lib/libtelnet/rsaencpwd.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/crypto/telnet/libtelnet/rsaencpwd.c,v 1.1.1.1.8.1 2002/04/13 10:59:07 markm Exp $");
  37
  38 #ifndef lint
  39 static char sccsid[] = "@(#)rsaencpwd.c 8.3 (Berkeley) 5/30/95";
  40 #endif /* not lint */
  41
  42
  43 #ifdef  RSA_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 <arpa/telnet.h>
  79 #include <pwd.h>
  80 #include <stdio.h>
  81 #include <stdlib.h>
  82 #include <string.h>
  83
  84 #include "encrypt.h"
  85 #include "auth.h"
  86 #include "misc.h"
  87 #include "cdc.h"
  88
  89 extern auth_debug_mode;
  90
  91 static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0,
  92                                         AUTHTYPE_RSA_ENCPWD, };
  93 static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION,
  94                                         TELQUAL_NAME, };
  95
  96 #define RSA_ENCPWD_AUTH 0       /* Authentication data follows */
  97 #define RSA_ENCPWD_REJECT       1       /* Rejected (reason might follow) */
  98 #define RSA_ENCPWD_ACCEPT       2       /* Accepted */
  99 #define RSA_ENCPWD_CHALLENGEKEY 3       /* Challenge and public key */
 100
 101 #define NAME_SZ   40
 102 #define CHAL_SZ   20
 103 #define PWD_SZ    40
 104
 105 static  KTEXT_ST auth;
 106 static  char name[NAME_SZ];
 107 static  char user_passwd[PWD_SZ];
 108 static  char key_file[2*NAME_SZ];
 109 static  char lhostname[NAME_SZ];
 110 static char  challenge[CHAL_SZ];
 111 static int   challenge_len;
 112
 113         static int
 114 Data(ap, type, d, c)
 115         Authenticator *ap;
 116         int type;
 117         void *d;
 118         int c;
 119 {
 120         unsigned char *p = str_data + 4;
 121         unsigned char *cd = (unsigned char *)d;
 122
 123         if (c == -1)
 124                 c = strlen((char *)cd);
 125
 126         if (0) {
 127                 printf("%s:%d: [%d] (%d)",
 128                         str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
 129                         str_data[3],
 130                         type, c);
 131                 printd(d, c);
 132                 printf("\r\n");
 133         }
 134         *p++ = ap->type;
 135         *p++ = ap->way;
 136         if (type != NULL) *p++ = type;
 137         while (c-- > 0) {
 138                 if ((*p++ = *cd++) == IAC)
 139                         *p++ = IAC;
 140         }
 141         *p++ = IAC;
 142         *p++ = SE;
 143         if (str_data[3] == TELQUAL_IS)
 144                 printsub('>', &str_data[2], p - (&str_data[2]));
 145         return(net_write(str_data, p - str_data));
 146 }
 147
 148         int
 149 rsaencpwd_init(ap, server)
 150         Authenticator *ap;
 151         int server;
 152 {
 153         char  *cp;
 154         FILE  *fp;
 155
 156         if (server) {
 157                 str_data[3] = TELQUAL_REPLY;
 158                 memset(key_file, 0, sizeof(key_file));
 159                 gethostname(lhostname, sizeof(lhostname));
 160                 if ((cp = strchr(lhostname, '.')) != 0)  *cp = '\0';
 161                 strcpy(key_file, "/etc/.");
 162                 strcat(key_file, lhostname);
 163                 strcat(key_file, "_privkey");
 164                 if ((fp=fopen(key_file, "r"))==NULL) return(0);
 165                 fclose(fp);
 166         } else {
 167                 str_data[3] = TELQUAL_IS;
 168         }
 169         return(1);
 170 }
 171
 172         int
 173 rsaencpwd_send(ap)
 174         Authenticator *ap;
 175 {
 176
 177         printf("[ Trying RSAENCPWD ... ]\n");
 178         if (!UserNameRequested) {
 179                 return(0);
 180         }
 181         if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) {
 182                 return(0);
 183         }
 184         if (!Data(ap, NULL, (void *)NULL, 0)) {
 185                 return(0);
 186         }
 187
 188
 189         return(1);
 190 }
 191
 192         void
 193 rsaencpwd_is(ap, data, cnt)
 194         Authenticator *ap;
 195         unsigned char *data;
 196         int cnt;
 197 {
 198         Session_Key skey;
 199         Block datablock;
 200         char  r_passwd[PWD_SZ], r_user[NAME_SZ];
 201         char  *cp, key[160];
 202         char  chalkey[160], *ptr;
 203         FILE  *fp;
 204         int r, i, j, chalkey_len, len;
 205         time_t now;
 206
 207         cnt--;
 208         switch (*data++) {
 209         case RSA_ENCPWD_AUTH:
 210                 memmove((void *)auth.dat, (void *)data, auth.length = cnt);
 211
 212                 if ((fp=fopen(key_file, "r"))==NULL) {
 213                   Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1);
 214                   auth_finished(ap, AUTH_REJECT);
 215                   return;
 216                 }
 217                 /*
 218                  *  get privkey
 219                  */
 220                 fscanf(fp, "%x;", &len);
 221                 for (i=0;i<len;i++) {
 222                   j = getc(fp);  key[i]=j;
 223                 }
 224                 fclose(fp);
 225
 226                 r = accept_rsa_encpwd(&auth, key, challenge,
 227                                       challenge_len, r_passwd);
 228                 if (r < 0) {
 229                   Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1);
 230                   auth_finished(ap, AUTH_REJECT);
 231                   return;
 232                 }
 233                 auth_encrypt_userpwd(r_passwd);
 234                 if (rsaencpwd_passwdok(UserNameRequested, UserPassword) == 0) {
 235                   /*
 236                    *  illegal username and password
 237                    */
 238                   Data(ap, RSA_ENCPWD_REJECT, (void *)"Illegal password", -1);
 239                   auth_finished(ap, AUTH_REJECT);
 240                   return;
 241                 }
 242
 243                 Data(ap, RSA_ENCPWD_ACCEPT, (void *)0, 0);
 244                 auth_finished(ap, AUTH_USER);
 245                 break;
 246
 247
 248         case IAC:
 249
 250                 /*
 251                  * If we are doing mutual authentication, get set up to send
 252                  * the challenge, and verify it when the response comes back.
 253                  */
 254                 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_ONE_WAY) {
 255                   register int i;
 256
 257
 258                   time(&now);
 259                   if ((now % 2) == 0) {
 260                     sprintf(challenge, "%x", now);
 261                     challenge_len = strlen(challenge);
 262                   } else {
 263                     strcpy(challenge, "randchal");
 264                     challenge_len = 8;
 265                   }
 266
 267                   if ((fp=fopen(key_file, "r"))==NULL) {
 268                     Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1);
 269                     auth_finished(ap, AUTH_REJECT);
 270                     return;
 271                   }
 272                   /*
 273                    *  skip privkey
 274                    */
 275                   fscanf(fp, "%x;", &len);
 276                   for (i=0;i<len;i++) {
 277                     j = getc(fp);
 278                   }
 279                   /*
 280                    * get pubkey
 281                    */
 282                   fscanf(fp, "%x;", &len);
 283                   for (i=0;i<len;i++) {
 284                     j = getc(fp);  key[i]=j;
 285                   }
 286                   fclose(fp);
 287                   chalkey[0] = 0x30;
 288                   ptr = (char *) &chalkey[1];
 289                   chalkey_len = 1+NumEncodeLengthOctets(i)+i+1+NumEncodeLengthOctets(challenge_len)+challenge_len;
 290                   EncodeLength(ptr, chalkey_len);
 291                   ptr +=NumEncodeLengthOctets(chalkey_len);
 292                   *ptr++ = 0x04;  /* OCTET STRING */
 293                   *ptr++ = challenge_len;
 294                   memmove(ptr, challenge, challenge_len);
 295                   ptr += challenge_len;
 296                   *ptr++ = 0x04;  /* OCTET STRING */
 297                   EncodeLength(ptr, i);
 298                   ptr += NumEncodeLengthOctets(i);
 299                   memmove(ptr, key, i);
 300                   chalkey_len = 1+NumEncodeLengthOctets(chalkey_len)+chalkey_len;
 301                   Data(ap, RSA_ENCPWD_CHALLENGEKEY, (void *)chalkey, chalkey_len);
 302                 }
 303                 break;
 304
 305         default:
 306                 Data(ap, RSA_ENCPWD_REJECT, 0, 0);
 307                 break;
 308         }
 309 }
 310
 311
 312         void
 313 rsaencpwd_reply(ap, data, cnt)
 314         Authenticator *ap;
 315         unsigned char *data;
 316         int cnt;
 317 {
 318         Session_Key skey;
 319         KTEXT_ST token;
 320         Block enckey;
 321         int r, pubkey_len;
 322         char    randchal[CHAL_SZ], *cp;
 323         char    chalkey[160], pubkey[128], *ptr;
 324
 325         if (cnt-- < 1)
 326                 return;
 327         switch (*data++) {
 328         case RSA_ENCPWD_REJECT:
 329                 if (cnt > 0) {
 330                         printf("[ RSA_ENCPWD refuses authentication because %.*s ]\r\n",
 331                                 cnt, data);
 332                 } else
 333                         printf("[ RSA_ENCPWD refuses authentication ]\r\n");
 334                 auth_send_retry();
 335                 return;
 336         case RSA_ENCPWD_ACCEPT:
 337                 printf("[ RSA_ENCPWD accepts you ]\n");
 338                 auth_finished(ap, AUTH_USER);
 339                 return;
 340         case RSA_ENCPWD_CHALLENGEKEY:
 341                 /*
 342                  * Verify that the response to the challenge is correct.
 343                  */
 344
 345                 memmove((void *)chalkey, (void *)data, cnt);
 346                 ptr = (char *) &chalkey[0];
 347                 ptr += DecodeHeaderLength(chalkey);
 348                 if (*ptr != 0x04) {
 349                   return;
 350                 }
 351                 *ptr++;
 352                 challenge_len = DecodeValueLength(ptr);
 353                 ptr += NumEncodeLengthOctets(challenge_len);
 354                 memmove(challenge, ptr, challenge_len);
 355                 ptr += challenge_len;
 356                 if (*ptr != 0x04) {
 357                   return;
 358                 }
 359                 *ptr++;
 360                 pubkey_len = DecodeValueLength(ptr);
 361                 ptr += NumEncodeLengthOctets(pubkey_len);
 362                 memmove(pubkey, ptr, pubkey_len);
 363                 memset(user_passwd, 0, sizeof(user_passwd));
 364                 local_des_read_pw_string(user_passwd, sizeof(user_passwd)-1, "Password: ", 0);
 365                 UserPassword = user_passwd;
 366                 Challenge = challenge;
 367                 r = init_rsa_encpwd(&token, user_passwd, challenge, challenge_len, pubkey);
 368                 if (r < 0) {
 369                   token.length = 1;
 370                 }
 371
 372                 if (!Data(ap, RSA_ENCPWD_AUTH, (void *)token.dat, token.length)) {
 373                   return;
 374                 }
 375
 376                 break;
 377
 378         default:
 379                 return;
 380         }
 381 }
 382
 383         int
 384 rsaencpwd_status(ap, name, level)
 385         Authenticator *ap;
 386         char *name;
 387         int level;
 388 {
 389
 390         if (level < AUTH_USER)
 391                 return(level);
 392
 393         if (UserNameRequested && rsaencpwd_passwdok(UserNameRequested, UserPassword)) {
 394                 strcpy(name, UserNameRequested);
 395                 return(AUTH_VALID);
 396         } else {
 397                 return(AUTH_USER);
 398         }
 399 }
 400
 401 #define BUMP(buf, len)          while (*(buf)) {++(buf), --(len);}
 402 #define ADDC(buf, len, c)       if ((len) > 0) {*(buf)++ = (c); --(len);}
 403
 404         void
 405 rsaencpwd_printsub(data, cnt, buf, buflen)
 406         unsigned char *data, *buf;
 407         int cnt, buflen;
 408 {
 409         char lbuf[32];
 410         register int i;
 411
 412         buf[buflen-1] = '\0';           /* make sure its NULL terminated */
 413         buflen -= 1;
 414
 415         switch(data[3]) {
 416         case RSA_ENCPWD_REJECT: /* Rejected (reason might follow) */
 417                 strncpy((char *)buf, " REJECT ", buflen);
 418                 goto common;
 419
 420         case RSA_ENCPWD_ACCEPT: /* Accepted (name might follow) */
 421                 strncpy((char *)buf, " ACCEPT ", buflen);
 422         common:
 423                 BUMP(buf, buflen);
 424                 if (cnt <= 4)
 425                         break;
 426                 ADDC(buf, buflen, '"');
 427                 for (i = 4; i < cnt; i++)
 428                         ADDC(buf, buflen, data[i]);
 429                 ADDC(buf, buflen, '"');
 430                 ADDC(buf, buflen, '\0');
 431                 break;
 432
 433         case RSA_ENCPWD_AUTH:           /* Authentication data follows */
 434                 strncpy((char *)buf, " AUTH", buflen);
 435                 goto common2;
 436
 437         case RSA_ENCPWD_CHALLENGEKEY:
 438                 strncpy((char *)buf, " CHALLENGEKEY", buflen);
 439                 goto common2;
 440
 441         default:
 442                 sprintf(lbuf, " %d (unknown)", data[3]);
 443                 strncpy((char *)buf, lbuf, buflen);
 444         common2:
 445                 BUMP(buf, buflen);
 446                 for (i = 4; i < cnt; i++) {
 447                         sprintf(lbuf, " %d", data[i]);
 448                         strncpy((char *)buf, lbuf, buflen);
 449                         BUMP(buf, buflen);
 450                 }
 451                 break;
 452         }
 453 }
 454
 455 int rsaencpwd_passwdok(name, passwd)
 456 char *name, *passwd;
 457 {
 458   char *crypt();
 459   char *salt, *p;
 460   struct passwd *pwd;
 461   int   passwdok_status = 0;
 462
 463   if (pwd = getpwnam(name))
 464     salt = pwd->pw_passwd;
 465   else salt = "xx";
 466
 467   p = crypt(passwd, salt);
 468
 469   if (pwd && !strcmp(p, pwd->pw_passwd)) {
 470     passwdok_status = 1;
 471   } else passwdok_status = 0;
 472   return(passwdok_status);
 473 }
 474
 475 #endif