1 /*- 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #ifndef lint 9 static char sccsid[] = "@(#)krb4encpwd.c 8.2 (Berkeley) 02/16/95"; 10 #endif /* not lint */ 11 12 13 #ifdef KRB4_ENCPWD 14 /* 15 * COPYRIGHT (C) 1990 DIGITAL EQUIPMENT CORPORATION 16 * ALL RIGHTS RESERVED 17 * 18 * "Digital Equipment Corporation authorizes the reproduction, 19 * distribution and modification of this software subject to the following 20 * restrictions: 21 * 22 * 1. Any partial or whole copy of this software, or any modification 23 * thereof, must include this copyright notice in its entirety. 24 * 25 * 2. This software is supplied "as is" with no warranty of any kind, 26 * expressed or implied, for any purpose, including any warranty of fitness 27 * or merchantibility. DIGITAL assumes no responsibility for the use or 28 * reliability of this software, nor promises to provide any form of 29 * support for it on any basis. 30 * 31 * 3. Distribution of this software is authorized only if no profit or 32 * remuneration of any kind is received in exchange for such distribution. 33 * 34 * 4. This software produces public key authentication certificates 35 * bearing an expiration date established by DIGITAL and RSA Data 36 * Security, Inc. It may cease to generate certificates after the expiration 37 * date. Any modification of this software that changes or defeats 38 * the expiration date or its effect is unauthorized. 39 * 40 * 5. Software that will renew or extend the expiration date of 41 * authentication certificates produced by this software may be obtained 42 * from RSA Data Security, Inc., 10 Twin Dolphin Drive, Redwood City, CA 43 * 94065, (415)595-8782, or from DIGITAL" 44 * 45 */ 46 47 #include <sys/types.h> 48 #include <arpa/telnet.h> 49 #include <pwd.h> 50 #include <stdio.h> 51 52 #include <des.h> 53 #include <krb.h> 54 #ifdef __STDC__ 55 #include <stdlib.h> 56 #endif 57 #ifdef NO_STRING_H 58 #include <strings.h> 59 #else 60 #include <string.h> 61 #endif 62 63 #include "encrypt.h" 64 #include "auth.h" 65 #include "misc.h" 66 67 int krb_mk_encpwd_req P((KTEXT, char *, char *, char *, char *, char *, char *)); 68 int krb_rd_encpwd_req P((KTEXT, char *, char *, u_long, AUTH_DAT *, char *, char *, char *, char *)); 69 70 extern auth_debug_mode; 71 72 static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0, 73 AUTHTYPE_KRB4_ENCPWD, }; 74 static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 75 TELQUAL_NAME, }; 76 77 #define KRB4_ENCPWD_AUTH 0 /* Authentication data follows */ 78 #define KRB4_ENCPWD_REJECT 1 /* Rejected (reason might follow) */ 79 #define KRB4_ENCPWD_ACCEPT 2 /* Accepted */ 80 #define KRB4_ENCPWD_CHALLENGE 3 /* Challenge for mutual auth. */ 81 #define KRB4_ENCPWD_ACK 4 /* Acknowledge */ 82 83 #define KRB_SERVICE_NAME "rcmd" 84 85 static KTEXT_ST auth; 86 static char name[ANAME_SZ]; 87 static char user_passwd[ANAME_SZ]; 88 static AUTH_DAT adat = { 0 }; 89 #ifdef ENCRYPTION 90 static Block session_key = { 0 }; 91 #endif /* ENCRYPTION */ 92 static Schedule sched; 93 static char challenge[REALM_SZ]; 94 95 static int 96 Data(ap, type, d, c) 97 Authenticator *ap; 98 int type; 99 void *d; 100 int c; 101 { 102 unsigned char *p = str_data + 4; 103 unsigned char *cd = (unsigned char *)d; 104 105 if (c == -1) 106 c = strlen((char *)cd); 107 108 if (0) { 109 printf("%s:%d: [%d] (%d)", 110 str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY", 111 str_data[3], 112 type, c); 113 printd(d, c); 114 printf("\r\n"); 115 } 116 *p++ = ap->type; 117 *p++ = ap->way; 118 *p++ = type; 119 while (c-- > 0) { 120 if ((*p++ = *cd++) == IAC) 121 *p++ = IAC; 122 } 123 *p++ = IAC; 124 *p++ = SE; 125 if (str_data[3] == TELQUAL_IS) 126 printsub('>', &str_data[2], p - (&str_data[2])); 127 return(net_write(str_data, p - str_data)); 128 } 129 130 int 131 krb4encpwd_init(ap, server) 132 Authenticator *ap; 133 int server; 134 { 135 char hostname[80], *cp, *realm; 136 C_Block skey; 137 138 if (server) { 139 str_data[3] = TELQUAL_REPLY; 140 } else { 141 str_data[3] = TELQUAL_IS; 142 gethostname(hostname, sizeof(hostname)); 143 realm = krb_realmofhost(hostname); 144 cp = index(hostname, '.'); 145 if (*cp != NULL) *cp = NULL; 146 if (read_service_key(KRB_SERVICE_NAME, hostname, realm, 0, 147 KEYFILE, (char *)skey)) { 148 return(0); 149 } 150 } 151 return(1); 152 } 153 154 int 155 krb4encpwd_send(ap) 156 Authenticator *ap; 157 { 158 159 printf("[ Trying KRB4ENCPWD ... ]\n"); 160 if (!UserNameRequested) { 161 return(0); 162 } 163 if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) { 164 return(0); 165 } 166 167 if (!Data(ap, KRB4_ENCPWD_ACK, (void *)NULL, 0)) { 168 return(0); 169 } 170 171 return(1); 172 } 173 174 void 175 krb4encpwd_is(ap, data, cnt) 176 Authenticator *ap; 177 unsigned char *data; 178 int cnt; 179 { 180 Session_Key skey; 181 Block datablock; 182 char r_passwd[ANAME_SZ], r_user[ANAME_SZ]; 183 char lhostname[ANAME_SZ], *cp; 184 int r; 185 time_t now; 186 187 if (cnt-- < 1) 188 return; 189 switch (*data++) { 190 case KRB4_ENCPWD_AUTH: 191 bcopy((void *)data, (void *)auth.dat, auth.length = cnt); 192 193 gethostname(lhostname, sizeof(lhostname)); 194 if ((cp = index(lhostname, '.')) != 0) *cp = '\0'; 195 196 if (r = krb_rd_encpwd_req(&auth, KRB_SERVICE_NAME, lhostname, 0, &adat, NULL, challenge, r_user, r_passwd)) { 197 Data(ap, KRB4_ENCPWD_REJECT, (void *)"Auth failed", -1); 198 auth_finished(ap, AUTH_REJECT); 199 return; 200 } 201 auth_encrypt_userpwd(r_passwd); 202 if (passwdok(UserNameRequested, UserPassword) == 0) { 203 /* 204 * illegal username and password 205 */ 206 Data(ap, KRB4_ENCPWD_REJECT, (void *)"Illegal password", -1); 207 auth_finished(ap, AUTH_REJECT); 208 return; 209 } 210 211 bcopy((void *)adat.session, (void *)session_key, sizeof(Block)); 212 Data(ap, KRB4_ENCPWD_ACCEPT, (void *)0, 0); 213 auth_finished(ap, AUTH_USER); 214 break; 215 216 case KRB4_ENCPWD_CHALLENGE: 217 /* 218 * Take the received random challenge text and save 219 * for future authentication. 220 */ 221 bcopy((void *)data, (void *)challenge, sizeof(Block)); 222 break; 223 224 225 case KRB4_ENCPWD_ACK: 226 /* 227 * Receive ack, if mutual then send random challenge 228 */ 229 230 /* 231 * If we are doing mutual authentication, get set up to send 232 * the challenge, and verify it when the response comes back. 233 */ 234 235 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) { 236 register int i; 237 238 time(&now); 239 sprintf(challenge, "%x", now); 240 Data(ap, KRB4_ENCPWD_CHALLENGE, (void *)challenge, strlen(challenge)); 241 } 242 break; 243 244 default: 245 Data(ap, KRB4_ENCPWD_REJECT, 0, 0); 246 break; 247 } 248 } 249 250 251 void 252 krb4encpwd_reply(ap, data, cnt) 253 Authenticator *ap; 254 unsigned char *data; 255 int cnt; 256 { 257 Session_Key skey; 258 KTEXT_ST krb_token; 259 Block enckey; 260 CREDENTIALS cred; 261 int r; 262 char randchal[REALM_SZ], instance[ANAME_SZ], *cp; 263 char hostname[80], *realm; 264 265 if (cnt-- < 1) 266 return; 267 switch (*data++) { 268 case KRB4_ENCPWD_REJECT: 269 if (cnt > 0) { 270 printf("[ KRB4_ENCPWD refuses authentication because %.*s ]\r\n", 271 cnt, data); 272 } else 273 printf("[ KRB4_ENCPWD refuses authentication ]\r\n"); 274 auth_send_retry(); 275 return; 276 case KRB4_ENCPWD_ACCEPT: 277 printf("[ KRB4_ENCPWD accepts you ]\n"); 278 auth_finished(ap, AUTH_USER); 279 return; 280 case KRB4_ENCPWD_CHALLENGE: 281 /* 282 * Verify that the response to the challenge is correct. 283 */ 284 285 gethostname(hostname, sizeof(hostname)); 286 realm = krb_realmofhost(hostname); 287 bcopy((void *)data, (void *)challenge, cnt); 288 bzero(user_passwd, sizeof(user_passwd)); 289 local_des_read_pw_string(user_passwd, sizeof(user_passwd)-1, "Password: ", 0); 290 UserPassword = user_passwd; 291 Challenge = challenge; 292 strcpy(instance, RemoteHostName); 293 if ((cp = index(instance, '.')) != 0) *cp = '\0'; 294 295 if (r = krb_mk_encpwd_req(&krb_token, KRB_SERVICE_NAME, instance, realm, Challenge, UserNameRequested, user_passwd)) { 296 krb_token.length = 0; 297 } 298 299 if (!Data(ap, KRB4_ENCPWD_AUTH, (void *)krb_token.dat, krb_token.length)) { 300 return; 301 } 302 303 break; 304 305 default: 306 return; 307 } 308 } 309 310 int 311 krb4encpwd_status(ap, name, level) 312 Authenticator *ap; 313 char *name; 314 int level; 315 { 316 317 if (level < AUTH_USER) 318 return(level); 319 320 if (UserNameRequested && passwdok(UserNameRequested, UserPassword)) { 321 strcpy(name, UserNameRequested); 322 return(AUTH_VALID); 323 } else { 324 return(AUTH_USER); 325 } 326 } 327 328 #define BUMP(buf, len) while (*(buf)) {++(buf), --(len);} 329 #define ADDC(buf, len, c) if ((len) > 0) {*(buf)++ = (c); --(len);} 330 331 void 332 krb4encpwd_printsub(data, cnt, buf, buflen) 333 unsigned char *data, *buf; 334 int cnt, buflen; 335 { 336 char lbuf[32]; 337 register int i; 338 339 buf[buflen-1] = '\0'; /* make sure its NULL terminated */ 340 buflen -= 1; 341 342 switch(data[3]) { 343 case KRB4_ENCPWD_REJECT: /* Rejected (reason might follow) */ 344 strncpy((char *)buf, " REJECT ", buflen); 345 goto common; 346 347 case KRB4_ENCPWD_ACCEPT: /* Accepted (name might follow) */ 348 strncpy((char *)buf, " ACCEPT ", buflen); 349 common: 350 BUMP(buf, buflen); 351 if (cnt <= 4) 352 break; 353 ADDC(buf, buflen, '"'); 354 for (i = 4; i < cnt; i++) 355 ADDC(buf, buflen, data[i]); 356 ADDC(buf, buflen, '"'); 357 ADDC(buf, buflen, '\0'); 358 break; 359 360 case KRB4_ENCPWD_AUTH: /* Authentication data follows */ 361 strncpy((char *)buf, " AUTH", buflen); 362 goto common2; 363 364 case KRB4_ENCPWD_CHALLENGE: 365 strncpy((char *)buf, " CHALLENGE", buflen); 366 goto common2; 367 368 case KRB4_ENCPWD_ACK: 369 strncpy((char *)buf, " ACK", buflen); 370 goto common2; 371 372 default: 373 sprintf(lbuf, " %d (unknown)", data[3]); 374 strncpy((char *)buf, lbuf, buflen); 375 common2: 376 BUMP(buf, buflen); 377 for (i = 4; i < cnt; i++) { 378 sprintf(lbuf, " %d", data[i]); 379 strncpy((char *)buf, lbuf, buflen); 380 BUMP(buf, buflen); 381 } 382 break; 383 } 384 } 385 386 int passwdok(name, passwd) 387 char *name, *passwd; 388 { 389 char *crypt(); 390 char *salt, *p; 391 struct passwd *pwd; 392 int passwdok_status = 0; 393 394 if (pwd = getpwnam(name)) 395 salt = pwd->pw_passwd; 396 else salt = "xx"; 397 398 p = crypt(passwd, salt); 399 400 if (pwd && !strcmp(p, pwd->pw_passwd)) { 401 passwdok_status = 1; 402 } else passwdok_status = 0; 403 return(passwdok_status); 404 } 405 406 #endif 407 408 #ifdef notdef 409 410 prkey(msg, key) 411 char *msg; 412 unsigned char *key; 413 { 414 register int i; 415 printf("%s:", msg); 416 for (i = 0; i < 8; i++) 417 printf(" %3d", key[i]); 418 printf("\r\n"); 419 } 420 #endif 421