crypto/dist/heimdal/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("$Heimdal: kerberos5.c 22071 2007-11-14 20:04:50Z lha $"
  57         "$NetBSD$");
  58
  59 #ifdef  KRB5
  60
  61 #include <arpa/telnet.h>
  62 #include <stdio.h>
  63 #include <stdlib.h>
  64 #include <string.h>
  65 #include <unistd.h>
  66 #include <netdb.h>
  67 #include <ctype.h>
  68 #include <pwd.h>
  69 #define Authenticator k5_Authenticator
  70 #include <krb5.h>
  71 #undef Authenticator
  72 #include <roken.h>
  73 #ifdef SOCKS
  74 #include <socks.h>
  75 #endif
  76
  77
  78 #include "encrypt.h"
  79 #include "auth.h"
  80 #include "misc.h"
  81
  82 #if defined(DCE)
  83 int dfsk5ok = 0;
  84 int dfspag = 0;
  85 int dfsfwd = 0;
  86 #endif
  87
  88 int forward_flags = 0;  /* Flags get set in telnet/main.c on -f and -F */
  89
  90 int forward(int);
  91 int forwardable(int);
  92
  93 /* These values need to be the same as those defined in telnet/main.c. */
  94 /* Either define them in both places, or put in some common header file. */
  95 #define OPTS_FORWARD_CREDS      0x00000002
  96 #define OPTS_FORWARDABLE_CREDS  0x00000001
  97
  98
  99 void kerberos5_forward (Authenticator *);
 100
 101 static unsigned char str_data[4] = { IAC, SB, TELOPT_AUTHENTICATION, 0 };
 102
 103 #define KRB_AUTH                0       /* Authentication data follows */
 104 #define KRB_REJECT              1       /* Rejected (reason might follow) */
 105 #define KRB_ACCEPT              2       /* Accepted */
 106 #define KRB_RESPONSE            3       /* Response for mutual auth. */
 107
 108 #define KRB_FORWARD             4       /* Forwarded credentials follow */
 109 #define KRB_FORWARD_ACCEPT      5       /* Forwarded credentials accepted */
 110 #define KRB_FORWARD_REJECT      6       /* Forwarded credentials rejected */
 111
 112 static  krb5_data auth;
 113 static  krb5_ticket *ticket;
 114
 115 static krb5_context context;
 116 static krb5_auth_context auth_context;
 117
 118 static int
 119 Data(Authenticator *ap, int type, const void *d, int c)
 120 {
 121     const unsigned char *cp, *cd = d;
 122     unsigned char *p0, *p;
 123     size_t len = sizeof(str_data) + 3 + 2;
 124     int ret;
 125
 126     if (c == -1)
 127         c = strlen((const char*)cd);
 128
 129     for (cp = cd; cp - cd < c; cp++, len++)
 130         if (*cp == IAC)
 131             len++;
 132
 133     p0 = malloc(len);
 134     if (p0 == NULL)
 135         return 0;
 136
 137     memcpy(p0, str_data, sizeof(str_data));
 138     p = p0 + sizeof(str_data);
 139
 140     if (auth_debug_mode) {
 141         printf("%s:%d: [%d] (%d)",
 142                str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
 143                str_data[3],
 144                type, c);
 145         printd(d, c);
 146         printf("\r\n");
 147     }
 148     *p++ = ap->type;
 149     *p++ = ap->way;
 150     *p++ = type;
 151     while (c-- > 0) {
 152         if ((*p++ = *cd++) == IAC)
 153             *p++ = IAC;
 154     }
 155     *p++ = IAC;
 156     *p++ = SE;
 157     if (str_data[3] == TELQUAL_IS)
 158         printsub('>', &p0[2], len - 2);
 159     ret = telnet_net_write(p0, len);
 160     free(p0);
 161     return ret;
 162 }
 163
 164 int
 165 kerberos5_init(Authenticator *ap, int server)
 166 {
 167     krb5_error_code ret;
 168
 169     ret = krb5_init_context(&context);
 170     if (ret)
 171         return 0;
 172     if (server) {
 173         krb5_keytab kt;
 174         krb5_kt_cursor cursor;
 175
 176         ret = krb5_kt_default(context, &kt);
 177         if (ret)
 178             return 0;
 179
 180         ret = krb5_kt_start_seq_get (context, kt, &cursor);
 181         if (ret) {
 182             krb5_kt_close (context, kt);
 183             return 0;
 184         }
 185         krb5_kt_end_seq_get (context, kt, &cursor);
 186         krb5_kt_close (context, kt);
 187
 188         str_data[3] = TELQUAL_REPLY;
 189     } else
 190         str_data[3] = TELQUAL_IS;
 191     return(1);
 192 }
 193
 194 extern int net;
 195 static int
 196 kerberos5_send(char *name, Authenticator *ap)
 197 {
 198     krb5_error_code ret;
 199     krb5_ccache ccache;
 200     int ap_opts;
 201     krb5_data cksum_data;
 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             printf("Kerberos V5: could not get default ccache: %s\r\n",
 215                    krb5_get_err_text (context, ret));
 216         }
 217         return 0;
 218     }
 219
 220     if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL)
 221         ap_opts = AP_OPTS_MUTUAL_REQUIRED;
 222     else
 223         ap_opts = 0;
 224
 225     ap_opts |= AP_OPTS_USE_SUBKEY;
 226
 227     ret = krb5_auth_con_init (context, &auth_context);
 228     if (ret) {
 229         if (auth_debug_mode) {
 230             printf("Kerberos V5: krb5_auth_con_init failed (%s)\r\n",
 231                    krb5_get_err_text(context, ret));
 232         }
 233         return(0);
 234     }
 235
 236     ret = krb5_auth_con_setaddrs_from_fd (context,
 237                                           auth_context,
 238                                           &net);
 239     if (ret) {
 240         if (auth_debug_mode) {
 241             printf ("Kerberos V5:"
 242                     " krb5_auth_con_setaddrs_from_fd failed (%s)\r\n",
 243                     krb5_get_err_text(context, ret));
 244         }
 245         return(0);
 246     }
 247
 248     krb5_auth_con_setkeytype (context, auth_context, KEYTYPE_DES);
 249
 250     ap_msg[0] = ap->type;
 251     ap_msg[1] = ap->way;
 252
 253     cksum_data.length = sizeof(ap_msg);
 254     cksum_data.data   = ap_msg;
 255
 256
 257     {
 258         krb5_principal service;
 259         char sname[128];
 260
 261
 262         ret = krb5_sname_to_principal (context,
 263                                        RemoteHostName,
 264                                        NULL,
 265                                        KRB5_NT_SRV_HST,
 266                                        &service);
 267         if(ret) {
 268             if (auth_debug_mode) {
 269                 printf ("Kerberos V5:"
 270                         " krb5_sname_to_principal(%s) failed (%s)\r\n",
 271                         RemoteHostName, krb5_get_err_text(context, ret));
 272             }
 273             return 0;
 274         }
 275         ret = krb5_unparse_name_fixed(context, service, sname, sizeof(sname));
 276         if(ret) {
 277             if (auth_debug_mode) {
 278                 printf ("Kerberos V5:"
 279                         " krb5_unparse_name_fixed failed (%s)\r\n",
 280                         krb5_get_err_text(context, ret));
 281             }
 282             return 0;
 283         }
 284         printf("[ Trying %s (%s)... ]\r\n", name, sname);
 285         ret = krb5_mk_req_exact(context, &auth_context, ap_opts,
 286                                 service,
 287                                 &cksum_data, ccache, &auth);
 288         krb5_free_principal (context, service);
 289
 290     }
 291     if (ret) {
 292         if (1 || auth_debug_mode) {
 293             printf("Kerberos V5: mk_req failed (%s)\r\n",
 294                    krb5_get_err_text(context, ret));
 295         }
 296         return(0);
 297     }
 298
 299     if (!auth_sendname((unsigned char *)UserNameRequested,
 300                        strlen(UserNameRequested))) {
 301         if (auth_debug_mode)
 302             printf("Not enough room for user name\r\n");
 303         return(0);
 304     }
 305     if (!Data(ap, KRB_AUTH, auth.data, auth.length)) {
 306         if (auth_debug_mode)
 307             printf("Not enough room for authentication data\r\n");
 308         return(0);
 309     }
 310     if (auth_debug_mode) {
 311         printf("Sent Kerberos V5 credentials to server\r\n");
 312     }
 313     return(1);
 314 }
 315
 316 int
 317 kerberos5_send_mutual(Authenticator *ap)
 318 {
 319     return kerberos5_send("mutual KERBEROS5", ap);
 320 }
 321
 322 int
 323 kerberos5_send_oneway(Authenticator *ap)
 324 {
 325     return kerberos5_send("KERBEROS5", ap);
 326 }
 327
 328 static void log_message(const char *fmt, ...)
 329 {
 330     va_list ap;
 331     va_start(ap, fmt);
 332     if (auth_debug_mode) {
 333         va_start(ap, fmt);
 334         vfprintf(stdout, fmt, ap);
 335         va_end(ap);
 336         fprintf(stdout, "\r\n");
 337     }
 338     va_start(ap, fmt);
 339     vsyslog(LOG_NOTICE, fmt, ap);
 340     va_end(ap);
 341 }
 342
 343 void
 344 kerberos5_is(Authenticator *ap, unsigned char *data, int cnt)
 345 {
 346     krb5_error_code ret;
 347     krb5_data outbuf;
 348     krb5_keyblock *key_block;
 349     char *name;
 350     krb5_principal server;
 351     int zero = 0;
 352
 353     if (cnt-- < 1)
 354         return;
 355     switch (*data++) {
 356     case KRB_AUTH:
 357         auth.data = (char *)data;
 358         auth.length = cnt;
 359
 360         auth_context = NULL;
 361
 362         ret = krb5_auth_con_init (context, &auth_context);
 363         if (ret) {
 364             Data(ap, KRB_REJECT, "krb5_auth_con_init failed", -1);
 365             auth_finished(ap, AUTH_REJECT);
 366             log_message("Kerberos V5: krb5_auth_con_init failed (%s)",
 367                         krb5_get_err_text(context, ret));
 368             return;
 369         }
 370
 371         ret = krb5_auth_con_setaddrs_from_fd (context,
 372                                               auth_context,
 373                                               &zero);
 374         if (ret) {
 375             Data(ap, KRB_REJECT, "krb5_auth_con_setaddrs_from_fd failed", -1);
 376             auth_finished(ap, AUTH_REJECT);
 377             log_message("Kerberos V5: "
 378                         "krb5_auth_con_setaddrs_from_fd failed (%s)",
 379                         krb5_get_err_text(context, ret));
 380             return;
 381         }
 382
 383         ret = krb5_sock_to_principal (context,
 384                                       0,
 385                                       "host",
 386                                       KRB5_NT_SRV_HST,
 387                                       &server);
 388         if (ret) {
 389             Data(ap, KRB_REJECT, "krb5_sock_to_principal failed", -1);
 390             auth_finished(ap, AUTH_REJECT);
 391             log_message("Kerberos V5: "
 392                         "krb5_sock_to_principal failed (%s)",
 393                         krb5_get_err_text(context, ret));
 394             return;
 395         }
 396
 397         ret = krb5_rd_req(context,
 398                           &auth_context,
 399                           &auth,
 400                           server,
 401                           NULL,
 402                           NULL,
 403                           &ticket);
 404
 405         krb5_free_principal (context, server);
 406         if (ret) {
 407             const char *errbuf2 = "Read req failed";
 408             char *errbuf;
 409             int ret2;
 410
 411             ret2 = asprintf(&errbuf,
 412                             "Read req failed: %s",
 413                             krb5_get_err_text(context, ret));
 414             if (ret2 != -1)
 415                 errbuf2 = errbuf;
 416             Data(ap, KRB_REJECT, errbuf2, -1);
 417             log_message("%s", errbuf2);
 418             if (ret2 != -1)
 419                 free (errbuf);
 420             return;
 421         }
 422
 423         {
 424             char ap_msg[2];
 425
 426             ap_msg[0] = ap->type;
 427             ap_msg[1] = ap->way;
 428
 429             ret = krb5_verify_authenticator_checksum(context,
 430                                                      auth_context,
 431                                                      ap_msg,
 432                                                      sizeof(ap_msg));
 433
 434             if (ret) {
 435                 const char *errbuf2 = "Bad checksum";
 436                 char *errbuf;
 437                 int ret2;
 438
 439                 ret2 = asprintf(&errbuf, "Bad checksum: %s",
 440                                 krb5_get_err_text(context, ret));
 441                 if (ret2 != -1)
 442                     errbuf2 = errbuf;
 443                 Data(ap, KRB_REJECT, errbuf2, -1);
 444                 log_message("%s", errbuf2);
 445                 if (ret2 != -1)
 446                     free(errbuf);
 447                 return;
 448             }
 449         }
 450         ret = krb5_auth_con_getremotesubkey (context,
 451                                              auth_context,
 452                                              &key_block);
 453
 454         if (ret) {
 455             Data(ap, KRB_REJECT, "krb5_auth_con_getremotesubkey failed", -1);
 456             auth_finished(ap, AUTH_REJECT);
 457             log_message("Kerberos V5: "
 458                         "krb5_auth_con_getremotesubkey failed (%s)",
 459                         krb5_get_err_text(context, ret));
 460             return;
 461         }
 462
 463         if (key_block == NULL) {
 464             ret = krb5_auth_con_getkey(context,
 465                                        auth_context,
 466                                        &key_block);
 467         }
 468         if (ret) {
 469             Data(ap, KRB_REJECT, "krb5_auth_con_getkey failed", -1);
 470             auth_finished(ap, AUTH_REJECT);
 471             log_message("Kerberos V5: "
 472                         "krb5_auth_con_getkey failed (%s)",
 473                         krb5_get_err_text(context, ret));
 474             return;
 475         }
 476         if (key_block == NULL) {
 477             Data(ap, KRB_REJECT, "no subkey received", -1);
 478             auth_finished(ap, AUTH_REJECT);
 479             log_message("Kerberos V5: "
 480                         "krb5_auth_con_getremotesubkey returned NULL key");
 481             return;
 482         }
 483
 484         if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
 485             ret = krb5_mk_rep(context, auth_context, &outbuf);
 486             if (ret) {
 487                 Data(ap, KRB_REJECT,
 488                      "krb5_mk_rep failed", -1);
 489                 auth_finished(ap, AUTH_REJECT);
 490                 log_message("Kerberos V5: "
 491                             "krb5_mk_rep failed (%s)",
 492                             krb5_get_err_text(context, ret));
 493                 return;
 494             }
 495             Data(ap, KRB_RESPONSE, outbuf.data, outbuf.length);
 496         }
 497         if (krb5_unparse_name(context, ticket->client, &name))
 498             name = 0;
 499
 500         if(UserNameRequested && krb5_kuserok(context,
 501                                              ticket->client,
 502                                              UserNameRequested)) {
 503             Data(ap, KRB_ACCEPT, name, name ? -1 : 0);
 504             log_message("%s accepted as user %s from %s",
 505                         name ? name : "<unknown>",
 506                         UserNameRequested ? UserNameRequested : "<unknown>",
 507                         RemoteHostName ? RemoteHostName : "<unknown>");
 508
 509             if(key_block->keytype == ETYPE_DES_CBC_MD5 ||
 510                key_block->keytype == ETYPE_DES_CBC_MD4 ||
 511                key_block->keytype == ETYPE_DES_CBC_CRC) {
 512                 Session_Key skey;
 513
 514                 skey.type = SK_DES;
 515                 skey.length = 8;
 516                 skey.data = key_block->keyvalue.data;
 517                 encrypt_session_key(&skey, 0);
 518             }
 519
 520         } else {
 521             const char *msg2 = "user is not authorized to login";
 522             char *msg;
 523
 524             ret = asprintf (&msg, "user `%s' is not authorized to "
 525                             "login as `%s'",
 526                             name ? name : "<unknown>",
 527                             UserNameRequested ? UserNameRequested : "<nobody>");
 528             if (ret != -1)
 529                 msg2 = msg;
 530             Data(ap, KRB_REJECT, (void *)msg2, -1);
 531             if (ret != -1)
 532                 free(msg);
 533             auth_finished (ap, AUTH_REJECT);
 534             krb5_free_keyblock_contents(context, key_block);
 535             break;
 536         }
 537         auth_finished(ap, AUTH_USER);
 538         krb5_free_keyblock_contents(context, key_block);
 539
 540         break;
 541     case KRB_FORWARD: {
 542         struct passwd *pwd;
 543         char ccname[1024];      /* XXX */
 544         krb5_data inbuf;
 545         krb5_ccache ccache;
 546         inbuf.data = (char *)data;
 547         inbuf.length = cnt;
 548
 549         pwd = getpwnam (UserNameRequested);
 550         if (pwd == NULL)
 551             break;
 552
 553         snprintf (ccname, sizeof(ccname),
 554                   "FILE:/tmp/krb5cc_%lu", (unsigned long)pwd->pw_uid);
 555
 556         ret = krb5_cc_resolve (context, ccname, &ccache);
 557         if (ret) {
 558             log_message("Kerberos V5: could not get ccache: %s",
 559                         krb5_get_err_text(context, ret));
 560             break;
 561         }
 562
 563         ret = krb5_cc_initialize (context,
 564                                   ccache,
 565                                   ticket->client);
 566         if (ret) {
 567             log_message("Kerberos V5: could not init ccache: %s",
 568                         krb5_get_err_text(context, ret));
 569             break;
 570         }
 571
 572 #if defined(DCE)
 573         esetenv("KRB5CCNAME", ccname, 1);
 574 #endif
 575         ret = krb5_rd_cred2 (context,
 576                              auth_context,
 577                              ccache,
 578                              &inbuf);
 579         if(ret) {
 580             const char *errbuf2 = "Read forwarded creds failed";
 581             char *errbuf;
 582             int ret2;
 583
 584             ret2 = asprintf (&errbuf,
 585                              "Read forwarded creds failed: %s",
 586                              krb5_get_err_text (context, ret));
 587             if (ret2 != -1)
 588                 errbuf2 = errbuf;
 589             Data(ap, KRB_FORWARD_REJECT, errbuf, -1);
 590             log_message("Could not read forwarded credentials: %s", errbuf);
 591
 592             if (ret2 != -1)
 593                 free (errbuf);
 594         } else {
 595             Data(ap, KRB_FORWARD_ACCEPT, 0, 0);
 596 #if defined(DCE)
 597             dfsfwd = 1;
 598 #endif
 599         }
 600         chown (ccname + 5, pwd->pw_uid, -1);
 601         log_message("Forwarded credentials obtained");
 602         break;
 603     }
 604     default:
 605         log_message("Unknown Kerberos option %d", data[-1]);
 606         Data(ap, KRB_REJECT, 0, 0);
 607         break;
 608     }
 609 }
 610
 611 void
 612 kerberos5_reply(Authenticator *ap, unsigned char *data, int cnt)
 613 {
 614     static int mutual_complete = 0;
 615
 616     if (cnt-- < 1)
 617         return;
 618     switch (*data++) {
 619     case KRB_REJECT:
 620         if (cnt > 0) {
 621             printf("[ Kerberos V5 refuses authentication because %.*s ]\r\n",
 622                    cnt, data);
 623         } else
 624             printf("[ Kerberos V5 refuses authentication ]\r\n");
 625         auth_send_retry();
 626         return;
 627     case KRB_ACCEPT: {
 628         krb5_error_code ret;
 629         Session_Key skey;
 630         krb5_keyblock *keyblock;
 631
 632         if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL &&
 633             !mutual_complete) {
 634             printf("[ Kerberos V5 accepted you, but didn't provide mutual authentication! ]\r\n");
 635             auth_send_retry();
 636             return;
 637         }
 638         if (cnt)
 639             printf("[ Kerberos V5 accepts you as ``%.*s'' ]\r\n", cnt, data);
 640         else
 641             printf("[ Kerberos V5 accepts you ]\r\n");
 642
 643         ret = krb5_auth_con_getlocalsubkey (context,
 644                                             auth_context,
 645                                             &keyblock);
 646         if (ret)
 647             ret = krb5_auth_con_getkey (context,
 648                                         auth_context,
 649                                         &keyblock);
 650         if(ret) {
 651             printf("[ krb5_auth_con_getkey: %s ]\r\n",
 652                    krb5_get_err_text(context, ret));
 653             auth_send_retry();
 654             return;
 655         }
 656
 657         skey.type = SK_DES;
 658         skey.length = 8;
 659         skey.data = keyblock->keyvalue.data;
 660         encrypt_session_key(&skey, 0);
 661         krb5_free_keyblock_contents (context, keyblock);
 662         auth_finished(ap, AUTH_USER);
 663         if (forward_flags & OPTS_FORWARD_CREDS)
 664             kerberos5_forward(ap);
 665         break;
 666     }
 667     case KRB_RESPONSE:
 668         if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
 669             /* the rest of the reply should contain a krb_ap_rep */
 670           krb5_ap_rep_enc_part *reply;
 671           krb5_data inbuf;
 672           krb5_error_code ret;
 673
 674           inbuf.length = cnt;
 675           inbuf.data = (char *)data;
 676
 677           ret = krb5_rd_rep(context, auth_context, &inbuf, &reply);
 678           if (ret) {
 679               printf("[ Mutual authentication failed: %s ]\r\n",
 680                      krb5_get_err_text (context, ret));
 681               auth_send_retry();
 682               return;
 683           }
 684           krb5_free_ap_rep_enc_part(context, reply);
 685           mutual_complete = 1;
 686         }
 687         return;
 688     case KRB_FORWARD_ACCEPT:
 689         printf("[ Kerberos V5 accepted forwarded credentials ]\r\n");
 690         return;
 691     case KRB_FORWARD_REJECT:
 692         printf("[ Kerberos V5 refuses forwarded credentials because %.*s ]\r\n",
 693                cnt, data);
 694         return;
 695     default:
 696         if (auth_debug_mode)
 697             printf("Unknown Kerberos option %d\r\n", data[-1]);
 698         return;
 699     }
 700 }
 701
 702 int
 703 kerberos5_status(Authenticator *ap, char *name, size_t name_sz, int level)
 704 {
 705     if (level < AUTH_USER)
 706         return(level);
 707
 708     if (UserNameRequested &&
 709         krb5_kuserok(context,
 710                      ticket->client,
 711                      UserNameRequested))
 712         {
 713             strlcpy(name, UserNameRequested, name_sz);
 714 #if defined(DCE)
 715             dfsk5ok = 1;
 716 #endif
 717             return(AUTH_VALID);
 718         } else
 719             return(AUTH_USER);
 720 }
 721
 722 #define BUMP(buf, len)          while (*(buf)) {++(buf), --(len);}
 723 #define ADDC(buf, len, c)       if ((len) > 0) {*(buf)++ = (c); --(len);}
 724
 725 void
 726 kerberos5_printsub(unsigned char *data, int cnt, unsigned char *buf, int buflen)
 727 {
 728     int i;
 729
 730     buf[buflen-1] = '\0';               /* make sure it's NULL terminated */
 731     buflen -= 1;
 732
 733     switch(data[3]) {
 734     case KRB_REJECT:            /* Rejected (reason might follow) */
 735         strlcpy((char *)buf, " REJECT ", buflen);
 736         goto common;
 737
 738     case KRB_ACCEPT:            /* Accepted (name might follow) */
 739         strlcpy((char *)buf, " ACCEPT ", buflen);
 740     common:
 741         BUMP(buf, buflen);
 742         if (cnt <= 4)
 743             break;
 744         ADDC(buf, buflen, '"');
 745         for (i = 4; i < cnt; i++)
 746             ADDC(buf, buflen, data[i]);
 747         ADDC(buf, buflen, '"');
 748         ADDC(buf, buflen, '\0');
 749         break;
 750
 751
 752     case KRB_AUTH:                      /* Authentication data follows */
 753         strlcpy((char *)buf, " AUTH", buflen);
 754         goto common2;
 755
 756     case KRB_RESPONSE:
 757         strlcpy((char *)buf, " RESPONSE", buflen);
 758         goto common2;
 759
 760     case KRB_FORWARD:           /* Forwarded credentials follow */
 761         strlcpy((char *)buf, " FORWARD", buflen);
 762         goto common2;
 763
 764     case KRB_FORWARD_ACCEPT:    /* Forwarded credentials accepted */
 765         strlcpy((char *)buf, " FORWARD_ACCEPT", buflen);
 766         goto common2;
 767
 768     case KRB_FORWARD_REJECT:    /* Forwarded credentials rejected */
 769         /* (reason might follow) */
 770         strlcpy((char *)buf, " FORWARD_REJECT", buflen);
 771         goto common2;
 772
 773     default:
 774         snprintf((char*)buf, buflen, " %d (unknown)", data[3]);
 775     common2:
 776         BUMP(buf, buflen);
 777         for (i = 4; i < cnt; i++) {
 778             snprintf((char*)buf, buflen, " %d", data[i]);
 779             BUMP(buf, buflen);
 780         }
 781         break;
 782     }
 783 }
 784
 785 void
 786 kerberos5_forward(Authenticator *ap)
 787 {
 788     krb5_error_code ret;
 789     krb5_ccache     ccache;
 790     krb5_creds      creds;
 791     KDCOptions      flags;
 792     krb5_data       out_data;
 793     krb5_principal  principal;
 794
 795     ret = krb5_cc_default (context, &ccache);
 796     if (ret) {
 797         if (auth_debug_mode)
 798             printf ("KerberosV5: could not get default ccache: %s\r\n",
 799                     krb5_get_err_text (context, ret));
 800         return;
 801     }
 802
 803     ret = krb5_cc_get_principal (context, ccache, &principal);
 804     if (ret) {
 805         if (auth_debug_mode)
 806             printf ("KerberosV5: could not get principal: %s\r\n",
 807                     krb5_get_err_text (context, ret));
 808         return;
 809     }
 810
 811     memset (&creds, 0, sizeof(creds));
 812
 813     creds.client = principal;
 814
 815     ret = krb5_build_principal (context,
 816                                 &creds.server,
 817                                 strlen(principal->realm),
 818                                 principal->realm,
 819                                 "krbtgt",
 820                                 principal->realm,
 821                                 NULL);
 822
 823     if (ret) {
 824         if (auth_debug_mode)
 825             printf ("KerberosV5: could not get principal: %s\r\n",
 826                     krb5_get_err_text (context, ret));
 827         return;
 828     }
 829
 830     creds.times.endtime = 0;
 831
 832     memset(&flags, 0, sizeof(flags));
 833     flags.forwarded = 1;
 834     if (forward_flags & OPTS_FORWARDABLE_CREDS)
 835         flags.forwardable = 1;
 836
 837     ret = krb5_get_forwarded_creds (context,
 838                                     auth_context,
 839                                     ccache,
 840                                     KDCOptions2int(flags),
 841                                     RemoteHostName,
 842                                     &creds,
 843                                     &out_data);
 844     if (ret) {
 845         if (auth_debug_mode)
 846             printf ("Kerberos V5: error getting forwarded creds: %s\r\n",
 847                     krb5_get_err_text (context, ret));
 848         return;
 849     }
 850
 851     if(!Data(ap, KRB_FORWARD, out_data.data, out_data.length)) {
 852         if (auth_debug_mode)
 853             printf("Not enough room for authentication data\r\n");
 854     } else {
 855         if (auth_debug_mode)
 856             printf("Forwarded local Kerberos V5 credentials to server\r\n");
 857     }
 858 }
 859
 860 #if defined(DCE)
 861 /* if this was a K5 authentication try and join a PAG for the user. */
 862 void
 863 kerberos5_dfspag(void)
 864 {
 865     if (dfsk5ok) {
 866         dfspag = krb5_dfs_pag(context, dfsfwd, ticket->client,
 867                               UserNameRequested);
 868     }
 869 }
 870 #endif
 871
 872 int
 873 kerberos5_set_forward(int on)
 874 {
 875     if(on == 0)
 876         forward_flags &= ~OPTS_FORWARD_CREDS;
 877     if(on == 1)
 878         forward_flags |= OPTS_FORWARD_CREDS;
 879     if(on == -1)
 880         forward_flags ^= OPTS_FORWARD_CREDS;
 881     return 0;
 882 }
 883
 884 int
 885 kerberos5_set_forwardable(int on)
 886 {
 887     if(on == 0)
 888         forward_flags &= ~OPTS_FORWARDABLE_CREDS;
 889     if(on == 1)
 890         forward_flags |= OPTS_FORWARDABLE_CREDS;
 891     if(on == -1)
 892         forward_flags ^= OPTS_FORWARDABLE_CREDS;
 893     return 0;
 894 }
 895
 896 #endif /* KRB5 */