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 #ifndef lint 31 static char sccsid[] = "@(#)rsaencpwd.c 8.3 (Berkeley) 5/30/95"; 32 #endif /* not lint */ 33 34 35 #ifdef RSA_ENCPWD 36 /* 37 * COPYRIGHT (C) 1990 DIGITAL EQUIPMENT CORPORATION 38 * ALL RIGHTS RESERVED 39 * 40 * "Digital Equipment Corporation authorizes the reproduction, 41 * distribution and modification of this software subject to the following 42 * restrictions: 43 * 44 * 1. Any partial or whole copy of this software, or any modification 45 * thereof, must include this copyright notice in its entirety. 46 * 47 * 2. This software is supplied "as is" with no warranty of any kind, 48 * expressed or implied, for any purpose, including any warranty of fitness 49 * or merchantibility. DIGITAL assumes no responsibility for the use or 50 * reliability of this software, nor promises to provide any form of 51 * support for it on any basis. 52 * 53 * 3. Distribution of this software is authorized only if no profit or 54 * remuneration of any kind is received in exchange for such distribution. 55 * 56 * 4. This software produces public key authentication certificates 57 * bearing an expiration date established by DIGITAL and RSA Data 58 * Security, Inc. It may cease to generate certificates after the expiration 59 * date. Any modification of this software that changes or defeats 60 * the expiration date or its effect is unauthorized. 61 * 62 * 5. Software that will renew or extend the expiration date of 63 * authentication certificates produced by this software may be obtained 64 * from RSA Data Security, Inc., 10 Twin Dolphin Drive, Redwood City, CA 65 * 94065, (415)595-8782, or from DIGITAL" 66 * 67 */ 68 69 #include <sys/types.h> 70 #include <arpa/telnet.h> 71 #include <pwd.h> 72 #include <stdio.h> 73 #include <stdlib.h> 74 #include <string.h> 75 76 #include "encrypt.h" 77 #include "auth.h" 78 #include "misc.h" 79 #include "cdc.h" 80 81 extern auth_debug_mode; 82 83 static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0, 84 AUTHTYPE_RSA_ENCPWD, }; 85 static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 86 TELQUAL_NAME, }; 87 88 #define RSA_ENCPWD_AUTH 0 /* Authentication data follows */ 89 #define RSA_ENCPWD_REJECT 1 /* Rejected (reason might follow) */ 90 #define RSA_ENCPWD_ACCEPT 2 /* Accepted */ 91 #define RSA_ENCPWD_CHALLENGEKEY 3 /* Challenge and public key */ 92 93 #define NAME_SZ 40 94 #define CHAL_SZ 20 95 #define PWD_SZ 40 96 97 static KTEXT_ST auth; 98 static char name[NAME_SZ]; 99 static char user_passwd[PWD_SZ]; 100 static char key_file[2*NAME_SZ]; 101 static char lhostname[NAME_SZ]; 102 static char challenge[CHAL_SZ]; 103 static int challenge_len; 104 105 static int 106 Data(ap, type, d, c) 107 Authenticator *ap; 108 int type; 109 void *d; 110 int c; 111 { 112 unsigned char *p = str_data + 4; 113 unsigned char *cd = (unsigned char *)d; 114 115 if (c == -1) 116 c = strlen((char *)cd); 117 118 if (0) { 119 printf("%s:%d: [%d] (%d)", 120 str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY", 121 str_data[3], 122 type, c); 123 printd(d, c); 124 printf("\r\n"); 125 } 126 *p++ = ap->type; 127 *p++ = ap->way; 128 if (type != NULL) *p++ = type; 129 while (c-- > 0) { 130 if ((*p++ = *cd++) == IAC) 131 *p++ = IAC; 132 } 133 *p++ = IAC; 134 *p++ = SE; 135 if (str_data[3] == TELQUAL_IS) 136 printsub('>', &str_data[2], p - (&str_data[2])); 137 return(net_write(str_data, p - str_data)); 138 } 139 140 int 141 rsaencpwd_init(ap, server) 142 Authenticator *ap; 143 int server; 144 { 145 char *cp; 146 FILE *fp; 147 148 if (server) { 149 str_data[3] = TELQUAL_REPLY; 150 memset(key_file, 0, sizeof(key_file)); 151 gethostname(lhostname, sizeof(lhostname)); 152 if ((cp = strchr(lhostname, '.')) != 0) *cp = '\0'; 153 strcpy(key_file, "/etc/."); 154 strcat(key_file, lhostname); 155 strcat(key_file, "_privkey"); 156 if ((fp=fopen(key_file, "r"))==NULL) return(0); 157 fclose(fp); 158 } else { 159 str_data[3] = TELQUAL_IS; 160 } 161 return(1); 162 } 163 164 int 165 rsaencpwd_send(ap) 166 Authenticator *ap; 167 { 168 169 printf("[ Trying RSAENCPWD ... ]\n"); 170 if (!UserNameRequested) { 171 return(0); 172 } 173 if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) { 174 return(0); 175 } 176 if (!Data(ap, NULL, (void *)NULL, 0)) { 177 return(0); 178 } 179 180 181 return(1); 182 } 183 184 void 185 rsaencpwd_is(ap, data, cnt) 186 Authenticator *ap; 187 unsigned char *data; 188 int cnt; 189 { 190 Session_Key skey; 191 Block datablock; 192 char r_passwd[PWD_SZ], r_user[NAME_SZ]; 193 char *cp, key[160]; 194 char chalkey[160], *ptr; 195 FILE *fp; 196 int r, i, j, chalkey_len, len; 197 time_t now; 198 199 cnt--; 200 switch (*data++) { 201 case RSA_ENCPWD_AUTH: 202 memmove((void *)auth.dat, (void *)data, auth.length = cnt); 203 204 if ((fp=fopen(key_file, "r"))==NULL) { 205 Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1); 206 auth_finished(ap, AUTH_REJECT); 207 return; 208 } 209 /* 210 * get privkey 211 */ 212 fscanf(fp, "%x;", &len); 213 for (i=0;i<len;i++) { 214 j = getc(fp); key[i]=j; 215 } 216 fclose(fp); 217 218 r = accept_rsa_encpwd(&auth, key, challenge, 219 challenge_len, r_passwd); 220 if (r < 0) { 221 Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1); 222 auth_finished(ap, AUTH_REJECT); 223 return; 224 } 225 auth_encrypt_userpwd(r_passwd); 226 if (rsaencpwd_passwdok(UserNameRequested, UserPassword) == 0) { 227 /* 228 * illegal username and password 229 */ 230 Data(ap, RSA_ENCPWD_REJECT, (void *)"Illegal password", -1); 231 auth_finished(ap, AUTH_REJECT); 232 return; 233 } 234 235 Data(ap, RSA_ENCPWD_ACCEPT, (void *)0, 0); 236 auth_finished(ap, AUTH_USER); 237 break; 238 239 240 case IAC: 241 242 /* 243 * If we are doing mutual authentication, get set up to send 244 * the challenge, and verify it when the response comes back. 245 */ 246 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_ONE_WAY) { 247 register int i; 248 249 250 time(&now); 251 if ((now % 2) == 0) { 252 sprintf(challenge, "%x", now); 253 challenge_len = strlen(challenge); 254 } else { 255 strcpy(challenge, "randchal"); 256 challenge_len = 8; 257 } 258 259 if ((fp=fopen(key_file, "r"))==NULL) { 260 Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1); 261 auth_finished(ap, AUTH_REJECT); 262 return; 263 } 264 /* 265 * skip privkey 266 */ 267 fscanf(fp, "%x;", &len); 268 for (i=0;i<len;i++) { 269 j = getc(fp); 270 } 271 /* 272 * get pubkey 273 */ 274 fscanf(fp, "%x;", &len); 275 for (i=0;i<len;i++) { 276 j = getc(fp); key[i]=j; 277 } 278 fclose(fp); 279 chalkey[0] = 0x30; 280 ptr = (char *) &chalkey[1]; 281 chalkey_len = 1+NumEncodeLengthOctets(i)+i+1+NumEncodeLengthOctets(challenge_len)+challenge_len; 282 EncodeLength(ptr, chalkey_len); 283 ptr +=NumEncodeLengthOctets(chalkey_len); 284 *ptr++ = 0x04; /* OCTET STRING */ 285 *ptr++ = challenge_len; 286 memmove(ptr, challenge, challenge_len); 287 ptr += challenge_len; 288 *ptr++ = 0x04; /* OCTET STRING */ 289 EncodeLength(ptr, i); 290 ptr += NumEncodeLengthOctets(i); 291 memmove(ptr, key, i); 292 chalkey_len = 1+NumEncodeLengthOctets(chalkey_len)+chalkey_len; 293 Data(ap, RSA_ENCPWD_CHALLENGEKEY, (void *)chalkey, chalkey_len); 294 } 295 break; 296 297 default: 298 Data(ap, RSA_ENCPWD_REJECT, 0, 0); 299 break; 300 } 301 } 302 303 304 void 305 rsaencpwd_reply(ap, data, cnt) 306 Authenticator *ap; 307 unsigned char *data; 308 int cnt; 309 { 310 Session_Key skey; 311 KTEXT_ST token; 312 Block enckey; 313 int r, pubkey_len; 314 char randchal[CHAL_SZ], *cp; 315 char chalkey[160], pubkey[128], *ptr; 316 317 if (cnt-- < 1) 318 return; 319 switch (*data++) { 320 case RSA_ENCPWD_REJECT: 321 if (cnt > 0) { 322 printf("[ RSA_ENCPWD refuses authentication because %.*s ]\r\n", 323 cnt, data); 324 } else 325 printf("[ RSA_ENCPWD refuses authentication ]\r\n"); 326 auth_send_retry(); 327 return; 328 case RSA_ENCPWD_ACCEPT: 329 printf("[ RSA_ENCPWD accepts you ]\n"); 330 auth_finished(ap, AUTH_USER); 331 return; 332 case RSA_ENCPWD_CHALLENGEKEY: 333 /* 334 * Verify that the response to the challenge is correct. 335 */ 336 337 memmove((void *)chalkey, (void *)data, cnt); 338 ptr = (char *) &chalkey[0]; 339 ptr += DecodeHeaderLength(chalkey); 340 if (*ptr != 0x04) { 341 return; 342 } 343 *ptr++; 344 challenge_len = DecodeValueLength(ptr); 345 ptr += NumEncodeLengthOctets(challenge_len); 346 memmove(challenge, ptr, challenge_len); 347 ptr += challenge_len; 348 if (*ptr != 0x04) { 349 return; 350 } 351 *ptr++; 352 pubkey_len = DecodeValueLength(ptr); 353 ptr += NumEncodeLengthOctets(pubkey_len); 354 memmove(pubkey, ptr, pubkey_len); 355 memset(user_passwd, 0, sizeof(user_passwd)); 356 local_des_read_pw_string(user_passwd, sizeof(user_passwd)-1, "Password: ", 0); 357 UserPassword = user_passwd; 358 Challenge = challenge; 359 r = init_rsa_encpwd(&token, user_passwd, challenge, challenge_len, pubkey); 360 if (r < 0) { 361 token.length = 1; 362 } 363 364 if (!Data(ap, RSA_ENCPWD_AUTH, (void *)token.dat, token.length)) { 365 return; 366 } 367 368 break; 369 370 default: 371 return; 372 } 373 } 374 375 int 376 rsaencpwd_status(ap, name, level) 377 Authenticator *ap; 378 char *name; 379 int level; 380 { 381 382 if (level < AUTH_USER) 383 return(level); 384 385 if (UserNameRequested && rsaencpwd_passwdok(UserNameRequested, UserPassword)) { 386 strcpy(name, UserNameRequested); 387 return(AUTH_VALID); 388 } else { 389 return(AUTH_USER); 390 } 391 } 392 393 #define BUMP(buf, len) while (*(buf)) {++(buf), --(len);} 394 #define ADDC(buf, len, c) if ((len) > 0) {*(buf)++ = (c); --(len);} 395 396 void 397 rsaencpwd_printsub(data, cnt, buf, buflen) 398 unsigned char *data, *buf; 399 int cnt, buflen; 400 { 401 char lbuf[32]; 402 register int i; 403 404 buf[buflen-1] = '\0'; /* make sure its NULL terminated */ 405 buflen -= 1; 406 407 switch(data[3]) { 408 case RSA_ENCPWD_REJECT: /* Rejected (reason might follow) */ 409 strncpy((char *)buf, " REJECT ", buflen); 410 goto common; 411 412 case RSA_ENCPWD_ACCEPT: /* Accepted (name might follow) */ 413 strncpy((char *)buf, " ACCEPT ", buflen); 414 common: 415 BUMP(buf, buflen); 416 if (cnt <= 4) 417 break; 418 ADDC(buf, buflen, '"'); 419 for (i = 4; i < cnt; i++) 420 ADDC(buf, buflen, data[i]); 421 ADDC(buf, buflen, '"'); 422 ADDC(buf, buflen, '\0'); 423 break; 424 425 case RSA_ENCPWD_AUTH: /* Authentication data follows */ 426 strncpy((char *)buf, " AUTH", buflen); 427 goto common2; 428 429 case RSA_ENCPWD_CHALLENGEKEY: 430 strncpy((char *)buf, " CHALLENGEKEY", buflen); 431 goto common2; 432 433 default: 434 sprintf(lbuf, " %d (unknown)", data[3]); 435 strncpy((char *)buf, lbuf, buflen); 436 common2: 437 BUMP(buf, buflen); 438 for (i = 4; i < cnt; i++) { 439 sprintf(lbuf, " %d", data[i]); 440 strncpy((char *)buf, lbuf, buflen); 441 BUMP(buf, buflen); 442 } 443 break; 444 } 445 } 446 447 int rsaencpwd_passwdok(name, passwd) 448 char *name, *passwd; 449 { 450 char *crypt(); 451 char *salt, *p; 452 struct passwd *pwd; 453 int passwdok_status = 0; 454 455 if (pwd = getpwnam(name)) 456 salt = pwd->pw_passwd; 457 else salt = "xx"; 458 459 p = crypt(passwd, salt); 460 461 if (pwd && !strcmp(p, pwd->pw_passwd)) { 462 passwdok_status = 1; 463 } else passwdok_status = 0; 464 return(passwdok_status); 465 } 466 467 #endif 468