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 * @(#)krb4encpwd.c 8.3 (Berkeley) 5/30/95 34 * $FreeBSD: src/crypto/telnet/libtelnet/krb4encpwd.c,v 1.3.2.1 2002/04/13 10:59:07 markm Exp $ 35 */ 36 37 #ifdef KRB4_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 <openssl/des.h> 73 #include <arpa/telnet.h> 74 #include <krb.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 84 int krb_mk_encpwd_req(KTEXT, char *, char *, char *, char *, char *, char *); 85 int krb_rd_encpwd_req(KTEXT, char *, char *, u_long, AUTH_DAT *, char *, char *, char *, char *); 86 87 extern auth_debug_mode; 88 89 static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0, 90 AUTHTYPE_KRB4_ENCPWD, }; 91 static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 92 TELQUAL_NAME, }; 93 94 #define KRB4_ENCPWD_AUTH 0 /* Authentication data follows */ 95 #define KRB4_ENCPWD_REJECT 1 /* Rejected (reason might follow) */ 96 #define KRB4_ENCPWD_ACCEPT 2 /* Accepted */ 97 #define KRB4_ENCPWD_CHALLENGE 3 /* Challenge for mutual auth. */ 98 #define KRB4_ENCPWD_ACK 4 /* Acknowledge */ 99 100 #define KRB_SERVICE_NAME "rcmd" 101 102 static KTEXT_ST auth; 103 static char name[ANAME_SZ]; 104 static char user_passwd[ANAME_SZ]; 105 static AUTH_DAT adat = { 0 }; 106 #ifdef ENCRYPTION 107 static Block session_key = { 0 }; 108 #endif /* ENCRYPTION */ 109 static char challenge[REALM_SZ]; 110 111 static int 112 Data(ap, type, d, c) 113 Authenticator *ap; 114 int type; 115 void *d; 116 int c; 117 { 118 unsigned char *p = str_data + 4; 119 unsigned char *cd = (unsigned char *)d; 120 121 if (c == -1) 122 c = strlen((char *)cd); 123 124 if (0) { 125 printf("%s:%d: [%d] (%d)", 126 str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY", 127 str_data[3], 128 type, c); 129 printd(d, c); 130 printf("\r\n"); 131 } 132 *p++ = ap->type; 133 *p++ = ap->way; 134 *p++ = type; 135 while (c-- > 0) { 136 if ((*p++ = *cd++) == IAC) 137 *p++ = IAC; 138 } 139 *p++ = IAC; 140 *p++ = SE; 141 if (str_data[3] == TELQUAL_IS) 142 printsub('>', &str_data[2], p - (&str_data[2])); 143 return(net_write(str_data, p - str_data)); 144 } 145 146 int 147 krb4encpwd_init(ap, server) 148 Authenticator *ap; 149 int server; 150 { 151 char hostname[80], *cp, *realm; 152 C_Block skey; 153 154 if (server) { 155 str_data[3] = TELQUAL_REPLY; 156 } else { 157 str_data[3] = TELQUAL_IS; 158 gethostname(hostname, sizeof(hostname)); 159 realm = krb_realmofhost(hostname); 160 cp = strchr(hostname, '.'); 161 if (*cp != NULL) *cp = NULL; 162 if (read_service_key(KRB_SERVICE_NAME, hostname, realm, 0, 163 KEYFILE, (char *)skey)) { 164 return(0); 165 } 166 } 167 return(1); 168 } 169 170 int 171 krb4encpwd_send(ap) 172 Authenticator *ap; 173 { 174 175 printf("[ Trying KRB4ENCPWD ... ]\n"); 176 if (!UserNameRequested) { 177 return(0); 178 } 179 if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) { 180 return(0); 181 } 182 183 if (!Data(ap, KRB4_ENCPWD_ACK, NULL, 0)) { 184 return(0); 185 } 186 187 return(1); 188 } 189 190 void 191 krb4encpwd_is(ap, data, cnt) 192 Authenticator *ap; 193 unsigned char *data; 194 int cnt; 195 { 196 Session_Key skey; 197 Block datablock; 198 char r_passwd[ANAME_SZ], r_user[ANAME_SZ]; 199 char lhostname[ANAME_SZ], *cp; 200 int r; 201 time_t now; 202 203 if (cnt-- < 1) 204 return; 205 switch (*data++) { 206 case KRB4_ENCPWD_AUTH: 207 memmove((void *)auth.dat, (void *)data, auth.length = cnt); 208 209 gethostname(lhostname, sizeof(lhostname)); 210 if ((cp = strchr(lhostname, '.')) != NULL) *cp = '\0'; 211 212 if (r = krb_rd_encpwd_req(&auth, KRB_SERVICE_NAME, lhostname, 0, &adat, NULL, challenge, r_user, r_passwd)) { 213 Data(ap, KRB4_ENCPWD_REJECT, (void *)"Auth failed", -1); 214 auth_finished(ap, AUTH_REJECT); 215 return; 216 } 217 auth_encrypt_userpwd(r_passwd); 218 if (passwdok(UserNameRequested, UserPassword) == 0) { 219 /* 220 * illegal username and password 221 */ 222 Data(ap, KRB4_ENCPWD_REJECT, (void *)"Illegal password", -1); 223 auth_finished(ap, AUTH_REJECT); 224 return; 225 } 226 227 memmove((void *)session_key, (void *)adat.session, sizeof(Block)); 228 Data(ap, KRB4_ENCPWD_ACCEPT, (void *)0, 0); 229 auth_finished(ap, AUTH_USER); 230 break; 231 232 case KRB4_ENCPWD_CHALLENGE: 233 /* 234 * Take the received random challenge text and save 235 * for future authentication. 236 */ 237 memmove((void *)challenge, (void *)data, sizeof(Block)); 238 break; 239 240 241 case KRB4_ENCPWD_ACK: 242 /* 243 * Receive ack, if mutual then send random challenge 244 */ 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 */ 250 251 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) { 252 register int i; 253 254 time(&now); 255 sprintf(challenge, "%x", now); 256 Data(ap, KRB4_ENCPWD_CHALLENGE, (void *)challenge, strlen(challenge)); 257 } 258 break; 259 260 default: 261 Data(ap, KRB4_ENCPWD_REJECT, 0, 0); 262 break; 263 } 264 } 265 266 267 void 268 krb4encpwd_reply(ap, data, cnt) 269 Authenticator *ap; 270 unsigned char *data; 271 int cnt; 272 { 273 Session_Key skey; 274 KTEXT_ST krb_token; 275 Block enckey; 276 CREDENTIALS cred; 277 int r; 278 char randchal[REALM_SZ], instance[ANAME_SZ], *cp; 279 char hostname[80], *realm; 280 281 if (cnt-- < 1) 282 return; 283 switch (*data++) { 284 case KRB4_ENCPWD_REJECT: 285 if (cnt > 0) { 286 printf("[ KRB4_ENCPWD refuses authentication because %.*s ]\r\n", 287 cnt, data); 288 } else 289 printf("[ KRB4_ENCPWD refuses authentication ]\r\n"); 290 auth_send_retry(); 291 return; 292 case KRB4_ENCPWD_ACCEPT: 293 printf("[ KRB4_ENCPWD accepts you ]\n"); 294 auth_finished(ap, AUTH_USER); 295 return; 296 case KRB4_ENCPWD_CHALLENGE: 297 /* 298 * Verify that the response to the challenge is correct. 299 */ 300 301 gethostname(hostname, sizeof(hostname)); 302 realm = krb_realmofhost(hostname); 303 memmove((void *)challenge, (void *)data, cnt); 304 memset(user_passwd, 0, sizeof(user_passwd)); 305 local_des_read_pw_string(user_passwd, sizeof(user_passwd)-1, "Password: ", 0); 306 UserPassword = user_passwd; 307 Challenge = challenge; 308 strcpy(instance, RemoteHostName); 309 if ((cp = strchr(instance, '.')) != NULL) *cp = '\0'; 310 311 if (r = krb_mk_encpwd_req(&krb_token, KRB_SERVICE_NAME, instance, realm, Challenge, UserNameRequested, user_passwd)) { 312 krb_token.length = 0; 313 } 314 315 if (!Data(ap, KRB4_ENCPWD_AUTH, (void *)krb_token.dat, krb_token.length)) { 316 return; 317 } 318 319 break; 320 321 default: 322 return; 323 } 324 } 325 326 int 327 krb4encpwd_status(ap, name, level) 328 Authenticator *ap; 329 char *name; 330 int level; 331 { 332 333 if (level < AUTH_USER) 334 return(level); 335 336 if (UserNameRequested && passwdok(UserNameRequested, UserPassword)) { 337 strcpy(name, UserNameRequested); 338 return(AUTH_VALID); 339 } else { 340 return(AUTH_USER); 341 } 342 } 343 344 #define BUMP(buf, len) while (*(buf)) {++(buf), --(len);} 345 #define ADDC(buf, len, c) if ((len) > 0) {*(buf)++ = (c); --(len);} 346 347 void 348 krb4encpwd_printsub(data, cnt, buf, buflen) 349 unsigned char *data, *buf; 350 int cnt, buflen; 351 { 352 char lbuf[32]; 353 register int i; 354 355 buf[buflen-1] = '\0'; /* make sure its NULL terminated */ 356 buflen -= 1; 357 358 switch(data[3]) { 359 case KRB4_ENCPWD_REJECT: /* Rejected (reason might follow) */ 360 strncpy((char *)buf, " REJECT ", buflen); 361 goto common; 362 363 case KRB4_ENCPWD_ACCEPT: /* Accepted (name might follow) */ 364 strncpy((char *)buf, " ACCEPT ", buflen); 365 common: 366 BUMP(buf, buflen); 367 if (cnt <= 4) 368 break; 369 ADDC(buf, buflen, '"'); 370 for (i = 4; i < cnt; i++) 371 ADDC(buf, buflen, data[i]); 372 ADDC(buf, buflen, '"'); 373 ADDC(buf, buflen, '\0'); 374 break; 375 376 case KRB4_ENCPWD_AUTH: /* Authentication data follows */ 377 strncpy((char *)buf, " AUTH", buflen); 378 goto common2; 379 380 case KRB4_ENCPWD_CHALLENGE: 381 strncpy((char *)buf, " CHALLENGE", buflen); 382 goto common2; 383 384 case KRB4_ENCPWD_ACK: 385 strncpy((char *)buf, " ACK", buflen); 386 goto common2; 387 388 default: 389 sprintf(lbuf, " %d (unknown)", data[3]); 390 strncpy((char *)buf, lbuf, buflen); 391 common2: 392 BUMP(buf, buflen); 393 for (i = 4; i < cnt; i++) { 394 sprintf(lbuf, " %d", data[i]); 395 strncpy((char *)buf, lbuf, buflen); 396 BUMP(buf, buflen); 397 } 398 break; 399 } 400 } 401 402 int passwdok(name, passwd) 403 char *name, *passwd; 404 { 405 char *crypt(); 406 char *salt, *p; 407 struct passwd *pwd; 408 int passwdok_status = 0; 409 410 if (pwd = getpwnam(name)) 411 salt = pwd->pw_passwd; 412 else salt = "xx"; 413 414 p = crypt(passwd, salt); 415 416 if (pwd && !strcmp(p, pwd->pw_passwd)) { 417 passwdok_status = 1; 418 } else passwdok_status = 0; 419 return(passwdok_status); 420 } 421 422 #endif 423