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  * @(#)rsaencpwd.c      8.3 (Berkeley) 5/30/95
  34  * $FreeBSD: src/crypto/telnet/libtelnet/rsaencpwd.c,v 1.1.1.1.8.1 2002/04/13 10:59:07 markm Exp $
  35  * $DragonFly: src/crypto/telnet/libtelnet/rsaencpwd.c,v 1.2 2003/06/17 04:24:37 dillon Exp $
  36  */
  37
  38 #ifdef  RSA_ENCPWD
  39 /*
  40  * COPYRIGHT (C) 1990 DIGITAL EQUIPMENT CORPORATION
  41  * ALL RIGHTS RESERVED
  42  *
  43  * "Digital Equipment Corporation authorizes the reproduction,
  44  * distribution and modification of this software subject to the following
  45  * restrictions:
  46  *
  47  * 1.  Any partial or whole copy of this software, or any modification
  48  * thereof, must include this copyright notice in its entirety.
  49  *
  50  * 2.  This software is supplied "as is" with no warranty of any kind,
  51  * expressed or implied, for any purpose, including any warranty of fitness
  52  * or merchantibility.  DIGITAL assumes no responsibility for the use or
  53  * reliability of this software, nor promises to provide any form of
  54  * support for it on any basis.
  55  *
  56  * 3.  Distribution of this software is authorized only if no profit or
  57  * remuneration of any kind is received in exchange for such distribution.
  58  *
  59  * 4.  This software produces public key authentication certificates
  60  * bearing an expiration date established by DIGITAL and RSA Data
  61  * Security, Inc.  It may cease to generate certificates after the expiration
  62  * date.  Any modification of this software that changes or defeats
  63  * the expiration date or its effect is unauthorized.
  64  *
  65  * 5.  Software that will renew or extend the expiration date of
  66  * authentication certificates produced by this software may be obtained
  67  * from RSA Data Security, Inc., 10 Twin Dolphin Drive, Redwood City, CA
  68  * 94065, (415)595-8782, or from DIGITAL"
  69  *
  70  */
  71
  72 #include <sys/types.h>
  73 #include <arpa/telnet.h>
  74 #include <pwd.h>
  75 #include <stdio.h>
  76 #include <stdlib.h>
  77 #include <string.h>
  78
  79 #include "encrypt.h"
  80 #include "auth.h"
  81 #include "misc.h"
  82 #include "cdc.h"
  83
  84 extern auth_debug_mode;
  85
  86 static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0,
  87                                         AUTHTYPE_RSA_ENCPWD, };
  88 static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION,
  89                                         TELQUAL_NAME, };
  90
  91 #define RSA_ENCPWD_AUTH 0       /* Authentication data follows */
  92 #define RSA_ENCPWD_REJECT       1       /* Rejected (reason might follow) */
  93 #define RSA_ENCPWD_ACCEPT       2       /* Accepted */
  94 #define RSA_ENCPWD_CHALLENGEKEY 3       /* Challenge and public key */
  95
  96 #define NAME_SZ   40
  97 #define CHAL_SZ   20
  98 #define PWD_SZ    40
  99
 100 static  KTEXT_ST auth;
 101 static  char name[NAME_SZ];
 102 static  char user_passwd[PWD_SZ];
 103 static  char key_file[2*NAME_SZ];
 104 static  char lhostname[NAME_SZ];
 105 static char  challenge[CHAL_SZ];
 106 static int   challenge_len;
 107
 108         static int
 109 Data(ap, type, d, c)
 110         Authenticator *ap;
 111         int type;
 112         void *d;
 113         int c;
 114 {
 115         unsigned char *p = str_data + 4;
 116         unsigned char *cd = (unsigned char *)d;
 117
 118         if (c == -1)
 119                 c = strlen((char *)cd);
 120
 121         if (0) {
 122                 printf("%s:%d: [%d] (%d)",
 123                         str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
 124                         str_data[3],
 125                         type, c);
 126                 printd(d, c);
 127                 printf("\r\n");
 128         }
 129         *p++ = ap->type;
 130         *p++ = ap->way;
 131         if (type != NULL) *p++ = type;
 132         while (c-- > 0) {
 133                 if ((*p++ = *cd++) == IAC)
 134                         *p++ = IAC;
 135         }
 136         *p++ = IAC;
 137         *p++ = SE;
 138         if (str_data[3] == TELQUAL_IS)
 139                 printsub('>', &str_data[2], p - (&str_data[2]));
 140         return(net_write(str_data, p - str_data));
 141 }
 142
 143         int
 144 rsaencpwd_init(ap, server)
 145         Authenticator *ap;
 146         int server;
 147 {
 148         char  *cp;
 149         FILE  *fp;
 150
 151         if (server) {
 152                 str_data[3] = TELQUAL_REPLY;
 153                 memset(key_file, 0, sizeof(key_file));
 154                 gethostname(lhostname, sizeof(lhostname));
 155                 if ((cp = strchr(lhostname, '.')) != 0)  *cp = '\0';
 156                 strcpy(key_file, "/etc/.");
 157                 strcat(key_file, lhostname);
 158                 strcat(key_file, "_privkey");
 159                 if ((fp=fopen(key_file, "r"))==NULL) return(0);
 160                 fclose(fp);
 161         } else {
 162                 str_data[3] = TELQUAL_IS;
 163         }
 164         return(1);
 165 }
 166
 167         int
 168 rsaencpwd_send(ap)
 169         Authenticator *ap;
 170 {
 171
 172         printf("[ Trying RSAENCPWD ... ]\n");
 173         if (!UserNameRequested) {
 174                 return(0);
 175         }
 176         if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) {
 177                 return(0);
 178         }
 179         if (!Data(ap, NULL, (void *)NULL, 0)) {
 180                 return(0);
 181         }
 182
 183
 184         return(1);
 185 }
 186
 187         void
 188 rsaencpwd_is(ap, data, cnt)
 189         Authenticator *ap;
 190         unsigned char *data;
 191         int cnt;
 192 {
 193         Session_Key skey;
 194         Block datablock;
 195         char  r_passwd[PWD_SZ], r_user[NAME_SZ];
 196         char  *cp, key[160];
 197         char  chalkey[160], *ptr;
 198         FILE  *fp;
 199         int r, i, j, chalkey_len, len;
 200         time_t now;
 201
 202         cnt--;
 203         switch (*data++) {
 204         case RSA_ENCPWD_AUTH:
 205                 memmove((void *)auth.dat, (void *)data, auth.length = cnt);
 206
 207                 if ((fp=fopen(key_file, "r"))==NULL) {
 208                   Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1);
 209                   auth_finished(ap, AUTH_REJECT);
 210                   return;
 211                 }
 212                 /*
 213                  *  get privkey
 214                  */
 215                 fscanf(fp, "%x;", &len);
 216                 for (i=0;i<len;i++) {
 217                   j = getc(fp);  key[i]=j;
 218                 }
 219                 fclose(fp);
 220
 221                 r = accept_rsa_encpwd(&auth, key, challenge,
 222                                       challenge_len, r_passwd);
 223                 if (r < 0) {
 224                   Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1);
 225                   auth_finished(ap, AUTH_REJECT);
 226                   return;
 227                 }
 228                 auth_encrypt_userpwd(r_passwd);
 229                 if (rsaencpwd_passwdok(UserNameRequested, UserPassword) == 0) {
 230                   /*
 231                    *  illegal username and password
 232                    */
 233                   Data(ap, RSA_ENCPWD_REJECT, (void *)"Illegal password", -1);
 234                   auth_finished(ap, AUTH_REJECT);
 235                   return;
 236                 }
 237
 238                 Data(ap, RSA_ENCPWD_ACCEPT, (void *)0, 0);
 239                 auth_finished(ap, AUTH_USER);
 240                 break;
 241
 242
 243         case IAC:
 244
 245                 /*
 246                  * If we are doing mutual authentication, get set up to send
 247                  * the challenge, and verify it when the response comes back.
 248                  */
 249                 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_ONE_WAY) {
 250                   register int i;
 251
 252
 253                   time(&now);
 254                   if ((now % 2) == 0) {
 255                     sprintf(challenge, "%x", now);
 256                     challenge_len = strlen(challenge);
 257                   } else {
 258                     strcpy(challenge, "randchal");
 259                     challenge_len = 8;
 260                   }
 261
 262                   if ((fp=fopen(key_file, "r"))==NULL) {
 263                     Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1);
 264                     auth_finished(ap, AUTH_REJECT);
 265                     return;
 266                   }
 267                   /*
 268                    *  skip privkey
 269                    */
 270                   fscanf(fp, "%x;", &len);
 271                   for (i=0;i<len;i++) {
 272                     j = getc(fp);
 273                   }
 274                   /*
 275                    * get pubkey
 276                    */
 277                   fscanf(fp, "%x;", &len);
 278                   for (i=0;i<len;i++) {
 279                     j = getc(fp);  key[i]=j;
 280                   }
 281                   fclose(fp);
 282                   chalkey[0] = 0x30;
 283                   ptr = (char *) &chalkey[1];
 284                   chalkey_len = 1+NumEncodeLengthOctets(i)+i+1+NumEncodeLengthOctets(challenge_len)+challenge_len;
 285                   EncodeLength(ptr, chalkey_len);
 286                   ptr +=NumEncodeLengthOctets(chalkey_len);
 287                   *ptr++ = 0x04;  /* OCTET STRING */
 288                   *ptr++ = challenge_len;
 289                   memmove(ptr, challenge, challenge_len);
 290                   ptr += challenge_len;
 291                   *ptr++ = 0x04;  /* OCTET STRING */
 292                   EncodeLength(ptr, i);
 293                   ptr += NumEncodeLengthOctets(i);
 294                   memmove(ptr, key, i);
 295                   chalkey_len = 1+NumEncodeLengthOctets(chalkey_len)+chalkey_len;
 296                   Data(ap, RSA_ENCPWD_CHALLENGEKEY, (void *)chalkey, chalkey_len);
 297                 }
 298                 break;
 299
 300         default:
 301                 Data(ap, RSA_ENCPWD_REJECT, 0, 0);
 302                 break;
 303         }
 304 }
 305
 306
 307         void
 308 rsaencpwd_reply(ap, data, cnt)
 309         Authenticator *ap;
 310         unsigned char *data;
 311         int cnt;
 312 {
 313         Session_Key skey;
 314         KTEXT_ST token;
 315         Block enckey;
 316         int r, pubkey_len;
 317         char    randchal[CHAL_SZ], *cp;
 318         char    chalkey[160], pubkey[128], *ptr;
 319
 320         if (cnt-- < 1)
 321                 return;
 322         switch (*data++) {
 323         case RSA_ENCPWD_REJECT:
 324                 if (cnt > 0) {
 325                         printf("[ RSA_ENCPWD refuses authentication because %.*s ]\r\n",
 326                                 cnt, data);
 327                 } else
 328                         printf("[ RSA_ENCPWD refuses authentication ]\r\n");
 329                 auth_send_retry();
 330                 return;
 331         case RSA_ENCPWD_ACCEPT:
 332                 printf("[ RSA_ENCPWD accepts you ]\n");
 333                 auth_finished(ap, AUTH_USER);
 334                 return;
 335         case RSA_ENCPWD_CHALLENGEKEY:
 336                 /*
 337                  * Verify that the response to the challenge is correct.
 338                  */
 339
 340                 memmove((void *)chalkey, (void *)data, cnt);
 341                 ptr = (char *) &chalkey[0];
 342                 ptr += DecodeHeaderLength(chalkey);
 343                 if (*ptr != 0x04) {
 344                   return;
 345                 }
 346                 *ptr++;
 347                 challenge_len = DecodeValueLength(ptr);
 348                 ptr += NumEncodeLengthOctets(challenge_len);
 349                 memmove(challenge, ptr, challenge_len);
 350                 ptr += challenge_len;
 351                 if (*ptr != 0x04) {
 352                   return;
 353                 }
 354                 *ptr++;
 355                 pubkey_len = DecodeValueLength(ptr);
 356                 ptr += NumEncodeLengthOctets(pubkey_len);
 357                 memmove(pubkey, ptr, pubkey_len);
 358                 memset(user_passwd, 0, sizeof(user_passwd));
 359                 local_des_read_pw_string(user_passwd, sizeof(user_passwd)-1, "Password: ", 0);
 360                 UserPassword = user_passwd;
 361                 Challenge = challenge;
 362                 r = init_rsa_encpwd(&token, user_passwd, challenge, challenge_len, pubkey);
 363                 if (r < 0) {
 364                   token.length = 1;
 365                 }
 366
 367                 if (!Data(ap, RSA_ENCPWD_AUTH, (void *)token.dat, token.length)) {
 368                   return;
 369                 }
 370
 371                 break;
 372
 373         default:
 374                 return;
 375         }
 376 }
 377
 378         int
 379 rsaencpwd_status(ap, name, level)
 380         Authenticator *ap;
 381         char *name;
 382         int level;
 383 {
 384
 385         if (level < AUTH_USER)
 386                 return(level);
 387
 388         if (UserNameRequested && rsaencpwd_passwdok(UserNameRequested, UserPassword)) {
 389                 strcpy(name, UserNameRequested);
 390                 return(AUTH_VALID);
 391         } else {
 392                 return(AUTH_USER);
 393         }
 394 }
 395
 396 #define BUMP(buf, len)          while (*(buf)) {++(buf), --(len);}
 397 #define ADDC(buf, len, c)       if ((len) > 0) {*(buf)++ = (c); --(len);}
 398
 399         void
 400 rsaencpwd_printsub(data, cnt, buf, buflen)
 401         unsigned char *data, *buf;
 402         int cnt, buflen;
 403 {
 404         char lbuf[32];
 405         register int i;
 406
 407         buf[buflen-1] = '\0';           /* make sure its NULL terminated */
 408         buflen -= 1;
 409
 410         switch(data[3]) {
 411         case RSA_ENCPWD_REJECT: /* Rejected (reason might follow) */
 412                 strncpy((char *)buf, " REJECT ", buflen);
 413                 goto common;
 414
 415         case RSA_ENCPWD_ACCEPT: /* Accepted (name might follow) */
 416                 strncpy((char *)buf, " ACCEPT ", buflen);
 417         common:
 418                 BUMP(buf, buflen);
 419                 if (cnt <= 4)
 420                         break;
 421                 ADDC(buf, buflen, '"');
 422                 for (i = 4; i < cnt; i++)
 423                         ADDC(buf, buflen, data[i]);
 424                 ADDC(buf, buflen, '"');
 425                 ADDC(buf, buflen, '\0');
 426                 break;
 427
 428         case RSA_ENCPWD_AUTH:           /* Authentication data follows */
 429                 strncpy((char *)buf, " AUTH", buflen);
 430                 goto common2;
 431
 432         case RSA_ENCPWD_CHALLENGEKEY:
 433                 strncpy((char *)buf, " CHALLENGEKEY", buflen);
 434                 goto common2;
 435
 436         default:
 437                 sprintf(lbuf, " %d (unknown)", data[3]);
 438                 strncpy((char *)buf, lbuf, buflen);
 439         common2:
 440                 BUMP(buf, buflen);
 441                 for (i = 4; i < cnt; i++) {
 442                         sprintf(lbuf, " %d", data[i]);
 443                         strncpy((char *)buf, lbuf, buflen);
 444                         BUMP(buf, buflen);
 445                 }
 446                 break;
 447         }
 448 }
 449
 450 int rsaencpwd_passwdok(name, passwd)
 451 char *name, *passwd;
 452 {
 453   char *crypt();
 454   char *salt, *p;
 455   struct passwd *pwd;
 456   int   passwdok_status = 0;
 457
 458   if (pwd = getpwnam(name))
 459     salt = pwd->pw_passwd;
 460   else salt = "xx";
 461
 462   p = crypt(passwd, salt);
 463
 464   if (pwd && !strcmp(p, pwd->pw_passwd)) {
 465     passwdok_status = 1;
 466   } else passwdok_status = 0;
 467   return(passwdok_status);
 468 }
 469
 470 #endif