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 #ifndef lint 35 static char sccsid[] = "@(#)rsaencpwd.c 8.3 (Berkeley) 5/30/95"; 36 #endif /* not lint */ 37 38 39 #ifdef RSA_ENCPWD 40 /* 41 * COPYRIGHT (C) 1990 DIGITAL EQUIPMENT CORPORATION 42 * ALL RIGHTS RESERVED 43 * 44 * "Digital Equipment Corporation authorizes the reproduction, 45 * distribution and modification of this software subject to the following 46 * restrictions: 47 * 48 * 1. Any partial or whole copy of this software, or any modification 49 * thereof, must include this copyright notice in its entirety. 50 * 51 * 2. This software is supplied "as is" with no warranty of any kind, 52 * expressed or implied, for any purpose, including any warranty of fitness 53 * or merchantibility. DIGITAL assumes no responsibility for the use or 54 * reliability of this software, nor promises to provide any form of 55 * support for it on any basis. 56 * 57 * 3. Distribution of this software is authorized only if no profit or 58 * remuneration of any kind is received in exchange for such distribution. 59 * 60 * 4. This software produces public key authentication certificates 61 * bearing an expiration date established by DIGITAL and RSA Data 62 * Security, Inc. It may cease to generate certificates after the expiration 63 * date. Any modification of this software that changes or defeats 64 * the expiration date or its effect is unauthorized. 65 * 66 * 5. Software that will renew or extend the expiration date of 67 * authentication certificates produced by this software may be obtained 68 * from RSA Data Security, Inc., 10 Twin Dolphin Drive, Redwood City, CA 69 * 94065, (415)595-8782, or from DIGITAL" 70 * 71 */ 72 73 #include <sys/types.h> 74 #include <arpa/telnet.h> 75 #include <pwd.h> 76 #include <stdio.h> 77 78 #ifdef __STDC__ 79 #include <stdlib.h> 80 #endif 81 #ifdef NO_STRING_H 82 #include <strings.h> 83 #else 84 #include <string.h> 85 #endif 86 87 #include "encrypt.h" 88 #include "auth.h" 89 #include "misc.h" 90 #include "cdc.h" 91 92 extern auth_debug_mode; 93 94 static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0, 95 AUTHTYPE_RSA_ENCPWD, }; 96 static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 97 TELQUAL_NAME, }; 98 99 #define RSA_ENCPWD_AUTH 0 /* Authentication data follows */ 100 #define RSA_ENCPWD_REJECT 1 /* Rejected (reason might follow) */ 101 #define RSA_ENCPWD_ACCEPT 2 /* Accepted */ 102 #define RSA_ENCPWD_CHALLENGEKEY 3 /* Challenge and public key */ 103 104 #define NAME_SZ 40 105 #define CHAL_SZ 20 106 #define PWD_SZ 40 107 108 static KTEXT_ST auth; 109 static char name[NAME_SZ]; 110 static char user_passwd[PWD_SZ]; 111 static char key_file[2*NAME_SZ]; 112 static char lhostname[NAME_SZ]; 113 static char challenge[CHAL_SZ]; 114 static int challenge_len; 115 116 static int 117 Data(ap, type, d, c) 118 Authenticator *ap; 119 int type; 120 void *d; 121 int c; 122 { 123 unsigned char *p = str_data + 4; 124 unsigned char *cd = (unsigned char *)d; 125 126 if (c == -1) 127 c = strlen((char *)cd); 128 129 if (0) { 130 printf("%s:%d: [%d] (%d)", 131 str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY", 132 str_data[3], 133 type, c); 134 printd(d, c); 135 printf("\r\n"); 136 } 137 *p++ = ap->type; 138 *p++ = ap->way; 139 if (type != NULL) *p++ = type; 140 while (c-- > 0) { 141 if ((*p++ = *cd++) == IAC) 142 *p++ = IAC; 143 } 144 *p++ = IAC; 145 *p++ = SE; 146 if (str_data[3] == TELQUAL_IS) 147 printsub('>', &str_data[2], p - (&str_data[2])); 148 return(net_write(str_data, p - str_data)); 149 } 150 151 int 152 rsaencpwd_init(ap, server) 153 Authenticator *ap; 154 int server; 155 { 156 char *cp; 157 FILE *fp; 158 159 if (server) { 160 str_data[3] = TELQUAL_REPLY; 161 memset(key_file, 0, sizeof(key_file)); 162 gethostname(lhostname, sizeof(lhostname)); 163 if ((cp = strchr(lhostname, '.')) != 0) *cp = '\0'; 164 strcpy(key_file, "/etc/."); 165 strcat(key_file, lhostname); 166 strcat(key_file, "_privkey"); 167 if ((fp=fopen(key_file, "r"))==NULL) return(0); 168 fclose(fp); 169 } else { 170 str_data[3] = TELQUAL_IS; 171 } 172 return(1); 173 } 174 175 int 176 rsaencpwd_send(ap) 177 Authenticator *ap; 178 { 179 180 printf("[ Trying RSAENCPWD ... ]\n"); 181 if (!UserNameRequested) { 182 return(0); 183 } 184 if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) { 185 return(0); 186 } 187 if (!Data(ap, NULL, (void *)NULL, 0)) { 188 return(0); 189 } 190 191 192 return(1); 193 } 194 195 void 196 rsaencpwd_is(ap, data, cnt) 197 Authenticator *ap; 198 unsigned char *data; 199 int cnt; 200 { 201 Session_Key skey; 202 Block datablock; 203 char r_passwd[PWD_SZ], r_user[NAME_SZ]; 204 char *cp, key[160]; 205 char chalkey[160], *ptr; 206 FILE *fp; 207 int r, i, j, chalkey_len, len; 208 time_t now; 209 210 cnt--; 211 switch (*data++) { 212 case RSA_ENCPWD_AUTH: 213 memmove((void *)auth.dat, (void *)data, auth.length = cnt); 214 215 if ((fp=fopen(key_file, "r"))==NULL) { 216 Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1); 217 auth_finished(ap, AUTH_REJECT); 218 return; 219 } 220 /* 221 * get privkey 222 */ 223 fscanf(fp, "%x;", &len); 224 for (i=0;i<len;i++) { 225 j = getc(fp); key[i]=j; 226 } 227 fclose(fp); 228 229 r = accept_rsa_encpwd(&auth, key, challenge, 230 challenge_len, r_passwd); 231 if (r < 0) { 232 Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1); 233 auth_finished(ap, AUTH_REJECT); 234 return; 235 } 236 auth_encrypt_userpwd(r_passwd); 237 if (rsaencpwd_passwdok(UserNameRequested, UserPassword) == 0) { 238 /* 239 * illegal username and password 240 */ 241 Data(ap, RSA_ENCPWD_REJECT, (void *)"Illegal password", -1); 242 auth_finished(ap, AUTH_REJECT); 243 return; 244 } 245 246 Data(ap, RSA_ENCPWD_ACCEPT, (void *)0, 0); 247 auth_finished(ap, AUTH_USER); 248 break; 249 250 251 case IAC: 252 253 /* 254 * If we are doing mutual authentication, get set up to send 255 * the challenge, and verify it when the response comes back. 256 */ 257 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_ONE_WAY) { 258 register int i; 259 260 261 time(&now); 262 if ((now % 2) == 0) { 263 sprintf(challenge, "%x", now); 264 challenge_len = strlen(challenge); 265 } else { 266 strcpy(challenge, "randchal"); 267 challenge_len = 8; 268 } 269 270 if ((fp=fopen(key_file, "r"))==NULL) { 271 Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1); 272 auth_finished(ap, AUTH_REJECT); 273 return; 274 } 275 /* 276 * skip privkey 277 */ 278 fscanf(fp, "%x;", &len); 279 for (i=0;i<len;i++) { 280 j = getc(fp); 281 } 282 /* 283 * get pubkey 284 */ 285 fscanf(fp, "%x;", &len); 286 for (i=0;i<len;i++) { 287 j = getc(fp); key[i]=j; 288 } 289 fclose(fp); 290 chalkey[0] = 0x30; 291 ptr = (char *) &chalkey[1]; 292 chalkey_len = 1+NumEncodeLengthOctets(i)+i+1+NumEncodeLengthOctets(challenge_len)+challenge_len; 293 EncodeLength(ptr, chalkey_len); 294 ptr +=NumEncodeLengthOctets(chalkey_len); 295 *ptr++ = 0x04; /* OCTET STRING */ 296 *ptr++ = challenge_len; 297 memmove(ptr, challenge, challenge_len); 298 ptr += challenge_len; 299 *ptr++ = 0x04; /* OCTET STRING */ 300 EncodeLength(ptr, i); 301 ptr += NumEncodeLengthOctets(i); 302 memmove(ptr, key, i); 303 chalkey_len = 1+NumEncodeLengthOctets(chalkey_len)+chalkey_len; 304 Data(ap, RSA_ENCPWD_CHALLENGEKEY, (void *)chalkey, chalkey_len); 305 } 306 break; 307 308 default: 309 Data(ap, RSA_ENCPWD_REJECT, 0, 0); 310 break; 311 } 312 } 313 314 315 void 316 rsaencpwd_reply(ap, data, cnt) 317 Authenticator *ap; 318 unsigned char *data; 319 int cnt; 320 { 321 Session_Key skey; 322 KTEXT_ST token; 323 Block enckey; 324 int r, pubkey_len; 325 char randchal[CHAL_SZ], *cp; 326 char chalkey[160], pubkey[128], *ptr; 327 328 if (cnt-- < 1) 329 return; 330 switch (*data++) { 331 case RSA_ENCPWD_REJECT: 332 if (cnt > 0) { 333 printf("[ RSA_ENCPWD refuses authentication because %.*s ]\r\n", 334 cnt, data); 335 } else 336 printf("[ RSA_ENCPWD refuses authentication ]\r\n"); 337 auth_send_retry(); 338 return; 339 case RSA_ENCPWD_ACCEPT: 340 printf("[ RSA_ENCPWD accepts you ]\n"); 341 auth_finished(ap, AUTH_USER); 342 return; 343 case RSA_ENCPWD_CHALLENGEKEY: 344 /* 345 * Verify that the response to the challenge is correct. 346 */ 347 348 memmove((void *)chalkey, (void *)data, cnt); 349 ptr = (char *) &chalkey[0]; 350 ptr += DecodeHeaderLength(chalkey); 351 if (*ptr != 0x04) { 352 return; 353 } 354 *ptr++; 355 challenge_len = DecodeValueLength(ptr); 356 ptr += NumEncodeLengthOctets(challenge_len); 357 memmove(challenge, ptr, challenge_len); 358 ptr += challenge_len; 359 if (*ptr != 0x04) { 360 return; 361 } 362 *ptr++; 363 pubkey_len = DecodeValueLength(ptr); 364 ptr += NumEncodeLengthOctets(pubkey_len); 365 memmove(pubkey, ptr, pubkey_len); 366 memset(user_passwd, 0, sizeof(user_passwd)); 367 local_des_read_pw_string(user_passwd, sizeof(user_passwd)-1, "Password: ", 0); 368 UserPassword = user_passwd; 369 Challenge = challenge; 370 r = init_rsa_encpwd(&token, user_passwd, challenge, challenge_len, pubkey); 371 if (r < 0) { 372 token.length = 1; 373 } 374 375 if (!Data(ap, RSA_ENCPWD_AUTH, (void *)token.dat, token.length)) { 376 return; 377 } 378 379 break; 380 381 default: 382 return; 383 } 384 } 385 386 int 387 rsaencpwd_status(ap, name, level) 388 Authenticator *ap; 389 char *name; 390 int level; 391 { 392 393 if (level < AUTH_USER) 394 return(level); 395 396 if (UserNameRequested && rsaencpwd_passwdok(UserNameRequested, UserPassword)) { 397 strcpy(name, UserNameRequested); 398 return(AUTH_VALID); 399 } else { 400 return(AUTH_USER); 401 } 402 } 403 404 #define BUMP(buf, len) while (*(buf)) {++(buf), --(len);} 405 #define ADDC(buf, len, c) if ((len) > 0) {*(buf)++ = (c); --(len);} 406 407 void 408 rsaencpwd_printsub(data, cnt, buf, buflen) 409 unsigned char *data, *buf; 410 int cnt, buflen; 411 { 412 char lbuf[32]; 413 register int i; 414 415 buf[buflen-1] = '\0'; /* make sure its NULL terminated */ 416 buflen -= 1; 417 418 switch(data[3]) { 419 case RSA_ENCPWD_REJECT: /* Rejected (reason might follow) */ 420 strncpy((char *)buf, " REJECT ", buflen); 421 goto common; 422 423 case RSA_ENCPWD_ACCEPT: /* Accepted (name might follow) */ 424 strncpy((char *)buf, " ACCEPT ", buflen); 425 common: 426 BUMP(buf, buflen); 427 if (cnt <= 4) 428 break; 429 ADDC(buf, buflen, '"'); 430 for (i = 4; i < cnt; i++) 431 ADDC(buf, buflen, data[i]); 432 ADDC(buf, buflen, '"'); 433 ADDC(buf, buflen, '\0'); 434 break; 435 436 case RSA_ENCPWD_AUTH: /* Authentication data follows */ 437 strncpy((char *)buf, " AUTH", buflen); 438 goto common2; 439 440 case RSA_ENCPWD_CHALLENGEKEY: 441 strncpy((char *)buf, " CHALLENGEKEY", buflen); 442 goto common2; 443 444 default: 445 sprintf(lbuf, " %d (unknown)", data[3]); 446 strncpy((char *)buf, lbuf, buflen); 447 common2: 448 BUMP(buf, buflen); 449 for (i = 4; i < cnt; i++) { 450 sprintf(lbuf, " %d", data[i]); 451 strncpy((char *)buf, lbuf, buflen); 452 BUMP(buf, buflen); 453 } 454 break; 455 } 456 } 457 458 int rsaencpwd_passwdok(name, passwd) 459 char *name, *passwd; 460 { 461 char *crypt(); 462 char *salt, *p; 463 struct passwd *pwd; 464 int passwdok_status = 0; 465 466 if (pwd = getpwnam(name)) 467 salt = pwd->pw_passwd; 468 else salt = "xx"; 469 470 p = crypt(passwd, salt); 471 472 if (pwd && !strcmp(p, pwd->pw_passwd)) { 473 passwdok_status = 1; 474 } else passwdok_status = 0; 475 return(passwdok_status); 476 } 477 478 #endif 479 480 #ifdef notdef 481 482 prkey(msg, key) 483 char *msg; 484 unsigned char *key; 485 { 486 register int i; 487 printf("%s:", msg); 488 for (i = 0; i < 8; i++) 489 printf(" %3d", key[i]); 490 printf("\r\n"); 491 } 492 #endif 493