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 * @(#)krb4encpwd.c 8.3 (Berkeley) 5/30/95 30 * $FreeBSD: src/crypto/telnet/libtelnet/krb4encpwd.c,v 1.3.2.1 2002/04/13 10:59:07 markm Exp $ 31 */ 32 33 #ifdef KRB4_ENCPWD 34 /* 35 * COPYRIGHT (C) 1990 DIGITAL EQUIPMENT CORPORATION 36 * ALL RIGHTS RESERVED 37 * 38 * "Digital Equipment Corporation authorizes the reproduction, 39 * distribution and modification of this software subject to the following 40 * restrictions: 41 * 42 * 1. Any partial or whole copy of this software, or any modification 43 * thereof, must include this copyright notice in its entirety. 44 * 45 * 2. This software is supplied "as is" with no warranty of any kind, 46 * expressed or implied, for any purpose, including any warranty of fitness 47 * or merchantability. DIGITAL assumes no responsibility for the use or 48 * reliability of this software, nor promises to provide any form of 49 * support for it on any basis. 50 * 51 * 3. Distribution of this software is authorized only if no profit or 52 * remuneration of any kind is received in exchange for such distribution. 53 * 54 * 4. This software produces public key authentication certificates 55 * bearing an expiration date established by DIGITAL and RSA Data 56 * Security, Inc. It may cease to generate certificates after the expiration 57 * date. Any modification of this software that changes or defeats 58 * the expiration date or its effect is unauthorized. 59 * 60 * 5. Software that will renew or extend the expiration date of 61 * authentication certificates produced by this software may be obtained 62 * from RSA Data Security, Inc., 10 Twin Dolphin Drive, Redwood City, CA 63 * 94065, (415)595-8782, or from DIGITAL" 64 * 65 */ 66 67 #include <sys/types.h> 68 #include <openssl/des.h> 69 #include <arpa/telnet.h> 70 #include <krb.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 80 int krb_mk_encpwd_req(KTEXT, char *, char *, char *, char *, char *, char *); 81 int krb_rd_encpwd_req(KTEXT, char *, char *, u_long, AUTH_DAT *, char *, char *, char *, char *); 82 83 extern auth_debug_mode; 84 85 static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0, 86 AUTHTYPE_KRB4_ENCPWD, }; 87 static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 88 TELQUAL_NAME, }; 89 90 #define KRB4_ENCPWD_AUTH 0 /* Authentication data follows */ 91 #define KRB4_ENCPWD_REJECT 1 /* Rejected (reason might follow) */ 92 #define KRB4_ENCPWD_ACCEPT 2 /* Accepted */ 93 #define KRB4_ENCPWD_CHALLENGE 3 /* Challenge for mutual auth. */ 94 #define KRB4_ENCPWD_ACK 4 /* Acknowledge */ 95 96 #define KRB_SERVICE_NAME "rcmd" 97 98 static KTEXT_ST auth; 99 static char name[ANAME_SZ]; 100 static char user_passwd[ANAME_SZ]; 101 static AUTH_DAT adat = { 0 }; 102 #ifdef ENCRYPTION 103 static Block session_key = { 0 }; 104 #endif /* ENCRYPTION */ 105 static char challenge[REALM_SZ]; 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 *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 krb4encpwd_init(ap, server) 144 Authenticator *ap; 145 int server; 146 { 147 char hostname[80], *cp, *realm; 148 C_Block skey; 149 150 if (server) { 151 str_data[3] = TELQUAL_REPLY; 152 } else { 153 str_data[3] = TELQUAL_IS; 154 gethostname(hostname, sizeof(hostname)); 155 realm = krb_realmofhost(hostname); 156 cp = strchr(hostname, '.'); 157 if (*cp != NULL) *cp = NULL; 158 if (read_service_key(KRB_SERVICE_NAME, hostname, realm, 0, 159 KEYFILE, (char *)skey)) { 160 return(0); 161 } 162 } 163 return(1); 164 } 165 166 int 167 krb4encpwd_send(ap) 168 Authenticator *ap; 169 { 170 171 printf("[ Trying KRB4ENCPWD ... ]\n"); 172 if (!UserNameRequested) { 173 return(0); 174 } 175 if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) { 176 return(0); 177 } 178 179 if (!Data(ap, KRB4_ENCPWD_ACK, NULL, 0)) { 180 return(0); 181 } 182 183 return(1); 184 } 185 186 void 187 krb4encpwd_is(ap, data, cnt) 188 Authenticator *ap; 189 unsigned char *data; 190 int cnt; 191 { 192 char r_passwd[ANAME_SZ], r_user[ANAME_SZ]; 193 char lhostname[ANAME_SZ], *cp; 194 int r; 195 time_t now; 196 197 if (cnt-- < 1) 198 return; 199 switch (*data++) { 200 case KRB4_ENCPWD_AUTH: 201 memmove((void *)auth.dat, (void *)data, auth.length = cnt); 202 203 gethostname(lhostname, sizeof(lhostname)); 204 if ((cp = strchr(lhostname, '.')) != NULL) *cp = '\0'; 205 206 if (r = krb_rd_encpwd_req(&auth, KRB_SERVICE_NAME, lhostname, 0, &adat, NULL, challenge, r_user, r_passwd)) { 207 Data(ap, KRB4_ENCPWD_REJECT, (void *)"Auth failed", -1); 208 auth_finished(ap, AUTH_REJECT); 209 return; 210 } 211 auth_encrypt_userpwd(r_passwd); 212 if (passwdok(UserNameRequested, UserPassword) == 0) { 213 /* 214 * illegal username and password 215 */ 216 Data(ap, KRB4_ENCPWD_REJECT, (void *)"Illegal password", -1); 217 auth_finished(ap, AUTH_REJECT); 218 return; 219 } 220 221 memmove((void *)session_key, (void *)adat.session, sizeof(Block)); 222 Data(ap, KRB4_ENCPWD_ACCEPT, (void *)0, 0); 223 auth_finished(ap, AUTH_USER); 224 break; 225 226 case KRB4_ENCPWD_CHALLENGE: 227 /* 228 * Take the received random challenge text and save 229 * for future authentication. 230 */ 231 memmove((void *)challenge, (void *)data, sizeof(Block)); 232 break; 233 234 235 case KRB4_ENCPWD_ACK: 236 /* 237 * Receive ack, if mutual then send random challenge 238 */ 239 240 /* 241 * If we are doing mutual authentication, get set up to send 242 * the challenge, and verify it when the response comes back. 243 */ 244 245 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) { 246 time(&now); 247 sprintf(challenge, "%x", now); 248 Data(ap, KRB4_ENCPWD_CHALLENGE, (void *)challenge, strlen(challenge)); 249 } 250 break; 251 252 default: 253 Data(ap, KRB4_ENCPWD_REJECT, 0, 0); 254 break; 255 } 256 } 257 258 259 void 260 krb4encpwd_reply(ap, data, cnt) 261 Authenticator *ap; 262 unsigned char *data; 263 int cnt; 264 { 265 KTEXT_ST krb_token; 266 int r; 267 char instance[ANAME_SZ], *cp; 268 char hostname[80], *realm; 269 270 if (cnt-- < 1) 271 return; 272 switch (*data++) { 273 case KRB4_ENCPWD_REJECT: 274 if (cnt > 0) { 275 printf("[ KRB4_ENCPWD refuses authentication because %.*s ]\r\n", 276 cnt, data); 277 } else 278 printf("[ KRB4_ENCPWD refuses authentication ]\r\n"); 279 auth_send_retry(); 280 return; 281 case KRB4_ENCPWD_ACCEPT: 282 printf("[ KRB4_ENCPWD accepts you ]\n"); 283 auth_finished(ap, AUTH_USER); 284 return; 285 case KRB4_ENCPWD_CHALLENGE: 286 /* 287 * Verify that the response to the challenge is correct. 288 */ 289 290 gethostname(hostname, sizeof(hostname)); 291 realm = krb_realmofhost(hostname); 292 memmove((void *)challenge, (void *)data, cnt); 293 memset(user_passwd, 0, sizeof(user_passwd)); 294 local_des_read_pw_string(user_passwd, sizeof(user_passwd)-1, "Password: ", 0); 295 UserPassword = user_passwd; 296 Challenge = challenge; 297 strcpy(instance, RemoteHostName); 298 if ((cp = strchr(instance, '.')) != NULL) *cp = '\0'; 299 300 if (r = krb_mk_encpwd_req(&krb_token, KRB_SERVICE_NAME, instance, realm, Challenge, UserNameRequested, user_passwd)) { 301 krb_token.length = 0; 302 } 303 304 if (!Data(ap, KRB4_ENCPWD_AUTH, (void *)krb_token.dat, krb_token.length)) { 305 return; 306 } 307 308 break; 309 310 default: 311 return; 312 } 313 } 314 315 int 316 krb4encpwd_status(ap, name, level) 317 Authenticator *ap; 318 char *name; 319 int level; 320 { 321 322 if (level < AUTH_USER) 323 return(level); 324 325 if (UserNameRequested && passwdok(UserNameRequested, UserPassword)) { 326 strcpy(name, UserNameRequested); 327 return(AUTH_VALID); 328 } else { 329 return(AUTH_USER); 330 } 331 } 332 333 #define BUMP(buf, len) while (*(buf)) {++(buf), --(len);} 334 #define ADDC(buf, len, c) if ((len) > 0) {*(buf)++ = (c); --(len);} 335 336 void 337 krb4encpwd_printsub(data, cnt, buf, buflen) 338 unsigned char *data, *buf; 339 int cnt, buflen; 340 { 341 char lbuf[32]; 342 register int i; 343 344 buf[buflen-1] = '\0'; /* make sure its NULL terminated */ 345 buflen -= 1; 346 347 switch(data[3]) { 348 case KRB4_ENCPWD_REJECT: /* Rejected (reason might follow) */ 349 strncpy((char *)buf, " REJECT ", buflen); 350 goto common; 351 352 case KRB4_ENCPWD_ACCEPT: /* Accepted (name might follow) */ 353 strncpy((char *)buf, " ACCEPT ", buflen); 354 common: 355 BUMP(buf, buflen); 356 if (cnt <= 4) 357 break; 358 ADDC(buf, buflen, '"'); 359 for (i = 4; i < cnt; i++) 360 ADDC(buf, buflen, data[i]); 361 ADDC(buf, buflen, '"'); 362 ADDC(buf, buflen, '\0'); 363 break; 364 365 case KRB4_ENCPWD_AUTH: /* Authentication data follows */ 366 strncpy((char *)buf, " AUTH", buflen); 367 goto common2; 368 369 case KRB4_ENCPWD_CHALLENGE: 370 strncpy((char *)buf, " CHALLENGE", buflen); 371 goto common2; 372 373 case KRB4_ENCPWD_ACK: 374 strncpy((char *)buf, " ACK", buflen); 375 goto common2; 376 377 default: 378 sprintf(lbuf, " %d (unknown)", data[3]); 379 strncpy((char *)buf, lbuf, buflen); 380 common2: 381 BUMP(buf, buflen); 382 for (i = 4; i < cnt; i++) { 383 sprintf(lbuf, " %d", data[i]); 384 strncpy((char *)buf, lbuf, buflen); 385 BUMP(buf, buflen); 386 } 387 break; 388 } 389 } 390 391 int passwdok(name, passwd) 392 char *name, *passwd; 393 { 394 char *crypt(); 395 char *salt, *p; 396 struct passwd *pwd; 397 int passwdok_status = 0; 398 399 if (pwd = getpwnam(name)) 400 salt = pwd->pw_passwd; 401 else salt = "xx"; 402 403 p = crypt(passwd, salt); 404 405 if (pwd && !strcmp(p, pwd->pw_passwd)) { 406 passwdok_status = 1; 407 } else passwdok_status = 0; 408 return(passwdok_status); 409 } 410 411 #endif 412