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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)rsaencpwd.c 8.3 (Berkeley) 5/30/95 30 * $FreeBSD: src/crypto/telnet/libtelnet/rsaencpwd.c,v 1.1.1.1.8.1 2002/04/13 10:59:07 markm Exp $ 31 */ 32 33 #ifdef RSA_ENCPWD 34 /* 35 * COPYRIGHT (C) 1990 DIGITAL EQUIPMENT CORPORATION 36 * ALL RIGHTS RESERVED 37 * 38 * "Digital Equipment Corporation authorizes the reproduction, 39 * distribution and modification of this software subject to the following 40 * restrictions: 41 * 42 * 1. Any partial or whole copy of this software, or any modification 43 * thereof, must include this copyright notice in its entirety. 44 * 45 * 2. This software is supplied "as is" with no warranty of any kind, 46 * expressed or implied, for any purpose, including any warranty of fitness 47 * or merchantability. DIGITAL assumes no responsibility for the use or 48 * reliability of this software, nor promises to provide any form of 49 * support for it on any basis. 50 * 51 * 3. Distribution of this software is authorized only if no profit or 52 * remuneration of any kind is received in exchange for such distribution. 53 * 54 * 4. This software produces public key authentication certificates 55 * bearing an expiration date established by DIGITAL and RSA Data 56 * Security, Inc. It may cease to generate certificates after the expiration 57 * date. Any modification of this software that changes or defeats 58 * the expiration date or its effect is unauthorized. 59 * 60 * 5. Software that will renew or extend the expiration date of 61 * authentication certificates produced by this software may be obtained 62 * from RSA Data Security, Inc., 10 Twin Dolphin Drive, Redwood City, CA 63 * 94065, (415)595-8782, or from DIGITAL" 64 * 65 */ 66 67 #include <sys/types.h> 68 #include <arpa/telnet.h> 69 #include <pwd.h> 70 #include <stdio.h> 71 #include <stdlib.h> 72 #include <string.h> 73 74 #include "encrypt.h" 75 #include "auth.h" 76 #include "misc.h" 77 #include "cdc.h" 78 79 extern auth_debug_mode; 80 81 static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0, 82 AUTHTYPE_RSA_ENCPWD, }; 83 static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 84 TELQUAL_NAME, }; 85 86 #define RSA_ENCPWD_AUTH 0 /* Authentication data follows */ 87 #define RSA_ENCPWD_REJECT 1 /* Rejected (reason might follow) */ 88 #define RSA_ENCPWD_ACCEPT 2 /* Accepted */ 89 #define RSA_ENCPWD_CHALLENGEKEY 3 /* Challenge and public key */ 90 91 #define NAME_SZ 40 92 #define CHAL_SZ 20 93 #define PWD_SZ 40 94 95 static KTEXT_ST auth; 96 static char name[NAME_SZ]; 97 static char user_passwd[PWD_SZ]; 98 static char key_file[2*NAME_SZ]; 99 static char lhostname[NAME_SZ]; 100 static char challenge[CHAL_SZ]; 101 static int challenge_len; 102 103 static int 104 Data(ap, type, d, c) 105 Authenticator *ap; 106 int type; 107 void *d; 108 int c; 109 { 110 unsigned char *p = str_data + 4; 111 unsigned char *cd = (unsigned char *)d; 112 113 if (c == -1) 114 c = strlen((char *)cd); 115 116 if (0) { 117 printf("%s:%d: [%d] (%d)", 118 str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY", 119 str_data[3], 120 type, c); 121 printd(d, c); 122 printf("\r\n"); 123 } 124 *p++ = ap->type; 125 *p++ = ap->way; 126 if (type != NULL) *p++ = type; 127 while (c-- > 0) { 128 if ((*p++ = *cd++) == IAC) 129 *p++ = IAC; 130 } 131 *p++ = IAC; 132 *p++ = SE; 133 if (str_data[3] == TELQUAL_IS) 134 printsub('>', &str_data[2], p - (&str_data[2])); 135 return(net_write(str_data, p - str_data)); 136 } 137 138 int 139 rsaencpwd_init(ap, server) 140 Authenticator *ap; 141 int server; 142 { 143 char *cp; 144 FILE *fp; 145 146 if (server) { 147 str_data[3] = TELQUAL_REPLY; 148 memset(key_file, 0, sizeof(key_file)); 149 gethostname(lhostname, sizeof(lhostname)); 150 if ((cp = strchr(lhostname, '.')) != NULL) *cp = '\0'; 151 strcpy(key_file, "/etc/."); 152 strcat(key_file, lhostname); 153 strcat(key_file, "_privkey"); 154 if ((fp=fopen(key_file, "r"))==NULL) return(0); 155 fclose(fp); 156 } else { 157 str_data[3] = TELQUAL_IS; 158 } 159 return(1); 160 } 161 162 int 163 rsaencpwd_send(ap) 164 Authenticator *ap; 165 { 166 167 printf("[ Trying RSAENCPWD ... ]\n"); 168 if (!UserNameRequested) { 169 return(0); 170 } 171 if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) { 172 return(0); 173 } 174 if (!Data(ap, NULL, NULL, 0)) { 175 return(0); 176 } 177 178 179 return(1); 180 } 181 182 void 183 rsaencpwd_is(ap, data, cnt) 184 Authenticator *ap; 185 unsigned char *data; 186 int cnt; 187 { 188 char r_passwd[PWD_SZ]; 189 char key[160]; 190 char chalkey[160], *ptr; 191 FILE *fp; 192 int r, i, j, chalkey_len, len; 193 time_t now; 194 195 cnt--; 196 switch (*data++) { 197 case RSA_ENCPWD_AUTH: 198 memmove((void *)auth.dat, (void *)data, auth.length = cnt); 199 200 if ((fp=fopen(key_file, "r"))==NULL) { 201 Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1); 202 auth_finished(ap, AUTH_REJECT); 203 return; 204 } 205 /* 206 * get privkey 207 */ 208 fscanf(fp, "%x;", &len); 209 for (i=0;i<len;i++) { 210 j = getc(fp); key[i]=j; 211 } 212 fclose(fp); 213 214 r = accept_rsa_encpwd(&auth, key, challenge, 215 challenge_len, r_passwd); 216 if (r < 0) { 217 Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1); 218 auth_finished(ap, AUTH_REJECT); 219 return; 220 } 221 auth_encrypt_userpwd(r_passwd); 222 if (rsaencpwd_passwdok(UserNameRequested, UserPassword) == 0) { 223 /* 224 * illegal username and password 225 */ 226 Data(ap, RSA_ENCPWD_REJECT, (void *)"Illegal password", -1); 227 auth_finished(ap, AUTH_REJECT); 228 return; 229 } 230 231 Data(ap, RSA_ENCPWD_ACCEPT, (void *)0, 0); 232 auth_finished(ap, AUTH_USER); 233 break; 234 235 236 case IAC: 237 238 /* 239 * If we are doing mutual authentication, get set up to send 240 * the challenge, and verify it when the response comes back. 241 */ 242 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_ONE_WAY) { 243 register int i; 244 245 246 time(&now); 247 if ((now % 2) == 0) { 248 sprintf(challenge, "%x", now); 249 challenge_len = strlen(challenge); 250 } else { 251 strcpy(challenge, "randchal"); 252 challenge_len = 8; 253 } 254 255 if ((fp=fopen(key_file, "r"))==NULL) { 256 Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1); 257 auth_finished(ap, AUTH_REJECT); 258 return; 259 } 260 /* 261 * skip privkey 262 */ 263 fscanf(fp, "%x;", &len); 264 for (i=0;i<len;i++) { 265 j = getc(fp); 266 } 267 /* 268 * get pubkey 269 */ 270 fscanf(fp, "%x;", &len); 271 for (i=0;i<len;i++) { 272 j = getc(fp); key[i]=j; 273 } 274 fclose(fp); 275 chalkey[0] = 0x30; 276 ptr = (char *) &chalkey[1]; 277 chalkey_len = 1+NumEncodeLengthOctets(i)+i+1+NumEncodeLengthOctets(challenge_len)+challenge_len; 278 EncodeLength(ptr, chalkey_len); 279 ptr +=NumEncodeLengthOctets(chalkey_len); 280 *ptr++ = 0x04; /* OCTET STRING */ 281 *ptr++ = challenge_len; 282 memmove(ptr, challenge, challenge_len); 283 ptr += challenge_len; 284 *ptr++ = 0x04; /* OCTET STRING */ 285 EncodeLength(ptr, i); 286 ptr += NumEncodeLengthOctets(i); 287 memmove(ptr, key, i); 288 chalkey_len = 1+NumEncodeLengthOctets(chalkey_len)+chalkey_len; 289 Data(ap, RSA_ENCPWD_CHALLENGEKEY, (void *)chalkey, chalkey_len); 290 } 291 break; 292 293 default: 294 Data(ap, RSA_ENCPWD_REJECT, 0, 0); 295 break; 296 } 297 } 298 299 300 void 301 rsaencpwd_reply(ap, data, cnt) 302 Authenticator *ap; 303 unsigned char *data; 304 int cnt; 305 { 306 KTEXT_ST token; 307 int r, pubkey_len; 308 char chalkey[160], pubkey[128], *ptr; 309 310 if (cnt-- < 1) 311 return; 312 switch (*data++) { 313 case RSA_ENCPWD_REJECT: 314 if (cnt > 0) { 315 printf("[ RSA_ENCPWD refuses authentication because %.*s ]\r\n", 316 cnt, data); 317 } else 318 printf("[ RSA_ENCPWD refuses authentication ]\r\n"); 319 auth_send_retry(); 320 return; 321 case RSA_ENCPWD_ACCEPT: 322 printf("[ RSA_ENCPWD accepts you ]\n"); 323 auth_finished(ap, AUTH_USER); 324 return; 325 case RSA_ENCPWD_CHALLENGEKEY: 326 /* 327 * Verify that the response to the challenge is correct. 328 */ 329 330 memmove((void *)chalkey, (void *)data, cnt); 331 ptr = (char *) &chalkey[0]; 332 ptr += DecodeHeaderLength(chalkey); 333 if (*ptr != 0x04) { 334 return; 335 } 336 ptr++; /* skip 0x04 */ 337 challenge_len = DecodeValueLength(ptr); 338 ptr += NumEncodeLengthOctets(challenge_len); 339 memmove(challenge, ptr, challenge_len); 340 ptr += challenge_len; 341 if (*ptr != 0x04) { 342 return; 343 } 344 ptr++; /* skip 0x04 */ 345 pubkey_len = DecodeValueLength(ptr); 346 ptr += NumEncodeLengthOctets(pubkey_len); 347 memmove(pubkey, ptr, pubkey_len); 348 memset(user_passwd, 0, sizeof(user_passwd)); 349 local_des_read_pw_string(user_passwd, sizeof(user_passwd)-1, "Password: ", 0); 350 UserPassword = user_passwd; 351 Challenge = challenge; 352 r = init_rsa_encpwd(&token, user_passwd, challenge, challenge_len, pubkey); 353 if (r < 0) { 354 token.length = 1; 355 } 356 357 if (!Data(ap, RSA_ENCPWD_AUTH, (void *)token.dat, token.length)) { 358 return; 359 } 360 361 break; 362 363 default: 364 return; 365 } 366 } 367 368 int 369 rsaencpwd_status(ap, name, level) 370 Authenticator *ap; 371 char *name; 372 int level; 373 { 374 375 if (level < AUTH_USER) 376 return(level); 377 378 if (UserNameRequested && rsaencpwd_passwdok(UserNameRequested, UserPassword)) { 379 strcpy(name, UserNameRequested); 380 return(AUTH_VALID); 381 } else { 382 return(AUTH_USER); 383 } 384 } 385 386 #define BUMP(buf, len) while (*(buf)) {++(buf), --(len);} 387 #define ADDC(buf, len, c) if ((len) > 0) {*(buf)++ = (c); --(len);} 388 389 void 390 rsaencpwd_printsub(data, cnt, buf, buflen) 391 unsigned char *data, *buf; 392 int cnt, buflen; 393 { 394 char lbuf[32]; 395 register int i; 396 397 buf[buflen-1] = '\0'; /* make sure its NULL terminated */ 398 buflen -= 1; 399 400 switch(data[3]) { 401 case RSA_ENCPWD_REJECT: /* Rejected (reason might follow) */ 402 strncpy((char *)buf, " REJECT ", buflen); 403 goto common; 404 405 case RSA_ENCPWD_ACCEPT: /* Accepted (name might follow) */ 406 strncpy((char *)buf, " ACCEPT ", buflen); 407 common: 408 BUMP(buf, buflen); 409 if (cnt <= 4) 410 break; 411 ADDC(buf, buflen, '"'); 412 for (i = 4; i < cnt; i++) 413 ADDC(buf, buflen, data[i]); 414 ADDC(buf, buflen, '"'); 415 ADDC(buf, buflen, '\0'); 416 break; 417 418 case RSA_ENCPWD_AUTH: /* Authentication data follows */ 419 strncpy((char *)buf, " AUTH", buflen); 420 goto common2; 421 422 case RSA_ENCPWD_CHALLENGEKEY: 423 strncpy((char *)buf, " CHALLENGEKEY", buflen); 424 goto common2; 425 426 default: 427 sprintf(lbuf, " %d (unknown)", data[3]); 428 strncpy((char *)buf, lbuf, buflen); 429 common2: 430 BUMP(buf, buflen); 431 for (i = 4; i < cnt; i++) { 432 sprintf(lbuf, " %d", data[i]); 433 strncpy((char *)buf, lbuf, buflen); 434 BUMP(buf, buflen); 435 } 436 break; 437 } 438 } 439 440 int rsaencpwd_passwdok(name, passwd) 441 char *name, *passwd; 442 { 443 char *crypt(); 444 char *salt, *p; 445 struct passwd *pwd; 446 int passwdok_status = 0; 447 448 if (pwd = getpwnam(name)) 449 salt = pwd->pw_passwd; 450 else salt = "xx"; 451 452 p = crypt(passwd, salt); 453 454 if (pwd && !strcmp(p, pwd->pw_passwd)) { 455 passwdok_status = 1; 456 } else passwdok_status = 0; 457 return(passwdok_status); 458 } 459 460 #endif 461