crypto/heimdal-0.6.3/appl/telnet/libtelnet/auth.c

   1 /*-
   2  * Copyright (c) 1991, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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 /*
  35  * Copyright (C) 1990 by the Massachusetts Institute of Technology
  36  *
  37  * Export of this software from the United States of America is assumed
  38  * to require a specific license from the United States Government.
  39  * It is the responsibility of any person or organization contemplating
  40  * export to obtain such a license before exporting.
  41  *
  42  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
  43  * distribute this software and its documentation for any purpose and
  44  * without fee is hereby granted, provided that the above copyright
  45  * notice appear in all copies and that both that copyright notice and
  46  * this permission notice appear in supporting documentation, and that
  47  * the name of M.I.T. not be used in advertising or publicity pertaining
  48  * to distribution of the software without specific, written prior
  49  * permission.  M.I.T. makes no representations about the suitability of
  50  * this software for any purpose.  It is provided "as is" without express
  51  * or implied warranty.
  52  */
  53
  54 #include <config.h>
  55
  56 RCSID("$Id: auth.c,v 1.25 2002/01/18 12:58:48 joda Exp $");
  57
  58 #if     defined(AUTHENTICATION)
  59 #include <stdio.h>
  60 #ifdef HAVE_SYS_TYPES_H
  61 #include <sys/types.h>
  62 #endif
  63 #include <signal.h>
  64 #define AUTH_NAMES
  65 #ifdef HAVE_ARPA_TELNET_H
  66 #include <arpa/telnet.h>
  67 #endif
  68 #include <stdlib.h>
  69 #include <string.h>
  70
  71 #include <roken.h>
  72
  73 #ifdef SOCKS
  74 #include <socks.h>
  75 #endif
  76
  77 #include "encrypt.h"
  78 #include "auth.h"
  79 #include "misc-proto.h"
  80 #include "auth-proto.h"
  81
  82 #define typemask(x)             (1<<((x)-1))
  83
  84 #ifdef  KRB4_ENCPWD
  85 extern krb4encpwd_init();
  86 extern krb4encpwd_send();
  87 extern krb4encpwd_is();
  88 extern krb4encpwd_reply();
  89 extern krb4encpwd_status();
  90 extern krb4encpwd_printsub();
  91 #endif
  92
  93 #ifdef  RSA_ENCPWD
  94 extern rsaencpwd_init();
  95 extern rsaencpwd_send();
  96 extern rsaencpwd_is();
  97 extern rsaencpwd_reply();
  98 extern rsaencpwd_status();
  99 extern rsaencpwd_printsub();
 100 #endif
 101
 102 int auth_debug_mode = 0;
 103 int auth_has_failed  = 0;
 104 int auth_enable_encrypt = 0;
 105 static  const   char    *Name = "Noname";
 106 static  int     Server = 0;
 107 static  Authenticator   *authenticated = 0;
 108 static  int     authenticating = 0;
 109 static  int     validuser = 0;
 110 static  unsigned char   _auth_send_data[256];
 111 static  unsigned char   *auth_send_data;
 112 static  int     auth_send_cnt = 0;
 113
 114 /*
 115  * Authentication types supported.  Plese note that these are stored
 116  * in priority order, i.e. try the first one first.
 117  */
 118 Authenticator authenticators[] = {
 119 #ifdef UNSAFE
 120     { AUTHTYPE_UNSAFE, AUTH_WHO_CLIENT|AUTH_HOW_ONE_WAY,
 121       unsafe_init,
 122       unsafe_send,
 123       unsafe_is,
 124       unsafe_reply,
 125       unsafe_status,
 126       unsafe_printsub },
 127 #endif
 128 #ifdef SRA
 129     { AUTHTYPE_SRA, AUTH_WHO_CLIENT|AUTH_HOW_ONE_WAY,
 130       sra_init,
 131       sra_send,
 132       sra_is,
 133       sra_reply,
 134       sra_status,
 135       sra_printsub },
 136 #endif
 137 #ifdef  SPX
 138     { AUTHTYPE_SPX, AUTH_WHO_CLIENT|AUTH_HOW_MUTUAL,
 139       spx_init,
 140       spx_send,
 141       spx_is,
 142       spx_reply,
 143       spx_status,
 144       spx_printsub },
 145     { AUTHTYPE_SPX, AUTH_WHO_CLIENT|AUTH_HOW_ONE_WAY,
 146       spx_init,
 147       spx_send,
 148       spx_is,
 149       spx_reply,
 150       spx_status,
 151       spx_printsub },
 152 #endif
 153 #ifdef  KRB5
 154     { AUTHTYPE_KERBEROS_V5, AUTH_WHO_CLIENT|AUTH_HOW_MUTUAL,
 155       kerberos5_init,
 156       kerberos5_send_mutual,
 157       kerberos5_is,
 158       kerberos5_reply,
 159       kerberos5_status,
 160       kerberos5_printsub },
 161     { AUTHTYPE_KERBEROS_V5, AUTH_WHO_CLIENT|AUTH_HOW_ONE_WAY,
 162       kerberos5_init,
 163       kerberos5_send_oneway,
 164       kerberos5_is,
 165       kerberos5_reply,
 166       kerberos5_status,
 167       kerberos5_printsub },
 168 #endif
 169 #ifdef  KRB4
 170     { AUTHTYPE_KERBEROS_V4, AUTH_WHO_CLIENT|AUTH_HOW_MUTUAL,
 171       kerberos4_init,
 172       kerberos4_send_mutual,
 173       kerberos4_is,
 174       kerberos4_reply,
 175       kerberos4_status,
 176       kerberos4_printsub },
 177     { AUTHTYPE_KERBEROS_V4, AUTH_WHO_CLIENT|AUTH_HOW_ONE_WAY,
 178       kerberos4_init,
 179       kerberos4_send_oneway,
 180       kerberos4_is,
 181       kerberos4_reply,
 182       kerberos4_status,
 183       kerberos4_printsub },
 184 #endif
 185 #ifdef  KRB4_ENCPWD
 186     { AUTHTYPE_KRB4_ENCPWD, AUTH_WHO_CLIENT|AUTH_HOW_MUTUAL,
 187       krb4encpwd_init,
 188       krb4encpwd_send,
 189       krb4encpwd_is,
 190       krb4encpwd_reply,
 191       krb4encpwd_status,
 192       krb4encpwd_printsub },
 193 #endif
 194 #ifdef  RSA_ENCPWD
 195     { AUTHTYPE_RSA_ENCPWD, AUTH_WHO_CLIENT|AUTH_HOW_ONE_WAY,
 196       rsaencpwd_init,
 197       rsaencpwd_send,
 198       rsaencpwd_is,
 199       rsaencpwd_reply,
 200       rsaencpwd_status,
 201       rsaencpwd_printsub },
 202 #endif
 203     { 0, },
 204 };
 205
 206 static Authenticator NoAuth = { 0 };
 207
 208 static int      i_support = 0;
 209 static int      i_wont_support = 0;
 210
 211 Authenticator *
 212 findauthenticator(int type, int way)
 213 {
 214     Authenticator *ap = authenticators;
 215
 216     while (ap->type && (ap->type != type || ap->way != way))
 217         ++ap;
 218     return(ap->type ? ap : 0);
 219 }
 220
 221 void
 222 auth_init(const char *name, int server)
 223 {
 224     Authenticator *ap = authenticators;
 225
 226     Server = server;
 227     Name = name;
 228
 229     i_support = 0;
 230     authenticated = 0;
 231     authenticating = 0;
 232     while (ap->type) {
 233         if (!ap->init || (*ap->init)(ap, server)) {
 234             i_support |= typemask(ap->type);
 235             if (auth_debug_mode)
 236                 printf(">>>%s: I support auth type %d %d\r\n",
 237                        Name,
 238                        ap->type, ap->way);
 239         }
 240         else if (auth_debug_mode)
 241             printf(">>>%s: Init failed: auth type %d %d\r\n",
 242                    Name, ap->type, ap->way);
 243         ++ap;
 244     }
 245 }
 246
 247 void
 248 auth_disable_name(char *name)
 249 {
 250     int x;
 251     for (x = 0; x < AUTHTYPE_CNT; ++x) {
 252         if (!strcasecmp(name, AUTHTYPE_NAME(x))) {
 253             i_wont_support |= typemask(x);
 254             break;
 255         }
 256     }
 257 }
 258
 259 int
 260 getauthmask(char *type, int *maskp)
 261 {
 262     int x;
 263
 264     if (!strcasecmp(type, AUTHTYPE_NAME(0))) {
 265         *maskp = -1;
 266         return(1);
 267     }
 268
 269     for (x = 1; x < AUTHTYPE_CNT; ++x) {
 270         if (!strcasecmp(type, AUTHTYPE_NAME(x))) {
 271             *maskp = typemask(x);
 272             return(1);
 273         }
 274     }
 275     return(0);
 276 }
 277
 278 int
 279 auth_enable(char *type)
 280 {
 281     return(auth_onoff(type, 1));
 282 }
 283
 284 int
 285 auth_disable(char *type)
 286 {
 287     return(auth_onoff(type, 0));
 288 }
 289
 290 int
 291 auth_onoff(char *type, int on)
 292 {
 293     int i, mask = -1;
 294     Authenticator *ap;
 295
 296     if (!strcasecmp(type, "?") || !strcasecmp(type, "help")) {
 297         printf("auth %s 'type'\n", on ? "enable" : "disable");
 298         printf("Where 'type' is one of:\n");
 299         printf("\t%s\n", AUTHTYPE_NAME(0));
 300         mask = 0;
 301         for (ap = authenticators; ap->type; ap++) {
 302             if ((mask & (i = typemask(ap->type))) != 0)
 303                 continue;
 304             mask |= i;
 305             printf("\t%s\n", AUTHTYPE_NAME(ap->type));
 306         }
 307         return(0);
 308     }
 309
 310     if (!getauthmask(type, &mask)) {
 311         printf("%s: invalid authentication type\n", type);
 312         return(0);
 313     }
 314     if (on)
 315         i_wont_support &= ~mask;
 316     else
 317         i_wont_support |= mask;
 318     return(1);
 319 }
 320
 321 int
 322 auth_togdebug(int on)
 323 {
 324     if (on < 0)
 325         auth_debug_mode ^= 1;
 326     else
 327         auth_debug_mode = on;
 328     printf("auth debugging %s\n", auth_debug_mode ? "enabled" : "disabled");
 329     return(1);
 330 }
 331
 332 int
 333 auth_status(void)
 334 {
 335     Authenticator *ap;
 336     int i, mask;
 337
 338     if (i_wont_support == -1)
 339         printf("Authentication disabled\n");
 340     else
 341         printf("Authentication enabled\n");
 342
 343     mask = 0;
 344     for (ap = authenticators; ap->type; ap++) {
 345         if ((mask & (i = typemask(ap->type))) != 0)
 346             continue;
 347         mask |= i;
 348         printf("%s: %s\n", AUTHTYPE_NAME(ap->type),
 349                (i_wont_support & typemask(ap->type)) ?
 350                "disabled" : "enabled");
 351     }
 352     return(1);
 353 }
 354
 355 /*
 356  * This routine is called by the server to start authentication
 357  * negotiation.
 358  */
 359 void
 360 auth_request(void)
 361 {
 362     static unsigned char str_request[64] = { IAC, SB,
 363                                              TELOPT_AUTHENTICATION,
 364                                              TELQUAL_SEND, };
 365     Authenticator *ap = authenticators;
 366     unsigned char *e = str_request + 4;
 367
 368     if (!authenticating) {
 369         authenticating = 1;
 370         while (ap->type) {
 371             if (i_support & ~i_wont_support & typemask(ap->type)) {
 372                 if (auth_debug_mode) {
 373                     printf(">>>%s: Sending type %d %d\r\n",
 374                            Name, ap->type, ap->way);
 375                 }
 376                 *e++ = ap->type;
 377                 *e++ = ap->way;
 378             }
 379             ++ap;
 380         }
 381         *e++ = IAC;
 382         *e++ = SE;
 383         telnet_net_write(str_request, e - str_request);
 384         printsub('>', &str_request[2], e - str_request - 2);
 385     }
 386 }
 387
 388 /*
 389  * This is called when an AUTH SEND is received.
 390  * It should never arrive on the server side (as only the server can
 391  * send an AUTH SEND).
 392  * You should probably respond to it if you can...
 393  *
 394  * If you want to respond to the types out of order (i.e. even
 395  * if he sends  LOGIN KERBEROS and you support both, you respond
 396  * with KERBEROS instead of LOGIN (which is against what the
 397  * protocol says)) you will have to hack this code...
 398  */
 399 void
 400 auth_send(unsigned char *data, 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(_auth_send_data, 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     auth_has_failed = 1;
 474 #ifdef KANNAN
 475     /*
 476      *  We requested strong authentication, however no mechanisms worked.
 477      *  Therefore, exit on client end.
 478      */
 479     printf("Unable to securely authenticate user ... exit\n");
 480     exit(0);
 481 #endif /* KANNAN */
 482 }
 483
 484 void
 485 auth_send_retry(void)
 486 {
 487     /*
 488      * if auth_send_cnt <= 0 then auth_send will end up rejecting
 489      * the authentication and informing the other side of this.
 490          */
 491     auth_send(auth_send_data, auth_send_cnt);
 492 }
 493
 494 void
 495 auth_is(unsigned char *data, int cnt)
 496 {
 497     Authenticator *ap;
 498
 499     if (cnt < 2)
 500         return;
 501
 502     if (data[0] == AUTHTYPE_NULL) {
 503         auth_finished(0, AUTH_REJECT);
 504         return;
 505     }
 506
 507     if ((ap = findauthenticator(data[0], data[1]))) {
 508         if (ap->is)
 509             (*ap->is)(ap, data+2, cnt-2);
 510     } else if (auth_debug_mode)
 511         printf(">>>%s: Invalid authentication in IS: %d\r\n",
 512                Name, *data);
 513 }
 514
 515 void
 516 auth_reply(unsigned char *data, int cnt)
 517 {
 518     Authenticator *ap;
 519
 520     if (cnt < 2)
 521         return;
 522
 523     if ((ap = findauthenticator(data[0], data[1]))) {
 524         if (ap->reply)
 525             (*ap->reply)(ap, data+2, cnt-2);
 526     } else if (auth_debug_mode)
 527         printf(">>>%s: Invalid authentication in SEND: %d\r\n",
 528                Name, *data);
 529 }
 530
 531 void
 532 auth_name(unsigned char *data, int cnt)
 533 {
 534     char savename[256];
 535
 536     if (cnt < 1) {
 537         if (auth_debug_mode)
 538             printf(">>>%s: Empty name in NAME\r\n", Name);
 539         return;
 540     }
 541     if (cnt > sizeof(savename) - 1) {
 542         if (auth_debug_mode)
 543             printf(">>>%s: Name in NAME (%d) exceeds %lu length\r\n",
 544                    Name, cnt, (unsigned long)(sizeof(savename)-1));
 545         return;
 546     }
 547     memmove(savename, data, cnt);
 548     savename[cnt] = '\0';       /* Null terminate */
 549     if (auth_debug_mode)
 550         printf(">>>%s: Got NAME [%s]\r\n", Name, savename);
 551     auth_encrypt_user(savename);
 552 }
 553
 554 int
 555 auth_sendname(unsigned char *cp, int len)
 556 {
 557     static unsigned char str_request[256+6]
 558         = { IAC, SB, TELOPT_AUTHENTICATION, TELQUAL_NAME, };
 559     unsigned char *e = str_request + 4;
 560     unsigned char *ee = &str_request[sizeof(str_request)-2];
 561
 562     while (--len >= 0) {
 563         if ((*e++ = *cp++) == IAC)
 564             *e++ = IAC;
 565         if (e >= ee)
 566             return(0);
 567     }
 568     *e++ = IAC;
 569     *e++ = SE;
 570     telnet_net_write(str_request, e - str_request);
 571     printsub('>', &str_request[2], e - &str_request[2]);
 572     return(1);
 573 }
 574
 575 void
 576 auth_finished(Authenticator *ap, int result)
 577 {
 578     if (!(authenticated = ap))
 579         authenticated = &NoAuth;
 580     validuser = result;
 581 }
 582
 583 /* ARGSUSED */
 584 static void
 585 auth_intr(int sig)
 586 {
 587     auth_finished(0, AUTH_REJECT);
 588 }
 589
 590 int
 591 auth_wait(char *name, size_t name_sz)
 592 {
 593     if (auth_debug_mode)
 594         printf(">>>%s: in auth_wait.\r\n", Name);
 595
 596     if (Server && !authenticating)
 597         return(0);
 598
 599     signal(SIGALRM, auth_intr);
 600     alarm(30);
 601     while (!authenticated)
 602         if (telnet_spin())
 603             break;
 604     alarm(0);
 605     signal(SIGALRM, SIG_DFL);
 606
 607     /*
 608      * Now check to see if the user is valid or not
 609      */
 610     if (!authenticated || authenticated == &NoAuth)
 611         return(AUTH_REJECT);
 612
 613     if (validuser == AUTH_VALID)
 614         validuser = AUTH_USER;
 615
 616     if (authenticated->status)
 617         validuser = (*authenticated->status)(authenticated,
 618                                              name, name_sz,
 619                                              validuser);
 620     return(validuser);
 621 }
 622
 623 void
 624 auth_debug(int mode)
 625 {
 626     auth_debug_mode = mode;
 627 }
 628
 629 void
 630 auth_printsub(unsigned char *data, int cnt, unsigned char *buf, int buflen)
 631 {
 632     Authenticator *ap;
 633
 634     if ((ap = findauthenticator(data[1], data[2])) && ap->printsub)
 635         (*ap->printsub)(data, cnt, buf, buflen);
 636     else
 637         auth_gen_printsub(data, cnt, buf, buflen);
 638 }
 639
 640 void
 641 auth_gen_printsub(unsigned char *data, int cnt, unsigned char *buf, int buflen)
 642 {
 643     unsigned char *cp;
 644     unsigned char tbuf[16];
 645
 646     cnt -= 3;
 647     data += 3;
 648     buf[buflen-1] = '\0';
 649     buf[buflen-2] = '*';
 650     buflen -= 2;
 651     for (; cnt > 0; cnt--, data++) {
 652         snprintf((char*)tbuf, sizeof(tbuf), " %d", *data);
 653         for (cp = tbuf; *cp && buflen > 0; --buflen)
 654             *buf++ = *cp++;
 655         if (buflen <= 0)
 656             return;
 657     }
 658     *buf = '\0';
 659 }
 660 #endif