crypto/dist/heimdal/appl/telnet/libtelnet/krb4encpwd.c

   1 /*-
   2  * Copyright (c) 1992, 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 #include <config.h>
  35
  36 __RCSID("$Heimdal: krb4encpwd.c 22071 2007-11-14 20:04:50Z lha $"
  37         "$NetBSD$");
  38
  39 #ifdef  KRB4_ENCPWD
  40 /*
  41  * COPYRIGHT (C) 1990 DIGITAL EQUIPMENT CORPORATION
  42  * ALL RIGHTS RESERVED
  43  *
  44  * "Digital Equipment Corporation authorizes the reproduction,
  45  * distribution and modification of this software subject to the following
  46  * restrictions:
  47  *
  48  * 1.  Any partial or whole copy of this software, or any modification
  49  * thereof, must include this copyright notice in its entirety.
  50  *
  51  * 2.  This software is supplied "as is" with no warranty of any kind,
  52  * expressed or implied, for any purpose, including any warranty of fitness
  53  * or merchantibility.  DIGITAL assumes no responsibility for the use or
  54  * reliability of this software, nor promises to provide any form of
  55  * support for it on any basis.
  56  *
  57  * 3.  Distribution of this software is authorized only if no profit or
  58  * remuneration of any kind is received in exchange for such distribution.
  59  *
  60  * 4.  This software produces public key authentication certificates
  61  * bearing an expiration date established by DIGITAL and RSA Data
  62  * Security, Inc.  It may cease to generate certificates after the expiration
  63  * date.  Any modification of this software that changes or defeats
  64  * the expiration date or its effect is unauthorized.
  65  *
  66  * 5.  Software that will renew or extend the expiration date of
  67  * authentication certificates produced by this software may be obtained
  68  * from RSA Data Security, Inc., 10 Twin Dolphin Drive, Redwood City, CA
  69  * 94065, (415)595-8782, or from DIGITAL"
  70  *
  71  */
  72
  73 #include <sys/types.h>
  74 #include <arpa/telnet.h>
  75 #include <pwd.h>
  76 #include <stdio.h>
  77
  78 #include <krb.h>
  79 #include <stdlib.h>
  80 #include <string.h>
  81 #ifdef SOCKS
  82 #include <socks.h>
  83 #endif
  84
  85 #include "encrypt.h"
  86 #include "auth.h"
  87 #include "misc.h"
  88
  89 int krb_mk_encpwd_req (KTEXT, char *, char *, char *, char *, char *, char *);
  90 int krb_rd_encpwd_req (KTEXT, char *, char *, u_long, AUTH_DAT *, char *, char *, char *, char *);
  91
  92 extern auth_debug_mode;
  93
  94 static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0,
  95                                         AUTHTYPE_KRB4_ENCPWD, };
  96 static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION,
  97                                         TELQUAL_NAME, };
  98
  99 #define KRB4_ENCPWD_AUTH        0       /* Authentication data follows */
 100 #define KRB4_ENCPWD_REJECT      1       /* Rejected (reason might follow) */
 101 #define KRB4_ENCPWD_ACCEPT      2       /* Accepted */
 102 #define KRB4_ENCPWD_CHALLENGE   3       /* Challenge for mutual auth. */
 103 #define KRB4_ENCPWD_ACK         4       /* Acknowledge */
 104
 105 #define KRB_SERVICE_NAME    "rcmd"
 106
 107 static  KTEXT_ST auth;
 108 static  char name[ANAME_SZ];
 109 static  char user_passwd[ANAME_SZ];
 110 static  AUTH_DAT adat = { 0 };
 111 static des_key_schedule sched;
 112 static char  challenge[REALM_SZ];
 113
 114         static int
 115 Data(ap, type, d, c)
 116         Authenticator *ap;
 117         int type;
 118         void *d;
 119         int c;
 120 {
 121         unsigned char *p = str_data + 4;
 122         unsigned char *cd = (unsigned char *)d;
 123
 124         if (c == -1)
 125                 c = strlen(cd);
 126
 127         if (0) {
 128                 printf("%s:%d: [%d] (%d)",
 129                         str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
 130                         str_data[3],
 131                         type, c);
 132                 printd(d, c);
 133                 printf("\r\n");
 134         }
 135         *p++ = ap->type;
 136         *p++ = ap->way;
 137         *p++ = type;
 138         while (c-- > 0) {
 139                 if ((*p++ = *cd++) == IAC)
 140                         *p++ = IAC;
 141         }
 142         *p++ = IAC;
 143         *p++ = SE;
 144         if (str_data[3] == TELQUAL_IS)
 145                 printsub('>', &str_data[2], p - (&str_data[2]));
 146         return(telnet_net_write(str_data, p - str_data));
 147 }
 148
 149         int
 150 krb4encpwd_init(ap, server)
 151         Authenticator *ap;
 152         int server;
 153 {
 154         char hostname[80], *cp, *realm;
 155         des_clock skey;
 156
 157         if (server) {
 158                 str_data[3] = TELQUAL_REPLY;
 159         } else {
 160                 str_data[3] = TELQUAL_IS;
 161                 gethostname(hostname, sizeof(hostname));
 162                 realm = krb_realmofhost(hostname);
 163                 cp = strchr(hostname, '.');
 164                 if (*cp != NULL) *cp = NULL;
 165                 if (read_service_key(KRB_SERVICE_NAME, hostname, realm, 0,
 166                                         KEYFILE, (char *)skey)) {
 167                   return(0);
 168                 }
 169         }
 170         return(1);
 171 }
 172
 173         int
 174 krb4encpwd_send(ap)
 175         Authenticator *ap;
 176 {
 177
 178         printf("[ Trying KRB4ENCPWD ... ]\r\n");
 179         if (!UserNameRequested) {
 180                 return(0);
 181         }
 182         if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) {
 183                 return(0);
 184         }
 185
 186         if (!Data(ap, KRB4_ENCPWD_ACK, NULL, 0)) {
 187                 return(0);
 188         }
 189
 190         return(1);
 191 }
 192
 193         void
 194 krb4encpwd_is(ap, data, cnt)
 195         Authenticator *ap;
 196         unsigned char *data;
 197         int cnt;
 198 {
 199         Session_Key skey;
 200         des_cblock datablock;
 201         char  r_passwd[ANAME_SZ], r_user[ANAME_SZ];
 202         char  lhostname[ANAME_SZ], *cp;
 203         int r;
 204         time_t now;
 205
 206         if (cnt-- < 1)
 207                 return;
 208         switch (*data++) {
 209         case KRB4_ENCPWD_AUTH:
 210                 memmove(auth.dat, data, auth.length = cnt);
 211
 212                 gethostname(lhostname, sizeof(lhostname));
 213                 if ((cp = strchr(lhostname, '.')) != 0)  *cp = '\0';
 214
 215                 if (r = krb_rd_encpwd_req(&auth, KRB_SERVICE_NAME, lhostname, 0, &adat, NULL, challenge, r_user, r_passwd)) {
 216                         Data(ap, KRB4_ENCPWD_REJECT, "Auth failed", -1);
 217                         auth_finished(ap, AUTH_REJECT);
 218                         return;
 219                 }
 220                 auth_encrypt_userpwd(r_passwd);
 221                 if (passwdok(UserNameRequested, UserPassword) == 0) {
 222                   /*
 223                    *  illegal username and password
 224                    */
 225                   Data(ap, KRB4_ENCPWD_REJECT, "Illegal password", -1);
 226                   auth_finished(ap, AUTH_REJECT);
 227                   return;
 228                 }
 229
 230                 memmove(session_key, adat.session, sizeof(des_cblock));
 231                 Data(ap, KRB4_ENCPWD_ACCEPT, 0, 0);
 232                 auth_finished(ap, AUTH_USER);
 233                 break;
 234
 235         case KRB4_ENCPWD_CHALLENGE:
 236                 /*
 237                  *  Take the received random challenge text and save
 238                  *  for future authentication.
 239                  */
 240                 memmove(challenge, data, sizeof(des_cblock));
 241                 break;
 242
 243
 244         case KRB4_ENCPWD_ACK:
 245                 /*
 246                  *  Receive ack, if mutual then send random challenge
 247                  */
 248
 249                 /*
 250                  * If we are doing mutual authentication, get set up to send
 251                  * the challenge, and verify it when the response comes back.
 252                  */
 253
 254                 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
 255                   int i;
 256
 257                   time(&now);
 258                   snprintf(challenge, sizeof(challenge), "%x", now);
 259                   Data(ap, KRB4_ENCPWD_CHALLENGE, challenge, strlen(challenge));
 260                 }
 261                 break;
 262
 263         default:
 264                 Data(ap, KRB4_ENCPWD_REJECT, 0, 0);
 265                 break;
 266         }
 267 }
 268
 269
 270         void
 271 krb4encpwd_reply(ap, data, cnt)
 272         Authenticator *ap;
 273         unsigned char *data;
 274         int cnt;
 275 {
 276         Session_Key skey;
 277         KTEXT_ST krb_token;
 278         des_cblock enckey;
 279         CREDENTIALS cred;
 280         int r;
 281         char    randchal[REALM_SZ], instance[ANAME_SZ], *cp;
 282         char    hostname[80], *realm;
 283
 284         if (cnt-- < 1)
 285                 return;
 286         switch (*data++) {
 287         case KRB4_ENCPWD_REJECT:
 288                 if (cnt > 0) {
 289                         printf("[ KRB4_ENCPWD refuses authentication because %.*s ]\r\n",
 290                                 cnt, data);
 291                 } else
 292                         printf("[ KRB4_ENCPWD refuses authentication ]\r\n");
 293                 auth_send_retry();
 294                 return;
 295         case KRB4_ENCPWD_ACCEPT:
 296                 printf("[ KRB4_ENCPWD accepts you ]\r\n");
 297                 auth_finished(ap, AUTH_USER);
 298                 return;
 299         case KRB4_ENCPWD_CHALLENGE:
 300                 /*
 301                  * Verify that the response to the challenge is correct.
 302                  */
 303
 304                 gethostname(hostname, sizeof(hostname));
 305                 realm = krb_realmofhost(hostname);
 306                 memmove(challenge, data, cnt);
 307                 memset(user_passwd, 0, sizeof(user_passwd));
 308                 des_read_pw_string(user_passwd, sizeof(user_passwd)-1, "Password: ", 0);
 309                 UserPassword = user_passwd;
 310                 Challenge = challenge;
 311                 strlcpy(instance, RemoteHostName, sizeof(instance));
 312                 if ((cp = strchr(instance, '.')) != 0)  *cp = '\0';
 313
 314                 if (r = krb_mk_encpwd_req(&krb_token, KRB_SERVICE_NAME, instance, realm, Challenge, UserNameRequested, user_passwd)) {
 315                   krb_token.length = 0;
 316                 }
 317
 318                 if (!Data(ap, KRB4_ENCPWD_AUTH, krb_token.dat, krb_token.length)) {
 319                   return;
 320                 }
 321
 322                 break;
 323
 324         default:
 325                 return;
 326         }
 327 }
 328
 329         int
 330 krb4encpwd_status(ap, name, name_sz, level)
 331         Authenticator *ap;
 332         char *name;
 333         size_t name_sz;
 334         int level;
 335 {
 336
 337         if (level < AUTH_USER)
 338                 return(level);
 339
 340         if (UserNameRequested && passwdok(UserNameRequested, UserPassword)) {
 341                 strlcpy(name, UserNameRequested, name_sz);
 342                 return(AUTH_VALID);
 343         } else {
 344                 return(AUTH_USER);
 345         }
 346 }
 347
 348 #define BUMP(buf, len)          while (*(buf)) {++(buf), --(len);}
 349 #define ADDC(buf, len, c)       if ((len) > 0) {*(buf)++ = (c); --(len);}
 350
 351         void
 352 krb4encpwd_printsub(data, cnt, buf, buflen)
 353         unsigned char *data, *buf;
 354         int cnt, buflen;
 355 {
 356         int i;
 357
 358         buf[buflen-1] = '\0';           /* make sure it's NULL terminated */
 359         buflen -= 1;
 360
 361         switch(data[3]) {
 362         case KRB4_ENCPWD_REJECT:        /* Rejected (reason might follow) */
 363                 strlcpy((char *)buf, " REJECT ", buflen);
 364                 goto common;
 365
 366         case KRB4_ENCPWD_ACCEPT:        /* Accepted (name might follow) */
 367                 strlcpy((char *)buf, " ACCEPT ", buflen);
 368         common:
 369                 BUMP(buf, buflen);
 370                 if (cnt <= 4)
 371                         break;
 372                 ADDC(buf, buflen, '"');
 373                 for (i = 4; i < cnt; i++)
 374                         ADDC(buf, buflen, data[i]);
 375                 ADDC(buf, buflen, '"');
 376                 ADDC(buf, buflen, '\0');
 377                 break;
 378
 379         case KRB4_ENCPWD_AUTH:          /* Authentication data follows */
 380                 strlcpy((char *)buf, " AUTH", buflen);
 381                 goto common2;
 382
 383         case KRB4_ENCPWD_CHALLENGE:
 384                 strlcpy((char *)buf, " CHALLENGE", buflen);
 385                 goto common2;
 386
 387         case KRB4_ENCPWD_ACK:
 388                 strlcpy((char *)buf, " ACK", buflen);
 389                 goto common2;
 390
 391         default:
 392                 snprintf(buf, buflen, " %d (unknown)", data[3]);
 393         common2:
 394                 BUMP(buf, buflen);
 395                 for (i = 4; i < cnt; i++) {
 396                         snprintf(buf, buflen, " %d", data[i]);
 397                         BUMP(buf, buflen);
 398                 }
 399                 break;
 400         }
 401 }
 402
 403 int passwdok(name, passwd)
 404 char *name, *passwd;
 405 {
 406   char *crypt();
 407   char *salt, *p;
 408   struct passwd *pwd;
 409   int   passwdok_status = 0;
 410
 411   if (pwd = k_getpwnam(name))
 412     salt = pwd->pw_passwd;
 413   else salt = "xx";
 414
 415   p = crypt(passwd, salt);
 416
 417   if (pwd && !strcmp(p, pwd->pw_passwd)) {
 418     passwdok_status = 1;
 419   } else passwdok_status = 0;
 420   return(passwdok_status);
 421 }
 422
 423 #endif
 424
 425 #ifdef notdef
 426
 427 prkey(msg, key)
 428         char *msg;
 429         unsigned char *key;
 430 {
 431         int i;
 432         printf("%s:", msg);
 433         for (i = 0; i < 8; i++)
 434                 printf(" %3d", key[i]);
 435         printf("\r\n");
 436 }
 437 #endif