1 /* $OpenBSD: authenticate.c,v 1.7 2002/02/05 07:51:52 mpech Exp $ */ 2 3 /*- 4 * Copyright (c) 1997 Berkeley Software Design, Inc. 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 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. All advertising materials mentioning features or use of this software 15 * must display the following acknowledgement: 16 * This product includes software developed by Berkeley Software Design, 17 * Inc. 18 * 4. The name of Berkeley Software Design, Inc. may not be used to endorse 19 * or promote products derived from this software without specific prior 20 * written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN, INC. ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN, INC. BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * BSDI $From: authenticate.c,v 2.21 1999/09/08 22:33:26 prb Exp $ 35 */ 36 #include <sys/param.h> 37 #include <sys/stat.h> 38 39 #include <ctype.h> 40 #include <err.h> 41 #include <fcntl.h> 42 #include <login_cap.h> 43 #include <paths.h> 44 #include <pwd.h> 45 #include <stdarg.h> 46 #include <stdio.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #include <syslog.h> 50 #include <unistd.h> 51 52 #include <bsd_auth.h> 53 54 static int _auth_checknologin(login_cap_t *, int); 55 56 char * 57 auth_mkvalue(char *value) 58 { 59 char *big, *p; 60 61 big = malloc(strlen(value) * 4 + 1); 62 if (big == NULL) 63 return (NULL); 64 /* 65 * XXX - There should be a more standardized 66 * routine for doing this sort of thing. 67 */ 68 for (p = big; *value; ++value) { 69 switch (*value) { 70 case '\r': 71 *p++ = '\\'; 72 *p++ = 'r'; 73 break; 74 case '\n': 75 *p++ = '\\'; 76 *p++ = 'n'; 77 break; 78 case '\\': 79 *p++ = '\\'; 80 *p++ = *value; 81 break; 82 case '\t': 83 case ' ': 84 if (p == big) 85 *p++ = '\\'; 86 *p++ = *value; 87 break; 88 default: 89 if (!isprint(*value)) { 90 *p++ = '\\'; 91 *p++ = ((*value >> 6) & 0x3) + '0'; 92 *p++ = ((*value >> 3) & 0x7) + '0'; 93 *p++ = ((*value ) & 0x7) + '0'; 94 } else 95 *p++ = *value; 96 break; 97 } 98 } 99 *p = '\0'; 100 return (big); 101 } 102 103 void 104 auth_checknologin(login_cap_t *lc) 105 { 106 if (_auth_checknologin(lc, 1)) 107 exit(1); 108 } 109 110 static int 111 _auth_checknologin(login_cap_t *lc, int print) 112 { 113 struct stat sb; 114 char *nologin; 115 int mustfree; 116 117 if (login_getcapbool(lc, "ignorenologin", 0)) 118 return (0); 119 120 /* 121 * If we fail to get the nologin file due to a database error, 122 * assume there should have been one... 123 */ 124 nologin = login_getcapstr(lc, "nologin", "", NULL); 125 mustfree = nologin && *nologin != '\0'; 126 if (nologin == NULL) 127 goto print_nologin; 128 129 /* First try the nologin file specified in login.conf. */ 130 if (*nologin != '\0' && stat(nologin, &sb) == 0) 131 goto print_nologin; 132 if (mustfree) 133 free(nologin); 134 135 /* If that doesn't exist try _PATH_NOLOGIN. */ 136 if (stat(_PATH_NOLOGIN, &sb) == 0) { 137 nologin = _PATH_NOLOGIN; 138 goto print_nologin; 139 } 140 141 /* Couldn't stat any nologin files, must be OK to login. */ 142 return (0); 143 144 print_nologin: 145 if (print) { 146 if (!nologin || *nologin == '\0' || auth_cat(nologin) == 0) { 147 puts("Logins are not allowed at this time."); 148 fflush(stdout); 149 } 150 } 151 if (mustfree) 152 free(nologin); 153 return (-1); 154 } 155 156 int 157 auth_cat(char *file) 158 { 159 int fd, nchars; 160 char tbuf[8192]; 161 162 if ((fd = open(file, O_RDONLY, 0)) < 0) 163 return (0); 164 while ((nchars = read(fd, tbuf, sizeof(tbuf))) > 0) 165 (void)write(fileno(stdout), tbuf, nchars); 166 (void)close(fd); 167 return (1); 168 } 169 170 int 171 auth_approval(auth_session_t *as, login_cap_t *lc, char *name, char *type) 172 { 173 int close_on_exit, close_lc_on_exit; 174 struct passwd *pwd; 175 char *approve, *s, path[MAXPATHLEN]; 176 177 pwd = NULL; 178 close_on_exit = as == NULL; 179 close_lc_on_exit = lc == NULL; 180 181 if (as != NULL && name == NULL) 182 name = auth_getitem(as, AUTHV_NAME); 183 184 if (as != NULL) 185 pwd = auth_getpwd(as); 186 187 if (pwd == NULL) { 188 if (name != NULL) 189 pwd = getpwnam(name); 190 else { 191 if ((pwd = getpwuid(getuid())) == NULL) { 192 syslog(LOG_ERR, "no such user id %d", getuid()); 193 _warnx("cannot approve who we don't recognize"); 194 return (0); 195 } 196 name = pwd->pw_name; 197 } 198 } 199 200 if (name == NULL) 201 name = pwd->pw_name; 202 203 if (lc == NULL) { 204 if (strlen(name) >= MAXPATHLEN) { 205 syslog(LOG_ERR, "username to login %.*s...", 206 MAXPATHLEN, name); 207 _warnx("username too long"); 208 return (0); 209 } 210 if (pwd == NULL && (approve = strchr(name, '.')) != NULL) { 211 strcpy(path, name); 212 path[approve-name] = '\0'; 213 pwd = getpwnam(name); 214 } 215 lc = login_getclass(pwd ? pwd->pw_class : NULL); 216 if (lc == NULL) { 217 _warnx("unable to classify user"); 218 return (0); 219 } 220 } 221 222 if (!type) 223 type = LOGIN_DEFSERVICE; 224 else { 225 if (strncmp(type, "approve-", 8) == 0) 226 type += 8; 227 228 snprintf(path, sizeof(path), "approve-%s", type); 229 } 230 231 if ((approve = login_getcapstr(lc, s = path, NULL, NULL)) == NULL) 232 approve = login_getcapstr(lc, s = "approve", NULL, NULL); 233 234 if (approve && approve[0] != '/') { 235 if (close_lc_on_exit) 236 login_close(lc); 237 syslog(LOG_ERR, "Invalid %s script: %s", s, approve); 238 _warnx("invalid path to approval script"); 239 return (0); 240 } 241 242 if (as == NULL && (as = auth_open()) == NULL) { 243 if (close_lc_on_exit) 244 login_close(lc); 245 syslog(LOG_ERR, "%m"); 246 _warn(NULL); 247 return (0); 248 } 249 250 auth_setstate(as, AUTH_OKAY); 251 if (auth_setitem(as, AUTHV_NAME, name) < 0) { 252 syslog(LOG_ERR, "%m"); 253 _warn(NULL); 254 goto out; 255 } 256 if (auth_check_expire(as) < 0) /* is this account expired */ 257 goto out; 258 if (_auth_checknologin(lc, 259 auth_getitem(as, AUTHV_INTERACTIVE) != NULL)) { 260 auth_setstate(as, (auth_getstate(as) & ~AUTH_ALLOW)); 261 goto out; 262 } 263 if (login_getcapbool(lc, "requirehome", 0) && pwd && pwd->pw_dir && 264 pwd->pw_dir[0]) { 265 struct stat sb; 266 267 if (stat(pwd->pw_dir, &sb) < 0 || 268 (sb.st_mode & 0170000) != S_IFDIR || 269 (pwd->pw_uid && sb.st_uid == pwd->pw_uid && 270 (sb.st_mode & S_IXUSR) == 0)) { 271 auth_setstate(as, (auth_getstate(as) & ~AUTH_ALLOW)); 272 goto out; 273 } 274 } 275 if (approve) 276 auth_call(as, approve, strrchr(approve, '/') + 1, name, 277 lc->lc_class, type, 0); 278 279 out: 280 if (close_lc_on_exit) 281 login_close(lc); 282 283 if (close_on_exit) 284 return (auth_close(as)); 285 return (auth_getstate(as) & AUTH_ALLOW); 286 } 287 288 auth_session_t * 289 auth_usercheck(char *name, char *style, char *type, char *password) 290 { 291 char namebuf[MAXLOGNAME + 1 + NAME_MAX + 1]; 292 auth_session_t *as; 293 login_cap_t *lc; 294 struct passwd *pwd; 295 char *sep, save; 296 297 if (strlen(name) >= sizeof(namebuf)) 298 return (NULL); 299 strcpy(namebuf, name); 300 name = namebuf; 301 302 /* 303 * Split up user:style names if we were not given a style 304 */ 305 if (style == NULL && (style = strchr(name, ':')) != NULL) 306 *style++ = '\0'; 307 308 /* 309 * Cope with user[./]instance. We are only using this to get 310 * the class so it is okay if we strip a root instance 311 * The actual login script will pay attention to the instance. 312 */ 313 if ((pwd = getpwnam(name)) == NULL) { 314 if ((sep = strpbrk(name, "./")) != NULL) { 315 save = *sep; 316 *sep = '\0'; 317 pwd = getpwnam(name); 318 *sep = save; 319 } 320 } 321 if ((lc = login_getclass(pwd ? pwd->pw_class : NULL)) == NULL) 322 return (NULL); 323 324 if ((style = login_getstyle(lc, style, type)) == NULL) { 325 login_close(lc); 326 return (NULL); 327 } 328 329 if (password) { 330 if ((as = auth_open()) == NULL) { 331 login_close(lc); 332 return (NULL); 333 } 334 auth_setitem(as, AUTHV_SERVICE, "response"); 335 auth_setdata(as, "", 1); 336 auth_setdata(as, password, strlen(password) + 1); 337 } else 338 as = NULL; 339 as = auth_verify(as, style, name, lc->lc_class, NULL); 340 login_close(lc); 341 return (as); 342 } 343 344 int 345 auth_userokay(char *name, char *style, char *type, char *password) 346 { 347 auth_session_t *as; 348 349 as = auth_usercheck(name, style, type, password); 350 351 return (as != NULL ? auth_close(as) : 0); 352 } 353 354 auth_session_t * 355 auth_userchallenge(char *name, char *style, char *type, char **challengep) 356 { 357 char namebuf[MAXLOGNAME + 1 + NAME_MAX + 1]; 358 auth_session_t *as; 359 login_cap_t *lc; 360 struct passwd *pwd; 361 char *sep, save; 362 363 if (strlen(name) >= sizeof(namebuf)) 364 return (NULL); 365 strcpy(namebuf, name); 366 name = namebuf; 367 368 /* 369 * Split up user:style names if we were not given a style 370 */ 371 if (style == NULL && (style = strchr(name, ':')) != NULL) 372 *style++ = '\0'; 373 374 /* 375 * Cope with user[./]instance. We are only using this to get 376 * the class so it is okay if we strip a root instance 377 * The actual login script will pay attention to the instance. 378 */ 379 if ((pwd = getpwnam(name)) == NULL) { 380 if ((sep = strpbrk(name, "./")) != NULL) { 381 save = *sep; 382 *sep = '\0'; 383 pwd = getpwnam(name); 384 *sep = save; 385 } 386 } 387 if ((lc = login_getclass(pwd ? pwd->pw_class : NULL)) == NULL) 388 return (NULL); 389 390 if ((style = login_getstyle(lc, style, type)) == NULL || 391 (as = auth_open()) == NULL) { 392 login_close(lc); 393 return (NULL); 394 } 395 if (auth_setitem(as, AUTHV_STYLE, style) < 0 || 396 auth_setitem(as, AUTHV_NAME, name) < 0 || 397 auth_setitem(as, AUTHV_CLASS, lc->lc_class) < 0) { 398 auth_close(as); 399 login_close(lc); 400 return (NULL); 401 } 402 login_close(lc); 403 *challengep = auth_challenge(as); 404 return (as); 405 } 406 407 int 408 auth_userresponse(auth_session_t *as, char *response, int more) 409 { 410 char path[MAXPATHLEN]; 411 char *style, *name, *challenge, *class; 412 413 if (as == NULL) 414 return (0); 415 416 auth_setstate(as, 0); 417 418 if ((style = auth_getitem(as, AUTHV_STYLE)) == NULL || 419 (name = auth_getitem(as, AUTHV_NAME)) == NULL) { 420 if (more == 0) 421 return (auth_close(as)); 422 return(0); 423 } 424 challenge = auth_getitem(as, AUTHV_CHALLENGE); 425 class = auth_getitem(as, AUTHV_CLASS); 426 427 if (challenge) 428 auth_setdata(as, challenge, strlen(challenge) + 1); 429 else 430 auth_setdata(as, "", 1); 431 if (response) 432 auth_setdata(as, response, strlen(response) + 1); 433 else 434 auth_setdata(as, "", 1); 435 436 snprintf(path, sizeof(path), _PATH_AUTHPROG "%s", style); 437 438 auth_call(as, path, style, "-s", "response", name, class, NULL); 439 440 /* 441 * If they authenticated then make sure they did not expire 442 */ 443 if (auth_getstate(as) & AUTH_ALLOW) 444 auth_check_expire(as); 445 if (more == 0) 446 return (auth_close(as)); 447 return (auth_getstate(as) & AUTH_ALLOW); 448 } 449 450 /* 451 * Authenticate name with the specified style. 452 * If ``as'' is NULL a new session is formed with the default service. 453 * Returns NULL only if ``as'' is NULL and we were unable to allocate 454 * a new session. 455 * 456 * Use auth_close() or auth_getstate() to determine if the authentication 457 * worked. 458 */ 459 auth_session_t * 460 auth_verify(auth_session_t *as, char *style, char *name, ...) 461 { 462 va_list ap; 463 char path[MAXPATHLEN]; 464 465 if ((name == NULL || style == NULL) && as == NULL) 466 return (as); 467 468 if (as == NULL && (as = auth_open()) == NULL) 469 return (NULL); 470 auth_setstate(as, 0); 471 472 if (style != NULL && auth_setitem(as, AUTHV_STYLE, style) < 0) 473 return (as); 474 475 if (name != NULL && auth_setitem(as, AUTHV_NAME, name) < 0) 476 return (as); 477 478 style = auth_getitem(as, AUTHV_STYLE); 479 name = auth_getitem(as, AUTHV_NAME); 480 481 snprintf(path, sizeof(path), _PATH_AUTHPROG "%s", style); 482 va_start(ap, name); 483 auth_set_va_list(as, ap); 484 auth_call(as, path, auth_getitem(as, AUTHV_STYLE), "-s", 485 auth_getitem(as, AUTHV_SERVICE), name, NULL); 486 return (as); 487 } 488