appl/telnet/libtelnet/kerberos5.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 may
  38  * 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("$Id$");
  57
  58 #ifdef  KRB5
  59
  60 #include <arpa/telnet.h>
  61 #include <stdio.h>
  62 #include <stdlib.h>
  63 #include <string.h>
  64 #include <unistd.h>
  65 #include <netdb.h>
  66 #include <ctype.h>
  67 #include <pwd.h>
  68 #define Authenticator k5_Authenticator
  69 #include <krb5.h>
  70 #undef Authenticator
  71 #include <roken.h>
  72 #ifdef SOCKS
  73 #include <socks.h>
  74 #endif
  75
  76
  77 #include "encrypt.h"
  78 #include "auth.h"
  79 #include "misc.h"
  80
  81 #if defined(DCE)
  82 int dfsk5ok = 0;
  83 int dfspag = 0;
  84 int dfsfwd = 0;
  85 #endif
  86
  87 int forward_flags = 0;  /* Flags get set in telnet/main.c on -f and -F */
  88
  89 int forward(int);
  90 int forwardable(int);
  91
  92 /* These values need to be the same as those defined in telnet/main.c. */
  93 /* Either define them in both places, or put in some common header file. */
  94 #define OPTS_FORWARD_CREDS      0x00000002
  95 #define OPTS_FORWARDABLE_CREDS  0x00000001
  96
  97
  98 void kerberos5_forward (Authenticator *);
  99
 100 static unsigned char str_data[4] = { IAC, SB, TELOPT_AUTHENTICATION, 0 };
 101
 102 #define KRB_AUTH                0       /* Authentication data follows */
 103 #define KRB_REJECT              1       /* Rejected (reason might follow) */
 104 #define KRB_ACCEPT              2       /* Accepted */
 105 #define KRB_RESPONSE            3       /* Response for mutual auth. */
 106
 107 #define KRB_FORWARD             4       /* Forwarded credentials follow */
 108 #define KRB_FORWARD_ACCEPT      5       /* Forwarded credentials accepted */
 109 #define KRB_FORWARD_REJECT      6       /* Forwarded credentials rejected */
 110
 111 static  krb5_data auth;
 112 static  krb5_ticket *ticket;
 113
 114 static krb5_context context;
 115 static krb5_auth_context auth_context;
 116
 117 static int
 118 Data(Authenticator *ap, int type, const void *d, int c)
 119 {
 120     const unsigned char *cp, *cd = d;
 121     unsigned char *p0, *p;
 122     size_t len = sizeof(str_data) + 3 + 2;
 123     int ret;
 124
 125     if (c == -1)
 126         c = strlen((const char*)cd);
 127
 128     for (cp = cd; cp - cd < c; cp++, len++)
 129         if (*cp == IAC)
 130             len++;
 131
 132     p0 = malloc(len);
 133     if (p0 == NULL)
 134         return 0;
 135
 136     memcpy(p0, str_data, sizeof(str_data));
 137     p = p0 + sizeof(str_data);
 138
 139     if (auth_debug_mode) {
 140         printf("%s:%d: [%d] (%d)",
 141                str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
 142                str_data[3],
 143                type, c);
 144         printd(d, c);
 145         printf("\r\n");
 146     }
 147     *p++ = ap->type;
 148     *p++ = ap->way;
 149     *p++ = type;
 150     while (c-- > 0) {
 151         if ((*p++ = *cd++) == IAC)
 152             *p++ = IAC;
 153     }
 154     *p++ = IAC;
 155     *p++ = SE;
 156     if (str_data[3] == TELQUAL_IS)
 157         printsub('>', &p0[2], len - 2);
 158     ret = telnet_net_write(p0, len);
 159     free(p0);
 160     return ret;
 161 }
 162
 163 int
 164 kerberos5_init(Authenticator *ap, int server)
 165 {
 166     krb5_error_code ret;
 167
 168     ret = krb5_init_context(&context);
 169     if (ret)
 170         return 0;
 171     if (server) {
 172         krb5_keytab kt;
 173         krb5_kt_cursor cursor;
 174
 175         ret = krb5_kt_default(context, &kt);
 176         if (ret)
 177             return 0;
 178
 179         ret = krb5_kt_start_seq_get (context, kt, &cursor);
 180         if (ret) {
 181             krb5_kt_close (context, kt);
 182             return 0;
 183         }
 184         krb5_kt_end_seq_get (context, kt, &cursor);
 185         krb5_kt_close (context, kt);
 186
 187         str_data[3] = TELQUAL_REPLY;
 188     } else
 189         str_data[3] = TELQUAL_IS;
 190     return(1);
 191 }
 192
 193 extern int net;
 194 static int
 195 kerberos5_send(char *name, Authenticator *ap)
 196 {
 197     krb5_error_code ret;
 198     krb5_ccache ccache;
 199     int ap_opts;
 200     krb5_data cksum_data;
 201     const char *estr;
 202     char ap_msg[2];
 203
 204     if (!UserNameRequested) {
 205         if (auth_debug_mode) {
 206             printf("Kerberos V5: no user name supplied\r\n");
 207         }
 208         return(0);
 209     }
 210
 211     ret = krb5_cc_default(context, &ccache);
 212     if (ret) {
 213         if (auth_debug_mode) {
 214             estr = krb5_get_error_message (context, ret);
 215             printf("Kerberos V5: could not get default ccache: %s\r\n", estr);
 216             krb5_free_error_message(context, estr);
 217         }
 218         return 0;
 219     }
 220
 221     if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL)
 222         ap_opts = AP_OPTS_MUTUAL_REQUIRED;
 223     else
 224         ap_opts = 0;
 225
 226     ap_opts |= AP_OPTS_USE_SUBKEY;
 227
 228     ret = krb5_auth_con_init (context, &auth_context);
 229     if (ret) {
 230         if (auth_debug_mode) {
 231             estr = krb5_get_error_message (context, ret);
 232             printf("Kerberos V5: krb5_auth_con_init failed (%s)\r\n", estr);
 233             krb5_free_error_message(context, estr);
 234         }
 235         return(0);
 236     }
 237
 238     ret = krb5_auth_con_setaddrs_from_fd (context,
 239                                           auth_context,
 240                                           &net);
 241     if (ret) {
 242         if (auth_debug_mode) {
 243             estr = krb5_get_error_message (context, ret);
 244             printf ("Kerberos V5:"
 245                     " krb5_auth_con_setaddrs_from_fd failed (%s)\r\n", estr);
 246             krb5_free_error_message(context, estr);
 247         }
 248         return(0);
 249     }
 250
 251     krb5_auth_con_setkeytype (context, auth_context, KRB5_ENCTYPE_DES_CBC_CRC);
 252
 253     ap_msg[0] = ap->type;
 254     ap_msg[1] = ap->way;
 255
 256     cksum_data.length = sizeof(ap_msg);
 257     cksum_data.data   = ap_msg;
 258
 259
 260     {
 261         krb5_principal service;
 262         char sname[128];
 263
 264
 265         ret = krb5_sname_to_principal (context,
 266                                        RemoteHostName,
 267                                        NULL,
 268                                        KRB5_NT_SRV_HST,
 269                                        &service);
 270         if(ret) {
 271             if (auth_debug_mode) {
 272                 estr = krb5_get_error_message (context, ret);
 273                 printf ("Kerberos V5:"
 274                         " krb5_sname_to_principal(%s) failed (%s)\r\n",
 275                         RemoteHostName, estr);
 276                 krb5_free_error_message(context, estr);
 277             }
 278             return 0;
 279         }
 280         ret = krb5_unparse_name_fixed(context, service, sname, sizeof(sname));
 281         if(ret) {
 282             if (auth_debug_mode) {
 283                 estr = krb5_get_error_message (context, ret);
 284                 printf ("Kerberos V5:"
 285                         " krb5_unparse_name_fixed failed (%s)\r\n", estr);
 286                 krb5_free_error_message(context, estr);
 287             }
 288             return 0;
 289         }
 290         printf("[ Trying %s (%s)... ]\r\n", name, sname);
 291         ret = krb5_mk_req_exact(context, &auth_context, ap_opts,
 292                                 service,
 293                                 &cksum_data, ccache, &auth);
 294         krb5_free_principal (context, service);
 295
 296     }
 297     if (ret) {
 298         if (1 || auth_debug_mode) {
 299             estr = krb5_get_error_message (context, ret);
 300             printf("Kerberos V5: mk_req failed (%s)\r\n", estr);
 301             krb5_free_error_message(context, estr);
 302         }
 303         return(0);
 304     }
 305
 306     if (!auth_sendname((unsigned char *)UserNameRequested,
 307                        strlen(UserNameRequested))) {
 308         if (auth_debug_mode)
 309             printf("Not enough room for user name\r\n");
 310         return(0);
 311     }
 312     if (!Data(ap, KRB_AUTH, auth.data, auth.length)) {
 313         if (auth_debug_mode)
 314             printf("Not enough room for authentication data\r\n");
 315         return(0);
 316     }
 317     if (auth_debug_mode) {
 318         printf("Sent Kerberos V5 credentials to server\r\n");
 319     }
 320     return(1);
 321 }
 322
 323 int
 324 kerberos5_send_mutual(Authenticator *ap)
 325 {
 326     return kerberos5_send("mutual KERBEROS5", ap);
 327 }
 328
 329 int
 330 kerberos5_send_oneway(Authenticator *ap)
 331 {
 332     return kerberos5_send("KERBEROS5", ap);
 333 }
 334
 335 static void log_message(const char *fmt, ...)
 336 {
 337     va_list ap;
 338     va_start(ap, fmt);
 339     if (auth_debug_mode) {
 340         va_start(ap, fmt);
 341         vfprintf(stdout, fmt, ap);
 342         va_end(ap);
 343         fprintf(stdout, "\r\n");
 344     }
 345     va_start(ap, fmt);
 346     vsyslog(LOG_NOTICE, fmt, ap);
 347     va_end(ap);
 348 }
 349
 350 void
 351 kerberos5_is(Authenticator *ap, unsigned char *data, int cnt)
 352 {
 353     krb5_error_code ret;
 354     krb5_data outbuf;
 355     krb5_keyblock *key_block;
 356     const char *estr;
 357     char *name;
 358     krb5_principal server;
 359     int zero = 0;
 360
 361     if (cnt-- < 1)
 362         return;
 363     switch (*data++) {
 364     case KRB_AUTH:
 365         auth.data = (char *)data;
 366         auth.length = cnt;
 367
 368         auth_context = NULL;
 369
 370         ret = krb5_auth_con_init (context, &auth_context);
 371         if (ret) {
 372             Data(ap, KRB_REJECT, "krb5_auth_con_init failed", -1);
 373             auth_finished(ap, AUTH_REJECT);
 374             estr = krb5_get_error_message (context, ret);
 375             log_message("Kerberos V5: krb5_auth_con_init failed (%s)", estr);
 376             krb5_free_error_message(context, estr);
 377             return;
 378         }
 379
 380         ret = krb5_auth_con_setaddrs_from_fd (context,
 381                                               auth_context,
 382                                               &zero);
 383         if (ret) {
 384             Data(ap, KRB_REJECT, "krb5_auth_con_setaddrs_from_fd failed", -1);
 385             auth_finished(ap, AUTH_REJECT);
 386             estr = krb5_get_error_message (context, ret);
 387             log_message("Kerberos V5: "
 388                         "krb5_auth_con_setaddrs_from_fd failed (%s)", estr);
 389             krb5_free_error_message(context, estr);
 390             return;
 391         }
 392
 393         ret = krb5_sock_to_principal (context,
 394                                       0,
 395                                       "host",
 396                                       KRB5_NT_SRV_HST,
 397                                       &server);
 398         if (ret) {
 399             Data(ap, KRB_REJECT, "krb5_sock_to_principal failed", -1);
 400             auth_finished(ap, AUTH_REJECT);
 401             estr = krb5_get_error_message (context, ret);
 402             log_message("Kerberos V5: "
 403                         "krb5_sock_to_principal failed (%s)", estr);
 404             krb5_free_error_message(context, estr);
 405             return;
 406         }
 407
 408         ret = krb5_rd_req(context,
 409                           &auth_context,
 410                           &auth,
 411                           server,
 412                           NULL,
 413                           NULL,
 414                           &ticket);
 415
 416         krb5_free_principal (context, server);
 417         if (ret) {
 418             const char *errbuf2 = "Read req failed";
 419             char *errbuf;
 420             int ret2;
 421
 422             estr = krb5_get_error_message (context, ret);
 423             ret2 = asprintf(&errbuf, "Read req failed: %s", estr);
 424             krb5_free_error_message(context, estr);
 425             if (ret2 != -1)
 426                 errbuf2 = errbuf;
 427             Data(ap, KRB_REJECT, errbuf2, -1);
 428             log_message("%s", errbuf2);
 429             if (ret2 != -1)
 430                 free (errbuf);
 431             return;
 432         }
 433
 434         {
 435             char ap_msg[2];
 436
 437             ap_msg[0] = ap->type;
 438             ap_msg[1] = ap->way;
 439
 440             ret = krb5_verify_authenticator_checksum(context,
 441                                                      auth_context,
 442                                                      ap_msg,
 443                                                      sizeof(ap_msg));
 444
 445             if (ret) {
 446                 const char *errbuf2 = "Bad checksum";
 447                 char *errbuf;
 448                 int ret2;
 449
 450                 estr = krb5_get_error_message (context, ret);
 451                 ret2 = asprintf(&errbuf, "Bad checksum: %s", estr);
 452                 krb5_free_error_message(context, estr);
 453                 if (ret2 != -1)
 454                     errbuf2 = errbuf;
 455                 Data(ap, KRB_REJECT, errbuf2, -1);
 456                 log_message("%s", errbuf2);
 457                 if (ret2 != -1)
 458                     free(errbuf);
 459                 return;
 460             }
 461         }
 462         ret = krb5_auth_con_getremotesubkey (context,
 463                                              auth_context,
 464                                              &key_block);
 465
 466         if (ret) {
 467             Data(ap, KRB_REJECT, "krb5_auth_con_getremotesubkey failed", -1);
 468             auth_finished(ap, AUTH_REJECT);
 469             estr = krb5_get_error_message (context, ret);
 470             log_message("Kerberos V5: "
 471                         "krb5_auth_con_getremotesubkey failed (%s)", estr);
 472             krb5_free_error_message(context, estr);
 473             return;
 474         }
 475
 476         if (key_block == NULL) {
 477             ret = krb5_auth_con_getkey(context,
 478                                        auth_context,
 479                                        &key_block);
 480         }
 481         if (ret) {
 482             Data(ap, KRB_REJECT, "krb5_auth_con_getkey failed", -1);
 483             auth_finished(ap, AUTH_REJECT);
 484             estr = krb5_get_error_message (context, ret);
 485             log_message("Kerberos V5: "
 486                         "krb5_auth_con_getkey failed (%s)", estr);
 487             krb5_free_error_message(context, estr);
 488             return;
 489         }
 490         if (key_block == NULL) {
 491             Data(ap, KRB_REJECT, "no subkey received", -1);
 492             auth_finished(ap, AUTH_REJECT);
 493             log_message("Kerberos V5: "
 494                         "krb5_auth_con_getremotesubkey returned NULL key");
 495             return;
 496         }
 497
 498         if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
 499             ret = krb5_mk_rep(context, auth_context, &outbuf);
 500             if (ret) {
 501                 Data(ap, KRB_REJECT,
 502                      "krb5_mk_rep failed", -1);
 503                 auth_finished(ap, AUTH_REJECT);
 504                 estr = krb5_get_error_message (context, ret);
 505                 log_message("Kerberos V5: "
 506                             "krb5_mk_rep failed (%s)", estr);
 507                 krb5_free_error_message(context, estr);
 508                 krb5_free_keyblock(context, key_block);
 509                 return;
 510             }
 511             Data(ap, KRB_RESPONSE, outbuf.data, outbuf.length);
 512         }
 513         if (krb5_unparse_name(context, ticket->client, &name))
 514             name = 0;
 515
 516         if(UserNameRequested && krb5_kuserok(context,
 517                                              ticket->client,
 518                                              UserNameRequested)) {
 519             Data(ap, KRB_ACCEPT, name, name ? -1 : 0);
 520             log_message("%s accepted as user %s from %s",
 521                         name ? name : "<unknown>",
 522                         UserNameRequested ? UserNameRequested : "<unknown>",
 523                         RemoteHostName ? RemoteHostName : "<unknown>");
 524
 525             if(key_block->keytype == ETYPE_DES_CBC_MD5 ||
 526                key_block->keytype == ETYPE_DES_CBC_MD4 ||
 527                key_block->keytype == ETYPE_DES_CBC_CRC) {
 528                 Session_Key skey;
 529
 530                 skey.type = SK_DES;
 531                 skey.length = 8;
 532                 skey.data = key_block->keyvalue.data;
 533                 encrypt_session_key(&skey, 0);
 534             }
 535
 536         } else {
 537             const char *msg2 = "user is not authorized to login";
 538             char *msg;
 539
 540             ret = asprintf (&msg, "user `%s' is not authorized to "
 541                             "login as `%s'",
 542                             name ? name : "<unknown>",
 543                             UserNameRequested ? UserNameRequested : "<nobody>");
 544             if (ret != -1)
 545                 msg2 = msg;
 546             Data(ap, KRB_REJECT, (void *)msg2, -1);
 547             if (ret != -1)
 548                 free(msg);
 549             auth_finished (ap, AUTH_REJECT);
 550             krb5_free_keyblock(context, key_block);
 551             break;
 552         }
 553         auth_finished(ap, AUTH_USER);
 554         krb5_free_keyblock(context, key_block);
 555
 556         break;
 557     case KRB_FORWARD: {
 558         struct passwd *pwd;
 559         char ccname[1024];      /* XXX */
 560         krb5_data inbuf;
 561         krb5_ccache ccache;
 562         inbuf.data = (char *)data;
 563         inbuf.length = cnt;
 564
 565         pwd = getpwnam (UserNameRequested);
 566         if (pwd == NULL)
 567             break;
 568
 569         snprintf (ccname, sizeof(ccname),
 570                   "FILE:/tmp/krb5cc_%lu", (unsigned long)pwd->pw_uid);
 571
 572         ret = krb5_cc_resolve (context, ccname, &ccache);
 573         if (ret) {
 574             estr = krb5_get_error_message (context, ret);
 575             log_message("Kerberos V5: could not get ccache: %s", estr);
 576             krb5_free_error_message(context, estr);
 577             break;
 578         }
 579
 580         ret = krb5_cc_initialize (context,
 581                                   ccache,
 582                                   ticket->client);
 583         if (ret) {
 584             estr = krb5_get_error_message (context, ret);
 585             log_message("Kerberos V5: could not init ccache: %s", estr);
 586             krb5_free_error_message(context, estr);
 587             break;
 588         }
 589
 590 #if defined(DCE)
 591         esetenv("KRB5CCNAME", ccname, 1);
 592 #endif
 593         ret = krb5_rd_cred2 (context,
 594                              auth_context,
 595                              ccache,
 596                              &inbuf);
 597         if(ret) {
 598             const char *errbuf2 = "Read forwarded creds failed";
 599             char *errbuf;
 600             int ret2;
 601
 602             estr = krb5_get_error_message (context, ret);
 603             ret2 = asprintf (&errbuf, "Read forwarded creds failed: %s", estr);
 604             krb5_free_error_message(context, estr);
 605             if (ret2 != -1)
 606                 errbuf2 = errbuf;
 607             Data(ap, KRB_FORWARD_REJECT, errbuf, -1);
 608             log_message("Could not read forwarded credentials: %s", errbuf2);
 609
 610             if (ret2 != -1)
 611                 free (errbuf);
 612         } else {
 613             Data(ap, KRB_FORWARD_ACCEPT, 0, 0);
 614 #if defined(DCE)
 615             dfsfwd = 1;
 616 #endif
 617         }
 618         chown (ccname + 5, pwd->pw_uid, -1);
 619         log_message("Forwarded credentials obtained");
 620         break;
 621     }
 622     default:
 623         log_message("Unknown Kerberos option %d", data[-1]);
 624         Data(ap, KRB_REJECT, 0, 0);
 625         break;
 626     }
 627 }
 628
 629 void
 630 kerberos5_reply(Authenticator *ap, unsigned char *data, int cnt)
 631 {
 632     static int mutual_complete = 0;
 633     const char *estr;
 634
 635     if (cnt-- < 1)
 636         return;
 637     switch (*data++) {
 638     case KRB_REJECT:
 639         if (cnt > 0) {
 640             printf("[ Kerberos V5 refuses authentication because %.*s ]\r\n",
 641                    cnt, data);
 642         } else
 643             printf("[ Kerberos V5 refuses authentication ]\r\n");
 644         auth_send_retry();
 645         return;
 646     case KRB_ACCEPT: {
 647         krb5_error_code ret;
 648         Session_Key skey;
 649         krb5_keyblock *keyblock;
 650
 651         if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL &&
 652             !mutual_complete) {
 653             printf("[ Kerberos V5 accepted you, but didn't provide mutual authentication! ]\r\n");
 654             auth_send_retry();
 655             return;
 656         }
 657         if (cnt)
 658             printf("[ Kerberos V5 accepts you as ``%.*s'' ]\r\n", cnt, data);
 659         else
 660             printf("[ Kerberos V5 accepts you ]\r\n");
 661
 662         ret = krb5_auth_con_getlocalsubkey (context,
 663                                             auth_context,
 664                                             &keyblock);
 665         if (ret)
 666             ret = krb5_auth_con_getkey (context,
 667                                         auth_context,
 668                                         &keyblock);
 669         if(ret) {
 670             estr = krb5_get_error_message (context, ret);
 671             printf("[ krb5_auth_con_getkey: %s ]\r\n", estr);
 672             krb5_free_error_message(context, estr);
 673             auth_send_retry();
 674             return;
 675         }
 676
 677         skey.type = SK_DES;
 678         skey.length = 8;
 679         skey.data = keyblock->keyvalue.data;
 680         encrypt_session_key(&skey, 0);
 681         krb5_free_keyblock (context, keyblock);
 682         auth_finished(ap, AUTH_USER);
 683         if (forward_flags & OPTS_FORWARD_CREDS)
 684             kerberos5_forward(ap);
 685         break;
 686     }
 687     case KRB_RESPONSE:
 688         if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
 689             /* the rest of the reply should contain a krb_ap_rep */
 690             krb5_ap_rep_enc_part *reply;
 691             krb5_data inbuf;
 692             krb5_error_code ret;
 693
 694             inbuf.length = cnt;
 695             inbuf.data = (char *)data;
 696
 697             ret = krb5_rd_rep(context, auth_context, &inbuf, &reply);
 698             if (ret) {
 699                 estr = krb5_get_error_message (context, ret);
 700                 printf("[ Mutual authentication failed: %s ]\r\n", estr);
 701                 krb5_free_error_message(context, estr);
 702                 auth_send_retry();
 703                 return;
 704             }
 705             krb5_free_ap_rep_enc_part(context, reply);
 706             mutual_complete = 1;
 707         }
 708         return;
 709     case KRB_FORWARD_ACCEPT:
 710         printf("[ Kerberos V5 accepted forwarded credentials ]\r\n");
 711         return;
 712     case KRB_FORWARD_REJECT:
 713         printf("[ Kerberos V5 refuses forwarded credentials because %.*s ]\r\n",
 714                cnt, data);
 715         return;
 716     default:
 717         if (auth_debug_mode)
 718             printf("Unknown Kerberos option %d\r\n", data[-1]);
 719         return;
 720     }
 721 }
 722
 723 int
 724 kerberos5_status(Authenticator *ap, char *name, size_t name_sz, int level)
 725 {
 726     if (level < AUTH_USER)
 727         return(level);
 728
 729     if (UserNameRequested &&
 730         krb5_kuserok(context,
 731                      ticket->client,
 732                      UserNameRequested))
 733         {
 734             strlcpy(name, UserNameRequested, name_sz);
 735 #if defined(DCE)
 736             dfsk5ok = 1;
 737 #endif
 738             return(AUTH_VALID);
 739         } else
 740             return(AUTH_USER);
 741 }
 742
 743 #define BUMP(buf, len)          while (*(buf)) {++(buf), --(len);}
 744 #define ADDC(buf, len, c)       if ((len) > 0) {*(buf)++ = (c); --(len);}
 745
 746 void
 747 kerberos5_printsub(unsigned char *data, size_t cnt,
 748                    unsigned char *buf, size_t buflen)
 749 {
 750     int i;
 751
 752     buf[buflen-1] = '\0';               /* make sure it's NULL terminated */
 753     buflen -= 1;
 754
 755     switch(data[3]) {
 756     case KRB_REJECT:            /* Rejected (reason might follow) */
 757         strlcpy((char *)buf, " REJECT ", buflen);
 758         goto common;
 759
 760     case KRB_ACCEPT:            /* Accepted (name might follow) */
 761         strlcpy((char *)buf, " ACCEPT ", buflen);
 762     common:
 763         BUMP(buf, buflen);
 764         if (cnt <= 4)
 765             break;
 766         ADDC(buf, buflen, '"');
 767         for (i = 4; i < cnt; i++)
 768             ADDC(buf, buflen, data[i]);
 769         ADDC(buf, buflen, '"');
 770         ADDC(buf, buflen, '\0');
 771         break;
 772
 773
 774     case KRB_AUTH:                      /* Authentication data follows */
 775         strlcpy((char *)buf, " AUTH", buflen);
 776         goto common2;
 777
 778     case KRB_RESPONSE:
 779         strlcpy((char *)buf, " RESPONSE", buflen);
 780         goto common2;
 781
 782     case KRB_FORWARD:           /* Forwarded credentials follow */
 783         strlcpy((char *)buf, " FORWARD", buflen);
 784         goto common2;
 785
 786     case KRB_FORWARD_ACCEPT:    /* Forwarded credentials accepted */
 787         strlcpy((char *)buf, " FORWARD_ACCEPT", buflen);
 788         goto common2;
 789
 790     case KRB_FORWARD_REJECT:    /* Forwarded credentials rejected */
 791         /* (reason might follow) */
 792         strlcpy((char *)buf, " FORWARD_REJECT", buflen);
 793         goto common2;
 794
 795     default:
 796         snprintf((char*)buf, buflen, " %d (unknown)", data[3]);
 797     common2:
 798         BUMP(buf, buflen);
 799         for (i = 4; i < cnt; i++) {
 800             snprintf((char*)buf, buflen, " %d", data[i]);
 801             BUMP(buf, buflen);
 802         }
 803         break;
 804     }
 805 }
 806
 807 void
 808 kerberos5_forward(Authenticator *ap)
 809 {
 810     krb5_error_code ret;
 811     krb5_ccache     ccache;
 812     krb5_creds      creds;
 813     KDCOptions      flags;
 814     krb5_data       out_data;
 815     krb5_principal  principal;
 816     const char *estr;
 817
 818     ret = krb5_cc_default (context, &ccache);
 819     if (ret) {
 820         if (auth_debug_mode) {
 821             estr = krb5_get_error_message (context, ret);
 822             printf ("KerberosV5: could not get default ccache: %s\r\n", estr);
 823             krb5_free_error_message(context, estr);
 824         }
 825         return;
 826     }
 827
 828     ret = krb5_cc_get_principal (context, ccache, &principal);
 829     if (ret) {
 830         if (auth_debug_mode) {
 831             estr = krb5_get_error_message (context, ret);
 832             printf ("KerberosV5: could not get principal: %s\r\n", estr);
 833             krb5_free_error_message(context, estr);
 834         }
 835         return;
 836     }
 837
 838     memset (&creds, 0, sizeof(creds));
 839
 840     creds.client = principal;
 841
 842     ret = krb5_make_principal(context,
 843                               &creds.server,
 844                               principal->realm,
 845                               "krbtgt",
 846                               principal->realm,
 847                               NULL);
 848
 849     if (ret) {
 850         if (auth_debug_mode) {
 851             estr = krb5_get_error_message (context, ret);
 852             printf ("KerberosV5: could not get principal: %s\r\n", estr);
 853             krb5_free_error_message(context, estr);
 854         }
 855         return;
 856     }
 857
 858     creds.times.endtime = 0;
 859
 860     memset(&flags, 0, sizeof(flags));
 861     flags.forwarded = 1;
 862     if (forward_flags & OPTS_FORWARDABLE_CREDS)
 863         flags.forwardable = 1;
 864
 865     ret = krb5_get_forwarded_creds (context,
 866                                     auth_context,
 867                                     ccache,
 868                                     KDCOptions2int(flags),
 869                                     RemoteHostName,
 870                                     &creds,
 871                                     &out_data);
 872     if (ret) {
 873         if (auth_debug_mode) {
 874             estr = krb5_get_error_message (context, ret);
 875             printf ("Kerberos V5: error getting forwarded creds: %s\r\n", estr);
 876             krb5_free_error_message(context, estr);
 877         }
 878         return;
 879     }
 880
 881     if(!Data(ap, KRB_FORWARD, out_data.data, out_data.length)) {
 882         if (auth_debug_mode)
 883             printf("Not enough room for authentication data\r\n");
 884     } else {
 885         if (auth_debug_mode)
 886             printf("Forwarded local Kerberos V5 credentials to server\r\n");
 887     }
 888 }
 889
 890 #if defined(DCE)
 891 /* if this was a K5 authentication try and join a PAG for the user. */
 892 void
 893 kerberos5_dfspag(void)
 894 {
 895     if (dfsk5ok) {
 896         dfspag = krb5_dfs_pag(context, dfsfwd, ticket->client,
 897                               UserNameRequested);
 898     }
 899 }
 900 #endif
 901
 902 int
 903 kerberos5_set_forward(int on)
 904 {
 905     if(on == 0)
 906         forward_flags &= ~OPTS_FORWARD_CREDS;
 907     if(on == 1)
 908         forward_flags |= OPTS_FORWARD_CREDS;
 909     if(on == -1)
 910         forward_flags ^= OPTS_FORWARD_CREDS;
 911     return 0;
 912 }
 913
 914 int
 915 kerberos5_set_forwardable(int on)
 916 {
 917     if(on == 0)
 918         forward_flags &= ~OPTS_FORWARDABLE_CREDS;
 919     if(on == 1)
 920         forward_flags |= OPTS_FORWARDABLE_CREDS;
 921     if(on == -1)
 922         forward_flags ^= OPTS_FORWARDABLE_CREDS;
 923     return 0;
 924 }
 925
 926 #endif /* KRB5 */