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[] = "@(#)krb4encpwd.c 8.3 (Berkeley) 5/30/95"; 36 #endif /* not lint */ 37 38 39 #ifdef KRB4_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 <openssl/des.h> 75 #include <arpa/telnet.h> 76 #include <krb.h> 77 #include <pwd.h> 78 #include <stdio.h> 79 #include <stdlib.h> 80 #include <string.h> 81 82 #include "encrypt.h" 83 #include "auth.h" 84 #include "misc.h" 85 86 int krb_mk_encpwd_req(KTEXT, char *, char *, char *, char *, char *, char *); 87 int krb_rd_encpwd_req(KTEXT, char *, char *, u_long, AUTH_DAT *, char *, char *, char *, char *); 88 89 extern auth_debug_mode; 90 91 static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0, 92 AUTHTYPE_KRB4_ENCPWD, }; 93 static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 94 TELQUAL_NAME, }; 95 96 #define KRB4_ENCPWD_AUTH 0 /* Authentication data follows */ 97 #define KRB4_ENCPWD_REJECT 1 /* Rejected (reason might follow) */ 98 #define KRB4_ENCPWD_ACCEPT 2 /* Accepted */ 99 #define KRB4_ENCPWD_CHALLENGE 3 /* Challenge for mutual auth. */ 100 #define KRB4_ENCPWD_ACK 4 /* Acknowledge */ 101 102 #define KRB_SERVICE_NAME "rcmd" 103 104 static KTEXT_ST auth; 105 static char name[ANAME_SZ]; 106 static char user_passwd[ANAME_SZ]; 107 static AUTH_DAT adat = { 0 }; 108 #ifdef ENCRYPTION 109 static Block session_key = { 0 }; 110 #endif /* ENCRYPTION */ 111 static char challenge[REALM_SZ]; 112 113 static int 114 Data(ap, type, d, c) 115 Authenticator *ap; 116 int type; 117 void *d; 118 int c; 119 { 120 unsigned char *p = str_data + 4; 121 unsigned char *cd = (unsigned char *)d; 122 123 if (c == -1) 124 c = strlen((char *)cd); 125 126 if (0) { 127 printf("%s:%d: [%d] (%d)", 128 str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY", 129 str_data[3], 130 type, c); 131 printd(d, c); 132 printf("\r\n"); 133 } 134 *p++ = ap->type; 135 *p++ = ap->way; 136 *p++ = type; 137 while (c-- > 0) { 138 if ((*p++ = *cd++) == IAC) 139 *p++ = IAC; 140 } 141 *p++ = IAC; 142 *p++ = SE; 143 if (str_data[3] == TELQUAL_IS) 144 printsub('>', &str_data[2], p - (&str_data[2])); 145 return(net_write(str_data, p - str_data)); 146 } 147 148 int 149 krb4encpwd_init(ap, server) 150 Authenticator *ap; 151 int server; 152 { 153 char hostname[80], *cp, *realm; 154 C_Block skey; 155 156 if (server) { 157 str_data[3] = TELQUAL_REPLY; 158 } else { 159 str_data[3] = TELQUAL_IS; 160 gethostname(hostname, sizeof(hostname)); 161 realm = krb_realmofhost(hostname); 162 cp = strchr(hostname, '.'); 163 if (*cp != NULL) *cp = NULL; 164 if (read_service_key(KRB_SERVICE_NAME, hostname, realm, 0, 165 KEYFILE, (char *)skey)) { 166 return(0); 167 } 168 } 169 return(1); 170 } 171 172 int 173 krb4encpwd_send(ap) 174 Authenticator *ap; 175 { 176 177 printf("[ Trying KRB4ENCPWD ... ]\n"); 178 if (!UserNameRequested) { 179 return(0); 180 } 181 if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) { 182 return(0); 183 } 184 185 if (!Data(ap, KRB4_ENCPWD_ACK, (void *)NULL, 0)) { 186 return(0); 187 } 188 189 return(1); 190 } 191 192 void 193 krb4encpwd_is(ap, data, cnt) 194 Authenticator *ap; 195 unsigned char *data; 196 int cnt; 197 { 198 Session_Key skey; 199 Block datablock; 200 char r_passwd[ANAME_SZ], r_user[ANAME_SZ]; 201 char lhostname[ANAME_SZ], *cp; 202 int r; 203 time_t now; 204 205 if (cnt-- < 1) 206 return; 207 switch (*data++) { 208 case KRB4_ENCPWD_AUTH: 209 memmove((void *)auth.dat, (void *)data, auth.length = cnt); 210 211 gethostname(lhostname, sizeof(lhostname)); 212 if ((cp = strchr(lhostname, '.')) != 0) *cp = '\0'; 213 214 if (r = krb_rd_encpwd_req(&auth, KRB_SERVICE_NAME, lhostname, 0, &adat, NULL, challenge, r_user, r_passwd)) { 215 Data(ap, KRB4_ENCPWD_REJECT, (void *)"Auth failed", -1); 216 auth_finished(ap, AUTH_REJECT); 217 return; 218 } 219 auth_encrypt_userpwd(r_passwd); 220 if (passwdok(UserNameRequested, UserPassword) == 0) { 221 /* 222 * illegal username and password 223 */ 224 Data(ap, KRB4_ENCPWD_REJECT, (void *)"Illegal password", -1); 225 auth_finished(ap, AUTH_REJECT); 226 return; 227 } 228 229 memmove((void *)session_key, (void *)adat.session, sizeof(Block)); 230 Data(ap, KRB4_ENCPWD_ACCEPT, (void *)0, 0); 231 auth_finished(ap, AUTH_USER); 232 break; 233 234 case KRB4_ENCPWD_CHALLENGE: 235 /* 236 * Take the received random challenge text and save 237 * for future authentication. 238 */ 239 memmove((void *)challenge, (void *)data, sizeof(Block)); 240 break; 241 242 243 case KRB4_ENCPWD_ACK: 244 /* 245 * Receive ack, if mutual then send random challenge 246 */ 247 248 /* 249 * If we are doing mutual authentication, get set up to send 250 * the challenge, and verify it when the response comes back. 251 */ 252 253 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) { 254 register int i; 255 256 time(&now); 257 sprintf(challenge, "%x", now); 258 Data(ap, KRB4_ENCPWD_CHALLENGE, (void *)challenge, strlen(challenge)); 259 } 260 break; 261 262 default: 263 Data(ap, KRB4_ENCPWD_REJECT, 0, 0); 264 break; 265 } 266 } 267 268 269 void 270 krb4encpwd_reply(ap, data, cnt) 271 Authenticator *ap; 272 unsigned char *data; 273 int cnt; 274 { 275 Session_Key skey; 276 KTEXT_ST krb_token; 277 Block enckey; 278 CREDENTIALS cred; 279 int r; 280 char randchal[REALM_SZ], instance[ANAME_SZ], *cp; 281 char hostname[80], *realm; 282 283 if (cnt-- < 1) 284 return; 285 switch (*data++) { 286 case KRB4_ENCPWD_REJECT: 287 if (cnt > 0) { 288 printf("[ KRB4_ENCPWD refuses authentication because %.*s ]\r\n", 289 cnt, data); 290 } else 291 printf("[ KRB4_ENCPWD refuses authentication ]\r\n"); 292 auth_send_retry(); 293 return; 294 case KRB4_ENCPWD_ACCEPT: 295 printf("[ KRB4_ENCPWD accepts you ]\n"); 296 auth_finished(ap, AUTH_USER); 297 return; 298 case KRB4_ENCPWD_CHALLENGE: 299 /* 300 * Verify that the response to the challenge is correct. 301 */ 302 303 gethostname(hostname, sizeof(hostname)); 304 realm = krb_realmofhost(hostname); 305 memmove((void *)challenge, (void *)data, cnt); 306 memset(user_passwd, 0, sizeof(user_passwd)); 307 local_des_read_pw_string(user_passwd, sizeof(user_passwd)-1, "Password: ", 0); 308 UserPassword = user_passwd; 309 Challenge = challenge; 310 strcpy(instance, RemoteHostName); 311 if ((cp = strchr(instance, '.')) != 0) *cp = '\0'; 312 313 if (r = krb_mk_encpwd_req(&krb_token, KRB_SERVICE_NAME, instance, realm, Challenge, UserNameRequested, user_passwd)) { 314 krb_token.length = 0; 315 } 316 317 if (!Data(ap, KRB4_ENCPWD_AUTH, (void *)krb_token.dat, krb_token.length)) { 318 return; 319 } 320 321 break; 322 323 default: 324 return; 325 } 326 } 327 328 int 329 krb4encpwd_status(ap, name, level) 330 Authenticator *ap; 331 char *name; 332 int level; 333 { 334 335 if (level < AUTH_USER) 336 return(level); 337 338 if (UserNameRequested && passwdok(UserNameRequested, UserPassword)) { 339 strcpy(name, UserNameRequested); 340 return(AUTH_VALID); 341 } else { 342 return(AUTH_USER); 343 } 344 } 345 346 #define BUMP(buf, len) while (*(buf)) {++(buf), --(len);} 347 #define ADDC(buf, len, c) if ((len) > 0) {*(buf)++ = (c); --(len);} 348 349 void 350 krb4encpwd_printsub(data, cnt, buf, buflen) 351 unsigned char *data, *buf; 352 int cnt, buflen; 353 { 354 char lbuf[32]; 355 register int i; 356 357 buf[buflen-1] = '\0'; /* make sure its NULL terminated */ 358 buflen -= 1; 359 360 switch(data[3]) { 361 case KRB4_ENCPWD_REJECT: /* Rejected (reason might follow) */ 362 strncpy((char *)buf, " REJECT ", buflen); 363 goto common; 364 365 case KRB4_ENCPWD_ACCEPT: /* Accepted (name might follow) */ 366 strncpy((char *)buf, " ACCEPT ", buflen); 367 common: 368 BUMP(buf, buflen); 369 if (cnt <= 4) 370 break; 371 ADDC(buf, buflen, '"'); 372 for (i = 4; i < cnt; i++) 373 ADDC(buf, buflen, data[i]); 374 ADDC(buf, buflen, '"'); 375 ADDC(buf, buflen, '\0'); 376 break; 377 378 case KRB4_ENCPWD_AUTH: /* Authentication data follows */ 379 strncpy((char *)buf, " AUTH", buflen); 380 goto common2; 381 382 case KRB4_ENCPWD_CHALLENGE: 383 strncpy((char *)buf, " CHALLENGE", buflen); 384 goto common2; 385 386 case KRB4_ENCPWD_ACK: 387 strncpy((char *)buf, " ACK", buflen); 388 goto common2; 389 390 default: 391 sprintf(lbuf, " %d (unknown)", data[3]); 392 strncpy((char *)buf, lbuf, buflen); 393 common2: 394 BUMP(buf, buflen); 395 for (i = 4; i < cnt; i++) { 396 sprintf(lbuf, " %d", data[i]); 397 strncpy((char *)buf, lbuf, buflen); 398 BUMP(buf, buflen); 399 } 400 break; 401 } 402 } 403 404 int passwdok(name, passwd) 405 char *name, *passwd; 406 { 407 char *crypt(); 408 char *salt, *p; 409 struct passwd *pwd; 410 int passwdok_status = 0; 411 412 if (pwd = getpwnam(name)) 413 salt = pwd->pw_passwd; 414 else salt = "xx"; 415 416 p = crypt(passwd, salt); 417 418 if (pwd && !strcmp(p, pwd->pw_passwd)) { 419 passwdok_status = 1; 420 } else passwdok_status = 0; 421 return(passwdok_status); 422 } 423 424 #endif 425