auth.c revision 1.16
1 /* $NetBSD: auth.c,v 1.16 2003/08/07 16:44:54 agc 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 1.16 2003/08/07 16:44:54 agc 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 KRB4_ENCPWD 84 extern krb4encpwd_init(); 85 extern krb4encpwd_send(); 86 extern krb4encpwd_is(); 87 extern krb4encpwd_reply(); 88 extern krb4encpwd_status(); 89 extern krb4encpwd_printsub(); 90 #endif 91 92 #ifdef RSA_ENCPWD 93 extern rsaencpwd_init(); 94 extern rsaencpwd_send(); 95 extern rsaencpwd_is(); 96 extern rsaencpwd_reply(); 97 extern rsaencpwd_status(); 98 extern rsaencpwd_printsub(); 99 #endif 100 101 int auth_debug_mode = 0; 102 static const char *Name = "Noname"; 103 static int Server = 0; 104 static Authenticator *authenticated = 0; 105 static int authenticating = 0; 106 static int validuser = 0; 107 static unsigned char _auth_send_data[256]; 108 static unsigned char *auth_send_data; 109 static int auth_send_cnt = 0; 110 111 static void auth_intr P((int)); 112 113 /* 114 * Authentication types supported. Plese note that these are stored 115 * in priority order, i.e. try the first one first. 116 */ 117 Authenticator authenticators[] = { 118 #ifdef SPX 119 { AUTHTYPE_SPX, AUTH_WHO_CLIENT|AUTH_HOW_MUTUAL, 120 spx_init, 121 spx_send, 122 spx_is, 123 spx_reply, 124 spx_status, 125 spx_printsub }, 126 { AUTHTYPE_SPX, AUTH_WHO_CLIENT|AUTH_HOW_ONE_WAY, 127 spx_init, 128 spx_send, 129 spx_is, 130 spx_reply, 131 spx_status, 132 spx_printsub }, 133 #endif 134 #ifdef KRB5 135 # ifdef ENCRYPTION 136 { AUTHTYPE_KERBEROS_V5, AUTH_WHO_CLIENT|AUTH_HOW_MUTUAL, 137 kerberos5_init, 138 kerberos5_send, 139 kerberos5_is, 140 kerberos5_reply, 141 kerberos5_status, 142 kerberos5_printsub }, 143 # endif /* ENCRYPTION */ 144 { AUTHTYPE_KERBEROS_V5, AUTH_WHO_CLIENT|AUTH_HOW_ONE_WAY, 145 kerberos5_init, 146 kerberos5_send, 147 kerberos5_is, 148 kerberos5_reply, 149 kerberos5_status, 150 kerberos5_printsub }, 151 #endif 152 #ifdef KRB4 153 # ifdef ENCRYPTION 154 { AUTHTYPE_KERBEROS_V4, AUTH_WHO_CLIENT|AUTH_HOW_MUTUAL, 155 kerberos4_init, 156 kerberos4_send, 157 kerberos4_is, 158 kerberos4_reply, 159 kerberos4_status, 160 kerberos4_printsub }, 161 # endif /* ENCRYPTION */ 162 { AUTHTYPE_KERBEROS_V4, AUTH_WHO_CLIENT|AUTH_HOW_ONE_WAY, 163 kerberos4_init, 164 kerberos4_send, 165 kerberos4_is, 166 kerberos4_reply, 167 kerberos4_status, 168 kerberos4_printsub }, 169 #endif 170 #ifdef KRB4_ENCPWD 171 { AUTHTYPE_KRB4_ENCPWD, AUTH_WHO_CLIENT|AUTH_HOW_MUTUAL, 172 krb4encpwd_init, 173 krb4encpwd_send, 174 krb4encpwd_is, 175 krb4encpwd_reply, 176 krb4encpwd_status, 177 krb4encpwd_printsub }, 178 #endif 179 #ifdef RSA_ENCPWD 180 { AUTHTYPE_RSA_ENCPWD, AUTH_WHO_CLIENT|AUTH_HOW_ONE_WAY, 181 rsaencpwd_init, 182 rsaencpwd_send, 183 rsaencpwd_is, 184 rsaencpwd_reply, 185 rsaencpwd_status, 186 rsaencpwd_printsub }, 187 #endif 188 { 0, }, 189 }; 190 191 static Authenticator NoAuth = { 0 }; 192 193 static int i_support = 0; 194 static int i_wont_support = 0; 195 196 Authenticator * 197 findauthenticator(type, way) 198 int type; 199 int way; 200 { 201 Authenticator *ap = authenticators; 202 203 while (ap->type && (ap->type != type || ap->way != way)) 204 ++ap; 205 return(ap->type ? ap : 0); 206 } 207 208 void 209 auth_init(name, server) 210 const char *name; 211 int server; 212 { 213 Authenticator *ap = authenticators; 214 215 Server = server; 216 Name = name; 217 218 i_support = 0; 219 authenticated = 0; 220 authenticating = 0; 221 while (ap->type) { 222 if (!ap->init || (*ap->init)(ap, server)) { 223 i_support |= typemask(ap->type); 224 if (auth_debug_mode) 225 printf(">>>%s: I support auth type %d %d\r\n", 226 Name, 227 ap->type, ap->way); 228 } 229 else if (auth_debug_mode) 230 printf(">>>%s: Init failed: auth type %d %d\r\n", 231 Name, ap->type, ap->way); 232 ++ap; 233 } 234 } 235 236 void 237 auth_disable_name(name) 238 char *name; 239 { 240 int x; 241 for (x = 0; x < AUTHTYPE_CNT; ++x) { 242 if (!strcasecmp(name, AUTHTYPE_NAME(x))) { 243 i_wont_support |= typemask(x); 244 break; 245 } 246 } 247 } 248 249 int 250 getauthmask(type, maskp) 251 char *type; 252 int *maskp; 253 { 254 register int x; 255 256 if (!strcasecmp(type, AUTHTYPE_NAME(0))) { 257 *maskp = -1; 258 return(1); 259 } 260 261 for (x = 1; x < AUTHTYPE_CNT; ++x) { 262 if (!strcasecmp(type, AUTHTYPE_NAME(x))) { 263 *maskp = typemask(x); 264 return(1); 265 } 266 } 267 return(0); 268 } 269 270 int 271 auth_enable(type) 272 char *type; 273 { 274 return(auth_onoff(type, 1)); 275 } 276 277 int 278 auth_disable(type) 279 char *type; 280 { 281 return(auth_onoff(type, 0)); 282 } 283 284 int 285 auth_onoff(type, on) 286 char *type; 287 int on; 288 { 289 int i, mask = -1; 290 Authenticator *ap; 291 292 if (!strcasecmp(type, "?") || !strcasecmp(type, "help")) { 293 printf("auth %s 'type'\n", on ? "enable" : "disable"); 294 printf("Where 'type' is one of:\n"); 295 printf("\t%s\n", AUTHTYPE_NAME(0)); 296 mask = 0; 297 for (ap = authenticators; ap->type; ap++) { 298 if ((mask & (i = typemask(ap->type))) != 0) 299 continue; 300 mask |= i; 301 printf("\t%s\n", AUTHTYPE_NAME(ap->type)); 302 } 303 return(0); 304 } 305 306 if (!getauthmask(type, &mask)) { 307 printf("%s: invalid authentication type\n", type); 308 return(0); 309 } 310 if (on) 311 i_wont_support &= ~mask; 312 else 313 i_wont_support |= mask; 314 return(1); 315 } 316 317 int 318 auth_togdebug(on) 319 int on; 320 { 321 if (on < 0) 322 auth_debug_mode ^= 1; 323 else 324 auth_debug_mode = on; 325 printf("auth debugging %s\n", auth_debug_mode ? "enabled" : "disabled"); 326 return(1); 327 } 328 329 int 330 auth_status(s) 331 char *s; 332 { 333 Authenticator *ap; 334 int i, mask; 335 336 if (i_wont_support == -1) 337 printf("Authentication disabled\n"); 338 else 339 printf("Authentication enabled\n"); 340 341 mask = 0; 342 for (ap = authenticators; ap->type; ap++) { 343 if ((mask & (i = typemask(ap->type))) != 0) 344 continue; 345 mask |= i; 346 printf("%s: %s\n", AUTHTYPE_NAME(ap->type), 347 (i_wont_support & typemask(ap->type)) ? 348 "disabled" : "enabled"); 349 } 350 return(1); 351 } 352 353 /* 354 * This routine is called by the server to start authentication 355 * negotiation. 356 */ 357 void 358 auth_request() 359 { 360 static unsigned char str_request[64] = { IAC, SB, 361 TELOPT_AUTHENTICATION, 362 TELQUAL_SEND, }; 363 Authenticator *ap = authenticators; 364 unsigned char *e = str_request + 4; 365 366 if (!authenticating) { 367 authenticating = 1; 368 while (ap->type) { 369 if (i_support & ~i_wont_support & typemask(ap->type)) { 370 if (auth_debug_mode) { 371 printf(">>>%s: Sending type %d %d\r\n", 372 Name, ap->type, ap->way); 373 } 374 *e++ = ap->type; 375 *e++ = ap->way; 376 } 377 ++ap; 378 } 379 *e++ = IAC; 380 *e++ = SE; 381 telnet_net_write(str_request, e - str_request); 382 printsub('>', &str_request[2], e - str_request - 2); 383 } 384 } 385 386 /* 387 * This is called when an AUTH SEND is received. 388 * It should never arrive on the server side (as only the server can 389 * send an AUTH SEND). 390 * You should probably respond to it if you can... 391 * 392 * If you want to respond to the types out of order (i.e. even 393 * if he sends LOGIN KERBEROS and you support both, you respond 394 * with KERBEROS instead of LOGIN (which is against what the 395 * protocol says)) you will have to hack this code... 396 */ 397 void 398 auth_send(data, cnt) 399 unsigned char *data; 400 int cnt; 401 { 402 Authenticator *ap; 403 static unsigned char str_none[] = { IAC, SB, TELOPT_AUTHENTICATION, 404 TELQUAL_IS, AUTHTYPE_NULL, 0, 405 IAC, SE }; 406 if (Server) { 407 if (auth_debug_mode) { 408 printf(">>>%s: auth_send called!\r\n", Name); 409 } 410 return; 411 } 412 413 if (auth_debug_mode) { 414 printf(">>>%s: auth_send got:", Name); 415 printd(data, cnt); printf("\r\n"); 416 } 417 418 /* 419 * Save the data, if it is new, so that we can continue looking 420 * at it if the authorization we try doesn't work 421 */ 422 if (data < _auth_send_data || 423 data > _auth_send_data + sizeof(_auth_send_data)) { 424 auth_send_cnt = cnt > sizeof(_auth_send_data) 425 ? sizeof(_auth_send_data) 426 : cnt; 427 memmove((void *)_auth_send_data, (void *)data, auth_send_cnt); 428 auth_send_data = _auth_send_data; 429 } else { 430 /* 431 * This is probably a no-op, but we just make sure 432 */ 433 auth_send_data = data; 434 auth_send_cnt = cnt; 435 } 436 while ((auth_send_cnt -= 2) >= 0) { 437 if (auth_debug_mode) 438 printf(">>>%s: He supports %d\r\n", 439 Name, *auth_send_data); 440 if ((i_support & ~i_wont_support) & typemask(*auth_send_data)) { 441 ap = findauthenticator(auth_send_data[0], 442 auth_send_data[1]); 443 if (ap && ap->send) { 444 if (auth_debug_mode) 445 printf(">>>%s: Trying %d %d\r\n", 446 Name, auth_send_data[0], 447 auth_send_data[1]); 448 if ((*ap->send)(ap)) { 449 /* 450 * Okay, we found one we like 451 * and did it. 452 * we can go home now. 453 */ 454 if (auth_debug_mode) 455 printf(">>>%s: Using type %d\r\n", 456 Name, *auth_send_data); 457 auth_send_data += 2; 458 return; 459 } 460 } 461 /* else 462 * just continue on and look for the 463 * next one if we didn't do anything. 464 */ 465 } 466 auth_send_data += 2; 467 } 468 telnet_net_write(str_none, sizeof(str_none)); 469 printsub('>', &str_none[2], sizeof(str_none) - 2); 470 if (auth_debug_mode) 471 printf(">>>%s: Sent failure message\r\n", Name); 472 auth_finished(0, AUTH_REJECT); 473 #ifdef KANNAN 474 /* 475 * We requested strong authentication, however no mechanisms worked. 476 * Therefore, exit on client end. 477 */ 478 printf("Unable to securely authenticate user ... exit\n"); 479 exit(0); 480 #endif /* KANNAN */ 481 } 482 483 void 484 auth_send_retry() 485 { 486 /* 487 * if auth_send_cnt <= 0 then auth_send will end up rejecting 488 * the authentication and informing the other side of this. 489 */ 490 auth_send(auth_send_data, auth_send_cnt); 491 } 492 493 void 494 auth_is(data, cnt) 495 unsigned char *data; 496 int cnt; 497 { 498 Authenticator *ap; 499 500 if (cnt < 2) 501 return; 502 503 if (data[0] == AUTHTYPE_NULL) { 504 auth_finished(0, AUTH_REJECT); 505 return; 506 } 507 508 if ((ap = findauthenticator(data[0], data[1])) != NULL) { 509 if (ap->is) 510 (*ap->is)(ap, data+2, cnt-2); 511 } else if (auth_debug_mode) 512 printf(">>>%s: Invalid authentication in IS: %d\r\n", 513 Name, *data); 514 } 515 516 void 517 auth_reply(data, cnt) 518 unsigned char *data; 519 int cnt; 520 { 521 Authenticator *ap; 522 523 if (cnt < 2) 524 return; 525 526 if ((ap = findauthenticator(data[0], data[1])) != NULL) { 527 if (ap->reply) 528 (*ap->reply)(ap, data+2, cnt-2); 529 } else if (auth_debug_mode) 530 printf(">>>%s: Invalid authentication in SEND: %d\r\n", 531 Name, *data); 532 } 533 534 void 535 auth_name(data, cnt) 536 unsigned char *data; 537 int cnt; 538 { 539 unsigned char savename[256]; 540 541 if (cnt < 1) { 542 if (auth_debug_mode) 543 printf(">>>%s: Empty name in NAME\r\n", Name); 544 return; 545 } 546 if (cnt > sizeof(savename) - 1) { 547 if (auth_debug_mode) 548 printf(">>>%s: Name in NAME (%d) exceeds %ld length\r\n", 549 Name, cnt, (long)sizeof(savename)-1); 550 return; 551 } 552 memmove((void *)savename, (void *)data, cnt); 553 savename[cnt] = '\0'; /* Null terminate */ 554 if (auth_debug_mode) 555 printf(">>>%s: Got NAME [%s]\r\n", Name, savename); 556 auth_encrypt_user(savename); 557 } 558 559 int 560 auth_sendname(cp, len) 561 unsigned char *cp; 562 int len; 563 { 564 static unsigned char str_request[256+6] 565 = { IAC, SB, TELOPT_AUTHENTICATION, TELQUAL_NAME, }; 566 register unsigned char *e = str_request + 4; 567 register unsigned char *ee = &str_request[sizeof(str_request)-2]; 568 569 while (--len >= 0) { 570 if ((*e++ = *cp++) == IAC) 571 *e++ = IAC; 572 if (e >= ee) 573 return(0); 574 } 575 *e++ = IAC; 576 *e++ = SE; 577 telnet_net_write(str_request, e - str_request); 578 printsub('>', &str_request[2], e - &str_request[2]); 579 return(1); 580 } 581 582 void 583 auth_finished(ap, result) 584 Authenticator *ap; 585 int result; 586 { 587 if (!(authenticated = ap)) 588 authenticated = &NoAuth; 589 validuser = result; 590 } 591 592 /* ARGSUSED */ 593 static void 594 auth_intr(sig) 595 int sig; 596 { 597 auth_finished(0, AUTH_REJECT); 598 } 599 600 int 601 auth_wait(name, l) 602 char *name; 603 size_t l; 604 { 605 if (auth_debug_mode) 606 printf(">>>%s: in auth_wait.\r\n", Name); 607 608 if (Server && !authenticating) 609 return(0); 610 611 (void) signal(SIGALRM, auth_intr); 612 alarm(30); 613 while (!authenticated) 614 if (telnet_spin()) 615 break; 616 alarm(0); 617 (void) signal(SIGALRM, SIG_DFL); 618 619 /* 620 * Now check to see if the user is valid or not 621 */ 622 if (!authenticated || authenticated == &NoAuth) 623 return(AUTH_REJECT); 624 625 if (validuser == AUTH_VALID) 626 validuser = AUTH_USER; 627 628 if (authenticated->status) 629 validuser = (*authenticated->status)(authenticated, 630 name, l, validuser); 631 return(validuser); 632 } 633 634 void 635 auth_debug(mode) 636 int mode; 637 { 638 auth_debug_mode = mode; 639 } 640 641 void 642 auth_printsub(data, cnt, buf, buflen) 643 unsigned char *data, *buf; 644 int cnt, buflen; 645 { 646 Authenticator *ap; 647 648 if ((ap = findauthenticator(data[1], data[2])) && ap->printsub) 649 (*ap->printsub)(data, cnt, buf, buflen); 650 else 651 auth_gen_printsub(data, cnt, buf, buflen); 652 } 653 654 void 655 auth_gen_printsub(data, cnt, buf, buflen) 656 unsigned char *data, *buf; 657 int cnt, buflen; 658 { 659 register unsigned char *cp; 660 unsigned char tbuf[16]; 661 662 cnt -= 3; 663 data += 3; 664 buf[buflen-1] = '\0'; 665 buf[buflen-2] = '*'; 666 buflen -= 2; 667 for (; cnt > 0; cnt--, data++) { 668 snprintf((char *)tbuf, sizeof(tbuf), " %d", *data); 669 for (cp = tbuf; *cp && buflen > 0; --buflen) 670 *buf++ = *cp++; 671 if (buflen <= 0) 672 return; 673 } 674 *buf = '\0'; 675 } 676 #endif 677
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