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
34 #include <config.h>
35
36 RCSID("$Id: krb4encpwd.c 22071 2007-11-14 20:04:50Z lha $");
37
38 #ifdef KRB4_ENCPWD
39 /*
40 * COPYRIGHT (C) 1990 DIGITAL EQUIPMENT CORPORATION
41 * ALL RIGHTS RESERVED
42 *
43 * "Digital Equipment Corporation authorizes the reproduction,
44 * distribution and modification of this software subject to the following
45 * restrictions:
46 *
47 * 1. Any partial or whole copy of this software, or any modification
48 * thereof, must include this copyright notice in its entirety.
49 *
50 * 2. This software is supplied "as is" with no warranty of any kind,
51 * expressed or implied, for any purpose, including any warranty of fitness
52 * or merchantibility. DIGITAL assumes no responsibility for the use or
53 * reliability of this software, nor promises to provide any form of
54 * support for it on any basis.
55 *
56 * 3. Distribution of this software is authorized only if no profit or
57 * remuneration of any kind is received in exchange for such distribution.
58 *
59 * 4. This software produces public key authentication certificates
60 * bearing an expiration date established by DIGITAL and RSA Data
61 * Security, Inc. It may cease to generate certificates after the expiration
62 * date. Any modification of this software that changes or defeats
63 * the expiration date or its effect is unauthorized.
64 *
65 * 5. Software that will renew or extend the expiration date of
66 * authentication certificates produced by this software may be obtained
67 * from RSA Data Security, Inc., 10 Twin Dolphin Drive, Redwood City, CA
68 * 94065, (415)595-8782, or from DIGITAL"
69 *
70 */
71
72 #include <sys/types.h>
73 #include <arpa/telnet.h>
74 #include <pwd.h>
75 #include <stdio.h>
76
77 #include <krb.h>
78 #include <stdlib.h>
79 #include <string.h>
80 #ifdef SOCKS
81 #include <socks.h>
82 #endif
83
84 #include "encrypt.h"
85 #include "auth.h"
86 #include "misc.h"
87
88 int krb_mk_encpwd_req (KTEXT, char *, char *, char *, char *, char *, char *);
89 int krb_rd_encpwd_req (KTEXT, char *, char *, u_long, AUTH_DAT *, char *, char *, char *, char *);
90
91 extern auth_debug_mode;
92
93 static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0,
94 AUTHTYPE_KRB4_ENCPWD, };
95 static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION,
96 TELQUAL_NAME, };
97
98 #define KRB4_ENCPWD_AUTH 0 /* Authentication data follows */
99 #define KRB4_ENCPWD_REJECT 1 /* Rejected (reason might follow) */
100 #define KRB4_ENCPWD_ACCEPT 2 /* Accepted */
101 #define KRB4_ENCPWD_CHALLENGE 3 /* Challenge for mutual auth. */
102 #define KRB4_ENCPWD_ACK 4 /* Acknowledge */
103
104 #define KRB_SERVICE_NAME "rcmd"
105
106 static KTEXT_ST auth;
107 static char name[ANAME_SZ];
108 static char user_passwd[ANAME_SZ];
109 static AUTH_DAT adat = { 0 };
110 static des_key_schedule sched;
111 static char challenge[REALM_SZ];
112
113 static int
Data(ap,type,d,c)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(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(telnet_net_write(str_data, p - str_data));
146 }
147
148 int
krb4encpwd_init(ap,server)149 krb4encpwd_init(ap, server)
150 Authenticator *ap;
151 int server;
152 {
153 char hostname[80], *cp, *realm;
154 des_clock 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
krb4encpwd_send(ap)173 krb4encpwd_send(ap)
174 Authenticator *ap;
175 {
176
177 printf("[ Trying KRB4ENCPWD ... ]\r\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, NULL, 0)) {
186 return(0);
187 }
188
189 return(1);
190 }
191
192 void
krb4encpwd_is(ap,data,cnt)193 krb4encpwd_is(ap, data, cnt)
194 Authenticator *ap;
195 unsigned char *data;
196 int cnt;
197 {
198 Session_Key skey;
199 des_cblock 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(auth.dat, 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, "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, "Illegal password", -1);
225 auth_finished(ap, AUTH_REJECT);
226 return;
227 }
228
229 memmove(session_key, adat.session, sizeof(des_cblock));
230 Data(ap, KRB4_ENCPWD_ACCEPT, 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(challenge, data, sizeof(des_cblock));
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 int i;
255
256 time(&now);
257 snprintf(challenge, sizeof(challenge), "%x", now);
258 Data(ap, KRB4_ENCPWD_CHALLENGE, 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
krb4encpwd_reply(ap,data,cnt)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 des_cblock 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 ]\r\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(challenge, data, cnt);
306 memset(user_passwd, 0, sizeof(user_passwd));
307 des_read_pw_string(user_passwd, sizeof(user_passwd)-1, "Password: ", 0);
308 UserPassword = user_passwd;
309 Challenge = challenge;
310 strlcpy(instance, RemoteHostName, sizeof(instance));
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, krb_token.dat, krb_token.length)) {
318 return;
319 }
320
321 break;
322
323 default:
324 return;
325 }
326 }
327
328 int
krb4encpwd_status(ap,name,name_sz,level)329 krb4encpwd_status(ap, name, name_sz, level)
330 Authenticator *ap;
331 char *name;
332 size_t name_sz;
333 int level;
334 {
335
336 if (level < AUTH_USER)
337 return(level);
338
339 if (UserNameRequested && passwdok(UserNameRequested, UserPassword)) {
340 strlcpy(name, UserNameRequested, name_sz);
341 return(AUTH_VALID);
342 } else {
343 return(AUTH_USER);
344 }
345 }
346
347 #define BUMP(buf, len) while (*(buf)) {++(buf), --(len);}
348 #define ADDC(buf, len, c) if ((len) > 0) {*(buf)++ = (c); --(len);}
349
350 void
krb4encpwd_printsub(data,cnt,buf,buflen)351 krb4encpwd_printsub(data, cnt, buf, buflen)
352 unsigned char *data, *buf;
353 int cnt, buflen;
354 {
355 int i;
356
357 buf[buflen-1] = '\0'; /* make sure it's NULL terminated */
358 buflen -= 1;
359
360 switch(data[3]) {
361 case KRB4_ENCPWD_REJECT: /* Rejected (reason might follow) */
362 strlcpy((char *)buf, " REJECT ", buflen);
363 goto common;
364
365 case KRB4_ENCPWD_ACCEPT: /* Accepted (name might follow) */
366 strlcpy((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 strlcpy((char *)buf, " AUTH", buflen);
380 goto common2;
381
382 case KRB4_ENCPWD_CHALLENGE:
383 strlcpy((char *)buf, " CHALLENGE", buflen);
384 goto common2;
385
386 case KRB4_ENCPWD_ACK:
387 strlcpy((char *)buf, " ACK", buflen);
388 goto common2;
389
390 default:
391 snprintf(buf, buflen, " %d (unknown)", data[3]);
392 common2:
393 BUMP(buf, buflen);
394 for (i = 4; i < cnt; i++) {
395 snprintf(buf, buflen, " %d", data[i]);
396 BUMP(buf, buflen);
397 }
398 break;
399 }
400 }
401
passwdok(name,passwd)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 = k_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
424 #ifdef notdef
425
prkey(msg,key)426 prkey(msg, key)
427 char *msg;
428 unsigned char *key;
429 {
430 int i;
431 printf("%s:", msg);
432 for (i = 0; i < 8; i++)
433 printf(" %3d", key[i]);
434 printf("\r\n");
435 }
436 #endif
437