1 /* $NetBSD: auth.c,v 1.21 2012/03/21 05:33:27 matt Exp $ */ 2 3 /*- 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #ifndef lint 34 #if 0 35 static char sccsid[] = "@(#)auth.c 8.3 (Berkeley) 5/30/95" 36 #else 37 __RCSID("$NetBSD: auth.c,v 1.21 2012/03/21 05:33:27 matt Exp $"); 38 #endif 39 #endif /* not lint */ 40 41 /* 42 * Copyright (C) 1990 by the Massachusetts Institute of Technology 43 * 44 * Export of this software from the United States of America is assumed 45 * to require a specific license from the United States Government. 46 * It is the responsibility of any person or organization contemplating 47 * export to obtain such a license before exporting. 48 * 49 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and 50 * distribute this software and its documentation for any purpose and 51 * without fee is hereby granted, provided that the above copyright 52 * notice appear in all copies and that both that copyright notice and 53 * this permission notice appear in supporting documentation, and that 54 * the name of M.I.T. not be used in advertising or publicity pertaining 55 * to distribution of the software without specific, written prior 56 * permission. M.I.T. makes no representations about the suitability of 57 * this software for any purpose. It is provided "as is" without express 58 * or implied warranty. 59 */ 60 61 62 #ifdef AUTHENTICATION 63 #include <stdio.h> 64 #include <sys/types.h> 65 #include <signal.h> 66 #define AUTH_NAMES 67 #include <arpa/telnet.h> 68 #include <stdlib.h> 69 #include <unistd.h> 70 #ifdef NO_STRING_H 71 #include <strings.h> 72 #else 73 #include <string.h> 74 #endif 75 76 #include "encrypt.h" 77 #include "auth.h" 78 #include "misc-proto.h" 79 #include "auth-proto.h" 80 81 #define typemask(x) (1<<((x)-1)) 82 83 #ifdef RSA_ENCPWD 84 extern rsaencpwd_init(); 85 extern rsaencpwd_send(); 86 extern rsaencpwd_is(); 87 extern rsaencpwd_reply(); 88 extern rsaencpwd_status(); 89 extern rsaencpwd_printsub(); 90 #endif 91 92 int auth_debug_mode = 0; 93 static const char *Name = "Noname"; 94 static int Server = 0; 95 static Authenticator *authenticated = 0; 96 static int authenticating = 0; 97 static int validuser = 0; 98 static unsigned char _auth_send_data[256]; 99 static unsigned char *auth_send_data; 100 static int auth_send_cnt = 0; 101 102 static void auth_intr(int); 103 104 /* 105 * Authentication types supported. Plese note that these are stored 106 * in priority order, i.e. try the first one first. 107 */ 108 Authenticator authenticators[] = { 109 #ifdef SPX 110 { AUTHTYPE_SPX, AUTH_WHO_CLIENT|AUTH_HOW_MUTUAL, 111 spx_init, 112 spx_send, 113 spx_is, 114 spx_reply, 115 spx_status, 116 spx_printsub }, 117 { AUTHTYPE_SPX, AUTH_WHO_CLIENT|AUTH_HOW_ONE_WAY, 118 spx_init, 119 spx_send, 120 spx_is, 121 spx_reply, 122 spx_status, 123 spx_printsub }, 124 #endif 125 #ifdef KRB5 126 # ifdef ENCRYPTION 127 { AUTHTYPE_KERBEROS_V5, AUTH_WHO_CLIENT|AUTH_HOW_MUTUAL, 128 kerberos5_init, 129 kerberos5_send, 130 kerberos5_is, 131 kerberos5_reply, 132 kerberos5_status, 133 kerberos5_printsub }, 134 # endif /* ENCRYPTION */ 135 { AUTHTYPE_KERBEROS_V5, AUTH_WHO_CLIENT|AUTH_HOW_ONE_WAY, 136 kerberos5_init, 137 kerberos5_send, 138 kerberos5_is, 139 kerberos5_reply, 140 kerberos5_status, 141 kerberos5_printsub }, 142 #endif 143 #ifdef RSA_ENCPWD 144 { AUTHTYPE_RSA_ENCPWD, AUTH_WHO_CLIENT|AUTH_HOW_ONE_WAY, 145 rsaencpwd_init, 146 rsaencpwd_send, 147 rsaencpwd_is, 148 rsaencpwd_reply, 149 rsaencpwd_status, 150 rsaencpwd_printsub }, 151 #endif 152 #ifdef SRA 153 { AUTHTYPE_SRA, AUTH_WHO_CLIENT|AUTH_HOW_ONE_WAY, 154 sra_init, 155 sra_send, 156 sra_is, 157 sra_reply, 158 sra_status, 159 sra_printsub }, 160 161 #endif 162 { 0, 0, 0, 0, 0, 0, 0, 0 }, 163 }; 164 165 static Authenticator NoAuth = { .type = 0 }; 166 167 static int i_support = 0; 168 static int i_wont_support = 0; 169 170 Authenticator * 171 findauthenticator(int type, int way) 172 { 173 Authenticator *ap = authenticators; 174 175 while (ap->type && (ap->type != type || ap->way != way)) 176 ++ap; 177 return(ap->type ? ap : 0); 178 } 179 180 void 181 auth_init(const char *name, int server) 182 { 183 Authenticator *ap = authenticators; 184 185 Server = server; 186 Name = name; 187 188 i_support = 0; 189 authenticated = 0; 190 authenticating = 0; 191 while (ap->type) { 192 if (!ap->init || (*ap->init)(ap, server)) { 193 i_support |= typemask(ap->type); 194 if (auth_debug_mode) 195 printf(">>>%s: I support auth type %d %d\r\n", 196 Name, 197 ap->type, ap->way); 198 } 199 else if (auth_debug_mode) 200 printf(">>>%s: Init failed: auth type %d %d\r\n", 201 Name, ap->type, ap->way); 202 ++ap; 203 } 204 } 205 206 void 207 auth_disable_name(char *name) 208 { 209 int x; 210 for (x = 0; x < AUTHTYPE_CNT; ++x) { 211 if (AUTHTYPE_NAME(x) && !strcasecmp(name, AUTHTYPE_NAME(x))) { 212 i_wont_support |= typemask(x); 213 break; 214 } 215 } 216 } 217 218 int 219 getauthmask(char *type, int *maskp) 220 { 221 register int x; 222 223 if (AUTHTYPE_NAME(0) && !strcasecmp(type, AUTHTYPE_NAME(0))) { 224 *maskp = -1; 225 return(1); 226 } 227 228 for (x = 1; x < AUTHTYPE_CNT; ++x) { 229 if (AUTHTYPE_NAME(x) && !strcasecmp(type, AUTHTYPE_NAME(x))) { 230 *maskp = typemask(x); 231 return(1); 232 } 233 } 234 return(0); 235 } 236 237 int 238 auth_enable(char *type) 239 { 240 return(auth_onoff(type, 1)); 241 } 242 243 int 244 auth_disable(char *type) 245 { 246 return(auth_onoff(type, 0)); 247 } 248 249 int 250 auth_onoff(char *type, int on) 251 { 252 int i, mask = -1; 253 Authenticator *ap; 254 255 if (!strcasecmp(type, "?") || !strcasecmp(type, "help")) { 256 printf("auth %s 'type'\n", on ? "enable" : "disable"); 257 printf("Where 'type' is one of:\n"); 258 printf("\t%s\n", AUTHTYPE_NAME(0)); 259 mask = 0; 260 for (ap = authenticators; ap->type; ap++) { 261 if ((mask & (i = typemask(ap->type))) != 0) 262 continue; 263 mask |= i; 264 printf("\t%s\n", AUTHTYPE_NAME(ap->type)); 265 } 266 return(0); 267 } 268 269 if (!getauthmask(type, &mask)) { 270 printf("%s: invalid authentication type\n", type); 271 return(0); 272 } 273 if (on) 274 i_wont_support &= ~mask; 275 else 276 i_wont_support |= mask; 277 return(1); 278 } 279 280 int 281 auth_togdebug(int on) 282 { 283 if (on < 0) 284 auth_debug_mode ^= 1; 285 else 286 auth_debug_mode = on; 287 printf("auth debugging %s\n", auth_debug_mode ? "enabled" : "disabled"); 288 return(1); 289 } 290 291 int 292 auth_status(char *s) 293 { 294 Authenticator *ap; 295 int i, mask; 296 297 if (i_wont_support == -1) 298 printf("Authentication disabled\n"); 299 else 300 printf("Authentication enabled\n"); 301 302 mask = 0; 303 for (ap = authenticators; ap->type; ap++) { 304 if ((mask & (i = typemask(ap->type))) != 0) 305 continue; 306 mask |= i; 307 printf("%s: %s\n", AUTHTYPE_NAME(ap->type), 308 (i_wont_support & typemask(ap->type)) ? 309 "disabled" : "enabled"); 310 } 311 return(1); 312 } 313 314 /* 315 * This routine is called by the server to start authentication 316 * negotiation. 317 */ 318 void 319 auth_request(void) 320 { 321 static unsigned char str_request[64] = { IAC, SB, 322 TELOPT_AUTHENTICATION, 323 TELQUAL_SEND, }; 324 Authenticator *ap = authenticators; 325 unsigned char *e = str_request + 4; 326 327 if (!authenticating) { 328 authenticating = 1; 329 while (ap->type) { 330 if (i_support & ~i_wont_support & typemask(ap->type)) { 331 if (auth_debug_mode) { 332 printf(">>>%s: Sending type %d %d\r\n", 333 Name, ap->type, ap->way); 334 } 335 *e++ = ap->type; 336 *e++ = ap->way; 337 } 338 ++ap; 339 } 340 *e++ = IAC; 341 *e++ = SE; 342 telnet_net_write(str_request, e - str_request); 343 printsub('>', &str_request[2], e - str_request - 2); 344 } 345 } 346 347 /* 348 * This is called when an AUTH SEND is received. 349 * It should never arrive on the server side (as only the server can 350 * send an AUTH SEND). 351 * You should probably respond to it if you can... 352 * 353 * If you want to respond to the types out of order (i.e. even 354 * if he sends LOGIN KERBEROS and you support both, you respond 355 * with KERBEROS instead of LOGIN (which is against what the 356 * protocol says)) you will have to hack this code... 357 */ 358 void 359 auth_send(unsigned char *data, int cnt) 360 { 361 Authenticator *ap; 362 static unsigned char str_none[] = { IAC, SB, TELOPT_AUTHENTICATION, 363 TELQUAL_IS, AUTHTYPE_NULL, 0, 364 IAC, SE }; 365 if (Server) { 366 if (auth_debug_mode) { 367 printf(">>>%s: auth_send called!\r\n", Name); 368 } 369 return; 370 } 371 372 if (auth_debug_mode) { 373 printf(">>>%s: auth_send got:", Name); 374 printd(data, cnt); printf("\r\n"); 375 } 376 377 /* 378 * Save the data, if it is new, so that we can continue looking 379 * at it if the authorization we try doesn't work 380 */ 381 if (data < _auth_send_data || 382 data > _auth_send_data + sizeof(_auth_send_data)) { 383 auth_send_cnt = (size_t)cnt > sizeof(_auth_send_data) 384 ? sizeof(_auth_send_data) 385 : (size_t)cnt; 386 memmove(_auth_send_data, data, auth_send_cnt); 387 auth_send_data = _auth_send_data; 388 } else { 389 /* 390 * This is probably a no-op, but we just make sure 391 */ 392 auth_send_data = data; 393 auth_send_cnt = cnt; 394 } 395 while ((auth_send_cnt -= 2) >= 0) { 396 if (auth_debug_mode) 397 printf(">>>%s: He supports %d\r\n", 398 Name, *auth_send_data); 399 if ((i_support & ~i_wont_support) & typemask(*auth_send_data)) { 400 ap = findauthenticator(auth_send_data[0], 401 auth_send_data[1]); 402 if (ap && ap->send) { 403 if (auth_debug_mode) 404 printf(">>>%s: Trying %d %d\r\n", 405 Name, auth_send_data[0], 406 auth_send_data[1]); 407 if ((*ap->send)(ap)) { 408 /* 409 * Okay, we found one we like 410 * and did it. 411 * we can go home now. 412 */ 413 if (auth_debug_mode) 414 printf(">>>%s: Using type %d\r\n", 415 Name, *auth_send_data); 416 auth_send_data += 2; 417 return; 418 } 419 } 420 /* else 421 * just continue on and look for the 422 * next one if we didn't do anything. 423 */ 424 } 425 auth_send_data += 2; 426 } 427 telnet_net_write(str_none, sizeof(str_none)); 428 printsub('>', &str_none[2], sizeof(str_none) - 2); 429 if (auth_debug_mode) 430 printf(">>>%s: Sent failure message\r\n", Name); 431 auth_finished(0, AUTH_REJECT); 432 #ifdef KANNAN 433 /* 434 * We requested strong authentication, however no mechanisms worked. 435 * Therefore, exit on client end. 436 */ 437 printf("Unable to securely authenticate user ... exit\n"); 438 exit(0); 439 #endif /* KANNAN */ 440 } 441 442 void 443 auth_send_retry(void) 444 { 445 /* 446 * if auth_send_cnt <= 0 then auth_send will end up rejecting 447 * the authentication and informing the other side of this. 448 */ 449 auth_send(auth_send_data, auth_send_cnt); 450 } 451 452 void 453 auth_is(unsigned char *data, int cnt) 454 { 455 Authenticator *ap; 456 457 if (cnt < 2) 458 return; 459 460 if (data[0] == AUTHTYPE_NULL) { 461 auth_finished(0, AUTH_REJECT); 462 return; 463 } 464 465 if ((ap = findauthenticator(data[0], data[1])) != NULL) { 466 if (ap->is) 467 (*ap->is)(ap, data+2, cnt-2); 468 } else if (auth_debug_mode) 469 printf(">>>%s: Invalid authentication in IS: %d\r\n", 470 Name, *data); 471 } 472 473 void 474 auth_reply(unsigned char *data, int cnt) 475 { 476 Authenticator *ap; 477 478 if (cnt < 2) 479 return; 480 481 if ((ap = findauthenticator(data[0], data[1])) != NULL) { 482 if (ap->reply) 483 (*ap->reply)(ap, data+2, cnt-2); 484 } else if (auth_debug_mode) 485 printf(">>>%s: Invalid authentication in SEND: %d\r\n", 486 Name, *data); 487 } 488 489 void 490 auth_name(unsigned char *data, int cnt) 491 { 492 unsigned char savename[256]; 493 494 if (cnt < 1) { 495 if (auth_debug_mode) 496 printf(">>>%s: Empty name in NAME\r\n", Name); 497 return; 498 } 499 if ((size_t)cnt > sizeof(savename) - 1) { 500 if (auth_debug_mode) 501 printf(">>>%s: Name in NAME (%d) exceeds %ld length\r\n", 502 Name, cnt, (long)sizeof(savename)-1); 503 return; 504 } 505 memmove((void *)savename, (void *)data, cnt); 506 savename[cnt] = '\0'; /* Null terminate */ 507 if (auth_debug_mode) 508 printf(">>>%s: Got NAME [%s]\r\n", Name, savename); 509 auth_encrypt_user(savename); 510 } 511 512 int 513 auth_sendname(unsigned char *cp, int len) 514 { 515 static unsigned char str_request[256+6] 516 = { IAC, SB, TELOPT_AUTHENTICATION, TELQUAL_NAME, }; 517 register unsigned char *e = str_request + 4; 518 register unsigned char *ee = &str_request[sizeof(str_request)-2]; 519 520 while (--len >= 0) { 521 if ((*e++ = *cp++) == IAC) 522 *e++ = IAC; 523 if (e >= ee) 524 return(0); 525 } 526 *e++ = IAC; 527 *e++ = SE; 528 telnet_net_write(str_request, e - str_request); 529 printsub('>', &str_request[2], e - &str_request[2]); 530 return(1); 531 } 532 533 void 534 auth_finished(Authenticator *ap, int result) 535 { 536 if (!(authenticated = ap)) 537 authenticated = &NoAuth; 538 validuser = result; 539 } 540 541 /* ARGSUSED */ 542 static void 543 auth_intr(int sig) 544 { 545 auth_finished(0, AUTH_REJECT); 546 } 547 548 int 549 auth_wait(char *name, size_t l) 550 { 551 if (auth_debug_mode) 552 printf(">>>%s: in auth_wait.\r\n", Name); 553 554 if (Server && !authenticating) 555 return(0); 556 557 (void) signal(SIGALRM, auth_intr); 558 alarm(30); 559 while (!authenticated) 560 if (telnet_spin()) 561 break; 562 alarm(0); 563 (void) signal(SIGALRM, SIG_DFL); 564 565 /* 566 * Now check to see if the user is valid or not 567 */ 568 if (!authenticated || authenticated == &NoAuth) 569 return(AUTH_REJECT); 570 571 if (validuser == AUTH_VALID) 572 validuser = AUTH_USER; 573 574 if (authenticated->status) 575 validuser = (*authenticated->status)(authenticated, 576 name, l, validuser); 577 return(validuser); 578 } 579 580 void 581 auth_debug(int mode) 582 { 583 auth_debug_mode = mode; 584 } 585 586 void 587 auth_printsub(unsigned char *data, int cnt, unsigned char *buf, int buflen) 588 { 589 Authenticator *ap; 590 591 if ((ap = findauthenticator(data[1], data[2])) && ap->printsub) 592 (*ap->printsub)(data, cnt, buf, buflen); 593 else 594 auth_gen_printsub(data, cnt, buf, buflen); 595 } 596 597 void 598 auth_gen_printsub(unsigned char *data, int cnt, unsigned char *buf, int buflen) 599 { 600 register unsigned char *cp; 601 unsigned char tbuf[16]; 602 603 cnt -= 3; 604 data += 3; 605 buf[buflen-1] = '\0'; 606 buf[buflen-2] = '*'; 607 buflen -= 2; 608 for (; cnt > 0; cnt--, data++) { 609 snprintf((char *)tbuf, sizeof(tbuf), " %d", *data); 610 for (cp = tbuf; *cp && buflen > 0; --buflen) 611 *buf++ = *cp++; 612 if (buflen <= 0) 613 return; 614 } 615 *buf = '\0'; 616 } 617 #endif 618