lib/drivers/lwip/src/netif/ppp/chap.c

   1 /*** WARNING - THIS HAS NEVER BEEN FINISHED ***/
   2 /*****************************************************************************
   3 * chap.c - Network Challenge Handshake Authentication Protocol program file.
   4 *
   5 * Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.
   6 * portions Copyright (c) 1997 by Global Election Systems Inc.
   7 *
   8 * The authors hereby grant permission to use, copy, modify, distribute,
   9 * and license this software and its documentation for any purpose, provided
  10 * that existing copyright notices are retained in all copies and that this
  11 * notice and the following disclaimer are included verbatim in any
  12 * distributions. No written agreement, license, or royalty fee is required
  13 * for any of the authorized uses.
  14 *
  15 * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR
  16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18 * IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25 *
  26 ******************************************************************************
  27 * REVISION HISTORY
  28 *
  29 * 03-01-01 Marc Boucher <marc@mbsi.ca>
  30 *   Ported to lwIP.
  31 * 97-12-04 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.
  32 *   Original based on BSD chap.c.
  33 *****************************************************************************/
  34 /*
  35  * chap.c - Challenge Handshake Authentication Protocol.
  36  *
  37  * Copyright (c) 1993 The Australian National University.
  38  * All rights reserved.
  39  *
  40  * Redistribution and use in source and binary forms are permitted
  41  * provided that the above copyright notice and this paragraph are
  42  * duplicated in all such forms and that any documentation,
  43  * advertising materials, and other materials related to such
  44  * distribution and use acknowledge that the software was developed
  45  * by the Australian National University.  The name of the University
  46  * may not be used to endorse or promote products derived from this
  47  * software without specific prior written permission.
  48  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  49  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  50  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  51  *
  52  * Copyright (c) 1991 Gregory M. Christy.
  53  * All rights reserved.
  54  *
  55  * Redistribution and use in source and binary forms are permitted
  56  * provided that the above copyright notice and this paragraph are
  57  * duplicated in all such forms and that any documentation,
  58  * advertising materials, and other materials related to such
  59  * distribution and use acknowledge that the software was developed
  60  * by Gregory M. Christy.  The name of the author may not be used to
  61  * endorse or promote products derived from this software without
  62  * specific prior written permission.
  63  *
  64  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  65  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  66  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  67  */
  68
  69 #include "lwip/opt.h"
  70
  71 #if PPP_SUPPORT  /* don't build if not configured for use in lwipopts.h */
  72
  73 #if CHAP_SUPPORT /* don't build if not configured for use in lwipopts.h */
  74
  75 #include "ppp.h"
  76 #include "pppdebug.h"
  77
  78 #include "magic.h"
  79 #include "randm.h"
  80 #include "auth.h"
  81 #include "md5.h"
  82 #include "chap.h"
  83 #include "chpms.h"
  84
  85 #include <string.h>
  86
  87 /*************************/
  88 /*** LOCAL DEFINITIONS ***/
  89 /*************************/
  90
  91
  92 /************************/
  93 /*** LOCAL DATA TYPES ***/
  94 /************************/
  95
  96
  97 /***********************************/
  98 /*** LOCAL FUNCTION DECLARATIONS ***/
  99 /***********************************/
 100 /*
 101  * Protocol entry points.
 102  */
 103 static void ChapInit (int);
 104 static void ChapLowerUp (int);
 105 static void ChapLowerDown (int);
 106 static void ChapInput (int, u_char *, int);
 107 static void ChapProtocolReject (int);
 108 #if 0
 109 static int  ChapPrintPkt (u_char *, int, void (*) (void *, char *, ...), void *);
 110 #endif
 111
 112 static void ChapChallengeTimeout (void *);
 113 static void ChapResponseTimeout (void *);
 114 static void ChapReceiveChallenge (chap_state *, u_char *, int, int);
 115 static void ChapRechallenge (void *);
 116 static void ChapReceiveResponse (chap_state *, u_char *, int, int);
 117 static void ChapReceiveSuccess(chap_state *cstate, u_char *inp, u_char id, int len);
 118 static void ChapReceiveFailure(chap_state *cstate, u_char *inp, u_char id, int len);
 119 static void ChapSendStatus (chap_state *, int);
 120 static void ChapSendChallenge (chap_state *);
 121 static void ChapSendResponse (chap_state *);
 122 static void ChapGenChallenge (chap_state *);
 123
 124
 125 /******************************/
 126 /*** PUBLIC DATA STRUCTURES ***/
 127 /******************************/
 128 chap_state chap[NUM_PPP]; /* CHAP state; one for each unit */
 129
 130 struct protent chap_protent = {
 131   PPP_CHAP,
 132   ChapInit,
 133   ChapInput,
 134   ChapProtocolReject,
 135   ChapLowerUp,
 136   ChapLowerDown,
 137   NULL,
 138   NULL,
 139 #if 0
 140   ChapPrintPkt,
 141   NULL,
 142 #endif
 143   1,
 144   "CHAP",
 145 #if 0
 146   NULL,
 147   NULL,
 148   NULL
 149 #endif
 150 };
 151
 152
 153 /***********************************/
 154 /*** PUBLIC FUNCTION DEFINITIONS ***/
 155 /***********************************/
 156 /*
 157  * ChapAuthWithPeer - Authenticate us with our peer (start client).
 158  *
 159  */
 160 void
 161 ChapAuthWithPeer(int unit, char *our_name, int digest)
 162 {
 163   chap_state *cstate = &chap[unit];
 164
 165   cstate->resp_name = our_name;
 166   cstate->resp_type = digest;
 167
 168   if (cstate->clientstate == CHAPCS_INITIAL ||
 169       cstate->clientstate == CHAPCS_PENDING) {
 170     /* lower layer isn't up - wait until later */
 171     cstate->clientstate = CHAPCS_PENDING;
 172     return;
 173   }
 174
 175   /*
 176    * We get here as a result of LCP coming up.
 177    * So even if CHAP was open before, we will
 178    * have to re-authenticate ourselves.
 179    */
 180   cstate->clientstate = CHAPCS_LISTEN;
 181 }
 182
 183
 184 /*
 185  * ChapAuthPeer - Authenticate our peer (start server).
 186  */
 187 void
 188 ChapAuthPeer(int unit, char *our_name, int digest)
 189 {
 190   chap_state *cstate = &chap[unit];
 191
 192   cstate->chal_name = our_name;
 193   cstate->chal_type = digest;
 194
 195   if (cstate->serverstate == CHAPSS_INITIAL ||
 196       cstate->serverstate == CHAPSS_PENDING) {
 197     /* lower layer isn't up - wait until later */
 198     cstate->serverstate = CHAPSS_PENDING;
 199     return;
 200   }
 201
 202   ChapGenChallenge(cstate);
 203   ChapSendChallenge(cstate);    /* crank it up dude! */
 204   cstate->serverstate = CHAPSS_INITIAL_CHAL;
 205 }
 206
 207
 208 /**********************************/
 209 /*** LOCAL FUNCTION DEFINITIONS ***/
 210 /**********************************/
 211 /*
 212  * ChapInit - Initialize a CHAP unit.
 213  */
 214 static void
 215 ChapInit(int unit)
 216 {
 217   chap_state *cstate = &chap[unit];
 218
 219   BZERO(cstate, sizeof(*cstate));
 220   cstate->unit = unit;
 221   cstate->clientstate = CHAPCS_INITIAL;
 222   cstate->serverstate = CHAPSS_INITIAL;
 223   cstate->timeouttime = CHAP_DEFTIMEOUT;
 224   cstate->max_transmits = CHAP_DEFTRANSMITS;
 225   /* random number generator is initialized in magic_init */
 226 }
 227
 228
 229 /*
 230  * ChapChallengeTimeout - Timeout expired on sending challenge.
 231  */
 232 static void
 233 ChapChallengeTimeout(void *arg)
 234 {
 235   chap_state *cstate = (chap_state *) arg;
 236
 237   /* if we aren't sending challenges, don't worry.  then again we */
 238   /* probably shouldn't be here either */
 239   if (cstate->serverstate != CHAPSS_INITIAL_CHAL &&
 240       cstate->serverstate != CHAPSS_RECHALLENGE) {
 241     return;
 242   }
 243
 244   if (cstate->chal_transmits >= cstate->max_transmits) {
 245     /* give up on peer */
 246     CHAPDEBUG((LOG_ERR, "Peer failed to respond to CHAP challenge\n"));
 247     cstate->serverstate = CHAPSS_BADAUTH;
 248     auth_peer_fail(cstate->unit, PPP_CHAP);
 249     return;
 250   }
 251
 252   ChapSendChallenge(cstate); /* Re-send challenge */
 253 }
 254
 255
 256 /*
 257  * ChapResponseTimeout - Timeout expired on sending response.
 258  */
 259 static void
 260 ChapResponseTimeout(void *arg)
 261 {
 262   chap_state *cstate = (chap_state *) arg;
 263
 264   /* if we aren't sending a response, don't worry. */
 265   if (cstate->clientstate != CHAPCS_RESPONSE) {
 266     return;
 267   }
 268
 269   ChapSendResponse(cstate);    /* re-send response */
 270 }
 271
 272
 273 /*
 274  * ChapRechallenge - Time to challenge the peer again.
 275  */
 276 static void
 277 ChapRechallenge(void *arg)
 278 {
 279   chap_state *cstate = (chap_state *) arg;
 280
 281   /* if we aren't sending a response, don't worry. */
 282   if (cstate->serverstate != CHAPSS_OPEN) {
 283     return;
 284   }
 285
 286   ChapGenChallenge(cstate);
 287   ChapSendChallenge(cstate);
 288   cstate->serverstate = CHAPSS_RECHALLENGE;
 289 }
 290
 291
 292 /*
 293  * ChapLowerUp - The lower layer is up.
 294  *
 295  * Start up if we have pending requests.
 296  */
 297 static void
 298 ChapLowerUp(int unit)
 299 {
 300   chap_state *cstate = &chap[unit];
 301
 302   if (cstate->clientstate == CHAPCS_INITIAL) {
 303     cstate->clientstate = CHAPCS_CLOSED;
 304   } else if (cstate->clientstate == CHAPCS_PENDING) {
 305     cstate->clientstate = CHAPCS_LISTEN;
 306   }
 307
 308   if (cstate->serverstate == CHAPSS_INITIAL) {
 309     cstate->serverstate = CHAPSS_CLOSED;
 310   } else if (cstate->serverstate == CHAPSS_PENDING) {
 311     ChapGenChallenge(cstate);
 312     ChapSendChallenge(cstate);
 313     cstate->serverstate = CHAPSS_INITIAL_CHAL;
 314   }
 315 }
 316
 317
 318 /*
 319  * ChapLowerDown - The lower layer is down.
 320  *
 321  * Cancel all timeouts.
 322  */
 323 static void
 324 ChapLowerDown(int unit)
 325 {
 326   chap_state *cstate = &chap[unit];
 327
 328   /* Timeout(s) pending?  Cancel if so. */
 329   if (cstate->serverstate == CHAPSS_INITIAL_CHAL ||
 330       cstate->serverstate == CHAPSS_RECHALLENGE) {
 331     UNTIMEOUT(ChapChallengeTimeout, cstate);
 332   } else if (cstate->serverstate == CHAPSS_OPEN
 333       && cstate->chal_interval != 0) {
 334     UNTIMEOUT(ChapRechallenge, cstate);
 335   }
 336   if (cstate->clientstate == CHAPCS_RESPONSE) {
 337     UNTIMEOUT(ChapResponseTimeout, cstate);
 338   }
 339   cstate->clientstate = CHAPCS_INITIAL;
 340   cstate->serverstate = CHAPSS_INITIAL;
 341 }
 342
 343
 344 /*
 345  * ChapProtocolReject - Peer doesn't grok CHAP.
 346  */
 347 static void
 348 ChapProtocolReject(int unit)
 349 {
 350   chap_state *cstate = &chap[unit];
 351
 352   if (cstate->serverstate != CHAPSS_INITIAL &&
 353       cstate->serverstate != CHAPSS_CLOSED) {
 354     auth_peer_fail(unit, PPP_CHAP);
 355   }
 356   if (cstate->clientstate != CHAPCS_INITIAL &&
 357       cstate->clientstate != CHAPCS_CLOSED) {
 358     auth_withpeer_fail(unit, PPP_CHAP);
 359   }
 360   ChapLowerDown(unit); /* shutdown chap */
 361 }
 362
 363
 364 /*
 365  * ChapInput - Input CHAP packet.
 366  */
 367 static void
 368 ChapInput(int unit, u_char *inpacket, int packet_len)
 369 {
 370   chap_state *cstate = &chap[unit];
 371   u_char *inp;
 372   u_char code, id;
 373   int len;
 374
 375   /*
 376    * Parse header (code, id and length).
 377    * If packet too short, drop it.
 378    */
 379   inp = inpacket;
 380   if (packet_len < CHAP_HEADERLEN) {
 381     CHAPDEBUG((LOG_INFO, "ChapInput: rcvd short header.\n"));
 382     return;
 383   }
 384   GETCHAR(code, inp);
 385   GETCHAR(id, inp);
 386   GETSHORT(len, inp);
 387   if (len < CHAP_HEADERLEN) {
 388     CHAPDEBUG((LOG_INFO, "ChapInput: rcvd illegal length.\n"));
 389     return;
 390   }
 391   if (len > packet_len) {
 392     CHAPDEBUG((LOG_INFO, "ChapInput: rcvd short packet.\n"));
 393     return;
 394   }
 395   len -= CHAP_HEADERLEN;
 396
 397   /*
 398    * Action depends on code (as in fact it usually does :-).
 399    */
 400   switch (code) {
 401     case CHAP_CHALLENGE:
 402       ChapReceiveChallenge(cstate, inp, id, len);
 403       break;
 404
 405     case CHAP_RESPONSE:
 406       ChapReceiveResponse(cstate, inp, id, len);
 407       break;
 408
 409     case CHAP_FAILURE:
 410       ChapReceiveFailure(cstate, inp, id, len);
 411       break;
 412
 413     case CHAP_SUCCESS:
 414       ChapReceiveSuccess(cstate, inp, id, len);
 415       break;
 416
 417     default:        /* Need code reject? */
 418       CHAPDEBUG((LOG_WARNING, "Unknown CHAP code (%d) received.\n", code));
 419       break;
 420   }
 421 }
 422
 423
 424 /*
 425  * ChapReceiveChallenge - Receive Challenge and send Response.
 426  */
 427 static void
 428 ChapReceiveChallenge(chap_state *cstate, u_char *inp, int id, int len)
 429 {
 430   int rchallenge_len;
 431   u_char *rchallenge;
 432   int secret_len;
 433   char secret[MAXSECRETLEN];
 434   char rhostname[256];
 435   MD5_CTX mdContext;
 436   u_char hash[MD5_SIGNATURE_SIZE];
 437
 438   CHAPDEBUG((LOG_INFO, "ChapReceiveChallenge: Rcvd id %d.\n", id));
 439   if (cstate->clientstate == CHAPCS_CLOSED ||
 440     cstate->clientstate == CHAPCS_PENDING) {
 441     CHAPDEBUG((LOG_INFO, "ChapReceiveChallenge: in state %d\n",
 442          cstate->clientstate));
 443     return;
 444   }
 445
 446   if (len < 2) {
 447     CHAPDEBUG((LOG_INFO, "ChapReceiveChallenge: rcvd short packet.\n"));
 448     return;
 449   }
 450
 451   GETCHAR(rchallenge_len, inp);
 452   len -= sizeof (u_char) + rchallenge_len;  /* now name field length */
 453   if (len < 0) {
 454     CHAPDEBUG((LOG_INFO, "ChapReceiveChallenge: rcvd short packet.\n"));
 455     return;
 456   }
 457   rchallenge = inp;
 458   INCPTR(rchallenge_len, inp);
 459
 460   if (len >= sizeof(rhostname)) {
 461     len = sizeof(rhostname) - 1;
 462   }
 463   BCOPY(inp, rhostname, len);
 464   rhostname[len] = '\000';
 465
 466   CHAPDEBUG((LOG_INFO, "ChapReceiveChallenge: received name field '%s'\n", rhostname));
 467
 468   /* Microsoft doesn't send their name back in the PPP packet */
 469   if (ppp_settings.remote_name[0] != 0 && (ppp_settings.explicit_remote || rhostname[0] == 0)) {
 470     strncpy(rhostname, ppp_settings.remote_name, sizeof(rhostname));
 471     rhostname[sizeof(rhostname) - 1] = 0;
 472     CHAPDEBUG((LOG_INFO, "ChapReceiveChallenge: using '%s' as remote name\n", rhostname));
 473   }
 474
 475   /* get secret for authenticating ourselves with the specified host */
 476   if (!get_secret(cstate->unit, cstate->resp_name, rhostname, secret, &secret_len, 0)) {
 477     secret_len = 0;    /* assume null secret if can't find one */
 478     CHAPDEBUG((LOG_WARNING, "No CHAP secret found for authenticating us to %s\n", rhostname));
 479   }
 480
 481   /* cancel response send timeout if necessary */
 482   if (cstate->clientstate == CHAPCS_RESPONSE) {
 483     UNTIMEOUT(ChapResponseTimeout, cstate);
 484   }
 485
 486   cstate->resp_id = id;
 487   cstate->resp_transmits = 0;
 488
 489   /*  generate MD based on negotiated type */
 490   switch (cstate->resp_type) {
 491
 492   case CHAP_DIGEST_MD5:
 493     MD5Init(&mdContext);
 494     MD5Update(&mdContext, &cstate->resp_id, 1);
 495     MD5Update(&mdContext, (u_char*)secret, secret_len);
 496     MD5Update(&mdContext, rchallenge, rchallenge_len);
 497     MD5Final(hash, &mdContext);
 498     BCOPY(hash, cstate->response, MD5_SIGNATURE_SIZE);
 499     cstate->resp_length = MD5_SIGNATURE_SIZE;
 500     break;
 501
 502 #ifdef CHAPMS
 503   case CHAP_MICROSOFT:
 504     ChapMS(cstate, rchallenge, rchallenge_len, secret, secret_len);
 505     break;
 506 #endif
 507
 508   default:
 509     CHAPDEBUG((LOG_INFO, "unknown digest type %d\n", cstate->resp_type));
 510     return;
 511   }
 512
 513   BZERO(secret, sizeof(secret));
 514   ChapSendResponse(cstate);
 515 }
 516
 517
 518 /*
 519  * ChapReceiveResponse - Receive and process response.
 520  */
 521 static void
 522 ChapReceiveResponse(chap_state *cstate, u_char *inp, int id, int len)
 523 {
 524   u_char *remmd, remmd_len;
 525   int secret_len, old_state;
 526   int code;
 527   char rhostname[256];
 528   MD5_CTX mdContext;
 529   char secret[MAXSECRETLEN];
 530   u_char hash[MD5_SIGNATURE_SIZE];
 531
 532   CHAPDEBUG((LOG_INFO, "ChapReceiveResponse: Rcvd id %d.\n", id));
 533
 534   if (cstate->serverstate == CHAPSS_CLOSED ||
 535       cstate->serverstate == CHAPSS_PENDING) {
 536     CHAPDEBUG((LOG_INFO, "ChapReceiveResponse: in state %d\n",
 537     cstate->serverstate));
 538     return;
 539   }
 540
 541   if (id != cstate->chal_id) {
 542     return;      /* doesn't match ID of last challenge */
 543   }
 544
 545   /*
 546   * If we have received a duplicate or bogus Response,
 547   * we have to send the same answer (Success/Failure)
 548   * as we did for the first Response we saw.
 549   */
 550   if (cstate->serverstate == CHAPSS_OPEN) {
 551     ChapSendStatus(cstate, CHAP_SUCCESS);
 552     return;
 553   }
 554   if (cstate->serverstate == CHAPSS_BADAUTH) {
 555     ChapSendStatus(cstate, CHAP_FAILURE);
 556     return;
 557   }
 558
 559   if (len < 2) {
 560     CHAPDEBUG((LOG_INFO, "ChapReceiveResponse: rcvd short packet.\n"));
 561     return;
 562   }
 563   GETCHAR(remmd_len, inp); /* get length of MD */
 564   remmd = inp;             /* get pointer to MD */
 565   INCPTR(remmd_len, inp);
 566
 567   len -= sizeof (u_char) + remmd_len;
 568   if (len < 0) {
 569     CHAPDEBUG((LOG_INFO, "ChapReceiveResponse: rcvd short packet.\n"));
 570     return;
 571   }
 572
 573   UNTIMEOUT(ChapChallengeTimeout, cstate);
 574
 575   if (len >= sizeof(rhostname)) {
 576     len = sizeof(rhostname) - 1;
 577   }
 578   BCOPY(inp, rhostname, len);
 579   rhostname[len] = '\000';
 580
 581   CHAPDEBUG((LOG_INFO, "ChapReceiveResponse: received name field: %s\n", rhostname));
 582
 583   /*
 584   * Get secret for authenticating them with us,
 585   * do the hash ourselves, and compare the result.
 586   */
 587   code = CHAP_FAILURE;
 588   if (!get_secret(cstate->unit, rhostname, cstate->chal_name, secret, &secret_len, 1)) {
 589     /* CHAPDEBUG((LOG_WARNING, TL_CHAP, "No CHAP secret found for authenticating %s\n", rhostname)); */
 590     CHAPDEBUG((LOG_WARNING, "No CHAP secret found for authenticating %s\n",
 591     rhostname));
 592   } else {
 593     /*  generate MD based on negotiated type */
 594     switch (cstate->chal_type) {
 595
 596       case CHAP_DIGEST_MD5:    /* only MD5 is defined for now */
 597         if (remmd_len != MD5_SIGNATURE_SIZE) {
 598           break;      /* it's not even the right length */
 599         }
 600         MD5Init(&mdContext);
 601         MD5Update(&mdContext, &cstate->chal_id, 1);
 602         MD5Update(&mdContext, (u_char*)secret, secret_len);
 603         MD5Update(&mdContext, cstate->challenge, cstate->chal_len);
 604         MD5Final(hash, &mdContext);
 605
 606         /* compare local and remote MDs and send the appropriate status */
 607         if (memcmp (hash, remmd, MD5_SIGNATURE_SIZE) == 0) {
 608           code = CHAP_SUCCESS;  /* they are the same! */
 609         }
 610         break;
 611
 612       default:
 613         CHAPDEBUG((LOG_INFO, "unknown digest type %d\n", cstate->chal_type));
 614     }
 615   }
 616
 617   BZERO(secret, sizeof(secret));
 618   ChapSendStatus(cstate, code);
 619
 620   if (code == CHAP_SUCCESS) {
 621     old_state = cstate->serverstate;
 622     cstate->serverstate = CHAPSS_OPEN;
 623     if (old_state == CHAPSS_INITIAL_CHAL) {
 624       auth_peer_success(cstate->unit, PPP_CHAP, rhostname, len);
 625     }
 626     if (cstate->chal_interval != 0) {
 627       TIMEOUT(ChapRechallenge, cstate, cstate->chal_interval);
 628     }
 629   } else {
 630     CHAPDEBUG((LOG_ERR, "CHAP peer authentication failed\n"));
 631     cstate->serverstate = CHAPSS_BADAUTH;
 632     auth_peer_fail(cstate->unit, PPP_CHAP);
 633   }
 634 }
 635
 636 /*
 637  * ChapReceiveSuccess - Receive Success
 638  */
 639 static void
 640 ChapReceiveSuccess(chap_state *cstate, u_char *inp, u_char id, int len)
 641 {
 642   LWIP_UNUSED_ARG(id);
 643   LWIP_UNUSED_ARG(inp);
 644
 645   CHAPDEBUG((LOG_INFO, "ChapReceiveSuccess: Rcvd id %d.\n", id));
 646
 647   if (cstate->clientstate == CHAPCS_OPEN) {
 648     /* presumably an answer to a duplicate response */
 649     return;
 650   }
 651
 652   if (cstate->clientstate != CHAPCS_RESPONSE) {
 653     /* don't know what this is */
 654     CHAPDEBUG((LOG_INFO, "ChapReceiveSuccess: in state %d\n", cstate->clientstate));
 655     return;
 656   }
 657
 658   UNTIMEOUT(ChapResponseTimeout, cstate);
 659
 660   /*
 661    * Print message.
 662    */
 663   if (len > 0) {
 664     PRINTMSG(inp, len);
 665   }
 666
 667   cstate->clientstate = CHAPCS_OPEN;
 668
 669   auth_withpeer_success(cstate->unit, PPP_CHAP);
 670 }
 671
 672
 673 /*
 674  * ChapReceiveFailure - Receive failure.
 675  */
 676 static void
 677 ChapReceiveFailure(chap_state *cstate, u_char *inp, u_char id, int len)
 678 {
 679   LWIP_UNUSED_ARG(id);
 680   LWIP_UNUSED_ARG(inp);
 681
 682   CHAPDEBUG((LOG_INFO, "ChapReceiveFailure: Rcvd id %d.\n", id));
 683
 684   if (cstate->clientstate != CHAPCS_RESPONSE) {
 685     /* don't know what this is */
 686     CHAPDEBUG((LOG_INFO, "ChapReceiveFailure: in state %d\n", cstate->clientstate));
 687     return;
 688   }
 689
 690   UNTIMEOUT(ChapResponseTimeout, cstate);
 691
 692   /*
 693    * Print message.
 694    */
 695   if (len > 0) {
 696     PRINTMSG(inp, len);
 697   }
 698
 699   CHAPDEBUG((LOG_ERR, "CHAP authentication failed\n"));
 700   auth_withpeer_fail(cstate->unit, PPP_CHAP);
 701 }
 702
 703
 704 /*
 705  * ChapSendChallenge - Send an Authenticate challenge.
 706  */
 707 static void
 708 ChapSendChallenge(chap_state *cstate)
 709 {
 710   u_char *outp;
 711   int chal_len, name_len;
 712   int outlen;
 713
 714   chal_len = cstate->chal_len;
 715   name_len = strlen(cstate->chal_name);
 716   outlen = CHAP_HEADERLEN + sizeof (u_char) + chal_len + name_len;
 717   outp = outpacket_buf[cstate->unit];
 718
 719   MAKEHEADER(outp, PPP_CHAP);    /* paste in a CHAP header */
 720
 721   PUTCHAR(CHAP_CHALLENGE, outp);
 722   PUTCHAR(cstate->chal_id, outp);
 723   PUTSHORT(outlen, outp);
 724
 725   PUTCHAR(chal_len, outp);    /* put length of challenge */
 726   BCOPY(cstate->challenge, outp, chal_len);
 727   INCPTR(chal_len, outp);
 728
 729   BCOPY(cstate->chal_name, outp, name_len);  /* append hostname */
 730
 731   pppWrite(cstate->unit, outpacket_buf[cstate->unit], outlen + PPP_HDRLEN);
 732
 733   CHAPDEBUG((LOG_INFO, "ChapSendChallenge: Sent id %d.\n", cstate->chal_id));
 734
 735   TIMEOUT(ChapChallengeTimeout, cstate, cstate->timeouttime);
 736   ++cstate->chal_transmits;
 737 }
 738
 739
 740 /*
 741  * ChapSendStatus - Send a status response (ack or nak).
 742  */
 743 static void
 744 ChapSendStatus(chap_state *cstate, int code)
 745 {
 746   u_char *outp;
 747   int outlen, msglen;
 748   char msg[256];
 749
 750   if (code == CHAP_SUCCESS) {
 751     strcpy(msg, "Welcome!");
 752   } else {
 753     strcpy(msg, "I don't like you.  Go 'way.");
 754   }
 755   msglen = strlen(msg);
 756
 757   outlen = CHAP_HEADERLEN + msglen;
 758   outp = outpacket_buf[cstate->unit];
 759
 760   MAKEHEADER(outp, PPP_CHAP);    /* paste in a header */
 761
 762   PUTCHAR(code, outp);
 763   PUTCHAR(cstate->chal_id, outp);
 764   PUTSHORT(outlen, outp);
 765   BCOPY(msg, outp, msglen);
 766   pppWrite(cstate->unit, outpacket_buf[cstate->unit], outlen + PPP_HDRLEN);
 767
 768   CHAPDEBUG((LOG_INFO, "ChapSendStatus: Sent code %d, id %d.\n", code, cstate->chal_id));
 769 }
 770
 771 /*
 772  * ChapGenChallenge is used to generate a pseudo-random challenge string of
 773  * a pseudo-random length between min_len and max_len.  The challenge
 774  * string and its length are stored in *cstate, and various other fields of
 775  * *cstate are initialized.
 776  */
 777
 778 static void
 779 ChapGenChallenge(chap_state *cstate)
 780 {
 781   int chal_len;
 782   u_char *ptr = cstate->challenge;
 783   int i;
 784
 785   /* pick a random challenge length between MIN_CHALLENGE_LENGTH and
 786      MAX_CHALLENGE_LENGTH */
 787   chal_len = (unsigned)
 788         ((((magic() >> 16) *
 789               (MAX_CHALLENGE_LENGTH - MIN_CHALLENGE_LENGTH)) >> 16)
 790            + MIN_CHALLENGE_LENGTH);
 791   cstate->chal_len = chal_len;
 792   cstate->chal_id = ++cstate->id;
 793   cstate->chal_transmits = 0;
 794
 795   /* generate a random string */
 796   for (i = 0; i < chal_len; i++ ) {
 797     *ptr++ = (char) (magic() & 0xff);
 798   }
 799 }
 800
 801 /*
 802  * ChapSendResponse - send a response packet with values as specified
 803  * in *cstate.
 804  */
 805 /* ARGSUSED */
 806 static void
 807 ChapSendResponse(chap_state *cstate)
 808 {
 809   u_char *outp;
 810   int outlen, md_len, name_len;
 811
 812   md_len = cstate->resp_length;
 813   name_len = strlen(cstate->resp_name);
 814   outlen = CHAP_HEADERLEN + sizeof (u_char) + md_len + name_len;
 815   outp = outpacket_buf[cstate->unit];
 816
 817   MAKEHEADER(outp, PPP_CHAP);
 818
 819   PUTCHAR(CHAP_RESPONSE, outp);  /* we are a response */
 820   PUTCHAR(cstate->resp_id, outp);  /* copy id from challenge packet */
 821   PUTSHORT(outlen, outp);      /* packet length */
 822
 823   PUTCHAR(md_len, outp);      /* length of MD */
 824   BCOPY(cstate->response, outp, md_len);    /* copy MD to buffer */
 825   INCPTR(md_len, outp);
 826
 827   BCOPY(cstate->resp_name, outp, name_len);  /* append our name */
 828
 829   /* send the packet */
 830   pppWrite(cstate->unit, outpacket_buf[cstate->unit], outlen + PPP_HDRLEN);
 831
 832   cstate->clientstate = CHAPCS_RESPONSE;
 833   TIMEOUT(ChapResponseTimeout, cstate, cstate->timeouttime);
 834   ++cstate->resp_transmits;
 835 }
 836
 837 #if 0
 838 static char *ChapCodenames[] = {
 839   "Challenge", "Response", "Success", "Failure"
 840 };
 841 /*
 842  * ChapPrintPkt - print the contents of a CHAP packet.
 843  */
 844 static int
 845 ChapPrintPkt( u_char *p, int plen, void (*printer) (void *, char *, ...), void *arg)
 846 {
 847   int code, id, len;
 848   int clen, nlen;
 849   u_char x;
 850
 851   if (plen < CHAP_HEADERLEN) {
 852     return 0;
 853   }
 854   GETCHAR(code, p);
 855   GETCHAR(id, p);
 856   GETSHORT(len, p);
 857   if (len < CHAP_HEADERLEN || len > plen) {
 858     return 0;
 859   }
 860   if (code >= 1 && code <= sizeof(ChapCodenames) / sizeof(char *)) {
 861     printer(arg, " %s", ChapCodenames[code-1]);
 862   } else {
 863     printer(arg, " code=0x%x", code);
 864   }
 865   printer(arg, " id=0x%x", id);
 866   len -= CHAP_HEADERLEN;
 867   switch (code) {
 868     case CHAP_CHALLENGE:
 869     case CHAP_RESPONSE:
 870       if (len < 1) {
 871         break;
 872       }
 873       clen = p[0];
 874       if (len < clen + 1) {
 875         break;
 876       }
 877       ++p;
 878       nlen = len - clen - 1;
 879       printer(arg, " <");
 880       for (; clen > 0; --clen) {
 881         GETCHAR(x, p);
 882         printer(arg, "%.2x", x);
 883       }
 884       printer(arg, ">, name = %.*Z", nlen, p);
 885       break;
 886     case CHAP_FAILURE:
 887     case CHAP_SUCCESS:
 888       printer(arg, " %.*Z", len, p);
 889       break;
 890     default:
 891       for (clen = len; clen > 0; --clen) {
 892         GETCHAR(x, p);
 893         printer(arg, " %.2x", x);
 894       }
 895   }
 896
 897   return len + CHAP_HEADERLEN;
 898 }
 899 #endif
 900
 901 #endif /* CHAP_SUPPORT */
 902
 903 #endif /* PPP_SUPPORT */