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("$Id$"); 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 #ifdef HAVE_ARPA_TELNET_H 74 #include <arpa/telnet.h> 75 #endif 76 #include <pwd.h> 77 #include <stdio.h> 78 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 #include "cdc.h" 89 90 extern auth_debug_mode; 91 92 static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0, 93 AUTHTYPE_RSA_ENCPWD, }; 94 static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 95 TELQUAL_NAME, }; 96 97 #define RSA_ENCPWD_AUTH 0 /* Authentication data follows */ 98 #define RSA_ENCPWD_REJECT 1 /* Rejected (reason might follow) */ 99 #define RSA_ENCPWD_ACCEPT 2 /* Accepted */ 100 #define RSA_ENCPWD_CHALLENGEKEY 3 /* Challenge and public key */ 101 102 #define NAME_SZ 40 103 #define CHAL_SZ 20 104 #define PWD_SZ 40 105 106 static KTEXT_ST auth; 107 static char name[NAME_SZ]; 108 static char user_passwd[PWD_SZ]; 109 static char key_file[2*NAME_SZ]; 110 static char lhostname[NAME_SZ]; 111 static char challenge[CHAL_SZ]; 112 static int challenge_len; 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((char *)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 if (type != NULL) *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 rsaencpwd_init(ap, server) 151 Authenticator *ap; 152 int server; 153 { 154 char *cp; 155 FILE *fp; 156 157 if (server) { 158 str_data[3] = TELQUAL_REPLY; 159 memset(key_file, 0, sizeof(key_file)); 160 gethostname(lhostname, sizeof(lhostname)); 161 if ((cp = strchr(lhostname, '.')) != 0) *cp = '\0'; 162 snprintf(key_file, sizeof(key_file), 163 SYSCONFDIR "/.%s_privkey", lhostname); 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 ... ]\r\n"); 178 if (!UserNameRequested) { 179 return(0); 180 } 181 if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) { 182 return(0); 183 } 184 if (!Data(ap, NULL, 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 des_cblock 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(auth.dat, data, auth.length = cnt); 211 212 if ((fp=fopen(key_file, "r"))==NULL) { 213 Data(ap, RSA_ENCPWD_REJECT, "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, "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, "Illegal password", -1); 239 auth_finished(ap, AUTH_REJECT); 240 return; 241 } 242 243 Data(ap, RSA_ENCPWD_ACCEPT, 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 int i; 256 257 258 time(&now); 259 if ((now % 2) == 0) { 260 snprintf(challenge, sizeof(challenge), "%x", now); 261 challenge_len = strlen(challenge); 262 } else { 263 strlcpy(challenge, "randchal", sizeof(challenge)); 264 challenge_len = 8; 265 } 266 267 if ((fp=fopen(key_file, "r"))==NULL) { 268 Data(ap, RSA_ENCPWD_REJECT, "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, 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 des_cblock 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 ]\r\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(chalkey, 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 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, 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, name_sz, level) 385 Authenticator *ap; 386 char *name; 387 size_t name_sz; 388 int level; 389 { 390 391 if (level < AUTH_USER) 392 return(level); 393 394 if (UserNameRequested && rsaencpwd_passwdok(UserNameRequested, UserPassword)) { 395 strlcpy(name, UserNameRequested, name_sz); 396 return(AUTH_VALID); 397 } else { 398 return(AUTH_USER); 399 } 400 } 401 402 #define BUMP(buf, len) while (*(buf)) {++(buf), --(len);} 403 #define ADDC(buf, len, c) if ((len) > 0) {*(buf)++ = (c); --(len);} 404 405 void 406 rsaencpwd_printsub(unsigned char *data, size_t cnt, 407 unsigned char * buf, size_t buflen) 408 { 409 size_t i; 410 411 buf[buflen-1] = '\0'; /* make sure it's NULL terminated */ 412 buflen -= 1; 413 414 switch(data[3]) { 415 case RSA_ENCPWD_REJECT: /* Rejected (reason might follow) */ 416 strlcpy((char *)buf, " REJECT ", buflen); 417 goto common; 418 419 case RSA_ENCPWD_ACCEPT: /* Accepted (name might follow) */ 420 strlcpy((char *)buf, " ACCEPT ", buflen); 421 common: 422 BUMP(buf, buflen); 423 if (cnt <= 4) 424 break; 425 ADDC(buf, buflen, '"'); 426 for (i = 4; i < cnt; i++) 427 ADDC(buf, buflen, data[i]); 428 ADDC(buf, buflen, '"'); 429 ADDC(buf, buflen, '\0'); 430 break; 431 432 case RSA_ENCPWD_AUTH: /* Authentication data follows */ 433 strlcpy((char *)buf, " AUTH", buflen); 434 goto common2; 435 436 case RSA_ENCPWD_CHALLENGEKEY: 437 strlcpy((char *)buf, " CHALLENGEKEY", buflen); 438 goto common2; 439 440 default: 441 snprintf(buf, buflen, " %d (unknown)", data[3]); 442 common2: 443 BUMP(buf, buflen); 444 for (i = 4; i < cnt; i++) { 445 snprintf(buf, buflen, " %d", data[i]); 446 BUMP(buf, buflen); 447 } 448 break; 449 } 450 } 451 452 int rsaencpwd_passwdok(name, passwd) 453 char *name, *passwd; 454 { 455 char *crypt(); 456 char *salt, *p; 457 struct passwd *pwd; 458 int passwdok_status = 0; 459 460 if (pwd = k_getpwnam(name)) 461 salt = pwd->pw_passwd; 462 else salt = "xx"; 463 464 p = crypt(passwd, salt); 465 466 if (pwd && !strcmp(p, pwd->pw_passwd)) { 467 passwdok_status = 1; 468 } else passwdok_status = 0; 469 return(passwdok_status); 470 } 471 472 #endif 473 474 #ifdef notdef 475 476 prkey(msg, key) 477 char *msg; 478 unsigned char *key; 479 { 480 int i; 481 printf("%s:", msg); 482 for (i = 0; i < 8; i++) 483 printf(" %3d", key[i]); 484 printf("\r\n"); 485 } 486 #endif 487