src/libs/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 <sys/cdefs.h>
  35
  36 __FBSDID("$FreeBSD: src/contrib/telnet/libtelnet/krb4encpwd.c,v 1.7 2001/11/30 22:28:07 markm Exp $");
  37
  38 #ifndef lint
  39 static char sccsid[] = "@(#)krb4encpwd.c        8.3 (Berkeley) 5/30/95";
  40 #endif /* not lint */
  41
  42
  43 #ifdef  KRB4_ENCPWD
  44 /*
  45  * COPYRIGHT (C) 1990 DIGITAL EQUIPMENT CORPORATION
  46  * ALL RIGHTS RESERVED
  47  *
  48  * "Digital Equipment Corporation authorizes the reproduction,
  49  * distribution and modification of this software subject to the following
  50  * restrictions:
  51  *
  52  * 1.  Any partial or whole copy of this software, or any modification
  53  * thereof, must include this copyright notice in its entirety.
  54  *
  55  * 2.  This software is supplied "as is" with no warranty of any kind,
  56  * expressed or implied, for any purpose, including any warranty of fitness
  57  * or merchantibility.  DIGITAL assumes no responsibility for the use or
  58  * reliability of this software, nor promises to provide any form of
  59  * support for it on any basis.
  60  *
  61  * 3.  Distribution of this software is authorized only if no profit or
  62  * remuneration of any kind is received in exchange for such distribution.
  63  *
  64  * 4.  This software produces public key authentication certificates
  65  * bearing an expiration date established by DIGITAL and RSA Data
  66  * Security, Inc.  It may cease to generate certificates after the expiration
  67  * date.  Any modification of this software that changes or defeats
  68  * the expiration date or its effect is unauthorized.
  69  *
  70  * 5.  Software that will renew or extend the expiration date of
  71  * authentication certificates produced by this software may be obtained
  72  * from RSA Data Security, Inc., 10 Twin Dolphin Drive, Redwood City, CA
  73  * 94065, (415)595-8782, or from DIGITAL"
  74  *
  75  */
  76
  77 #include <sys/types.h>
  78 #include <openssl/des.h>
  79 #include <arpa/telnet.h>
  80 #include <krb.h>
  81 #include <pwd.h>
  82 #include <stdio.h>
  83 #include <stdlib.h>
  84 #include <string.h>
  85
  86 #include "encrypt.h"
  87 #include "auth.h"
  88 #include "misc.h"
  89
  90 int krb_mk_encpwd_req(KTEXT, char *, char *, char *, char *, char *, char *);
  91 int krb_rd_encpwd_req(KTEXT, char *, char *, u_long, AUTH_DAT *, char *, char *, char *, char *);
  92
  93 extern auth_debug_mode;
  94
  95 static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0,
  96                                         AUTHTYPE_KRB4_ENCPWD, };
  97 static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION,
  98                                         TELQUAL_NAME, };
  99
 100 #define KRB4_ENCPWD_AUTH        0       /* Authentication data follows */
 101 #define KRB4_ENCPWD_REJECT      1       /* Rejected (reason might follow) */
 102 #define KRB4_ENCPWD_ACCEPT      2       /* Accepted */
 103 #define KRB4_ENCPWD_CHALLENGE   3       /* Challenge for mutual auth. */
 104 #define KRB4_ENCPWD_ACK         4       /* Acknowledge */
 105
 106 #define KRB_SERVICE_NAME    "rcmd"
 107
 108 static  KTEXT_ST auth;
 109 static  char name[ANAME_SZ];
 110 static  char user_passwd[ANAME_SZ];
 111 static  AUTH_DAT adat = { 0 };
 112 #ifdef  ENCRYPTION
 113 static Block    session_key     = { 0 };
 114 #endif  /* ENCRYPTION */
 115 static char  challenge[REALM_SZ];
 116
 117         static int
 118 Data(ap, type, d, c)
 119         Authenticator *ap;
 120         int type;
 121         void *d;
 122         int c;
 123 {
 124         unsigned char *p = str_data + 4;
 125         unsigned char *cd = (unsigned char *)d;
 126
 127         if (c == -1)
 128                 c = strlen((char *)cd);
 129
 130         if (0) {
 131                 printf("%s:%d: [%d] (%d)",
 132                         str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
 133                         str_data[3],
 134                         type, c);
 135                 printd(d, c);
 136                 printf("\r\n");
 137         }
 138         *p++ = ap->type;
 139         *p++ = ap->way;
 140         *p++ = type;
 141         while (c-- > 0) {
 142                 if ((*p++ = *cd++) == IAC)
 143                         *p++ = IAC;
 144         }
 145         *p++ = IAC;
 146         *p++ = SE;
 147         if (str_data[3] == TELQUAL_IS)
 148                 printsub('>', &str_data[2], p - (&str_data[2]));
 149         return(net_write(str_data, p - str_data));
 150 }
 151
 152         int
 153 krb4encpwd_init(ap, server)
 154         Authenticator *ap;
 155         int server;
 156 {
 157         char hostname[80], *cp, *realm;
 158         C_Block skey;
 159
 160         if (server) {
 161                 str_data[3] = TELQUAL_REPLY;
 162         } else {
 163                 str_data[3] = TELQUAL_IS;
 164                 gethostname(hostname, sizeof(hostname));
 165                 realm = krb_realmofhost(hostname);
 166                 cp = strchr(hostname, '.');
 167                 if (*cp != NULL) *cp = NULL;
 168                 if (read_service_key(KRB_SERVICE_NAME, hostname, realm, 0,
 169                                         KEYFILE, (char *)skey)) {
 170                   return(0);
 171                 }
 172         }
 173         return(1);
 174 }
 175
 176         int
 177 krb4encpwd_send(ap)
 178         Authenticator *ap;
 179 {
 180
 181         printf("[ Trying KRB4ENCPWD ... ]\n");
 182         if (!UserNameRequested) {
 183                 return(0);
 184         }
 185         if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) {
 186                 return(0);
 187         }
 188
 189         if (!Data(ap, KRB4_ENCPWD_ACK, (void *)NULL, 0)) {
 190                 return(0);
 191         }
 192
 193         return(1);
 194 }
 195
 196         void
 197 krb4encpwd_is(ap, data, cnt)
 198         Authenticator *ap;
 199         unsigned char *data;
 200         int cnt;
 201 {
 202         Session_Key skey;
 203         Block datablock;
 204         char  r_passwd[ANAME_SZ], r_user[ANAME_SZ];
 205         char  lhostname[ANAME_SZ], *cp;
 206         int r;
 207         time_t now;
 208
 209         if (cnt-- < 1)
 210                 return;
 211         switch (*data++) {
 212         case KRB4_ENCPWD_AUTH:
 213                 memmove((void *)auth.dat, (void *)data, auth.length = cnt);
 214
 215                 gethostname(lhostname, sizeof(lhostname));
 216                 if ((cp = strchr(lhostname, '.')) != 0)  *cp = '\0';
 217
 218                 if (r = krb_rd_encpwd_req(&auth, KRB_SERVICE_NAME, lhostname, 0, &adat, NULL, challenge, r_user, r_passwd)) {
 219                         Data(ap, KRB4_ENCPWD_REJECT, (void *)"Auth failed", -1);
 220                         auth_finished(ap, AUTH_REJECT);
 221                         return;
 222                 }
 223                 auth_encrypt_userpwd(r_passwd);
 224                 if (passwdok(UserNameRequested, UserPassword) == 0) {
 225                   /*
 226                    *  illegal username and password
 227                    */
 228                   Data(ap, KRB4_ENCPWD_REJECT, (void *)"Illegal password", -1);
 229                   auth_finished(ap, AUTH_REJECT);
 230                   return;
 231                 }
 232
 233                 memmove((void *)session_key, (void *)adat.session, sizeof(Block));
 234                 Data(ap, KRB4_ENCPWD_ACCEPT, (void *)0, 0);
 235                 auth_finished(ap, AUTH_USER);
 236                 break;
 237
 238         case KRB4_ENCPWD_CHALLENGE:
 239                 /*
 240                  *  Take the received random challenge text and save
 241                  *  for future authentication.
 242                  */
 243                 memmove((void *)challenge, (void *)data, sizeof(Block));
 244                 break;
 245
 246
 247         case KRB4_ENCPWD_ACK:
 248                 /*
 249                  *  Receive ack, if mutual then send random challenge
 250                  */
 251
 252                 /*
 253                  * If we are doing mutual authentication, get set up to send
 254                  * the challenge, and verify it when the response comes back.
 255                  */
 256
 257                 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
 258                   register int i;
 259
 260                   time(&now);
 261                   sprintf(challenge, "%x", now);
 262                   Data(ap, KRB4_ENCPWD_CHALLENGE, (void *)challenge, strlen(challenge));
 263                 }
 264                 break;
 265
 266         default:
 267                 Data(ap, KRB4_ENCPWD_REJECT, 0, 0);
 268                 break;
 269         }
 270 }
 271
 272
 273         void
 274 krb4encpwd_reply(ap, data, cnt)
 275         Authenticator *ap;
 276         unsigned char *data;
 277         int cnt;
 278 {
 279         Session_Key skey;
 280         KTEXT_ST krb_token;
 281         Block enckey;
 282         CREDENTIALS cred;
 283         int r;
 284         char    randchal[REALM_SZ], instance[ANAME_SZ], *cp;
 285         char    hostname[80], *realm;
 286
 287         if (cnt-- < 1)
 288                 return;
 289         switch (*data++) {
 290         case KRB4_ENCPWD_REJECT:
 291                 if (cnt > 0) {
 292                         printf("[ KRB4_ENCPWD refuses authentication because %.*s ]\r\n",
 293                                 cnt, data);
 294                 } else
 295                         printf("[ KRB4_ENCPWD refuses authentication ]\r\n");
 296                 auth_send_retry();
 297                 return;
 298         case KRB4_ENCPWD_ACCEPT:
 299                 printf("[ KRB4_ENCPWD accepts you ]\n");
 300                 auth_finished(ap, AUTH_USER);
 301                 return;
 302         case KRB4_ENCPWD_CHALLENGE:
 303                 /*
 304                  * Verify that the response to the challenge is correct.
 305                  */
 306
 307                 gethostname(hostname, sizeof(hostname));
 308                 realm = krb_realmofhost(hostname);
 309                 memmove((void *)challenge, (void *)data, cnt);
 310                 memset(user_passwd, 0, sizeof(user_passwd));
 311                 local_des_read_pw_string(user_passwd, sizeof(user_passwd)-1, "Password: ", 0);
 312                 UserPassword = user_passwd;
 313                 Challenge = challenge;
 314                 strcpy(instance, RemoteHostName);
 315                 if ((cp = strchr(instance, '.')) != 0)  *cp = '\0';
 316
 317                 if (r = krb_mk_encpwd_req(&krb_token, KRB_SERVICE_NAME, instance, realm, Challenge, UserNameRequested, user_passwd)) {
 318                   krb_token.length = 0;
 319                 }
 320
 321                 if (!Data(ap, KRB4_ENCPWD_AUTH, (void *)krb_token.dat, krb_token.length)) {
 322                   return;
 323                 }
 324
 325                 break;
 326
 327         default:
 328                 return;
 329         }
 330 }
 331
 332         int
 333 krb4encpwd_status(ap, name, level)
 334         Authenticator *ap;
 335         char *name;
 336         int level;
 337 {
 338
 339         if (level < AUTH_USER)
 340                 return(level);
 341
 342         if (UserNameRequested && passwdok(UserNameRequested, UserPassword)) {
 343                 strcpy(name, UserNameRequested);
 344                 return(AUTH_VALID);
 345         } else {
 346                 return(AUTH_USER);
 347         }
 348 }
 349
 350 #define BUMP(buf, len)          while (*(buf)) {++(buf), --(len);}
 351 #define ADDC(buf, len, c)       if ((len) > 0) {*(buf)++ = (c); --(len);}
 352
 353         void
 354 krb4encpwd_printsub(data, cnt, buf, buflen)
 355         unsigned char *data, *buf;
 356         int cnt, buflen;
 357 {
 358         char lbuf[32];
 359         register int i;
 360
 361         buf[buflen-1] = '\0';           /* make sure its NULL terminated */
 362         buflen -= 1;
 363
 364         switch(data[3]) {
 365         case KRB4_ENCPWD_REJECT:        /* Rejected (reason might follow) */
 366                 strncpy((char *)buf, " REJECT ", buflen);
 367                 goto common;
 368
 369         case KRB4_ENCPWD_ACCEPT:        /* Accepted (name might follow) */
 370                 strncpy((char *)buf, " ACCEPT ", buflen);
 371         common:
 372                 BUMP(buf, buflen);
 373                 if (cnt <= 4)
 374                         break;
 375                 ADDC(buf, buflen, '"');
 376                 for (i = 4; i < cnt; i++)
 377                         ADDC(buf, buflen, data[i]);
 378                 ADDC(buf, buflen, '"');
 379                 ADDC(buf, buflen, '\0');
 380                 break;
 381
 382         case KRB4_ENCPWD_AUTH:          /* Authentication data follows */
 383                 strncpy((char *)buf, " AUTH", buflen);
 384                 goto common2;
 385
 386         case KRB4_ENCPWD_CHALLENGE:
 387                 strncpy((char *)buf, " CHALLENGE", buflen);
 388                 goto common2;
 389
 390         case KRB4_ENCPWD_ACK:
 391                 strncpy((char *)buf, " ACK", buflen);
 392                 goto common2;
 393
 394         default:
 395                 sprintf(lbuf, " %d (unknown)", data[3]);
 396                 strncpy((char *)buf, lbuf, buflen);
 397         common2:
 398                 BUMP(buf, buflen);
 399                 for (i = 4; i < cnt; i++) {
 400                         sprintf(lbuf, " %d", data[i]);
 401                         strncpy((char *)buf, lbuf, buflen);
 402                         BUMP(buf, buflen);
 403                 }
 404                 break;
 405         }
 406 }
 407
 408 int passwdok(name, passwd)
 409 char *name, *passwd;
 410 {
 411   char *crypt();
 412   char *salt, *p;
 413   struct passwd *pwd;
 414   int   passwdok_status = 0;
 415
 416   if (pwd = getpwnam(name))
 417     salt = pwd->pw_passwd;
 418   else salt = "xx";
 419
 420   p = crypt(passwd, salt);
 421
 422   if (pwd && !strcmp(p, pwd->pw_passwd)) {
 423     passwdok_status = 1;
 424   } else passwdok_status = 0;
 425   return(passwdok_status);
 426 }
 427
 428 #endif