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 30 #include <sys/cdefs.h> 31 32 __FBSDID("$FreeBSD$"); 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 #include <stdlib.h> 78 #include <string.h> 79 80 #include "encrypt.h" 81 #include "auth.h" 82 #include "misc.h" 83 #include "cdc.h" 84 85 extern auth_debug_mode; 86 87 static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0, 88 AUTHTYPE_RSA_ENCPWD, }; 89 static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 90 TELQUAL_NAME, }; 91 92 #define RSA_ENCPWD_AUTH 0 /* Authentication data follows */ 93 #define RSA_ENCPWD_REJECT 1 /* Rejected (reason might follow) */ 94 #define RSA_ENCPWD_ACCEPT 2 /* Accepted */ 95 #define RSA_ENCPWD_CHALLENGEKEY 3 /* Challenge and public key */ 96 97 #define NAME_SZ 40 98 #define CHAL_SZ 20 99 #define PWD_SZ 40 100 101 static KTEXT_ST auth; 102 static char name[NAME_SZ]; 103 static char user_passwd[PWD_SZ]; 104 static char key_file[2*NAME_SZ]; 105 static char lhostname[NAME_SZ]; 106 static char challenge[CHAL_SZ]; 107 static int challenge_len; 108 109 static int 110 Data(ap, type, d, c) 111 Authenticator *ap; 112 int type; 113 void *d; 114 int c; 115 { 116 unsigned char *p = str_data + 4; 117 unsigned char *cd = (unsigned char *)d; 118 119 if (c == -1) 120 c = strlen((char *)cd); 121 122 if (0) { 123 printf("%s:%d: [%d] (%d)", 124 str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY", 125 str_data[3], 126 type, c); 127 printd(d, c); 128 printf("\r\n"); 129 } 130 *p++ = ap->type; 131 *p++ = ap->way; 132 if (type != NULL) *p++ = type; 133 while (c-- > 0) { 134 if ((*p++ = *cd++) == IAC) 135 *p++ = IAC; 136 } 137 *p++ = IAC; 138 *p++ = SE; 139 if (str_data[3] == TELQUAL_IS) 140 printsub('>', &str_data[2], p - (&str_data[2])); 141 return(net_write(str_data, p - str_data)); 142 } 143 144 int 145 rsaencpwd_init(ap, server) 146 Authenticator *ap; 147 int server; 148 { 149 char *cp; 150 FILE *fp; 151 152 if (server) { 153 str_data[3] = TELQUAL_REPLY; 154 memset(key_file, 0, sizeof(key_file)); 155 gethostname(lhostname, sizeof(lhostname)); 156 if ((cp = strchr(lhostname, '.')) != 0) *cp = '\0'; 157 strcpy(key_file, "/etc/."); 158 strcat(key_file, lhostname); 159 strcat(key_file, "_privkey"); 160 if ((fp=fopen(key_file, "r"))==NULL) return(0); 161 fclose(fp); 162 } else { 163 str_data[3] = TELQUAL_IS; 164 } 165 return(1); 166 } 167 168 int 169 rsaencpwd_send(ap) 170 Authenticator *ap; 171 { 172 173 printf("[ Trying RSAENCPWD ... ]\n"); 174 if (!UserNameRequested) { 175 return(0); 176 } 177 if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) { 178 return(0); 179 } 180 if (!Data(ap, NULL, (void *)NULL, 0)) { 181 return(0); 182 } 183 184 185 return(1); 186 } 187 188 void 189 rsaencpwd_is(ap, data, cnt) 190 Authenticator *ap; 191 unsigned char *data; 192 int cnt; 193 { 194 Session_Key skey; 195 Block datablock; 196 char r_passwd[PWD_SZ], r_user[NAME_SZ]; 197 char *cp, key[160]; 198 char chalkey[160], *ptr; 199 FILE *fp; 200 int r, i, j, chalkey_len, len; 201 time_t now; 202 203 cnt--; 204 switch (*data++) { 205 case RSA_ENCPWD_AUTH: 206 memmove((void *)auth.dat, (void *)data, auth.length = cnt); 207 208 if ((fp=fopen(key_file, "r"))==NULL) { 209 Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1); 210 auth_finished(ap, AUTH_REJECT); 211 return; 212 } 213 /* 214 * get privkey 215 */ 216 fscanf(fp, "%x;", &len); 217 for (i=0;i<len;i++) { 218 j = getc(fp); key[i]=j; 219 } 220 fclose(fp); 221 222 r = accept_rsa_encpwd(&auth, key, challenge, 223 challenge_len, r_passwd); 224 if (r < 0) { 225 Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1); 226 auth_finished(ap, AUTH_REJECT); 227 return; 228 } 229 auth_encrypt_userpwd(r_passwd); 230 if (rsaencpwd_passwdok(UserNameRequested, UserPassword) == 0) { 231 /* 232 * illegal username and password 233 */ 234 Data(ap, RSA_ENCPWD_REJECT, (void *)"Illegal password", -1); 235 auth_finished(ap, AUTH_REJECT); 236 return; 237 } 238 239 Data(ap, RSA_ENCPWD_ACCEPT, (void *)0, 0); 240 auth_finished(ap, AUTH_USER); 241 break; 242 243 244 case IAC: 245 246 /* 247 * If we are doing mutual authentication, get set up to send 248 * the challenge, and verify it when the response comes back. 249 */ 250 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_ONE_WAY) { 251 register int i; 252 253 254 time(&now); 255 if ((now % 2) == 0) { 256 sprintf(challenge, "%x", now); 257 challenge_len = strlen(challenge); 258 } else { 259 strcpy(challenge, "randchal"); 260 challenge_len = 8; 261 } 262 263 if ((fp=fopen(key_file, "r"))==NULL) { 264 Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1); 265 auth_finished(ap, AUTH_REJECT); 266 return; 267 } 268 /* 269 * skip privkey 270 */ 271 fscanf(fp, "%x;", &len); 272 for (i=0;i<len;i++) { 273 j = getc(fp); 274 } 275 /* 276 * get pubkey 277 */ 278 fscanf(fp, "%x;", &len); 279 for (i=0;i<len;i++) { 280 j = getc(fp); key[i]=j; 281 } 282 fclose(fp); 283 chalkey[0] = 0x30; 284 ptr = (char *) &chalkey[1]; 285 chalkey_len = 1+NumEncodeLengthOctets(i)+i+1+NumEncodeLengthOctets(challenge_len)+challenge_len; 286 EncodeLength(ptr, chalkey_len); 287 ptr +=NumEncodeLengthOctets(chalkey_len); 288 *ptr++ = 0x04; /* OCTET STRING */ 289 *ptr++ = challenge_len; 290 memmove(ptr, challenge, challenge_len); 291 ptr += challenge_len; 292 *ptr++ = 0x04; /* OCTET STRING */ 293 EncodeLength(ptr, i); 294 ptr += NumEncodeLengthOctets(i); 295 memmove(ptr, key, i); 296 chalkey_len = 1+NumEncodeLengthOctets(chalkey_len)+chalkey_len; 297 Data(ap, RSA_ENCPWD_CHALLENGEKEY, (void *)chalkey, chalkey_len); 298 } 299 break; 300 301 default: 302 Data(ap, RSA_ENCPWD_REJECT, 0, 0); 303 break; 304 } 305 } 306 307 308 void 309 rsaencpwd_reply(ap, data, cnt) 310 Authenticator *ap; 311 unsigned char *data; 312 int cnt; 313 { 314 Session_Key skey; 315 KTEXT_ST token; 316 Block enckey; 317 int r, pubkey_len; 318 char randchal[CHAL_SZ], *cp; 319 char chalkey[160], pubkey[128], *ptr; 320 321 if (cnt-- < 1) 322 return; 323 switch (*data++) { 324 case RSA_ENCPWD_REJECT: 325 if (cnt > 0) { 326 printf("[ RSA_ENCPWD refuses authentication because %.*s ]\r\n", 327 cnt, data); 328 } else 329 printf("[ RSA_ENCPWD refuses authentication ]\r\n"); 330 auth_send_retry(); 331 return; 332 case RSA_ENCPWD_ACCEPT: 333 printf("[ RSA_ENCPWD accepts you ]\n"); 334 auth_finished(ap, AUTH_USER); 335 return; 336 case RSA_ENCPWD_CHALLENGEKEY: 337 /* 338 * Verify that the response to the challenge is correct. 339 */ 340 341 memmove((void *)chalkey, (void *)data, cnt); 342 ptr = (char *) &chalkey[0]; 343 ptr += DecodeHeaderLength(chalkey); 344 if (*ptr != 0x04) { 345 return; 346 } 347 *ptr++; 348 challenge_len = DecodeValueLength(ptr); 349 ptr += NumEncodeLengthOctets(challenge_len); 350 memmove(challenge, ptr, challenge_len); 351 ptr += challenge_len; 352 if (*ptr != 0x04) { 353 return; 354 } 355 *ptr++; 356 pubkey_len = DecodeValueLength(ptr); 357 ptr += NumEncodeLengthOctets(pubkey_len); 358 memmove(pubkey, ptr, pubkey_len); 359 memset(user_passwd, 0, sizeof(user_passwd)); 360 local_des_read_pw_string(user_passwd, sizeof(user_passwd)-1, "Password: ", 0); 361 UserPassword = user_passwd; 362 Challenge = challenge; 363 r = init_rsa_encpwd(&token, user_passwd, challenge, challenge_len, pubkey); 364 if (r < 0) { 365 token.length = 1; 366 } 367 368 if (!Data(ap, RSA_ENCPWD_AUTH, (void *)token.dat, token.length)) { 369 return; 370 } 371 372 break; 373 374 default: 375 return; 376 } 377 } 378 379 int 380 rsaencpwd_status(ap, name, level) 381 Authenticator *ap; 382 char *name; 383 int level; 384 { 385 386 if (level < AUTH_USER) 387 return(level); 388 389 if (UserNameRequested && rsaencpwd_passwdok(UserNameRequested, UserPassword)) { 390 strcpy(name, UserNameRequested); 391 return(AUTH_VALID); 392 } else { 393 return(AUTH_USER); 394 } 395 } 396 397 #define BUMP(buf, len) while (*(buf)) {++(buf), --(len);} 398 #define ADDC(buf, len, c) if ((len) > 0) {*(buf)++ = (c); --(len);} 399 400 void 401 rsaencpwd_printsub(data, cnt, buf, buflen) 402 unsigned char *data, *buf; 403 int cnt, buflen; 404 { 405 char lbuf[32]; 406 register int i; 407 408 buf[buflen-1] = '\0'; /* make sure its NULL terminated */ 409 buflen -= 1; 410 411 switch(data[3]) { 412 case RSA_ENCPWD_REJECT: /* Rejected (reason might follow) */ 413 strncpy((char *)buf, " REJECT ", buflen); 414 goto common; 415 416 case RSA_ENCPWD_ACCEPT: /* Accepted (name might follow) */ 417 strncpy((char *)buf, " ACCEPT ", buflen); 418 common: 419 BUMP(buf, buflen); 420 if (cnt <= 4) 421 break; 422 ADDC(buf, buflen, '"'); 423 for (i = 4; i < cnt; i++) 424 ADDC(buf, buflen, data[i]); 425 ADDC(buf, buflen, '"'); 426 ADDC(buf, buflen, '\0'); 427 break; 428 429 case RSA_ENCPWD_AUTH: /* Authentication data follows */ 430 strncpy((char *)buf, " AUTH", buflen); 431 goto common2; 432 433 case RSA_ENCPWD_CHALLENGEKEY: 434 strncpy((char *)buf, " CHALLENGEKEY", buflen); 435 goto common2; 436 437 default: 438 sprintf(lbuf, " %d (unknown)", data[3]); 439 strncpy((char *)buf, lbuf, buflen); 440 common2: 441 BUMP(buf, buflen); 442 for (i = 4; i < cnt; i++) { 443 sprintf(lbuf, " %d", data[i]); 444 strncpy((char *)buf, lbuf, buflen); 445 BUMP(buf, buflen); 446 } 447 break; 448 } 449 } 450 451 int rsaencpwd_passwdok(name, passwd) 452 char *name, *passwd; 453 { 454 char *crypt(); 455 char *salt, *p; 456 struct passwd *pwd; 457 int passwdok_status = 0; 458 459 if (pwd = getpwnam(name)) 460 salt = pwd->pw_passwd; 461 else salt = "xx"; 462 463 p = crypt(passwd, salt); 464 465 if (pwd && !strcmp(p, pwd->pw_passwd)) { 466 passwdok_status = 1; 467 } else passwdok_status = 0; 468 return(passwdok_status); 469 } 470 471 #endif 472