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
Data(ap,type,d,c)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
krb4encpwd_init(ap,server)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
krb4encpwd_send(ap)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
krb4encpwd_is(ap,data,cnt)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
krb4encpwd_reply(ap,data,cnt)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
krb4encpwd_status(ap,name,level)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
krb4encpwd_printsub(data,cnt,buf,buflen)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
passwdok(name,passwd)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