[unix-history] / lib / libcrypt / kerberos.c

/*-
 * Copyright (c) 1991 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static char sccsid[] = "@(#)kerberos.c	5.2 (Berkeley) 3/22/91";
#endif /* not lint */

/*
 * Copyright (C) 1990 by the Massachusetts Institute of Technology
 *
 * Export of this software from the United States of America is assumed
 * to require a specific license from the United States Government.
 * It is the responsibility of any person or organization contemplating
 * export to obtain such a license before exporting.
 *
 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
 * distribute this software and its documentation for any purpose and
 * without fee is hereby granted, provided that the above copyright
 * notice appear in all copies and that both that copyright notice and
 * this permission notice appear in supporting documentation, and that
 * the name of M.I.T. not be used in advertising or publicity pertaining
 * to distribution of the software without specific, written prior
 * permission.  M.I.T. makes no representations about the suitability of
 * this software for any purpose.  It is provided "as is" without express
 * or implied warranty.
 */

#ifdef	KRB4
#include <sys/types.h>
#include <arpa/telnet.h>
#include <stdio.h>
#if	defined(ENCRYPT)
#define	__NEED_ENCRYPT__
#undef	ENCRYPT
#endif
#include <des.h>        /* BSD wont include this in krb.h, so we do it here */
#include <krb.h>
#if	defined(__NEED_ENCRYPT__) && !defined(ENCRYPT)
#define	ENCRYPT
#undef	__NEED_ENCRYPT__
#endif
#ifdef	__STDC__
#include <stdlib.h>
#endif
#ifdef	NO_STRING_H
#include <strings.h>
#else
#include <string.h>
#endif

#include "encrypt.h"
#include "auth.h"
#include "misc.h"

int cksum P((unsigned char *, int));
int krb_mk_req P((KTEXT, char *, char *, char *, u_long));
int krb_rd_req P((KTEXT, char *, char *, u_long, AUTH_DAT *, char *));
int krb_kntoln P((AUTH_DAT *, char *));
int krb_get_cred P((char *, char *, char *, CREDENTIALS *));
int krb_get_lrealm P((char *, int));
int kuserok P((AUTH_DAT *, char *));

extern auth_debug_mode;

static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0,
			  		AUTHTYPE_KERBEROS_V4, };
static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION,
					TELQUAL_NAME, };

#define	KRB_AUTH	0		/* Authentication data follows */
#define	KRB_REJECT	1		/* Rejected (reason might follow) */
#define	KRB_ACCEPT	2		/* Accepted */
#define	KRB_CHALLANGE	3		/* Challange for mutual auth. */
#define	KRB_RESPONSE	4		/* Response for mutual auth. */

static	KTEXT_ST auth;
static	char name[ANAME_SZ];
static	AUTH_DAT adat = { 0 };
#if	defined(ENCRYPT)
static Block	session_key	= { 0 };
#endif
static Schedule sched;
static Block	challange	= { 0 };

	static int
Data(ap, type, d, c)
	Authenticator *ap;
	int type;
	void *d;
	int c;
{
        unsigned char *p = str_data + 4;
	unsigned char *cd = (unsigned char *)d;

	if (c == -1)
		c = strlen((char *)cd);

        if (auth_debug_mode) {
                printf("%s:%d: [%d] (%d)",
                        str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
                        str_data[3],
                        type, c);
                printd(d, c);
                printf("\r\n");
        }
	*p++ = ap->type;
	*p++ = ap->way;
	*p++ = type;
        while (c-- > 0) {
                if ((*p++ = *cd++) == IAC)
                        *p++ = IAC;
        }
        *p++ = IAC;
        *p++ = SE;
	if (str_data[3] == TELQUAL_IS)
		printsub('>', &str_data[2], p - (&str_data[2]));
        return(net_write(str_data, p - str_data));
}

	int
kerberos4_init(ap, server)
	Authenticator *ap;
	int server;
{
	if (server)
		str_data[3] = TELQUAL_REPLY;
	else
		str_data[3] = TELQUAL_IS;
	return(1);
}

char dst_realm_buf[REALM_SZ], *dest_realm = NULL;
int dst_realm_sz = REALM_SZ;

	int
kerberos4_send(ap)
	Authenticator *ap;
{
	KTEXT_ST auth;
	Block enckey;
	char instance[INST_SZ];
	char *realm;
	char *krb_realmofhost();
	char *krb_get_phost();
	CREDENTIALS cred;
	int r;
	
	if (!UserNameRequested) {
		if (auth_debug_mode) {
			printf("Kerberos V4: no user name supplied\r\n");
		}
		return(0);
	}

	bzero(instance, sizeof(instance));
	if (realm = krb_get_phost(RemoteHostName))
		strncpy(instance, realm, sizeof(instance));
	instance[sizeof(instance)-1] = '\0';

	realm = dest_realm ? dest_realm : krb_realmofhost(RemoteHostName);
	if (!realm) {
		if (auth_debug_mode) {
			printf("Kerberos V4: no realm for %s\r\n", RemoteHostName);
		}
		return(0);
	}
	if (r = krb_mk_req(&auth, "rcmd", instance, realm, 0L)) {
		if (auth_debug_mode) {
			printf("mk_req failed: %s\r\n", krb_err_txt[r]);
		}
		return(0);
	}
	if (r = krb_get_cred("rcmd", instance, realm, &cred)) {
		if (auth_debug_mode) {
			printf("get_cred failed: %s\r\n", krb_err_txt[r]);
		}
		return(0);
	}
	if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) {
		if (auth_debug_mode)
			printf("Not enough room for user name\r\n");
		return(0);
	}
	if (auth_debug_mode)
		printf("Sent %d bytes of authentication data\r\n", auth.length);
	if (!Data(ap, KRB_AUTH, (void *)auth.dat, auth.length)) {
		if (auth_debug_mode)
			printf("Not enough room for authentication data\r\n");
		return(0);
	}
	/*
	 * If we are doing mutual authentication, get set up to send
	 * the challange, and verify it when the response comes back.
	 */
	if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
		register int i;

		des_key_sched(cred.session, sched);
		des_set_random_generator_seed(cred.session);
		des_new_random_key(challange);
		des_ecb_encrypt(challange, session_key, sched, 1);
		/*
		 * Increment the challange by 1, and encrypt it for
		 * later comparison.
		 */
		for (i = 7; i >= 0; --i) {
			register int x;
			x = (unsigned int)challange[i] + 1;
			challange[i] = x;	/* ignore overflow */
			if (x < 256)		/* if no overflow, all done */
				break;
		}
		des_ecb_encrypt(challange, challange, sched, 1);
	}
	
	if (auth_debug_mode) {
		printf("CK: %d:", cksum(auth.dat, auth.length));
		printd(auth.dat, auth.length);
		printf("\r\n");
		printf("Sent Kerberos V4 credentials to server\r\n");
	}
	return(1);
}

	void
kerberos4_is(ap, data, cnt)
	Authenticator *ap;
	unsigned char *data;
	int cnt;
{
	Session_Key skey;
	Block datablock;
	char realm[REALM_SZ];
	char instance[INST_SZ];
	int r;

	if (cnt-- < 1)
		return;
	switch (*data++) {
	case KRB_AUTH:
		if (krb_get_lrealm(realm, 1) != KSUCCESS) {
			Data(ap, KRB_REJECT, (void *)"No local V4 Realm.", -1);
			auth_finished(ap, AUTH_REJECT);
			if (auth_debug_mode)
				printf("No local realm\r\n");
			return;
		}
		bcopy((void *)data, (void *)auth.dat, auth.length = cnt);
		if (auth_debug_mode) {
			printf("Got %d bytes of authentication data\r\n", cnt);
			printf("CK: %d:", cksum(auth.dat, auth.length));
			printd(auth.dat, auth.length);
			printf("\r\n");
		}
		instance[0] = '*'; instance[1] = 0;
		if (r = krb_rd_req(&auth, "rcmd", instance, 0, &adat, "")) {
			if (auth_debug_mode)
				printf("Kerberos failed him as %s\r\n", name);
			Data(ap, KRB_REJECT, (void *)krb_err_txt[r], -1);
			auth_finished(ap, AUTH_REJECT);
			return;
		}
		bcopy((void *)adat.session, (void *)session_key, sizeof(Block));
		krb_kntoln(&adat, name);
		Data(ap, KRB_ACCEPT, (void *)0, 0);
		auth_finished(ap, AUTH_USER);
		if (auth_debug_mode) {
			printf("Kerberos accepting him as %s\r\n", name);
		}
		break;

	case KRB_CHALLANGE:
		if (!VALIDKEY(session_key)) {
			/*
			 * We don't have a valid session key, so just
			 * send back a response with an empty session
			 * key.
			 */
			Data(ap, KRB_RESPONSE, (void *)0, 0);
			break;
		}

		des_key_sched(session_key, sched);
		bcopy((void *)data, (void *)datablock, sizeof(Block));
		/*
		 * Take the received encrypted challange, and encrypt
		 * it again to get a unique session_key for the
		 * ENCRYPT option.
		 */
		des_ecb_encrypt(datablock, session_key, sched, 1);
		skey.type = SK_DES;
		skey.length = 8;
		skey.data = session_key;
		encrypt_session_key(&skey, 1);
		/*
		 * Now decrypt the received encrypted challange,
		 * increment by one, re-encrypt it and send it back.
		 */
		des_ecb_encrypt(datablock, challange, sched, 0);
		for (r = 7; r >= 0; r++) {
			register int t;
			t = (unsigned int)challange[r] + 1;
			challange[r] = t;	/* ignore overflow */
			if (t < 256)		/* if no overflow, all done */
				break;
		}
		des_ecb_encrypt(challange, challange, sched, 1);
		Data(ap, KRB_RESPONSE, (void *)challange, sizeof(challange));
		break;

	default:
		if (auth_debug_mode)
			printf("Unknown Kerberos option %d\r\n", data[-1]);
		Data(ap, KRB_REJECT, 0, 0);
		break;
	}
}

	void
kerberos4_reply(ap, data, cnt)
	Authenticator *ap;
	unsigned char *data;
	int cnt;
{
	Session_Key skey;

	if (cnt-- < 1)
		return;
	switch (*data++) {
	case KRB_REJECT:
		if (cnt > 0) {
			printf("[ Kerberos V4 refuses authentication because %.*s ]\r\n",
				cnt, data);
		} else
			printf("[ Kerberos V4 refuses authentication ]\r\n");
		auth_send_retry();
		return;
	case KRB_ACCEPT:
		printf("[ Kerberos V4 accepts you ]\n");
		if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
			/*
			 * Send over the encrypted challange.
		 	 */
			Data(ap, KRB_CHALLANGE, (void *)session_key,
						sizeof(session_key));
#if	defined(ENCRYPT)
			des_ecb_encrypt(session_key, session_key, sched, 1);
			skey.type = SK_DES;
			skey.length = 8;
			skey.data = session_key;
			encrypt_session_key(&skey, 0);
#endif
			return;
		}
		auth_finished(ap, AUTH_USER);
		return;
	case KRB_RESPONSE:
		/*
		 * Verify that the response to the challange is correct.
		 */
		if ((cnt != sizeof(Block)) ||
		    (0 != memcmp((void *)data, (void *)challange,
						sizeof(challange))))
		{
			printf("[ Kerberos V4 challange failed!!! ]\r\n");
			auth_send_retry();
			return;
		}
		printf("[ Kerberos V4 challange successful ]\r\n");
		auth_finished(ap, AUTH_USER);
		break;
	default:
		if (auth_debug_mode)
			printf("Unknown Kerberos option %d\r\n", data[-1]);
		return;
	}
}

	int
kerberos4_status(ap, name, level)
	Authenticator *ap;
	char *name;
	int level;
{
	if (level < AUTH_USER)
		return(level);

	if (UserNameRequested && !kuserok(&adat, UserNameRequested)) {
		strcpy(name, UserNameRequested);
		return(AUTH_VALID);
	} else
		return(AUTH_USER);
}

#define	BUMP(buf, len)		while (*(buf)) {++(buf), --(len);}
#define	ADDC(buf, len, c)	if ((len) > 0) {*(buf)++ = (c); --(len);}

	void
kerberos4_printsub(data, cnt, buf, buflen)
	unsigned char *data, *buf;
	int cnt, buflen;
{
	char lbuf[32];
	register int i;

	buf[buflen-1] = '\0';		/* make sure its NULL terminated */
	buflen -= 1;

	switch(data[3]) {
	case KRB_REJECT:		/* Rejected (reason might follow) */
		strncpy((char *)buf, " REJECT ", buflen);
		goto common;

	case KRB_ACCEPT:		/* Accepted (name might follow) */
		strncpy((char *)buf, " ACCEPT ", buflen);
	common:
		BUMP(buf, buflen);
		if (cnt <= 4)
			break;
		ADDC(buf, buflen, '"');
		for (i = 4; i < cnt; i++)
			ADDC(buf, buflen, data[i]);
		ADDC(buf, buflen, '"');
		ADDC(buf, buflen, '\0');
		break;

	case KRB_AUTH:			/* Authentication data follows */
		strncpy((char *)buf, " AUTH", buflen);
		goto common2;

	case KRB_CHALLANGE:
		strncpy((char *)buf, " CHALLANGE", buflen);
		goto common2;

	case KRB_RESPONSE:
		strncpy((char *)buf, " RESPONSE", buflen);
		goto common2;

	default:
		sprintf(lbuf, " %d (unknown)", data[3]);
		strncpy((char *)buf, lbuf, buflen);
	common2:
		BUMP(buf, buflen);
		for (i = 4; i < cnt; i++) {
			sprintf(lbuf, " %d", data[i]);
			strncpy((char *)buf, lbuf, buflen);
			BUMP(buf, buflen);
		}
		break;
	}
}

	int
cksum(d, n)
	unsigned char *d;
	int n;
{
	int ck = 0;

	switch (n&03)
	while (n > 0) {
	case 0:
		ck ^= *d++ << 24;
		--n;
	case 3:
		ck ^= *d++ << 16;
		--n;
	case 2:
		ck ^= *d++ << 8;
		--n;
	case 1:
		ck ^= *d++;
		--n;
	}
	return(ck);
}
#endif

#ifdef notdef

prkey(msg, key)
	char *msg;
	unsigned char *key;
{
	register int i;
	printf("%s:", msg);
	for (i = 0; i < 8; i++)
		printf(" %3d", key[i]);
	printf("\r\n");
}
#endif
Commit	Line	Data
ab4f9135 NW	1	/*-
	2	* Copyright (c) 1991 The Regents of the University of California.
	3	* 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	#ifndef lint
	35	static char sccsid[] = "@(#)kerberos.c 5.2 (Berkeley) 3/22/91";
	36	#endif /* not lint */
	37
	38	/*
	39	* Copyright (C) 1990 by the Massachusetts Institute of Technology
	40	*
	41	* Export of this software from the United States of America is assumed
	42	* to require a specific license from the United States Government.
	43	* It is the responsibility of any person or organization contemplating
	44	* export to obtain such a license before exporting.
	45	*
	46	* WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
	47	* distribute this software and its documentation for any purpose and
	48	* without fee is hereby granted, provided that the above copyright
	49	* notice appear in all copies and that both that copyright notice and
	50	* this permission notice appear in supporting documentation, and that
	51	* the name of M.I.T. not be used in advertising or publicity pertaining
	52	* to distribution of the software without specific, written prior
	53	* permission. M.I.T. makes no representations about the suitability of
	54	* this software for any purpose. It is provided "as is" without express
	55	* or implied warranty.
	56	*/
	57
	58	#ifdef KRB4
	59	#include <sys/types.h>
	60	#include <arpa/telnet.h>
	61	#include <stdio.h>
	62	#if defined(ENCRYPT)
	63	#define __NEED_ENCRYPT__
	64	#undef ENCRYPT
65	#endif
66	#include <des.h> /* BSD wont include this in krb.h, so we do it here */
67	#include <krb.h>
68	#if defined(__NEED_ENCRYPT__) && !defined(ENCRYPT)
69	#define ENCRYPT
70	#undef __NEED_ENCRYPT__
71	#endif
72	#ifdef __STDC__
73	#include <stdlib.h>
74	#endif
75	#ifdef NO_STRING_H
76	#include <strings.h>
77	#else
78	#include <string.h>
79	#endif
80
81	#include "encrypt.h"
82	#include "auth.h"
83	#include "misc.h"
84
85	int cksum P((unsigned char *, int));
86	int krb_mk_req P((KTEXT, char , char , char *, u_long));
87	int krb_rd_req P((KTEXT, char , char , u_long, AUTH_DAT , char ));
88	int krb_kntoln P((AUTH_DAT , char ));
89	int krb_get_cred P((char , char , char , CREDENTIALS ));
90	int krb_get_lrealm P((char *, int));
91	int kuserok P((AUTH_DAT , char ));
92
93	extern auth_debug_mode;
94
95	static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0,
96	AUTHTYPE_KERBEROS_V4, };
97	static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION,
98	TELQUAL_NAME, };
99
100	#define KRB_AUTH 0 /* Authentication data follows */
101	#define KRB_REJECT 1 /* Rejected (reason might follow) */
102	#define KRB_ACCEPT 2 /* Accepted */
103	#define KRB_CHALLANGE 3 /* Challange for mutual auth. */
104	#define KRB_RESPONSE 4 /* Response for mutual auth. */
105
106	static KTEXT_ST auth;
107	static char name[ANAME_SZ];
108	static AUTH_DAT adat = { 0 };
109	#if defined(ENCRYPT)
110	static Block session_key = { 0 };
111	#endif
112	static Schedule sched;
113	static Block challange = { 0 };
114
115	static int
116	Data(ap, type, d, c)
117	Authenticator *ap;
118	int type;
119	void *d;
120	int c;
121	{
122	unsigned char *p = str_data + 4;
123	unsigned char cd = (unsigned char )d;
124
125	if (c == -1)
126	c = strlen((char *)cd);
127
128	if (auth_debug_mode) {
129	printf("%s:%d: [%d] (%d)",
130	str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
131	str_data[3],
132	type, c);
133	printd(d, c);
134	printf("\r\n");
135	}
136	*p++ = ap->type;
137	*p++ = ap->way;
138	*p++ = type;
139	while (c-- > 0) {
140	if ((p++ = cd++) == IAC)
141	*p++ = IAC;
142	}
143	*p++ = IAC;
144	*p++ = SE;
145	if (str_data[3] == TELQUAL_IS)
146	printsub('>', &str_data[2], p - (&str_data[2]));
147	return(net_write(str_data, p - str_data));
148	}
149
150	int
151	kerberos4_init(ap, server)
152	Authenticator *ap;
153	int server;
154	{
155	if (server)
156	str_data[3] = TELQUAL_REPLY;
157	else
158	str_data[3] = TELQUAL_IS;
159	return(1);
160	}
161
162	char dst_realm_buf[REALM_SZ], *dest_realm = NULL;
163	int dst_realm_sz = REALM_SZ;
164
165	int
166	kerberos4_send(ap)
167	Authenticator *ap;
168	{
169	KTEXT_ST auth;
170	Block enckey;
171	char instance[INST_SZ];
172	char *realm;
173	char *krb_realmofhost();
174	char *krb_get_phost();
175	CREDENTIALS cred;
176	int r;
177
178	if (!UserNameRequested) {
179	if (auth_debug_mode) {
180	printf("Kerberos V4: no user name supplied\r\n");
181	}
182	return(0);
183	}
184
185	bzero(instance, sizeof(instance));
186	if (realm = krb_get_phost(RemoteHostName))
187	strncpy(instance, realm, sizeof(instance));
188	instance[sizeof(instance)-1] = '\0';
189
190	realm = dest_realm ? dest_realm : krb_realmofhost(RemoteHostName);
191	if (!realm) {
192	if (auth_debug_mode) {
193	printf("Kerberos V4: no realm for %s\r\n", RemoteHostName);
194	}
195	return(0);
196	}
197	if (r = krb_mk_req(&auth, "rcmd", instance, realm, 0L)) {
198	if (auth_debug_mode) {
199	printf("mk_req failed: %s\r\n", krb_err_txt[r]);
200	}
201	return(0);
202	}
203	if (r = krb_get_cred("rcmd", instance, realm, &cred)) {
204	if (auth_debug_mode) {
205	printf("get_cred failed: %s\r\n", krb_err_txt[r]);
206	}
207	return(0);
208	}
209	if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) {
210	if (auth_debug_mode)
211	printf("Not enough room for user name\r\n");
212	return(0);
213	}
214	if (auth_debug_mode)
215	printf("Sent %d bytes of authentication data\r\n", auth.length);
216	if (!Data(ap, KRB_AUTH, (void *)auth.dat, auth.length)) {
217	if (auth_debug_mode)
218	printf("Not enough room for authentication data\r\n");
219	return(0);
220	}
221	/*
222	* If we are doing mutual authentication, get set up to send
223	* the challange, and verify it when the response comes back.
224	*/
225	if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
226	register int i;
227
228	des_key_sched(cred.session, sched);
229	des_set_random_generator_seed(cred.session);
230	des_new_random_key(challange);
231	des_ecb_encrypt(challange, session_key, sched, 1);
232	/*
233	* Increment the challange by 1, and encrypt it for
234	* later comparison.
235	*/
236	for (i = 7; i >= 0; --i) {
237	register int x;
238	x = (unsigned int)challange[i] + 1;
239	challange[i] = x; /* ignore overflow */
240	if (x < 256) /* if no overflow, all done */
241	break;
242	}
243	des_ecb_encrypt(challange, challange, sched, 1);
244	}
245
246	if (auth_debug_mode) {
247	printf("CK: %d:", cksum(auth.dat, auth.length));
248	printd(auth.dat, auth.length);
249	printf("\r\n");
250	printf("Sent Kerberos V4 credentials to server\r\n");
251	}
252	return(1);
253	}
254
255	void
256	kerberos4_is(ap, data, cnt)
257	Authenticator *ap;
258	unsigned char *data;
259	int cnt;
260	{
261	Session_Key skey;
262	Block datablock;
263	char realm[REALM_SZ];
264	char instance[INST_SZ];
265	int r;
266
267	if (cnt-- < 1)
268	return;
269	switch (*data++) {
270	case KRB_AUTH:
271	if (krb_get_lrealm(realm, 1) != KSUCCESS) {
272	Data(ap, KRB_REJECT, (void *)"No local V4 Realm.", -1);
273	auth_finished(ap, AUTH_REJECT);
274	if (auth_debug_mode)
275	printf("No local realm\r\n");
276	return;
277	}
278	bcopy((void )data, (void )auth.dat, auth.length = cnt);
279	if (auth_debug_mode) {
280	printf("Got %d bytes of authentication data\r\n", cnt);
281	printf("CK: %d:", cksum(auth.dat, auth.length));
282	printd(auth.dat, auth.length);
283	printf("\r\n");
284	}
285	instance[0] = '*'; instance[1] = 0;
286	if (r = krb_rd_req(&auth, "rcmd", instance, 0, &adat, "")) {
287	if (auth_debug_mode)
288	printf("Kerberos failed him as %s\r\n", name);
289	Data(ap, KRB_REJECT, (void *)krb_err_txt[r], -1);
290	auth_finished(ap, AUTH_REJECT);
291	return;
292	}
293	bcopy((void )adat.session, (void )session_key, sizeof(Block));
294	krb_kntoln(&adat, name);
295	Data(ap, KRB_ACCEPT, (void *)0, 0);
296	auth_finished(ap, AUTH_USER);
297	if (auth_debug_mode) {
298	printf("Kerberos accepting him as %s\r\n", name);
299	}
300	break;
301
302	case KRB_CHALLANGE:
303	if (!VALIDKEY(session_key)) {
304	/*
305	* We don't have a valid session key, so just
306	* send back a response with an empty session
307	* key.
308	*/
309	Data(ap, KRB_RESPONSE, (void *)0, 0);
310	break;
311	}
312
313	des_key_sched(session_key, sched);
314	bcopy((void )data, (void )datablock, sizeof(Block));
315	/*
316	* Take the received encrypted challange, and encrypt
317	* it again to get a unique session_key for the
318	* ENCRYPT option.
319	*/
320	des_ecb_encrypt(datablock, session_key, sched, 1);
321	skey.type = SK_DES;
322	skey.length = 8;
323	skey.data = session_key;
324	encrypt_session_key(&skey, 1);
325	/*
326	* Now decrypt the received encrypted challange,
327	* increment by one, re-encrypt it and send it back.
328	*/
329	des_ecb_encrypt(datablock, challange, sched, 0);
330	for (r = 7; r >= 0; r++) {
331	register int t;
332	t = (unsigned int)challange[r] + 1;
333	challange[r] = t; /* ignore overflow */
334	if (t < 256) /* if no overflow, all done */
335	break;
336	}
337	des_ecb_encrypt(challange, challange, sched, 1);
338	Data(ap, KRB_RESPONSE, (void *)challange, sizeof(challange));
339	break;
340
341	default:
342	if (auth_debug_mode)
343	printf("Unknown Kerberos option %d\r\n", data[-1]);
344	Data(ap, KRB_REJECT, 0, 0);
345	break;
346	}
347	}
348
349	void
350	kerberos4_reply(ap, data, cnt)
351	Authenticator *ap;
352	unsigned char *data;
353	int cnt;
354	{
355	Session_Key skey;
356
357	if (cnt-- < 1)
358	return;
359	switch (*data++) {
360	case KRB_REJECT:
361	if (cnt > 0) {
362	printf("[ Kerberos V4 refuses authentication because %.*s ]\r\n",
363	cnt, data);
364	} else
365	printf("[ Kerberos V4 refuses authentication ]\r\n");
366	auth_send_retry();
367	return;
368	case KRB_ACCEPT:
369	printf("[ Kerberos V4 accepts you ]\n");
370	if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
371	/*
372	* Send over the encrypted challange.
373	*/
374	Data(ap, KRB_CHALLANGE, (void *)session_key,
375	sizeof(session_key));
376	#if defined(ENCRYPT)
377	des_ecb_encrypt(session_key, session_key, sched, 1);
378	skey.type = SK_DES;
379	skey.length = 8;
380	skey.data = session_key;
381	encrypt_session_key(&skey, 0);
382	#endif
383	return;
384	}
385	auth_finished(ap, AUTH_USER);
386	return;
387	case KRB_RESPONSE:
388	/*
389	* Verify that the response to the challange is correct.
390	*/
391	if ((cnt != sizeof(Block)) \|\|
392	(0 != memcmp((void )data, (void )challange,
393	sizeof(challange))))
394	{
395	printf("[ Kerberos V4 challange failed!!! ]\r\n");
396	auth_send_retry();
397	return;
398	}
399	printf("[ Kerberos V4 challange successful ]\r\n");
400	auth_finished(ap, AUTH_USER);
401	break;
402	default:
403	if (auth_debug_mode)
404	printf("Unknown Kerberos option %d\r\n", data[-1]);
405	return;
406	}
407	}
408
409	int
410	kerberos4_status(ap, name, level)
411	Authenticator *ap;
412	char *name;
413	int level;
414	{
415	if (level < AUTH_USER)
416	return(level);
417
418	if (UserNameRequested && !kuserok(&adat, UserNameRequested)) {
419	strcpy(name, UserNameRequested);
420	return(AUTH_VALID);
421	} else
422	return(AUTH_USER);
423	}
424
425	#define BUMP(buf, len) while (*(buf)) {++(buf), --(len);}
426	#define ADDC(buf, len, c) if ((len) > 0) {*(buf)++ = (c); --(len);}
427
428	void
429	kerberos4_printsub(data, cnt, buf, buflen)
430	unsigned char data, buf;
431	int cnt, buflen;
432	{
433	char lbuf[32];
434	register int i;
435
436	buf[buflen-1] = '\0'; /* make sure its NULL terminated */
437	buflen -= 1;
438
439	switch(data[3]) {
440	case KRB_REJECT: /* Rejected (reason might follow) */
441	strncpy((char *)buf, " REJECT ", buflen);
442	goto common;
443
444	case KRB_ACCEPT: /* Accepted (name might follow) */
445	strncpy((char *)buf, " ACCEPT ", buflen);
446	common:
447	BUMP(buf, buflen);
448	if (cnt <= 4)
449	break;
450	ADDC(buf, buflen, '"');
451	for (i = 4; i < cnt; i++)
452	ADDC(buf, buflen, data[i]);
453	ADDC(buf, buflen, '"');
454	ADDC(buf, buflen, '\0');
455	break;
456
457	case KRB_AUTH: /* Authentication data follows */
458	strncpy((char *)buf, " AUTH", buflen);
459	goto common2;
460
461	case KRB_CHALLANGE:
462	strncpy((char *)buf, " CHALLANGE", buflen);
463	goto common2;
464
465	case KRB_RESPONSE:
466	strncpy((char *)buf, " RESPONSE", buflen);
467	goto common2;
468
469	default:
470	sprintf(lbuf, " %d (unknown)", data[3]);
471	strncpy((char *)buf, lbuf, buflen);
472	common2:
473	BUMP(buf, buflen);
474	for (i = 4; i < cnt; i++) {
475	sprintf(lbuf, " %d", data[i]);
476	strncpy((char *)buf, lbuf, buflen);
477	BUMP(buf, buflen);
478	}
479	break;
480	}
481	}
482
483	int
484	cksum(d, n)
485	unsigned char *d;
486	int n;
487	{
488	int ck = 0;
489
490	switch (n&03)
491	while (n > 0) {
492	case 0:
493	ck ^= *d++ << 24;
494	--n;
495	case 3:
496	ck ^= *d++ << 16;
497	--n;
498	case 2:
499	ck ^= *d++ << 8;
500	--n;
501	case 1:
502	ck ^= *d++;
503	--n;
504	}
505	return(ck);
506	}
507	#endif
508
509	#ifdef notdef
510
511	prkey(msg, key)
512	char *msg;
513	unsigned char *key;
514	{
515	register int i;
516	printf("%s:", msg);
517	for (i = 0; i < 8; i++)
518	printf(" %3d", key[i]);
519	printf("\r\n");
520	}
521	#endif