_t *, const char *, pam_facility_t); 55 56 /* 57 * Validate a service name. 58 * 59 * Returns a non-zero value if the argument points to a NUL-terminated 60 * string consisting entirely of characters in the POSIX portable filename 61 * character set, excluding the path separator character. 62 */ 63 static int 64 valid_service_name(const char *name) 65 { 66 const char *p; 67 68 if (OPENPAM_FEATURE(RESTRICT_SERVICE_NAME)) { 69 /* path separator not allowed */ 70 for (p = name; *p != '\0'; ++p) 71 if (!is_pfcs(*p)) 72 return (0); 73 } else { 74 /* path separator allowed */ 75 for (p = name; *p != '\0'; ++p) 76 if (!is_pfcs(*p) && *p != '/') 77 return (0); 78 } 79 return (1); 80 } 81 82 /* 83 * Parse the facility name. 84 * 85 * Returns the corresponding pam_facility_t value, or -1 if the argument 86 * is not a valid facility name. 87 */ 88 static pam_facility_t 89 parse_facility_name(const char *name) 90 { 91 int i; 92 93 for (i = 0; i < PAM_NUM_FACILITIES; ++i) 94 if (strcmp(pam_facility_name[i], name) == 0) 95 return (i); 96 return ((pam_facility_t)-1); 97 } 98 99 /* 100 * Parse the control flag. 101 * 102 * Returns the corresponding pam_control_t value, or -1 if the argument is 103 * not a valid control flag name. 104 */ 105 static pam_control_t 106 parse_control_flag(const char *name) 107 { 108 int i; 109 110 for (i = 0; i < PAM_NUM_CONTROL_FLAGS; ++i) 111 if (strcmp(pam_control_flag_name[i], name) == 0) 112 return (i); 113 return ((pam_control_t)-1); 114 } 115 116 /* 117 * Validate a file name. 118 * 119 * Returns a non-zero value if the argument points to a NUL-terminated 120 * string consisting entirely of characters in the POSIX portable filename 121 * character set, including the path separator character. 122 */ 123 static int 124 valid_module_name(const char *name) 125 { 126 const char *p; 127 128 if (OPENPAM_FEATURE(RESTRICT_MODULE_NAME)) { 129 /* path separator not allowed */ 130 for (p = name; *p != '\0'; ++p) 131 if (!is_pfcs(*p)) 132 return (0); 133 } else { 134 /* path separator allowed */ 135 for (p = name; *p != '\0'; ++p) 136 if (!is_pfcs(*p) && *p != '/') 137 return (0); 138 } 139 return (1); 140 } 141 142 typedef enum { pam_conf_style, pam_d_style } openpam_style_t; 143 144 /* 145 * Extracts given chains from a policy file. 146 * 147 * Returns the number of policy entries which were found for the specified 148 * service and facility, or -1 if a system error occurred or a syntax 149 * error was encountered. 150 */ 151 static int 152 openpam_parse_chain(pam_handle_t *pamh, 153 const char *service, 154 pam_facility_t facility, 155 FILE *f, 156 const char *filename, 157 openpam_style_t style) 158 { 159 pam_chain_t *this, **next; 160 pam_facility_t fclt; 161 pam_control_t ctlf; 162 char *name, *servicename, *modulename; 163 int count, lineno, ret, serrno; 164 char **wordv, *word; 165 int i, wordc; 166 167 count = 0; 168 this = NULL; 169 name = NULL; 170 lineno = 0; 171 wordc = 0; 172 wordv = NULL; 173 while ((wordv = openpam_readlinev(f, &lineno, &wordc)) != NULL) { 174 /* blank line? */ 175 if (wordc == 0) { 176 FREEV(wordc, wordv); 177 continue; 178 } 179 i = 0; 180 181 /* check service name if necessary */ 182 if (style == pam_conf_style && 183 strcmp(wordv[i++], service) != 0) { 184 FREEV(wordc, wordv); 185 continue; 186 } 187 188 /* check facility name */ 189 if ((word = wordv[i++]) == NULL || 190 (fclt = parse_facility_name(word)) == (pam_facility_t)-1) { 191 openpam_log(PAM_LOG_ERROR, 192 "%s(%d): missing or invalid facility", 193 filename, lineno); 194 errno = EINVAL; 195 goto fail; 196 } 197 if (facility != fclt && facility != PAM_FACILITY_ANY) { 198 FREEV(wordc, wordv); 199 continue; 200 } 201 202 /* check for "include" */ 203 if ((word = wordv[i++]) != NULL && 204 strcmp(word, "include") == 0) { 205 if ((servicename = wordv[i++]) == NULL || 206 !valid_service_name(servicename)) { 207 openpam_log(PAM_LOG_ERROR, 208 "%s(%d): missing or invalid service name", 209 filename, lineno); 210 errno = EINVAL; 211 goto fail; 212 } 213 if (wordv[i] != NULL) { 214 openpam_log(PAM_LOG_ERROR, 215 "%s(%d): garbage at end of line", 216 filename, lineno); 217 errno = EINVAL; 218 goto fail; 219 } 220 ret = openpam_load_chain(pamh, servicename, fclt); 221 FREEV(wordc, wordv); 222 if (ret < 0) { 223 /* 224 * Bogus errno, but this ensures that the 225 * outer loop does not just ignore the 226 * error and keep searching. 227 */ 228 if (errno == ENOENT) 229 errno = EINVAL; 230 goto fail; 231 } 232 continue; 233 } 234 235 /* get control flag */ 236 if (word == NULL || /* same word we compared to "include" */ 237 (ctlf = parse_control_flag(word)) == (pam_control_t)-1) { 238 openpam_log(PAM_LOG_ERROR, 239 "%s(%d): missing or invalid control flag", 240 filename, lineno); 241 errno = EINVAL; 242 goto fail; 243 } 244 245 /* get module name */ 246 if ((modulename = wordv[i++]) == NULL || 247 !valid_module_name(modulename)) { 248 openpam_log(PAM_LOG_ERROR, 249 "%s(%d): missing or invalid module name", 250 filename, lineno); 251 errno = EINVAL; 252 goto fail; 253 } 254 255 /* allocate new entry */ 256 if ((this = calloc(1, sizeof *this)) == NULL) 257 goto syserr; 258 this->flag = ctlf; 259 260 /* load module */ 261 if ((this->module = openpam_load_module(modulename)) == NULL) { 262 if (errno == ENOENT) 263 errno = ENOEXEC; 264 goto fail; 265 } 266 267 /* 268 * The remaining items in wordv are the module's 269 * arguments. We could set this->optv = wordv + i, but 270 * then free(this->optv) wouldn't work. Instead, we free 271 * the words we've already consumed, shift the rest up, 272 * and clear the tail end of the array. 273 */ 274 this->optc = wordc - i; 275 for (i = 0; i < wordc - this->optc; ++i) { 276 FREE(wordv[i]); 277 } 278 for (i = 0; i < this->optc; ++i) { 279 wordv[i] = wordv[wordc - this->optc + i]; 280 wordv[wordc - this->optc + i] = NULL; 281 } 282 this->optv = wordv; 283 wordv = NULL; 284 wordc = 0; 285 286 /* hook it up */ 287 for (next = &pamh->chains[fclt]; *next != NULL; 288 next = &(*next)->next) 289 /* nothing */ ; 290 *next = this; 291 this = NULL; 292 ++count; 293 } 294 /* 295 * The loop ended because openpam_readword() returned NULL, which 296 * can happen for four different reasons: an I/O error (ferror(f) 297 * is true), a memory allocation failure (ferror(f) is false, 298 * feof(f) is false, errno is non-zero), the file ended with an 299 * unterminated quote or backslash escape (ferror(f) is false, 300 * feof(f) is true, errno is non-zero), or the end of the file was 301 * reached without error (ferror(f) is false, feof(f) is true, 302 * errno is zero). 303 */ 304 if (ferror(f) || errno != 0) 305 goto syserr; 306 if (!feof(f)) 307 goto fail; 308 fclose(f); 309 return (count); 310 syserr: 311 serrno = errno; 312 openpam_log(PAM_LOG_ERROR, "%s: %m", filename); 313 errno = serrno; 314 /* fall through */ 315 fail: 316 serrno = errno; 317 if (this && this->optc && this->optv) 318 FREEV(this->optc, this->optv); 319 FREE(this); 320 FREEV(wordc, wordv); 321 FREE(wordv); 322 FREE(name); 323 fclose(f); 324 errno = serrno; 325 return (-1); 326 } 327 328 /* 329 * Read the specified chains from the specified file. 330 * 331 * Returns 0 if the file exists but does not contain any matching lines. 332 * 333 * Returns -1 and sets errno to ENOENT if the file does not exist. 334 * 335 * Returns -1 and sets errno to some other non-zero value if the file 336 * exists but is unsafe or unreadable, or an I/O error occurs. 337 */ 338 static int 339 openpam_load_file(pam_handle_t *pamh, 340 const char *service, 341 pam_facility_t facility, 342 const char *filename, 343 openpam_style_t style) 344 { 345 FILE *f; 346 int ret, serrno; 347 348 /* attempt to open the file */ 349 if ((f = fopen(filename, "r")) == NULL) { 350 serrno = errno; 351 openpam_log(errno == ENOENT ? PAM_LOG_DEBUG : PAM_LOG_ERROR, 352 "%s: %m", filename); 353 errno = serrno; 354 RETURNN(-1); 355 } else { 356 openpam_log(PAM_LOG_DEBUG, "found %s", filename); 357 } 358 359 /* verify type, ownership and permissions */ 360 if (OPENPAM_FEATURE(VERIFY_POLICY_FILE) && 361 openpam_check_desc_owner_perms(filename, fileno(f)) != 0) { 362 /* already logged the cause */ 363 serrno = errno; 364 fclose(f); 365 errno = serrno; 366 RETURNN(-1); 367 } 368 369 /* parse the file */ 370 ret = openpam_parse_chain(pamh, service, facility, 371 f, filename, style); 372 RETURNN(ret); 373 } 374 375 /* 376 * Locates the policy file for a given service and reads the given chains 377 * from it. 378 * 379 * Returns the number of policy entries which were found for the specified 380 * service and facility, or -1 if a system error occurred or a syntax 381 * error was encountered. 382 */ 383 static int 384 openpam_load_chain(pam_handle_t *pamh, 385 const char *service, 386 pam_facility_t facility) 387 { 388 const char *p, **path; 389 char filename[PATH_MAX]; 390 size_t len; 391 openpam_style_t style; 392 int ret; 393 394 ENTERS(facility < 0 ? "any" : pam_facility_name[facility]); 395 396 /* either absolute or relative to cwd */ 397 if (strchr(service, '/') != NULL) { 398 if ((p = strrchr(service, '.')) != NULL && strcmp(p, ".conf") == 0) 399 style = pam_conf_style; 400 else 401 style = pam_d_style; 402 ret = openpam_load_file(pamh, service, facility, 403 service, style); 404 RETURNN(ret); 405 } 406 407 /* search standard locations */ 408 for (path = openpam_policy_path; *path != NULL; ++path) { 409 /* construct filename */ 410 len = strlcpy(filename, *path, sizeof filename); 411 if (len >= sizeof filename) { 412 errno = ENAMETOOLONG; 413 RETURNN(-1); 414 } 415 if (filename[len - 1] == '/') { 416 len = strlcat(filename, service, sizeof filename); 417 if (len >= sizeof filename) { 418 errno = ENAMETOOLONG; 419 RETURNN(-1); 420 } 421 style = pam_d_style; 422 } else { 423 style = pam_conf_style; 424 } 425 ret = openpam_load_file(pamh, service, facility, 426 filename, style); 427 /* success */ 428 if (ret > 0) 429 RETURNN(ret); 430 /* the file exists, but an error occurred */ 431 if (ret == -1 && errno != ENOENT) 432 RETURNN(ret); 433 /* in pam.d style, an empty file counts as a hit */ 434 if (ret == 0 && style == pam_d_style) 435 RETURNN(ret); 436 } 437 438 /* no hit */ 439 errno = ENOENT; 440 RETURNN(-1); 441 } 442 443 /* 444 * OpenPAM internal 445 * 446 * Configure a service 447 */ 448 449 int 450 openpam_configure(pam_handle_t *pamh, 451 const char *service) 452 { 453 pam_facility_t fclt; 454 int serrno; 455 456 ENTERS(service); 457 if (!valid_service_name(service)) { 458 openpam_log(PAM_LOG_ERROR, "invalid service name"); 459 RETURNC(PAM_SYSTEM_ERR); 460 } 461 if (openpam_load_chain(pamh, service, PAM_FACILITY_ANY) < 0) { 462 if (errno != ENOENT) 463 goto load_err; 464 } 465 for (fclt = 0; fclt < PAM_NUM_FACILITIES; ++fclt) { 466 if (pamh->chains[fclt] != NULL) 467 continue; 468 if (OPENPAM_FEATURE(FALLBACK_TO_OTHER)) { 469 if (openpam_load_chain(pamh, PAM_OTHER, fclt) < 0) 470 goto load_err; 471 } 472 } 473 RETURNC(PAM_SUCCESS); 474 load_err: 475 serrno = errno; 476 openpam_clear_chains(pamh->chains); 477 errno = serrno; 478 RETURNC(PAM_SYSTEM_ERR); 479 } 480 481 /* 482 * NODOC 483 * 484 * Error codes: 485 * PAM_SYSTEM_ERR 486 */ 487