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