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 <sys/cdefs.h>
35
36#ifdef __FBSDID
37__FBSDID("$FreeBSD: src/crypto/telnet/libtelnet/krb4encpwd.c,v 1.3.2.1 2002/04/13 10:59:07 markm Exp $");
38#endif
39
40#ifndef lint
41static const char sccsid[] = "@(#)krb4encpwd.c	8.3 (Berkeley) 5/30/95";
42#endif /* not lint */
43
44
45#ifdef	KRB4_ENCPWD
46/*
47 * COPYRIGHT (C) 1990 DIGITAL EQUIPMENT CORPORATION
48 * ALL RIGHTS RESERVED
49 *
50 * "Digital Equipment Corporation authorizes the reproduction,
51 * distribution and modification of this software subject to the following
52 * restrictions:
53 *
54 * 1.  Any partial or whole copy of this software, or any modification
55 * thereof, must include this copyright notice in its entirety.
56 *
57 * 2.  This software is supplied "as is" with no warranty of any kind,
58 * expressed or implied, for any purpose, including any warranty of fitness
59 * or merchantibility.  DIGITAL assumes no responsibility for the use or
60 * reliability of this software, nor promises to provide any form of
61 * support for it on any basis.
62 *
63 * 3.  Distribution of this software is authorized only if no profit or
64 * remuneration of any kind is received in exchange for such distribution.
65 *
66 * 4.  This software produces public key authentication certificates
67 * bearing an expiration date established by DIGITAL and RSA Data
68 * Security, Inc.  It may cease to generate certificates after the expiration
69 * date.  Any modification of this software that changes or defeats
70 * the expiration date or its effect is unauthorized.
71 *
72 * 5.  Software that will renew or extend the expiration date of
73 * authentication certificates produced by this software may be obtained
74 * from RSA Data Security, Inc., 10 Twin Dolphin Drive, Redwood City, CA
75 * 94065, (415)595-8782, or from DIGITAL"
76 *
77 */
78
79#include <sys/types.h>
80#include <openssl/des.h>
81#include <arpa/telnet.h>
82#include <krb.h>
83#include <pwd.h>
84#include <stdio.h>
85#include <stdlib.h>
86#include <string.h>
87
88#include "encrypt.h"
89#include "auth.h"
90#include "misc.h"
91
92int krb_mk_encpwd_req(KTEXT, char *, char *, char *, char *, char *, char *);
93int krb_rd_encpwd_req(KTEXT, char *, char *, u_long, AUTH_DAT *, char *, char *, char *, char *);
94
95extern auth_debug_mode;
96
97static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0,
98			  		AUTHTYPE_KRB4_ENCPWD, };
99static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION,
100					TELQUAL_NAME, };
101
102#define	KRB4_ENCPWD_AUTH	0	/* Authentication data follows */
103#define	KRB4_ENCPWD_REJECT	1	/* Rejected (reason might follow) */
104#define KRB4_ENCPWD_ACCEPT	2	/* Accepted */
105#define	KRB4_ENCPWD_CHALLENGE	3	/* Challenge for mutual auth. */
106#define	KRB4_ENCPWD_ACK		4	/* Acknowledge */
107
108#define KRB_SERVICE_NAME    "rcmd"
109
110static	KTEXT_ST auth;
111static	char name[ANAME_SZ];
112static	char user_passwd[ANAME_SZ];
113static	AUTH_DAT adat = { 0 };
114#ifdef	ENCRYPTION
115static Block	session_key	= { 0 };
116#endif	/* ENCRYPTION */
117static char  challenge[REALM_SZ];
118
119	static int
120Data(ap, type, d, c)
121	Authenticator *ap;
122	int type;
123	void *d;
124	int c;
125{
126	unsigned char *p = str_data + 4;
127	unsigned char *cd = (unsigned char *)d;
128
129	if (c == -1)
130		c = strlen((char *)cd);
131
132	if (0) {
133		printf("%s:%d: [%d] (%d)",
134			str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
135			str_data[3],
136			type, c);
137		printd(d, c);
138		printf("\r\n");
139	}
140	*p++ = ap->type;
141	*p++ = ap->way;
142	*p++ = type;
143	while (c-- > 0) {
144		if ((*p++ = *cd++) == IAC)
145			*p++ = IAC;
146	}
147	*p++ = IAC;
148	*p++ = SE;
149	if (str_data[3] == TELQUAL_IS)
150		printsub('>', &str_data[2], p - (&str_data[2]));
151	return(net_write(str_data, p - str_data));
152}
153
154	int
155krb4encpwd_init(ap, server)
156	Authenticator *ap;
157	int server;
158{
159	char hostname[80], *cp, *realm;
160	C_Block skey;
161
162	if (server) {
163		str_data[3] = TELQUAL_REPLY;
164	} else {
165		str_data[3] = TELQUAL_IS;
166		gethostname(hostname, sizeof(hostname));
167		realm = krb_realmofhost(hostname);
168		cp = strchr(hostname, '.');
169		if (*cp != NULL) *cp = NULL;
170		if (read_service_key(KRB_SERVICE_NAME, hostname, realm, 0,
171					KEYFILE, (char *)skey)) {
172		  return(0);
173		}
174	}
175	return(1);
176}
177
178	int
179krb4encpwd_send(ap)
180	Authenticator *ap;
181{
182
183	printf("[ Trying KRB4ENCPWD ... ]\n");
184	if (!UserNameRequested) {
185		return(0);
186	}
187	if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) {
188		return(0);
189	}
190
191	if (!Data(ap, KRB4_ENCPWD_ACK, (void *)NULL, 0)) {
192		return(0);
193	}
194
195	return(1);
196}
197
198	void
199krb4encpwd_is(ap, data, cnt)
200	Authenticator *ap;
201	unsigned char *data;
202	int cnt;
203{
204	Session_Key skey;
205	Block datablock;
206	char  r_passwd[ANAME_SZ], r_user[ANAME_SZ];
207	char  lhostname[ANAME_SZ], *cp;
208	int r;
209	time_t now;
210
211	if (cnt-- < 1)
212		return;
213	switch (*data++) {
214	case KRB4_ENCPWD_AUTH:
215		memmove((void *)auth.dat, (void *)data, auth.length = cnt);
216
217		gethostname(lhostname, sizeof(lhostname));
218		if ((cp = strchr(lhostname, '.')) != 0)  *cp = '\0';
219
220		if (r = krb_rd_encpwd_req(&auth, KRB_SERVICE_NAME, lhostname, 0, &adat, NULL, challenge, r_user, r_passwd)) {
221			Data(ap, KRB4_ENCPWD_REJECT, (void *)"Auth failed", -1);
222			auth_finished(ap, AUTH_REJECT);
223			return;
224		}
225		auth_encrypt_userpwd(r_passwd);
226		if (passwdok(UserNameRequested, UserPassword) == 0) {
227		  /*
228		   *  illegal username and password
229		   */
230		  Data(ap, KRB4_ENCPWD_REJECT, (void *)"Illegal password", -1);
231		  auth_finished(ap, AUTH_REJECT);
232		  return;
233		}
234
235		memmove((void *)session_key, (void *)adat.session, sizeof(Block));
236		Data(ap, KRB4_ENCPWD_ACCEPT, (void *)0, 0);
237		auth_finished(ap, AUTH_USER);
238		break;
239
240	case KRB4_ENCPWD_CHALLENGE:
241		/*
242		 *  Take the received random challenge text and save
243		 *  for future authentication.
244		 */
245		memmove((void *)challenge, (void *)data, sizeof(Block));
246		break;
247
248
249	case KRB4_ENCPWD_ACK:
250		/*
251		 *  Receive ack, if mutual then send random challenge
252		 */
253
254		/*
255		 * If we are doing mutual authentication, get set up to send
256		 * the challenge, and verify it when the response comes back.
257		 */
258
259		if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
260		  register int i;
261
262		  time(&now);
263		  sprintf(challenge, "%x", now);
264		  Data(ap, KRB4_ENCPWD_CHALLENGE, (void *)challenge, strlen(challenge));
265		}
266		break;
267
268	default:
269		Data(ap, KRB4_ENCPWD_REJECT, 0, 0);
270		break;
271	}
272}
273
274
275	void
276krb4encpwd_reply(ap, data, cnt)
277	Authenticator *ap;
278	unsigned char *data;
279	int cnt;
280{
281	Session_Key skey;
282	KTEXT_ST krb_token;
283	Block enckey;
284	CREDENTIALS cred;
285	int r;
286	char	randchal[REALM_SZ], instance[ANAME_SZ], *cp;
287	char	hostname[80], *realm;
288
289	if (cnt-- < 1)
290		return;
291	switch (*data++) {
292	case KRB4_ENCPWD_REJECT:
293		if (cnt > 0) {
294			printf("[ KRB4_ENCPWD refuses authentication because %.*s ]\r\n",
295				cnt, data);
296		} else
297			printf("[ KRB4_ENCPWD refuses authentication ]\r\n");
298		auth_send_retry();
299		return;
300	case KRB4_ENCPWD_ACCEPT:
301		printf("[ KRB4_ENCPWD accepts you ]\n");
302		auth_finished(ap, AUTH_USER);
303		return;
304	case KRB4_ENCPWD_CHALLENGE:
305		/*
306		 * Verify that the response to the challenge is correct.
307		 */
308
309		gethostname(hostname, sizeof(hostname));
310		realm = krb_realmofhost(hostname);
311		memmove((void *)challenge, (void *)data, cnt);
312		memset(user_passwd, 0, sizeof(user_passwd));
313		local_des_read_pw_string(user_passwd, sizeof(user_passwd)-1, "Password: ", 0);
314		UserPassword = user_passwd;
315		Challenge = challenge;
316		strcpy(instance, RemoteHostName);
317		if ((cp = strchr(instance, '.')) != 0)  *cp = '\0';
318
319		if (r = krb_mk_encpwd_req(&krb_token, KRB_SERVICE_NAME, instance, realm, Challenge, UserNameRequested, user_passwd)) {
320		  krb_token.length = 0;
321		}
322
323		if (!Data(ap, KRB4_ENCPWD_AUTH, (void *)krb_token.dat, krb_token.length)) {
324		  return;
325		}
326
327		break;
328
329	default:
330		return;
331	}
332}
333
334	int
335krb4encpwd_status(ap, name, level)
336	Authenticator *ap;
337	char *name;
338	int level;
339{
340
341	if (level < AUTH_USER)
342		return(level);
343
344	if (UserNameRequested && passwdok(UserNameRequested, UserPassword)) {
345		strcpy(name, UserNameRequested);
346		return(AUTH_VALID);
347	} else {
348		return(AUTH_USER);
349	}
350}
351
352#define	BUMP(buf, len)		while (*(buf)) {++(buf), --(len);}
353#define	ADDC(buf, len, c)	if ((len) > 0) {*(buf)++ = (c); --(len);}
354
355	void
356krb4encpwd_printsub(data, cnt, buf, buflen)
357	unsigned char *data, *buf;
358	int cnt, buflen;
359{
360	char lbuf[32];
361	register int i;
362
363	buf[buflen-1] = '\0';		/* make sure its NULL terminated */
364	buflen -= 1;
365
366	switch(data[3]) {
367	case KRB4_ENCPWD_REJECT:	/* Rejected (reason might follow) */
368		strncpy((char *)buf, " REJECT ", buflen);
369		goto common;
370
371	case KRB4_ENCPWD_ACCEPT:	/* Accepted (name might follow) */
372		strncpy((char *)buf, " ACCEPT ", buflen);
373	common:
374		BUMP(buf, buflen);
375		if (cnt <= 4)
376			break;
377		ADDC(buf, buflen, '"');
378		for (i = 4; i < cnt; i++)
379			ADDC(buf, buflen, data[i]);
380		ADDC(buf, buflen, '"');
381		ADDC(buf, buflen, '\0');
382		break;
383
384	case KRB4_ENCPWD_AUTH:		/* Authentication data follows */
385		strncpy((char *)buf, " AUTH", buflen);
386		goto common2;
387
388	case KRB4_ENCPWD_CHALLENGE:
389		strncpy((char *)buf, " CHALLENGE", buflen);
390		goto common2;
391
392	case KRB4_ENCPWD_ACK:
393		strncpy((char *)buf, " ACK", buflen);
394		goto common2;
395
396	default:
397		sprintf(lbuf, " %d (unknown)", data[3]);
398		strncpy((char *)buf, lbuf, buflen);
399	common2:
400		BUMP(buf, buflen);
401		for (i = 4; i < cnt; i++) {
402			sprintf(lbuf, " %d", data[i]);
403			strncpy((char *)buf, lbuf, buflen);
404			BUMP(buf, buflen);
405		}
406		break;
407	}
408}
409
410int passwdok(name, passwd)
411char *name, *passwd;
412{
413  char *crypt();
414  char *salt, *p;
415  struct passwd *pwd;
416  int   passwdok_status = 0;
417
418  if (pwd = getpwnam(name))
419    salt = pwd->pw_passwd;
420  else salt = "xx";
421
422  p = crypt(passwd, salt);
423
424  if (pwd && !strcmp(p, pwd->pw_passwd)) {
425    passwdok_status = 1;
426  } else passwdok_status = 0;
427  return(passwdok_status);
428}
429
430#endif
431