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[] = "@(#)krb4encpwd.c 8.3 (Berkeley) 5/30/95"; 32 #endif /* not lint */ 33 34 35 #ifdef KRB4_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 <openssl/des.h> 71 #include <arpa/telnet.h> 72 #include <krb.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 82 int krb_mk_encpwd_req(KTEXT, char *, char *, char *, char *, char *, char *); 83 int krb_rd_encpwd_req(KTEXT, char *, char *, u_long, AUTH_DAT *, char *, char *, char *, char *); 84 85 extern auth_debug_mode; 86 87 static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0, 88 AUTHTYPE_KRB4_ENCPWD, }; 89 static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 90 TELQUAL_NAME, }; 91 92 #define KRB4_ENCPWD_AUTH 0 /* Authentication data follows */ 93 #define KRB4_ENCPWD_REJECT 1 /* Rejected (reason might follow) */ 94 #define KRB4_ENCPWD_ACCEPT 2 /* Accepted */ 95 #define KRB4_ENCPWD_CHALLENGE 3 /* Challenge for mutual auth. */ 96 #define KRB4_ENCPWD_ACK 4 /* Acknowledge */ 97 98 #define KRB_SERVICE_NAME "rcmd" 99 100 static KTEXT_ST auth; 101 static char name[ANAME_SZ]; 102 static char user_passwd[ANAME_SZ]; 103 static AUTH_DAT adat = { 0 }; 104 #ifdef ENCRYPTION 105 static Block session_key = { 0 }; 106 #endif /* ENCRYPTION */ 107 static char challenge[REALM_SZ]; 108 109 static int 110 Data(ap, type, d, c) 111 Authenticator *ap; 112 int type; 113 void *d; 114 int c; 115 { 116 unsigned char *p = str_data + 4; 117 unsigned char *cd = (unsigned char *)d; 118 119 if (c == -1) 120 c = strlen((char *)cd); 121 122 if (0) { 123 printf("%s:%d: [%d] (%d)", 124 str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY", 125 str_data[3], 126 type, c); 127 printd(d, c); 128 printf("\r\n"); 129 } 130 *p++ = ap->type; 131 *p++ = ap->way; 132 *p++ = type; 133 while (c-- > 0) { 134 if ((*p++ = *cd++) == IAC) 135 *p++ = IAC; 136 } 137 *p++ = IAC; 138 *p++ = SE; 139 if (str_data[3] == TELQUAL_IS) 140 printsub('>', &str_data[2], p - (&str_data[2])); 141 return(net_write(str_data, p - str_data)); 142 } 143 144 int 145 krb4encpwd_init(ap, server) 146 Authenticator *ap; 147 int server; 148 { 149 char hostname[80], *cp, *realm; 150 C_Block skey; 151 152 if (server) { 153 str_data[3] = TELQUAL_REPLY; 154 } else { 155 str_data[3] = TELQUAL_IS; 156 gethostname(hostname, sizeof(hostname)); 157 realm = krb_realmofhost(hostname); 158 cp = strchr(hostname, '.'); 159 if (*cp != NULL) *cp = NULL; 160 if (read_service_key(KRB_SERVICE_NAME, hostname, realm, 0, 161 KEYFILE, (char *)skey)) { 162 return(0); 163 } 164 } 165 return(1); 166 } 167 168 int 169 krb4encpwd_send(ap) 170 Authenticator *ap; 171 { 172 173 printf("[ Trying KRB4ENCPWD ... ]\n"); 174 if (!UserNameRequested) { 175 return(0); 176 } 177 if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) { 178 return(0); 179 } 180 181 if (!Data(ap, KRB4_ENCPWD_ACK, (void *)NULL, 0)) { 182 return(0); 183 } 184 185 return(1); 186 } 187 188 void 189 krb4encpwd_is(ap, data, cnt) 190 Authenticator *ap; 191 unsigned char *data; 192 int cnt; 193 { 194 Session_Key skey; 195 Block datablock; 196 char r_passwd[ANAME_SZ], r_user[ANAME_SZ]; 197 char lhostname[ANAME_SZ], *cp; 198 int r; 199 time_t now; 200 201 if (cnt-- < 1) 202 return; 203 switch (*data++) { 204 case KRB4_ENCPWD_AUTH: 205 memmove((void *)auth.dat, (void *)data, auth.length = cnt); 206 207 gethostname(lhostname, sizeof(lhostname)); 208 if ((cp = strchr(lhostname, '.')) != 0) *cp = '\0'; 209 210 if (r = krb_rd_encpwd_req(&auth, KRB_SERVICE_NAME, lhostname, 0, &adat, NULL, challenge, r_user, r_passwd)) { 211 Data(ap, KRB4_ENCPWD_REJECT, (void *)"Auth failed", -1); 212 auth_finished(ap, AUTH_REJECT); 213 return; 214 } 215 auth_encrypt_userpwd(r_passwd); 216 if (passwdok(UserNameRequested, UserPassword) == 0) { 217 /* 218 * illegal username and password 219 */ 220 Data(ap, KRB4_ENCPWD_REJECT, (void *)"Illegal password", -1); 221 auth_finished(ap, AUTH_REJECT); 222 return; 223 } 224 225 memmove((void *)session_key, (void *)adat.session, sizeof(Block)); 226 Data(ap, KRB4_ENCPWD_ACCEPT, (void *)0, 0); 227 auth_finished(ap, AUTH_USER); 228 break; 229 230 case KRB4_ENCPWD_CHALLENGE: 231 /* 232 * Take the received random challenge text and save 233 * for future authentication. 234 */ 235 memmove((void *)challenge, (void *)data, sizeof(Block)); 236 break; 237 238 239 case KRB4_ENCPWD_ACK: 240 /* 241 * Receive ack, if mutual then send random challenge 242 */ 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 */ 248 249 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) { 250 register int i; 251 252 time(&now); 253 sprintf(challenge, "%x", now); 254 Data(ap, KRB4_ENCPWD_CHALLENGE, (void *)challenge, strlen(challenge)); 255 } 256 break; 257 258 default: 259 Data(ap, KRB4_ENCPWD_REJECT, 0, 0); 260 break; 261 } 262 } 263 264 265 void 266 krb4encpwd_reply(ap, data, cnt) 267 Authenticator *ap; 268 unsigned char *data; 269 int cnt; 270 { 271 Session_Key skey; 272 KTEXT_ST krb_token; 273 Block enckey; 274 CREDENTIALS cred; 275 int r; 276 char randchal[REALM_SZ], instance[ANAME_SZ], *cp; 277 char hostname[80], *realm; 278 279 if (cnt-- < 1) 280 return; 281 switch (*data++) { 282 case KRB4_ENCPWD_REJECT: 283 if (cnt > 0) { 284 printf("[ KRB4_ENCPWD refuses authentication because %.*s ]\r\n", 285 cnt, data); 286 } else 287 printf("[ KRB4_ENCPWD refuses authentication ]\r\n"); 288 auth_send_retry(); 289 return; 290 case KRB4_ENCPWD_ACCEPT: 291 printf("[ KRB4_ENCPWD accepts you ]\n"); 292 auth_finished(ap, AUTH_USER); 293 return; 294 case KRB4_ENCPWD_CHALLENGE: 295 /* 296 * Verify that the response to the challenge is correct. 297 */ 298 299 gethostname(hostname, sizeof(hostname)); 300 realm = krb_realmofhost(hostname); 301 memmove((void *)challenge, (void *)data, cnt); 302 memset(user_passwd, 0, sizeof(user_passwd)); 303 local_des_read_pw_string(user_passwd, sizeof(user_passwd)-1, "Password: ", 0); 304 UserPassword = user_passwd; 305 Challenge = challenge; 306 strcpy(instance, RemoteHostName); 307 if ((cp = strchr(instance, '.')) != 0) *cp = '\0'; 308 309 if (r = krb_mk_encpwd_req(&krb_token, KRB_SERVICE_NAME, instance, realm, Challenge, UserNameRequested, user_passwd)) { 310 krb_token.length = 0; 311 } 312 313 if (!Data(ap, KRB4_ENCPWD_AUTH, (void *)krb_token.dat, krb_token.length)) { 314 return; 315 } 316 317 break; 318 319 default: 320 return; 321 } 322 } 323 324 int 325 krb4encpwd_status(ap, name, level) 326 Authenticator *ap; 327 char *name; 328 int level; 329 { 330 331 if (level < AUTH_USER) 332 return(level); 333 334 if (UserNameRequested && passwdok(UserNameRequested, UserPassword)) { 335 strcpy(name, UserNameRequested); 336 return(AUTH_VALID); 337 } else { 338 return(AUTH_USER); 339 } 340 } 341 342 #define BUMP(buf, len) while (*(buf)) {++(buf), --(len);} 343 #define ADDC(buf, len, c) if ((len) > 0) {*(buf)++ = (c); --(len);} 344 345 void 346 krb4encpwd_printsub(data, cnt, buf, buflen) 347 unsigned char *data, *buf; 348 int cnt, buflen; 349 { 350 char lbuf[32]; 351 register int i; 352 353 buf[buflen-1] = '\0'; /* make sure its NULL terminated */ 354 buflen -= 1; 355 356 switch(data[3]) { 357 case KRB4_ENCPWD_REJECT: /* Rejected (reason might follow) */ 358 strncpy((char *)buf, " REJECT ", buflen); 359 goto common; 360 361 case KRB4_ENCPWD_ACCEPT: /* Accepted (name might follow) */ 362 strncpy((char *)buf, " ACCEPT ", buflen); 363 common: 364 BUMP(buf, buflen); 365 if (cnt <= 4) 366 break; 367 ADDC(buf, buflen, '"'); 368 for (i = 4; i < cnt; i++) 369 ADDC(buf, buflen, data[i]); 370 ADDC(buf, buflen, '"'); 371 ADDC(buf, buflen, '\0'); 372 break; 373 374 case KRB4_ENCPWD_AUTH: /* Authentication data follows */ 375 strncpy((char *)buf, " AUTH", buflen); 376 goto common2; 377 378 case KRB4_ENCPWD_CHALLENGE: 379 strncpy((char *)buf, " CHALLENGE", buflen); 380 goto common2; 381 382 case KRB4_ENCPWD_ACK: 383 strncpy((char *)buf, " ACK", buflen); 384 goto common2; 385 386 default: 387 sprintf(lbuf, " %d (unknown)", data[3]); 388 strncpy((char *)buf, lbuf, buflen); 389 common2: 390 BUMP(buf, buflen); 391 for (i = 4; i < cnt; i++) { 392 sprintf(lbuf, " %d", data[i]); 393 strncpy((char *)buf, lbuf, buflen); 394 BUMP(buf, buflen); 395 } 396 break; 397 } 398 } 399 400 int passwdok(name, passwd) 401 char *name, *passwd; 402 { 403 char *crypt(); 404 char *salt, *p; 405 struct passwd *pwd; 406 int passwdok_status = 0; 407 408 if (pwd = getpwnam(name)) 409 salt = pwd->pw_passwd; 410 else salt = "xx"; 411 412 p = crypt(passwd, salt); 413 414 if (pwd && !strcmp(p, pwd->pw_passwd)) { 415 passwdok_status = 1; 416 } else passwdok_status = 0; 417 return(passwdok_status); 418 } 419 420 #endif 421