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, void *d, int c)
 119 {
 120     unsigned char *cd = (unsigned char *)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((char*)cd);
 127
 128     for (p = cd; p - cd < c; p++, len++)
 129         if (*p == 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     char foo[2];
 202
 203     if (!UserNameRequested) {
 204         if (auth_debug_mode) {
 205             printf("Kerberos V5: no user name supplied\r\n");
 206         }
 207         return(0);
 208     }
 209
 210     ret = krb5_cc_default(context, &ccache);
 211     if (ret) {
 212         if (auth_debug_mode) {
 213             printf("Kerberos V5: could not get default ccache: %s\r\n",
 214                    krb5_get_err_text (context, ret));
 215         }
 216         return 0;
 217     }
 218
 219     if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL)
 220         ap_opts = AP_OPTS_MUTUAL_REQUIRED;
 221     else
 222         ap_opts = 0;
 223
 224     ap_opts |= AP_OPTS_USE_SUBKEY;
 225
 226     ret = krb5_auth_con_init (context, &auth_context);
 227     if (ret) {
 228         if (auth_debug_mode) {
 229             printf("Kerberos V5: krb5_auth_con_init failed (%s)\r\n",
 230                    krb5_get_err_text(context, ret));
 231         }
 232         return(0);
 233     }
 234
 235     ret = krb5_auth_con_setaddrs_from_fd (context,
 236                                           auth_context,
 237                                           &net);
 238     if (ret) {
 239         if (auth_debug_mode) {
 240             printf ("Kerberos V5:"
 241                     " krb5_auth_con_setaddrs_from_fd failed (%s)\r\n",
 242                     krb5_get_err_text(context, ret));
 243         }
 244         return(0);
 245     }
 246
 247     krb5_auth_con_setkeytype (context, auth_context, KEYTYPE_DES);
 248
 249     foo[0] = ap->type;
 250     foo[1] = ap->way;
 251
 252     cksum_data.length = sizeof(foo);
 253     cksum_data.data   = foo;
 254
 255
 256     {
 257         krb5_principal service;
 258         char sname[128];
 259
 260
 261         ret = krb5_sname_to_principal (context,
 262                                        RemoteHostName,
 263                                        NULL,
 264                                        KRB5_NT_SRV_HST,
 265                                        &service);
 266         if(ret) {
 267             if (auth_debug_mode) {
 268                 printf ("Kerberos V5:"
 269                         " krb5_sname_to_principal(%s) failed (%s)\r\n",
 270                         RemoteHostName, krb5_get_err_text(context, ret));
 271             }
 272             return 0;
 273         }
 274         ret = krb5_unparse_name_fixed(context, service, sname, sizeof(sname));
 275         if(ret) {
 276             if (auth_debug_mode) {
 277                 printf ("Kerberos V5:"
 278                         " krb5_unparse_name_fixed failed (%s)\r\n",
 279                         krb5_get_err_text(context, ret));
 280             }
 281             return 0;
 282         }
 283         printf("[ Trying %s (%s)... ]\r\n", name, sname);
 284         ret = krb5_mk_req_exact(context, &auth_context, ap_opts,
 285                                 service,
 286                                 &cksum_data, ccache, &auth);
 287         krb5_free_principal (context, service);
 288
 289     }
 290     if (ret) {
 291         if (1 || auth_debug_mode) {
 292             printf("Kerberos V5: mk_req failed (%s)\r\n",
 293                    krb5_get_err_text(context, ret));
 294         }
 295         return(0);
 296     }
 297
 298     if (!auth_sendname((unsigned char *)UserNameRequested,
 299                        strlen(UserNameRequested))) {
 300         if (auth_debug_mode)
 301             printf("Not enough room for user name\r\n");
 302         return(0);
 303     }
 304     if (!Data(ap, KRB_AUTH, auth.data, auth.length)) {
 305         if (auth_debug_mode)
 306             printf("Not enough room for authentication data\r\n");
 307         return(0);
 308     }
 309     if (auth_debug_mode) {
 310         printf("Sent Kerberos V5 credentials to server\r\n");
 311     }
 312     return(1);
 313 }
 314
 315 int
 316 kerberos5_send_mutual(Authenticator *ap)
 317 {
 318     return kerberos5_send("mutual KERBEROS5", ap);
 319 }
 320
 321 int
 322 kerberos5_send_oneway(Authenticator *ap)
 323 {
 324     return kerberos5_send("KERBEROS5", ap);
 325 }
 326
 327 void
 328 kerberos5_is(Authenticator *ap, unsigned char *data, int cnt)
 329 {
 330     krb5_error_code ret;
 331     krb5_data outbuf;
 332     krb5_keyblock *key_block;
 333     char *name;
 334     krb5_principal server;
 335     int zero = 0;
 336
 337     if (cnt-- < 1)
 338         return;
 339     switch (*data++) {
 340     case KRB_AUTH:
 341         auth.data = (char *)data;
 342         auth.length = cnt;
 343
 344         auth_context = NULL;
 345
 346         ret = krb5_auth_con_init (context, &auth_context);
 347         if (ret) {
 348             Data(ap, KRB_REJECT, "krb5_auth_con_init failed", -1);
 349             auth_finished(ap, AUTH_REJECT);
 350             if (auth_debug_mode)
 351                 printf("Kerberos V5: krb5_auth_con_init failed (%s)\r\n",
 352                        krb5_get_err_text(context, ret));
 353             return;
 354         }
 355
 356         ret = krb5_auth_con_setaddrs_from_fd (context,
 357                                               auth_context,
 358                                               &zero);
 359         if (ret) {
 360             Data(ap, KRB_REJECT, "krb5_auth_con_setaddrs_from_fd failed", -1);
 361             auth_finished(ap, AUTH_REJECT);
 362             if (auth_debug_mode)
 363                 printf("Kerberos V5: "
 364                        "krb5_auth_con_setaddrs_from_fd failed (%s)\r\n",
 365                        krb5_get_err_text(context, ret));
 366             return;
 367         }
 368
 369         ret = krb5_sock_to_principal (context,
 370                                       0,
 371                                       "host",
 372                                       KRB5_NT_SRV_HST,
 373                                       &server);
 374         if (ret) {
 375             Data(ap, KRB_REJECT, "krb5_sock_to_principal failed", -1);
 376             auth_finished(ap, AUTH_REJECT);
 377             if (auth_debug_mode)
 378                 printf("Kerberos V5: "
 379                        "krb5_sock_to_principal failed (%s)\r\n",
 380                        krb5_get_err_text(context, ret));
 381             return;
 382         }
 383
 384         ret = krb5_rd_req(context,
 385                           &auth_context,
 386                           &auth,
 387                           server,
 388                           NULL,
 389                           NULL,
 390                           &ticket);
 391
 392         krb5_free_principal (context, server);
 393         if (ret) {
 394             char *errbuf;
 395
 396             asprintf(&errbuf,
 397                      "Read req failed: %s",
 398                      krb5_get_err_text(context, ret));
 399             Data(ap, KRB_REJECT, errbuf, -1);
 400             if (auth_debug_mode)
 401                 printf("%s\r\n", errbuf);
 402             free (errbuf);
 403             return;
 404         }
 405
 406         {
 407             char foo[2];
 408
 409             foo[0] = ap->type;
 410             foo[1] = ap->way;
 411
 412             ret = krb5_verify_authenticator_checksum(context,
 413                                                      auth_context,
 414                                                      foo,
 415                                                      sizeof(foo));
 416
 417             if (ret) {
 418                 char *errbuf;
 419                 asprintf(&errbuf, "Bad checksum: %s",
 420                          krb5_get_err_text(context, ret));
 421                 Data(ap, KRB_REJECT, errbuf, -1);
 422                 if (auth_debug_mode)
 423                     printf ("%s\r\n", errbuf);
 424                 free(errbuf);
 425                 return;
 426             }
 427         }
 428         ret = krb5_auth_con_getremotesubkey (context,
 429                                              auth_context,
 430                                              &key_block);
 431
 432         if (ret) {
 433             Data(ap, KRB_REJECT, "krb5_auth_con_getremotesubkey failed", -1);
 434             auth_finished(ap, AUTH_REJECT);
 435             if (auth_debug_mode)
 436                 printf("Kerberos V5: "
 437                        "krb5_auth_con_getremotesubkey failed (%s)\r\n",
 438                        krb5_get_err_text(context, ret));
 439             return;
 440         }
 441
 442         if (key_block == NULL) {
 443             ret = krb5_auth_con_getkey(context,
 444                                        auth_context,
 445                                        &key_block);
 446         }
 447         if (ret) {
 448             Data(ap, KRB_REJECT, "krb5_auth_con_getkey failed", -1);
 449             auth_finished(ap, AUTH_REJECT);
 450             if (auth_debug_mode)
 451                 printf("Kerberos V5: "
 452                        "krb5_auth_con_getkey failed (%s)\r\n",
 453                        krb5_get_err_text(context, ret));
 454             return;
 455         }
 456         if (key_block == NULL) {
 457             Data(ap, KRB_REJECT, "no subkey received", -1);
 458             auth_finished(ap, AUTH_REJECT);
 459             if (auth_debug_mode)
 460                 printf("Kerberos V5: "
 461                        "krb5_auth_con_getremotesubkey returned NULL key\r\n");
 462             return;
 463         }
 464
 465         if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
 466             ret = krb5_mk_rep(context, auth_context, &outbuf);
 467             if (ret) {
 468                 Data(ap, KRB_REJECT,
 469                      "krb5_mk_rep failed", -1);
 470                 auth_finished(ap, AUTH_REJECT);
 471                 if (auth_debug_mode)
 472                     printf("Kerberos V5: "
 473                            "krb5_mk_rep failed (%s)\r\n",
 474                            krb5_get_err_text(context, ret));
 475                 return;
 476             }
 477             Data(ap, KRB_RESPONSE, outbuf.data, outbuf.length);
 478         }
 479         if (krb5_unparse_name(context, ticket->client, &name))
 480             name = 0;
 481
 482         if(UserNameRequested && krb5_kuserok(context,
 483                                              ticket->client,
 484                                              UserNameRequested)) {
 485             Data(ap, KRB_ACCEPT, name, name ? -1 : 0);
 486             if (auth_debug_mode) {
 487                 printf("Kerberos5 identifies him as ``%s''\r\n",
 488                        name ? name : "");
 489             }
 490
 491             if(key_block->keytype == ETYPE_DES_CBC_MD5 ||
 492                key_block->keytype == ETYPE_DES_CBC_MD4 ||
 493                key_block->keytype == ETYPE_DES_CBC_CRC) {
 494                 Session_Key skey;
 495
 496                 skey.type = SK_DES;
 497                 skey.length = 8;
 498                 skey.data = key_block->keyvalue.data;
 499                 encrypt_session_key(&skey, 0);
 500             }
 501
 502         } else {
 503             char *msg;
 504
 505             asprintf (&msg, "user `%s' is not authorized to "
 506                       "login as `%s'",
 507                       name ? name : "<unknown>",
 508                       UserNameRequested ? UserNameRequested : "<nobody>");
 509             if (msg == NULL)
 510                 Data(ap, KRB_REJECT, NULL, 0);
 511             else {
 512                 Data(ap, KRB_REJECT, (void *)msg, -1);
 513                 free(msg);
 514             }
 515             auth_finished (ap, AUTH_REJECT);
 516             krb5_free_keyblock_contents(context, key_block);
 517             break;
 518         }
 519         auth_finished(ap, AUTH_USER);
 520         krb5_free_keyblock_contents(context, key_block);
 521
 522         break;
 523     case KRB_FORWARD: {
 524         struct passwd *pwd;
 525         char ccname[1024];      /* XXX */
 526         krb5_data inbuf;
 527         krb5_ccache ccache;
 528         inbuf.data = (char *)data;
 529         inbuf.length = cnt;
 530
 531         pwd = getpwnam (UserNameRequested);
 532         if (pwd == NULL)
 533             break;
 534
 535         snprintf (ccname, sizeof(ccname),
 536                   "FILE:/tmp/krb5cc_%u", pwd->pw_uid);
 537
 538         ret = krb5_cc_resolve (context, ccname, &ccache);
 539         if (ret) {
 540             if (auth_debug_mode)
 541                 printf ("Kerberos V5: could not get ccache: %s\r\n",
 542                         krb5_get_err_text(context, ret));
 543             break;
 544         }
 545
 546         ret = krb5_cc_initialize (context,
 547                                   ccache,
 548                                   ticket->client);
 549         if (ret) {
 550             if (auth_debug_mode)
 551                 printf ("Kerberos V5: could not init ccache: %s\r\n",
 552                         krb5_get_err_text(context, ret));
 553             break;
 554         }
 555
 556 #if defined(DCE)
 557         esetenv("KRB5CCNAME", ccname, 1);
 558 #endif
 559         ret = krb5_rd_cred2 (context,
 560                              auth_context,
 561                              ccache,
 562                              &inbuf);
 563         if(ret) {
 564             char *errbuf;
 565
 566             asprintf (&errbuf,
 567                       "Read forwarded creds failed: %s",
 568                       krb5_get_err_text (context, ret));
 569             if(errbuf == NULL)
 570                 Data(ap, KRB_FORWARD_REJECT, NULL, 0);
 571             else
 572                 Data(ap, KRB_FORWARD_REJECT, errbuf, -1);
 573             if (auth_debug_mode)
 574                 printf("Could not read forwarded credentials: %s\r\n",
 575                        errbuf);
 576             free (errbuf);
 577         } else {
 578             Data(ap, KRB_FORWARD_ACCEPT, 0, 0);
 579 #if defined(DCE)
 580             dfsfwd = 1;
 581 #endif
 582         }
 583         chown (ccname + 5, pwd->pw_uid, -1);
 584         if (auth_debug_mode)
 585             printf("Forwarded credentials obtained\r\n");
 586         break;
 587     }
 588     default:
 589         if (auth_debug_mode)
 590             printf("Unknown Kerberos option %d\r\n", data[-1]);
 591         Data(ap, KRB_REJECT, 0, 0);
 592         break;
 593     }
 594 }
 595
 596 void
 597 kerberos5_reply(Authenticator *ap, unsigned char *data, int cnt)
 598 {
 599     static int mutual_complete = 0;
 600
 601     if (cnt-- < 1)
 602         return;
 603     switch (*data++) {
 604     case KRB_REJECT:
 605         if (cnt > 0) {
 606             printf("[ Kerberos V5 refuses authentication because %.*s ]\r\n",
 607                    cnt, data);
 608         } else
 609             printf("[ Kerberos V5 refuses authentication ]\r\n");
 610         auth_send_retry();
 611         return;
 612     case KRB_ACCEPT: {
 613         krb5_error_code ret;
 614         Session_Key skey;
 615         krb5_keyblock *keyblock;
 616
 617         if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL &&
 618             !mutual_complete) {
 619             printf("[ Kerberos V5 accepted you, but didn't provide mutual authentication! ]\r\n");
 620             auth_send_retry();
 621             return;
 622         }
 623         if (cnt)
 624             printf("[ Kerberos V5 accepts you as ``%.*s'' ]\r\n", cnt, data);
 625         else
 626             printf("[ Kerberos V5 accepts you ]\r\n");
 627
 628         ret = krb5_auth_con_getlocalsubkey (context,
 629                                             auth_context,
 630                                             &keyblock);
 631         if (ret)
 632             ret = krb5_auth_con_getkey (context,
 633                                         auth_context,
 634                                         &keyblock);
 635         if(ret) {
 636             printf("[ krb5_auth_con_getkey: %s ]\r\n",
 637                    krb5_get_err_text(context, ret));
 638             auth_send_retry();
 639             return;
 640         }
 641
 642         skey.type = SK_DES;
 643         skey.length = 8;
 644         skey.data = keyblock->keyvalue.data;
 645         encrypt_session_key(&skey, 0);
 646         krb5_free_keyblock_contents (context, keyblock);
 647         auth_finished(ap, AUTH_USER);
 648         if (forward_flags & OPTS_FORWARD_CREDS)
 649             kerberos5_forward(ap);
 650         break;
 651     }
 652     case KRB_RESPONSE:
 653         if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
 654             /* the rest of the reply should contain a krb_ap_rep */
 655           krb5_ap_rep_enc_part *reply;
 656           krb5_data inbuf;
 657           krb5_error_code ret;
 658
 659           inbuf.length = cnt;
 660           inbuf.data = (char *)data;
 661
 662           ret = krb5_rd_rep(context, auth_context, &inbuf, &reply);
 663           if (ret) {
 664               printf("[ Mutual authentication failed: %s ]\r\n",
 665                      krb5_get_err_text (context, ret));
 666               auth_send_retry();
 667               return;
 668           }
 669           krb5_free_ap_rep_enc_part(context, reply);
 670           mutual_complete = 1;
 671         }
 672         return;
 673     case KRB_FORWARD_ACCEPT:
 674         printf("[ Kerberos V5 accepted forwarded credentials ]\r\n");
 675         return;
 676     case KRB_FORWARD_REJECT:
 677         printf("[ Kerberos V5 refuses forwarded credentials because %.*s ]\r\n",
 678                cnt, data);
 679         return;
 680     default:
 681         if (auth_debug_mode)
 682             printf("Unknown Kerberos option %d\r\n", data[-1]);
 683         return;
 684     }
 685 }
 686
 687 int
 688 kerberos5_status(Authenticator *ap, char *name, size_t name_sz, int level)
 689 {
 690     if (level < AUTH_USER)
 691         return(level);
 692
 693     if (UserNameRequested &&
 694         krb5_kuserok(context,
 695                      ticket->client,
 696                      UserNameRequested))
 697         {
 698             strlcpy(name, UserNameRequested, name_sz);
 699 #if defined(DCE)
 700             dfsk5ok = 1;
 701 #endif
 702             return(AUTH_VALID);
 703         } else
 704             return(AUTH_USER);
 705 }
 706
 707 #define BUMP(buf, len)          while (*(buf)) {++(buf), --(len);}
 708 #define ADDC(buf, len, c)       if ((len) > 0) {*(buf)++ = (c); --(len);}
 709
 710 void
 711 kerberos5_printsub(unsigned char *data, int cnt, unsigned char *buf, int buflen)
 712 {
 713     int i;
 714
 715     buf[buflen-1] = '\0';               /* make sure its NULL terminated */
 716     buflen -= 1;
 717
 718     switch(data[3]) {
 719     case KRB_REJECT:            /* Rejected (reason might follow) */
 720         strlcpy((char *)buf, " REJECT ", buflen);
 721         goto common;
 722
 723     case KRB_ACCEPT:            /* Accepted (name might follow) */
 724         strlcpy((char *)buf, " ACCEPT ", buflen);
 725     common:
 726         BUMP(buf, buflen);
 727         if (cnt <= 4)
 728             break;
 729         ADDC(buf, buflen, '"');
 730         for (i = 4; i < cnt; i++)
 731             ADDC(buf, buflen, data[i]);
 732         ADDC(buf, buflen, '"');
 733         ADDC(buf, buflen, '\0');
 734         break;
 735
 736
 737     case KRB_AUTH:                      /* Authentication data follows */
 738         strlcpy((char *)buf, " AUTH", buflen);
 739         goto common2;
 740
 741     case KRB_RESPONSE:
 742         strlcpy((char *)buf, " RESPONSE", buflen);
 743         goto common2;
 744
 745     case KRB_FORWARD:           /* Forwarded credentials follow */
 746         strlcpy((char *)buf, " FORWARD", buflen);
 747         goto common2;
 748
 749     case KRB_FORWARD_ACCEPT:    /* Forwarded credentials accepted */
 750         strlcpy((char *)buf, " FORWARD_ACCEPT", buflen);
 751         goto common2;
 752
 753     case KRB_FORWARD_REJECT:    /* Forwarded credentials rejected */
 754         /* (reason might follow) */
 755         strlcpy((char *)buf, " FORWARD_REJECT", buflen);
 756         goto common2;
 757
 758     default:
 759         snprintf((char*)buf, buflen, " %d (unknown)", data[3]);
 760     common2:
 761         BUMP(buf, buflen);
 762         for (i = 4; i < cnt; i++) {
 763             snprintf((char*)buf, buflen, " %d", data[i]);
 764             BUMP(buf, buflen);
 765         }
 766         break;
 767     }
 768 }
 769
 770 void
 771 kerberos5_forward(Authenticator *ap)
 772 {
 773     krb5_error_code ret;
 774     krb5_ccache     ccache;
 775     krb5_creds      creds;
 776     krb5_kdc_flags  flags;
 777     krb5_data       out_data;
 778     krb5_principal  principal;
 779
 780     ret = krb5_cc_default (context, &ccache);
 781     if (ret) {
 782         if (auth_debug_mode)
 783             printf ("KerberosV5: could not get default ccache: %s\r\n",
 784                     krb5_get_err_text (context, ret));
 785         return;
 786     }
 787
 788     ret = krb5_cc_get_principal (context, ccache, &principal);
 789     if (ret) {
 790         if (auth_debug_mode)
 791             printf ("KerberosV5: could not get principal: %s\r\n",
 792                     krb5_get_err_text (context, ret));
 793         return;
 794     }
 795
 796     memset (&creds, 0, sizeof(creds));
 797
 798     creds.client = principal;
 799
 800     ret = krb5_build_principal (context,
 801                                 &creds.server,
 802                                 strlen(principal->realm),
 803                                 principal->realm,
 804                                 "krbtgt",
 805                                 principal->realm,
 806                                 NULL);
 807
 808     if (ret) {
 809         if (auth_debug_mode)
 810             printf ("KerberosV5: could not get principal: %s\r\n",
 811                     krb5_get_err_text (context, ret));
 812         return;
 813     }
 814
 815     creds.times.endtime = 0;
 816
 817     flags.i = 0;
 818     flags.b.forwarded = 1;
 819     if (forward_flags & OPTS_FORWARDABLE_CREDS)
 820         flags.b.forwardable = 1;
 821
 822     ret = krb5_get_forwarded_creds (context,
 823                                     auth_context,
 824                                     ccache,
 825                                     flags.i,
 826                                     RemoteHostName,
 827                                     &creds,
 828                                     &out_data);
 829     if (ret) {
 830         if (auth_debug_mode)
 831             printf ("Kerberos V5: error getting forwarded creds: %s\r\n",
 832                     krb5_get_err_text (context, ret));
 833         return;
 834     }
 835
 836     if(!Data(ap, KRB_FORWARD, out_data.data, out_data.length)) {
 837         if (auth_debug_mode)
 838             printf("Not enough room for authentication data\r\n");
 839     } else {
 840         if (auth_debug_mode)
 841             printf("Forwarded local Kerberos V5 credentials to server\r\n");
 842     }
 843 }
 844
 845 #if defined(DCE)
 846 /* if this was a K5 authentication try and join a PAG for the user. */
 847 void
 848 kerberos5_dfspag(void)
 849 {
 850     if (dfsk5ok) {
 851         dfspag = krb5_dfs_pag(context, dfsfwd, ticket->client,
 852                               UserNameRequested);
 853     }
 854 }
 855 #endif
 856
 857 int
 858 kerberos5_set_forward(int on)
 859 {
 860     if(on == 0)
 861         forward_flags &= ~OPTS_FORWARD_CREDS;
 862     if(on == 1)
 863         forward_flags |= OPTS_FORWARD_CREDS;
 864     if(on == -1)
 865         forward_flags ^= OPTS_FORWARD_CREDS;
 866     return 0;
 867 }
 868
 869 int
 870 kerberos5_set_forwardable(int on)
 871 {
 872     if(on == 0)
 873         forward_flags &= ~OPTS_FORWARDABLE_CREDS;
 874     if(on == 1)
 875         forward_flags |= OPTS_FORWARDABLE_CREDS;
 876     if(on == -1)
 877         forward_flags ^= OPTS_FORWARDABLE_CREDS;
 878     return 0;
 879 }
 880
 881 #endif /* KRB5 */